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Astronomers Search For Dyson Spheres of Alien Civilizations

Hugh Pickens writes "An article by Ross Andersen makes note of Freeman Dyson's prediction in 1960 that every civilization in the Universe eventually runs out of energy on its home planet, a major hurdle in a civilization's evolution. Dyson argued that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Last month astronomers began a two-year search for Dyson Spheres, a search that will span the Milky Way, along with millions of other galaxies. The search is funded by a sizable grant from the Templeton Foundation, a philanthropic organization that funds research on the 'big questions' that face humanity, questions relating to 'human purpose and ultimate reality.' Compared with SETI, a search for Dyson Spheres assumes that the larger the civilization, the more energy it uses and the more heat it re-radiates. If Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to see through our infrared telescopes. 'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright. 'Just like your body, which is invisible in the dark, but shines brightly in mid-infrared goggles.' A civilization that built a Dyson Sphere would have to go to great lengths to avoid detection, building massive radiators that give off heat so cool it would be undetectable, a solution that would involve building a sphere that was a hundred times larger than necessary. 'If a civilization wants to hide, it's certainly possible to hide,' says Wright, 'but it requires massive amounts of deliberate engineering across an entire civilization.'"

487 of 686 comments (clear)

  1. series of tubes by xavieramont · · Score: 2

    Don't they mean Matrioshka brain?

    --
    If it is natural to die, then to hell with nature. --FM 2030
    1. Re:series of tubes by History's+Coming+To · · Score: 2

      Not necessarily - a Matrioshka brain is constructed from (or in the same way as) a Dyson sphere, the difference being that the brain is designed to compute using the energy it collects, while a Dyson sphere is more generic - it collects the energy and you can then do what you want with it. Advanced civilizations may only use a fraction of their power supply for computing, the rest could be used for a (very literally) unimaginable range of things.

      Of course, this presumes that advanced civilizations will simply re-radiate the left-over thermal energy, it's entirely possible that they would have close to 100% efficient systems or have a economically sensible way of storing thermal energy to re-use at a later date.

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    2. Re:series of tubes by Dr_Barnowl · · Score: 4, Insightful

      You have to release heat. The laws of thermodynamics demand it ; even if you have a fractally complex energy usage system, it has to move outwards, or it will all grind to a halt. So you'd see a large sphere at a temperature somewhere above cosmic background - how far above would depend on the efficiency of their engineering.

    3. Re:series of tubes by icebike · · Score: 5, Insightful

      Of course, this presumes that advanced civilizations will simply re-radiate the left-over thermal energy, it's entirely possible that they would have close to 100% efficient systems or have a economically sensible way of storing thermal energy to re-use at a later date.

      It also presumes that advanced civilizations would waste their time and resources building such a contraption, when, given the technology necessary to do so, it would be far easier to find another planet.

      The level of sophistication necessary to deploy such a thing would require a level of technology where Fusion is childs play. There would be no energy shortage.

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    4. Re:series of tubes by tgibbs · · Score: 3, Insightful

      It also presumes that advanced civilizations would waste their time and resources building such a contraption, when, given the technology necessary to do so, it would be far easier to find another planet.

      Would it? The technology required to build any kind of Dyson sphere and the technology required to move a large population to another star are both so far beyond our own capability that there is little basis to judge which is easiest.

    5. Re:series of tubes by LastDawnOfMan · · Score: 2

      Came here to say something like this. This is akin to reading something from the 1880s saying we should be looking for signs of giant steam engines on other worlds. It is a nice thought experiment, and it's harmless enough to look for these things, but we should be shocked if anyone was actually silly enough to do it.

    6. Re:series of tubes by History's+Coming+To · · Score: 2

      A Dyson sphere captures the entire (or close to) energy output of an entire star. Moving planet isn't the argument to use against it, moving an entire colonised solar system is. Building a Dyson sphere is pointless unless you're outgrowing the major system bodies.

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    7. Re:series of tubes by KDR_11k · · Score: 2

      A star is also an extremely powerful energy source, if you need very high amounts of energy for something it may just be the only option to build solar panels very close to a star (barring some as of yet undiscovered energy production method there's no real way to compete with the energy output of a star simply because of how much fuel those things have, you'll have a hard time even finding enough matter that isn't already part of a star or former star). Colonizing a planet won't give nearly that much power.

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    8. Re:series of tubes by bef · · Score: 1

      In fact the best way to look for aliens capable of mega-engineering (like Dyson spheres) would be too look for telltale flares of vast quantities of infrared radiation. But there aren't any around.

    9. Re:series of tubes by RockDoctor · · Score: 1

      The technology required to build any kind of Dyson sphere and the technology required to move a large population

      Why move a large population, when all that you need if for enough(*) to decide or agree to move. Once that happens, the species can move. Whether the species remains viable on their planet of origin is a problem for the ones who chose to stay behind to solve. (Individual survival is of course, implausible. Unless your species has effectively achieved personal immortality, and the inevitably associated birth control.)

      * How many is "enough" is a very moot point, even for our species, even discounting things like taking some full-size adults and lots of eggs / sperm / embryos in liquid nitrogen and lead shielding. Or, even, once you've decided on a destination, sending multiple colony ships over an extended period of time, slowly increasing your colony's gene pool.

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    10. Re:series of tubes by History's+Coming+To · · Score: 1

      The ultimate result presumably being a sphere the size of the observable universe with a very small and pure black body spectrum, say around 2.7K, and with a vaguely fractal internal construction?

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  2. Flawed assumptions. by Anonymous Coward · · Score: 5, Insightful

    Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth, much like humanity.

    I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

    1. Re:Flawed assumptions. by alvinrod · · Score: 5, Insightful

      It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic if we possessed them. Our assumptions are limited by our current understanding. In the next thousand years we could see all kinds of advancements that render building a Dyson sphere completely unnecessary.

    2. Re:Flawed assumptions. by Guido+von+Guido+II · · Score: 5, Interesting

      Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth, much like humanity.

      I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

      But where is that threshold? Is it before or after they build a Dyson sphere?

    3. Re:Flawed assumptions. by ByOhTek · · Score: 5, Interesting

      There's the /civilization's/ recognition of the limit, vs. the individual's desire to procreate, in the battle of need vs. freedom/rights.
      I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

      Also, as for remaining hidden, a race may decide instead of building a Dyson sphere which radiates over it's whole surface, to instead radiate over a smaller portion of the surface, and at a narrower angle. While you could be detected from the right angle, if you point it the right way, the closest thing that could bother you, probably wouldn't be close enough to care about.

      Then again, the amount of mass needed for a Dyson sphere would be insane, if you have that level of tech, to acquire that mass, you probably have other solutions to the problem (direct matter->energy conversion perhaps?)

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    4. Re:Flawed assumptions. by ShanghaiBill · · Score: 5, Insightful

      It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic

      Which is a reasonable assumption. Advanced civilizations will certainly have more advanced technology, but basic laws of reality will still apply. There is no reason to believe that the second law of thermodynamics can be violated, and overwhelming evidence that it cannot.

    5. Re:Flawed assumptions. by Anonymous Coward · · Score: 5, Insightful

      I recognize that humanity has overpopulated the earth

      What do you base that on? Humanity may have overpopulated Calcutta, or Sao Paulo.
      We haven't overpopulated Wyoming.

    6. Re:Flawed assumptions. by danlip · · Score: 1

      I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

      It may not diminish your desire, but hopefully it alters your actions. At the very least I would hope you would choose have 1 or 2 and not 3 or more. If all couples had just 1 child the population would drop by 50% each generation (obviously with a time delay since people live much longer than one generation). 2 is steady state.

    7. Re:Flawed assumptions. by ShanghaiBill · · Score: 4, Insightful

      Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth,

      No, he didn't assume that all civilizations would take this path, just some of them. The Universe should contain billions of civilizations. If even a tiny fraction of them build Dyson Spheres, then this search may find something.

      Alien civilizations are likely products of the same kind of Darwinian process that produced humans, so the desire to expand and grow will be innate, because species which lack that desire are replaced by those that possess it.

    8. Re:Flawed assumptions. by zifn4b · · Score: 5, Interesting

      Basic laws of reality? Isn't science about increasing our understanding of reality? Many theories and ideas have come and gone and been replaced by more refined ones. We would be extremely naive to think our current understanding is even remotely close to all there is to know and completely correct. There is much to learn my friend.

      --
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    9. Re:Flawed assumptions. by Daniel_Staal · · Score: 1

      Dyson's original proposal wasn't they built it all at once, or even that it was solid piece: Building ever more solar energy collectors and putting them into different orbits will eventually do the same job, and put out the same signature radiation.

      Basically, the assumption is that the one true limiter on growth/productivity is energy (a reasonable assumption looking at human history) and that eventually a growing race will capture all the energy they have available to them.

      --
      'Sensible' is a curse word.
    10. Re:Flawed assumptions. by dragon-file · · Score: 1

      I recognize that humanity has overpopulated the earth

      What do you base that on? Humanity may have overpopulated Calcutta, or Sao Paulo. We haven't overpopulated Wyoming.

      And there's still the ocean... we could go all Kevin Costner.

      --
      Whenever a player quits EVE to go play WoW, the Average IQ of both games increase.
    11. Re:Flawed assumptions. by Bill,+Shooter+of+Bul · · Score: 5, Interesting

      Well, the second law is more of a statistical observational law than one deduced from higher principles. Its really good at predicting things and seems really reliable and is tied into all kinds of other areas of physics. I would be shocked to near death if we found a repetable, observable violation.

      But the science fiction lover in me would prefer to think of it a just a setting in the universe that could be switched off when convineint. Its also linked to time, so if we can just step out of the stream of time then we're good and possibly gods.

      --
      Well.. maybe. Or Maybe not. But Definitely not sort of.
    12. Re:Flawed assumptions. by hierofalcon · · Score: 1

      Actually Wyoming would be challenged by water resources to support a very large population since most water is required to be released to the downstream users of the various rivers - whether agricultural or human in any direction you'd care to look and the population centers in the far south - Phoenix or various California cities want more all the time. Part of it is classified as desert and most of the rest is pretty arid in general. As the winters become less severe, the available water will be drastically reduced as the state relies on a lot of snow melt for the water it does store for its own use.

      So although you're welcome to try to overpopulate WY, it wouldn't be easy to do.

    13. Re:Flawed assumptions. by Impy+the+Impiuos+Imp · · Score: 1

      You are probably right, but not for the reasons you think. As long as people want to grow, and can think, (and don't have stupidity like a North Korean government) they will figure ot ways to grow. The kinds of limits Dyson talks about can be fought wih increasing efficiencies, if nothing else, and tech will be more than advanced long before we remotely migt consider a Dyson sphere.

      More likely people will turn inward to advanced virtual realities -- more efficient for energy and much easier to manipulate to do fantastic engineering feats.

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    14. Re:Flawed assumptions. by operagost · · Score: 1

      What do you mean by growth? Growth in size, or technology?

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    15. Re:Flawed assumptions. by Anonymous Coward · · Score: 5, Interesting

      I can't recall who said it but someone (more famous than myself) put the idea out there that if you had the resources to build a Dyson sphere you wouldn't need to build one. Makes sense to me but I'm not an engineer.

    16. Re:Flawed assumptions. by JoeMerchant · · Score: 1

      Zero Point energy, man. It's cool, huh?

    17. Re:Flawed assumptions. by 0xdeadbeef · · Score: 3, Funny

      Indeed. Shakespeare said it first: "there are more things in heaven and earth than exist in your philosophy." Science is just how we're trained to look at reality, It doesn't explain love or spirituality. How does science explain psychics? Auras, the afterlife, the power of prayer?

    18. Re:Flawed assumptions. by omglolbah · · Score: 1

      This of course assumes that nobody dies before procreating ;)

    19. Re:Flawed assumptions. by Bengie · · Score: 5, Insightful

      As far as we can tell, no macro-level system can violate thermodynamics, so the postulate should hold true. There should be IR energy given off anywhere energy is consumed as IR is the end result of an system that is not 100% efficient.

    20. Re:Flawed assumptions. by deoxyribonucleose · · Score: 5, Funny

      How does science explain psychics? Auras, the afterlife, the power of prayer?

      Easily.

    21. Re:Flawed assumptions. by Applekid · · Score: 1

      Ideally, unexpected death would balance out the selfish that would have as many children as they'd like.

      --
      More Twoson than Cupertino
    22. Re:Flawed assumptions. by Grishnakh · · Score: 1

      Lawns don't use as much water as agricultural users.

    23. Re:Flawed assumptions. by Scarred+Intellect · · Score: 1

      Or maybe WE'RE the most advanced civilization.

    24. Re:Flawed assumptions. by mdarksbane · · Score: 1

      I believe you mean "like every successful organism we have encountered so far."

      Those who do not believe in growth tend to be beaten out by those who do.

    25. Re:Flawed assumptions. by rhsanborn · · Score: 5, Insightful

      If I've read my recent physics correctly, 95% of the energy in our universe is in a form we don't know much about (dark matter/energy). If a sufficiently advanced civilization could harness that, they are likely going to do something to target that, instead of star light.

    26. Re:Flawed assumptions. by 0xdeadbeef · · Score: 5, Insightful

      I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

      It's funny how these armchair physicists who got their education from bad science fiction are so adamant that we can't possibly know what magical technology we might invent that will get us around the laws of thermodynamics, so capturing starlight is crude and stupid and this project is obviously a waste of time.

      But boy do they sure know the motivations of future humanity, the path of technological and societal growth, and the psychology of hypothetical aliens, and that knowledge also tells them that this project is a waste of time.

    27. Re:Flawed assumptions. by rufty_tufty · · Score: 5, Informative

      For those who don't get the reference it's a beat poem called Storm by Tim Minchin
      http://www.youtube.com/watch?v=HhGuXCuDb1U
      He's very much being derisive of that sort of viewpoint.
      Sorry to spoil the joke.

      --
      "The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
    28. Re:Flawed assumptions. by TheMathemagician · · Score: 1

      It would have been utterly impossible for humans just over a hundred years ago to predict the existence of nuclear power stations generating huge amounts of energy. We cannot possibly anticipate the energy generation technology of an alien civilisation.

    29. Re:Flawed assumptions. by ShanghaiBill · · Score: 4, Insightful

      How does science explain psychics? Auras, the afterlife, the power of prayer?

      Science also fails to explain unicorns. And don't get me started on Santa Claus. How does he deliver toys to over a billion homes in one night? Science offers no plausible explanation for that.

    30. Re:Flawed assumptions. by WrongMonkey · · Score: 1

      Darwinian processes don't always result in a drive to overpopulate. Ants, bees and other social insects are highly successful species where reproduction is limited to a tiny percentage of the population. If an intelligent species evolved along those lines, it would be a lot easier for rationale decisions to be made about limiting growth to match available resources.

    31. Re:Flawed assumptions. by jmerlin · · Score: 1

      Do I detect a challenge?

    32. Re:Flawed assumptions. by Hatta · · Score: 1

      I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

      Why is that point before one constructs a Dyson sphere? That's a lot of energy escaping into space that could be put to use.

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    33. Re:Flawed assumptions. by NatasRevol · · Score: 1

      Science has explained psychics in one word.

      False.

      or even Repeatedly False.

      Also, love = chemistry.

      --
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    34. Re:Flawed assumptions. by The+Grim+Reefer · · Score: 5, Funny

      And don't get me started on Santa Claus. How does he deliver toys to over a billion homes in one night? Science offers no plausible explanation for that.

      Relative velocity time dilation has been understood for years. Please leave your geek card at the door on the way out.

    35. Re:Flawed assumptions. by Nethemas+the+Great · · Score: 1

      *shhh* someone's looking for means of funding their institution. Don't spoil it for them.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    36. Re:Flawed assumptions. by aristotle-dude · · Score: 2

      There's the /civilization's/ recognition of the limit, vs. the individual's desire to procreate, in the battle of need vs. freedom/rights.
      I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

      Humanity has done no such thing. Certain societies have lead to overpopulation of particular regions of our planet. Have you ever heard of the concept that you are responsible to your fellow man but not "for" them? You cannot take responsibility for the actions of others. Humanity is single homogeneous society.

      You and like minded people in the "west" are doing our species more harm than good by limiting your choices and contributions to the human gene pool based on the irresponsible actions of other nations and cultures. Limiting the birth rate in the west does virtually nothing to halt the overall growth rate and absolutely nothing to curb the birth rate in those other regions while potentially limiting the genetic diversity of future generations to people living in the third world.

      You can care for your neighbour but you are not their keeper.

      --
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    37. Re:Flawed assumptions. by ColdWetDog · · Score: 5, Informative

      How does science explain psychics?

      It doesn't have to. Science doesn't have to deal with fairy tales.
       

      Auras

      If you mean Auroras, we've got you covered. If you mean the fuzzy, ill defined fields that come up when you overexpose film or electronic sensors, well, we've got that covered as well.
       

      the afterlife

      What afterlife? Before it needs explaining, it needs existing.
       

      the power of prayer?

      What "power of prayer"? The non existent causal relationship between other people praying for someone and having an outcomes change? That doesn't happen. The ability of the plastic human mind to influence the rest of the body (to which it's intimately connected)? May I introduce you to the concept of neurobiology in all it's complexity and splendor?

      --
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    38. Re:Flawed assumptions. by aristotle-dude · · Score: 1

      Sorry, that should read "Humanity is NOT a single homogeneous society".

      --
      Jesus was a compassionate social conservative who called individuals to sin no more.
    39. Re:Flawed assumptions. by NatasRevol · · Score: 1

      Or ban interstate water sales.

      Make do with what you have.

      --
      There are two types of people in the world: Those who crave closure
    40. Re:Flawed assumptions. by jeffmeden · · Score: 1

      It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic

      Which is a reasonable assumption. Advanced civilizations will certainly have more advanced technology, but basic laws of reality will still apply. There is no reason to believe that the second law of thermodynamics can be violated, and overwhelming evidence that it cannot.

      The speculation Dyson did basically extrapolated on the existing trend of Humanity... We evolved from organisms that basically used sunlight directly. We started eating organisms that used sunlight directly. Soon, we would be digging up old organisms that used sunlight directly, and releasing the energy for our own benefit. We are starting to understand how to use sunlight directly again, either by capturing the radiation directly or by harnessing the sun's ability to push air around. In case you didn't notice the trend, we have *always* relied on sunlight. It is so much more energetic than anything we can possibly imagine on our own planet (even E=MC^2) and unless the second law of thermodynamics is proven wrong, we will be best served by taking advantage of the sun for many centuries to come.

      However, a step before the sphere is practical (probably by many thousands of years) a civilization will be building large collectors that orbit like planets. We ought to be looking for those.

    41. Re:Flawed assumptions. by aristotle-dude · · Score: 1

      I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

      It may not diminish your desire, but hopefully it alters your actions. At the very least I would hope you would choose have 1 or 2 and not 3 or more. If all couples had just 1 child the population would drop by 50% each generation (obviously with a time delay since people live much longer than one generation). 2 is steady state.

      You are still not getting it. Chances are that if you are posting on here, then you are not part of the problem and any change or lack there of will have a negligible effect on the growth of the population overall but it could have an effect on the future diversity or lack there of in the human gene pool. If you want to curb over population, go preach a change in attitudes to the third world.

      --
      Jesus was a compassionate social conservative who called individuals to sin no more.
    42. Re:Flawed assumptions. by EverlastingPhelps · · Score: 4, Informative

      These are known as Dyson Swarms and Dyson Bubbles, and would have similar characteristics.

    43. Re:Flawed assumptions. by IndustrialComplex · · Score: 1

      2 is actually a decrease as well since the probability of death before sexual maturity is still greater than 0.

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    44. Re:Flawed assumptions. by Bengie · · Score: 1

      That has already been covered. dumping waste heat into a wormhole/etc means they went out of their way to mask their existence. It can be done, but it is extra work that needs to be done and makes things harder. Routing energy costs energy, no matter how you look at it. They must consume energy to mask energy, which means they would be purposefully hiding. The article already said "A civilization that built a Dyson Sphere would have to go to great lengths to avoid detection".

      No one is saying it can't be done, just that with our current knowledge of physics, it would be hard enough that one would need to do it on purpose.

    45. Re:Flawed assumptions. by Nethemas+the+Great · · Score: 1

      Most people that rail against unlimited growth do so with the idea that it must all be housed on Earth, which is to say within restrictions of limited resources. To suggest that that view is myopic would be a gross understatement. The only necessary governor on growth would be that which our technology enables us to sustain.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    46. Re:Flawed assumptions. by jeffmeden · · Score: 4, Interesting

      I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

      It may not diminish your desire, but hopefully it alters your actions. At the very least I would hope you would choose have 1 or 2 and not 3 or more. If all couples had just 1 child the population would drop by 50% each generation (obviously with a time delay since people live much longer than one generation). 2 is steady state.

      You'd be surprised how many people simply don't ever procreate. Your point is still valid, but if everyone who wanted/could have kids did have just 2 that lived to maturity (another factor) the population would still decline. Three kids (during your child bearing years) per willing/able couple is more practical for holding a steady population. A guilt trip for having 3 kids is completely unwarranted.

    47. Re:Flawed assumptions. by Nethemas+the+Great · · Score: 5, Insightful

      Just ignore him, he's one of those frustrating, myopic people that thinks we are limited to the resources of the ball of mud on which we presently live.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    48. Re:Flawed assumptions. by WrongMonkey · · Score: 1

      Wyoming is not physically crowded, but in terms of carrying capacity, it's just as overcrowded as Calcutta. There's not enough water and arable land to support the population without importing outside resources.

    49. Re:Flawed assumptions. by samkass · · Score: 1

      Waiting for the Sun to release its nucleic binding energy in fusion then allow it to percolate to the surface, only to build a collector to capture some percent of it is for pussies.

      REAL civilizations covert their Sun's mass directly to energy before moving on to the next one.

      Is anyone looking for THAT?

      --
      E pluribus unum
    50. Re:Flawed assumptions. by Nethemas+the+Great · · Score: 1

      If a civilization is able to build a Dyson sphere then that would mean that they are no longer constrained to the limited resources of the ball of mud on which they were conceived. Our solution to the over-consumption of finite resources should not be to constrain our population but to push our technology. To reach out for the fruit that is not so low on the tree, and even as we do, we push our technology still further to learn how to plant our own life giving trees.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    51. Re:Flawed assumptions. by Carewolf · · Score: 1

      A ringworld? Still an insane idea, but a few magnitudes less insane.

    52. Re:Flawed assumptions. by HiThere · · Score: 1

      Sorry, but while chemistry is involved, it isn't even approximately the same as love. Love is *much* more complicated. So is hat, but it's simpler than love. Both love and hate require a computational model that hasn't been properly developed yet. It *is* clear that chemistry is used in the current implementation of the model, but saying it's required appears to be like saying computation requires an abacus.

      Granted, I'm being nitpicky, but this *is* slashdot. And oversimplistic answers are ... oversimplistic.

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    53. Re:Flawed assumptions. by ChronoFish · · Score: 4, Insightful

      Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth....

      I don't know anything about Dyson, but based on our "civilization" we don't "believe" in infinite growth... we just grow to point where our growth is no longer sustainable. There is no belief or consciousness involved. Sure you you may have individuals warning about the "tipping point" of the world the civilization lives in... but until the tipping point is reached there is little the civilization can do to stop its growth. That's life in general. Every population grows until it can't. When it's over populated it shrinks. When no resources can be consumed, it dies. Populations growth will always be towards equilibrium with what-ever its surrounding can support.

      If a population is advanced enough to build a a dyson sphere, and a dyson sphere is the only way to survive, then a dyson sphere will be built or the population will decrease towards 0 until the population stabilizes (which very well may be at "0").

      But regardless there is no belief here. There is no concerted attempt to grow infinitely. Just ask a deer or fruit-fly. They have no clue what you're asking...but their population will certainly increase when it can and decrease when it has to.

      -CF

    54. Re:Flawed assumptions. by Anonymous Coward · · Score: 1

      Actually we have overpopulated Wyoming. It might not seem that way when you're standing there, looking at the vast empty spaces, but that land has use and is used, to provide food amongst other things, even if those other things are just useless other species. A world in which the only animals live on farms and the only vegetation is corn, wheat and rice is not really a world worth living in, no matter how long you spend in your parents' basement. There is a given amount of space and resources available on Earth, and we are over using them. The only truly sustainable country is Cuba.
      China for a while showed what sustainability would look like... This will change as technology changes but we don't have that technology now.

    55. Re:Flawed assumptions. by Hatta · · Score: 1

      My understanding is that a sphere is gravitationally stable but a ring is not.

      --
      Give me Classic Slashdot or give me death!
    56. Re:Flawed assumptions. by SpanglerIsAGod · · Score: 1

      I'm not saying you are wrong, but how would we look for large collectors? How would we be able to tell the difference between a collector and a moon or planet passing in front of a star?

      --
      War doesn't show who is right - just who is left.
    57. Re:Flawed assumptions. by Anonymous Coward · · Score: 1

      Dark matter is just a bunch of Dyson spheres? What a nice thought.

    58. Re:Flawed assumptions. by DamnStupidElf · · Score: 1

      Or they're just made out of/turned themselves into dark energy and matter to avoid the bother of conversion.

    59. Re:Flawed assumptions. by gutnor · · Score: 1

      When looking for a dyson sphere you assume that an advanced society would need such an amount of energy in a - relatively - small location. If there is a technology that allows you to tap other convenient source of energy, a society may very well spread itself so that it does not radiate that much.

      Let's take a plausible example that assume not so fancy technology. If you have a species that live for example 10K years, they may very well be a lot less enclined to stick to their solar system and a few hundred years of travel is daunting but not more than creating a colony on Mars for our civilisation. Even if that civilisation evolve to the level of being able to create a dyson sphere, they may simply not be interested.

    60. Re:Flawed assumptions. by tftp · · Score: 5, Interesting

      we have *always* relied on sunlight

      Past performance is not an indicator of future performance. Humans always used horses... until they invented a car. Humans were using only land transport.. until they invented an airplane. Humans were always planet-bound, until they flew into space.

      A Dyson sphere is not a scientific fact, it's only a possibility, and not trivial one at that. The approach has many problems.

      First, the Dyson Sphere, even if it is ideally constructed, will only supply energy to your sites near the star. However it is logical to expect that an advanced civilization will need spaceships for all kinds of purposes, from research to migration. This cannot be done without movable sources of energy (thermonuclear at the least.) Once you have them, the effort of building the Dyson sphere appears to be too high.

      Then the Dyson sphere needs to be constructed. There isn't much material in an average planetary system to do that, unless you can transmute your common silicon and carbon into scrith and make a thin foil out of it. You also need to deliver that material to where it is needed, and join it. A Ringworld is a much easier possibility at this point.

      Once you build the sphere you need to equip it with collectors of solar energy. Where would they come from? If we build a sphere at 1AU from the Sun, do you think we can line it with solar panels? We'd have not one atom left in this Solar system after we built the sphere. Besides, the sheer volume of the effort would be impossible.

      The sphere would need to be thermally balanced. (This is how they intend to find it.) If you collect all the energy and keep it inside it will heat up to the temperature of the star - and that is perhaps not what you want. So you need to cool it. Earth is rotating, radiating heat every night and collecting it every day. Planets like Mercury show what happens when a planet is thermally overloaded. The Dyson sphere would have to have radiators of energy somewhere on the external side, and there would have to be conduits. This is a lot of work.

      Then the question would arise of atmosphere. Is your Dyson sphere is at 1AU then you need to live on that sphere - and that means that you must have means of holding the atmosphere in place. If you leave Earth (for example) in place and instead build the sphere on a farther orbit then the surface of your sphere grows and you need even more material. Also the problem of transportation of collected energy arises.

      Considering these and other technological and conceptual difficulties, it may be easier to just use local sources of energy, like thermonuclear reactors or better. Astronomers, of course, want something to look at, and you can't look for reactors that far away. I don't think they will find Dyson spheres, though. A civilization that is advanced enough to build such a sphere probably does not need it.

    61. Re:Flawed assumptions. by Genda · · Score: 3, Interesting

      I dunno, let's give it a try...

      Love; the evolutionary behavior surrounding mating and parenting designed to ensure members of your gene pool proliferate.

      Spirituality, the embrionic cognitive appreciate of a finite being and its relationship to a virtually infinite universe.

      Science doesn't explain psychics, the Amazing Randy explains psychics.

      Auras look up "Phosphenes."

      Hhhhmmm, After life there is what? Decomposition? Tea and crumpets with St. Peter?

      The power of prayer? Seeing as the Amygdala is the part of the brain doing the heavy lifting during a prayer, let's say the power of a prayer is 15-45 microwatts depending on how hard you pray and whether you are concentrating.

      I know I'm being sarcastic, but you just said it yourself, Science doesn't dabble in unreality. That would be the realm of mystics and metaphysicists. I'm not even saying none of these thing may exist. I'm saying that until you can separate the magical thinking from some describable real world phenomenon, there's nothing for science to do, but nod its head and thank you for sharing.

    62. Re:Flawed assumptions. by SpanglerIsAGod · · Score: 1

      Fortunately we already produce enough food so we wouldn't need to increase agriculture.

      --
      War doesn't show who is right - just who is left.
    63. Re:Flawed assumptions. by Jason+Levine · · Score: 1

      Easy: Santa is a Time Lord and has a TARDIS. That also explains how he can live for so long.

      Now the tricky question is why he likes milk and cookies and not fish fingers and custard or jelly babies.

      --
      My sci-fi novel, Ghost Thief, is now available from Amazon.com.
    64. Re:Flawed assumptions. by TFAFalcon · · Score: 1

      So? From the viewpoint of someone standing still, he can still not move faster then the speed of light. And any time he drops off a toy, he has to either slow down slowly, or subject the toy itself to extreme g forces. Since toys arrive in a non-squished condition (and they are generally not resistant to high g, as the kids soon discover), then Santa has to slow them down slowly - taking quite a bit of time for every toy dropped off.

    65. Re:Flawed assumptions. by ShanghaiBill · · Score: 1

      My understanding is that a sphere is gravitationally stable but a ring is not.

      You have this backwards. A hollow sphere is not gravitationally stable because the poles are not rotating, so there is no centripetal force to keep them from collapsing.

      A ring can be gravitationally stable. Proof: Saturn.

    66. Re:Flawed assumptions. by HiThere · · Score: 2

      The real question is, what is the lowest level of energy difference that can be profitably collected. When you decide that, you've decided on the band of em-radiation that will be radiated. I'm not convinced that we can yet say what that would be, so it's possible that we should be looking for radio-waves. OTOH, mid-low infrared is certainly plausible. (Even if you *could* collect a tiny bit more, you've already extracted most of the energy, and building the collector would require a LOT of work. But it's also possible that we should be looking at red giants. Quite plausibly extracting the energy that falls below red requires a structure that costs more to build and maintain than it will ever yield in value.

      OTOH, I'm not convinced by the Dyson sphere. It takes too much material, and disaters are too all-encompassing. I prefer topopolis (also know as "cosmic spaghetti"), which has many of the values of a Dyson sphere, but isn't quite as complete at collecting energy, but has many fewer engineering problems. Think of it as a linear space habitat 10-20 miles in diameter, and indefinitely long. It can come in chunks that are coupled together like train cars, only using magnetic couplers, so the sections are free to rotate with respect to each other. This allows Y juctions, and more (which don't rotate). But each chunk in in orbit. Ends can split and join. Etc. And it could be long enough to loop around the sun as many times as you have material to build. Another problem of the Dyson sphere is atmosphere. This seems to require two or more layers, and I have serious doubts that there is enough material even if you disassemble all the planets. Unless you are presuming efficient matter conversion, so that you can change granite and basalt into good steel...and even then I'm a bit dubious. And gravity. Topopolis solves this by rotating the chunks (which could be long enough to completely circle the sun multiple times, but why do it that way, still, if you did steel will flex enough that a 20 mile diameter tube wrapping around the sun wouldn't even notice the flexing).

      So I really doubt they'll find anything. Still, it's worth looking, since the data needs to be collected for normal astronomical purposes anyway.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    67. Re:Flawed assumptions. by NFN_NLN · · Score: 1

      Basic laws of reality? Isn't science about increasing our understanding of reality? Many theories and ideas have come and gone and been replaced by more refined ones. We would be extremely naive to think our current understanding is even remotely close to all there is to know and completely correct. There is much to learn my friend.

      No matter how much we advance our understanding of mathematics, 1+1=2 still holds. Some things are fundamental.

    68. Re:Flawed assumptions. by Bengie · · Score: 2

      It's not the issue of energy generation, but energy consumption. 100% efficient systems are theoretically impossible based on our current knowledge. If it's not 100% efficient, expect IR to be released at some point.

    69. Re:Flawed assumptions. by Jason+Levine · · Score: 1

      You don't need to violate the laws of thermodynamics to get futuristic energy advancements. Off the top of my head: Suppose that there was a way to convert matter directly into energy (ala e = mc^2). We'll assume that Future Tech makes this feasible in the way that nuclear fission power plants are feasible today. So you take a lump of rock, convert it into energy (likely at under 100% efficiency), and use that energy to power your civilization (somehow... via more Future Tech). No violations of thermodynamics have occurred and your energy source is using technology that we don't possess.

      --
      My sci-fi novel, Ghost Thief, is now available from Amazon.com.
    70. Re:Flawed assumptions. by Nadaka · · Score: 2

      How?

      A century ago we knew that nuclear power was possible. We understood that the transmutation of elements would release energy in a form of heat, which we know how to transform into various forms of work.

      Quantum Power? There is no net release of energy in the spontaneous creation and destruction of virtual particles.

      Dark Energy? we don't even know what it actually is, if it is energy, or if it can do anything useful.

      Comparing nuclear power today to power generation a hundred years ago is like comparing a puma and mountain lion. Quantum and Dark energy at best alien beasts that may be cat shaped, like a Ceourl, and that is if they are cats at all, for all we know they may not even be animals.

    71. Re:Flawed assumptions. by pscottdv · · Score: 1

      No. Neither is stable.

      It is pretty easy to see. Imagine the sphere moving a tiny amount so the star is no longer at the center of the sphere. Now the question is, do the resulting gravitational forces pull the sphere back towards the position where the star is at the center, or do they pull the sphere further off-center? Clearly, they are now unbalanced in favor of pulling the close side of the sphere even closer and, thus, sphere-world is also unstable.

      --

      this signature has been removed due to a DMCA takedown notice

    72. Re:Flawed assumptions. by angelbar · · Score: 1

      Arable?... Maybe that's the wrong approach. There are deserts converted to arable land and there is the hidrophonics focus in recyclable use of water. http://en.wikipedia.org/wiki/Desert_farming

      --
      -no sig today-
    73. Re:Flawed assumptions. by chichilalescu · · Score: 1

      Most energy that's not coming from the star of your system will have very low density, low enough so that it's useless.
      Unless reality decides to have fun, and the whole zeropoint energy idea turns out to work.

      --
      new sig
    74. Re:Flawed assumptions. by MartinSchou · · Score: 1

      I don't know anything about Dyson, but based on our "civilization" we don't "believe" in infinite growth... we just grow to point where our growth is no longer sustainable.

      I'm not sure that's true. If you look at the statistics available, the number of children per woman drops over time as the child survivability increases.

      This means that barring something that really fucks up child mortality, we'll likely reach a something very close to a population steady state by about 2050.

      Sadly I'm not adept enough at using Gapminder.org to pull up a reference - it's simply what I recall from one of Hans Rosling's many TED talks.

    75. Re:Flawed assumptions. by mabhatter654 · · Score: 2

      The sheer amount of material needed to build a Dyson Sphere is fantastically unpractical. The earth covers 60 times its surface circumference in a day. That's 23,000 times the circumference just to build a "ring world" ... Volume CUBES that number.

      A space civilization would have to move MANY entire solar systems just for a simple "halo" size ring world....

      I could see sol-centric orbiting stations to gather power as the earth visits each one throughout the year... But a Dyson Shpere is WAY say that... If they didn't want to be found, WE veritably wouldn't find them.

    76. Re:Flawed assumptions. by angelbar · · Score: 1

      Bah !! your signature its relative: http://www.eveonline.com/

      --
      -no sig today-
    77. Re:Flawed assumptions. by jeffmeden · · Score: 4, Insightful

      we have *always* relied on sunlight

      Past performance is not an indicator of future performance. Humans always used horses... until they invented a car. Humans were using only land transport.. until they invented an airplane. Humans were always planet-bound, until they flew into space.

      In the midst of ALL of that (horses, cars, planes, spaceships) they have all been powered (as well as the humans in them) indirectly (by about 2 or 3 steps of conversion) by the sun... Sure things change, but given how different humanity of 2012 looks compared to that of only 1000 years ago, and still it's entirely thanks to the sun, is a pretty clear suggestion that humanity will rely on the sun from now until the end of our existence. There's just too much energy shooting out of it in every direction for it to be ignored, barring something that literally violates the laws of physics as they are currently understood.

    78. Re:Flawed assumptions. by ShanghaiBill · · Score: 2

      REAL civilizations covert their Sun's mass directly to energy before moving on to the next one.

      Is anyone looking for THAT?

      Yes. If an advanced civilization dismantles their sun and generates energy by directly fusing the hydrogen, they still have to dispose of the waste heat. So they would have an IR signature exactly like a Dyson Sphere. So this search would find them.

    79. Re:Flawed assumptions. by tftp · · Score: 1

      That's a lot of energy escaping into space that could be put to use.

      OK. Launch a mirror, 1000 x 1000 miles, onto the LEO and focus it onto your house. What will happen?

      1. You get oodles of free energy and you can now keep all your computers running 24/7
      2. There will be a burned hole where your house was, all the way to the Earth's mantle.

      We, here on Earth, already are having thermal problems even though we only release chemical energy from fossil fuels. If more energy is magically delivered to Earth (by increasing Sun's output, for example) the planet will overheat. Imagine if every house on Earth has 1 MW power station in the basement, and 1 MW of loads?

    80. Re:Flawed assumptions. by sexconker · · Score: 5, Funny

      So? From the viewpoint of someone standing still, he can still not move faster then the speed of light. And any time he drops off a toy, he has to either slow down slowly, or subject the toy itself to extreme g forces. Since toys arrive in a non-squished condition (and they are generally not resistant to high g, as the kids soon discover), then Santa has to slow them down slowly - taking quite a bit of time for every toy dropped off.

      Each toy is delivered with the elf who made it.
      The elf slows the toy down on descent, places it neatly, and promptly burns itself to death in the fire place. If you don't have a fireplace the elf will flush itself, use the garbage disposal, provoke the dog into eating it, or, failing all of those, walk outside and freeze to death. Most people confuse their bodies for garden gnomes.

    81. Re:Flawed assumptions. by Anonymous Coward · · Score: 2, Interesting

      There are basically 2 kinds of "Dyson Spheres" the kind from the Star Trek episode (Relics), and the kind that Dyson actually theorized about.

      The former (a single-structure hollow sphere that encapsulates a star) are impractical because of the amount of material they require and the mind boggling stresses that would be exerted on the structure during construction. The later on the other hand (a cloud of small satellites in orbits that result in a dense "shell" around the star) doesn't take any more technology that we have now (except maybe incremental improvident in wireless power transmission efficacy). It mostly just requires a big enough energy need to justify the scale of the project.

    82. Re:Flawed assumptions. by pscottdv · · Score: 1

      Of course, if the "sphere" is really a swarm of independently orbiting objects, that would be (very nearly) stable.

      The same is true for a "ring-world" of independently orbiting objects.

      --

      this signature has been removed due to a DMCA takedown notice

    83. Re:Flawed assumptions. by sexconker · · Score: 1

      Science has explained psychics in one word.

      False.

      or even Repeatedly False.

      Also, love = chemistry.

      Chemistry makes it so bandages love the water, and condoms love the pussy.
      When we do chemistry, we talk about the "human element" and show children being happy because you morons don't understand chemistry.

      BASF
      The chemical company.

    84. Re:Flawed assumptions. by Genda · · Score: 2, Informative

      I know Santa's big, but he ain't big enough to bend space time!!!

    85. Re:Flawed assumptions. by sexconker · · Score: 1

      I don't think searching for Dysan spheres is a bad idea, but if we don't find any, it raises more questions than it answers. Fortunately, they're interesting questions.

      The first question raised would be "Why did we listen to the sci-fi ramblings of this coot and spend billions of dollars looking for these ridiculous things?".

    86. Re:Flawed assumptions. by wierd_w · · Score: 4, Interesting

      Bees, ants, wasps, and nearly all other social insects are also adapted to living with a gender-bending endo-parasite.

      Namely, the wolbachia parasite. It is a protozoan that inhabits cellular cytoplasm of the cells of those species of insects, and procreates through forcing males to develop as females, because it can only perptuate itself through the larger ova of those species, and not through the smaller sperm of those species.

      As such, the centralized reproductive practice of those organisms is directly tied to the limitations imposed upon them by the highly aggressive wolbachia parasite.

      Removal of the parasite through aggressive use of antibiotics has shown radical changes in cytoplasmic composition and embryonic development, which results in sexual infertility and even outright death in many infected species.

      http://www.tandfonline.com/doi/abs/10.1080/0958315031000110355

      Literally, these lifeforms have become very efficient host vehicles for their parasites, and their reproductive strategies more closely favor proliferation of the parasite than their own.

      Essentially, the parasites have forces their hosts to evolve in such a way that the host's behavior has been altered significantly.

      The effects of wolbachia infection on the behavior of insect model species has been well researched. Take for instance, a study of wolbachia on mosquitos.

      http://m.sciencemag.org/content/323/5910/141.short

      What I a getting at here is that the existence of communal reproduction centric organisms like bees and wasps does not negate the validity of the prior poster's statement, because the bees and wasps did not develop this strategy so much as have it impose upon them by a more aggressive species that does conserve the poster's conjecture.

    87. Re:Flawed assumptions. by icebike · · Score: 2

      It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic if we possessed them. Our assumptions are limited by our current understanding. In the next thousand years we could see all kinds of advancements that render building a Dyson sphere completely unnecessary.

      Dyson never heard of Fusion other than used as a weapon. It was a pipe dream back then. The first commercial nuclear fission reactors has only operational for a few years at great cost.

      This is just another pipe-dream solution to a problem that will never appear.

      You can not harness the full power of the sun and bring even a fraction of it to earth without melting the planet.

      --
      Sig Battery depleted. Reverting to safe mode.
    88. Re:Flawed assumptions. by leonardluen · · Score: 4, Funny

      Most people confuse their bodies for garden gnomes.

      the parent has a point, have you actually seen anyone purchase a garden gnome?

    89. Re:Flawed assumptions. by xaxa · · Score: 1

      What do you base that on? Humanity may have overpopulated Calcutta, or Sao Paulo.
      We haven't overpopulated Wyoming.

      If we all lived like the average Calcuttan or Sao Pauloan we'd be fine.

      It's trying to live like the average Wyominger that's the problem.

    90. Re:Flawed assumptions. by leonardluen · · Score: 2

      i can think of at least 1 scenario where 1+1=10

    91. Re:Flawed assumptions. by Hatta · · Score: 1

      A hollow sphere is not gravitationally stable because the poles are not rotating, so there is no centripetal force to keep them from collapsing.

      The poles are like the key stone in an arch.

      A ring can be gravitationally stable. Proof: Saturn.

      Saturns rings aren't solid rings. They're particulate matter arranged in a ring.

      --
      Give me Classic Slashdot or give me death!
    92. Re:Flawed assumptions. by maxwell+demon · · Score: 3, Insightful

      It is very simple: If you don't want to boil your self to death, you must ultimately radiate away all the energy you get from your star. The biggest common misunderstanding about energy is the idea that we consume it. We don't consume energy, we just pass it through our systems. Now in what form do you radiate it away? Well, in the most useless form possible, because otherwise you'd waste precious energy. That form is the form of heat radiation, and the spectrum is determined by only two parameters: How much energy the star produces (which is the amount of energy to be radiated away), and how large the Dyson sphere is.

      Think about it like the water of a river used to drive machines. We let the water run through our machines to use its power, but if we would keep that water, we'd soon drown. Instead we have to let all the water we use flow out again.

      With energy it is basically the same. If we don't ultimately get rid of all the energy we use, we heat up and boil to death. We have to eventually re-emit all the energy; we just do so in the form of heat radiation.

      OK, there's one thing which could actually lower the energy emission: Conversion of energy into matter and antimatter. So if we assume that the advanced civilisation use up a considerable part of the energy in order to produce matter and antimatter, it would reduce their energy output. The matter could be used to build things inside the sphere. However, unless they found a way to convert antimatter to matter, they would have to get rid of all the antimatter (transforming back into energy would lead back to the original emission). If they just throw it into space, it would react with other matter there (remember, we are speaking about massive amounts of antimatter, if it shall make a noticeable difference in the energy output), which would give a very obvious signal which I'm sure would already have been detected.

      So the only way to have lower energy output would be if the advanced civilisation found a way to transform antimatter into matter, and uses a large fraction of the energy to create new matter.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    93. Re:Flawed assumptions. by Migraineman · · Score: 1

      Funny ... about a week ago I was thinking about Dyson spheres on the drive in to work. I did some quick math when I got in. To create a Dyson sphere 1km thick at an earth-radius from a star, you'd only need 197 or so Jupiter-sized planets of suitable material to do so. I was expecting it to be several orders of magnitude more. Not that I think that's a plausible number, considering that gas giants aren't composed of useful building materials.

    94. Re:Flawed assumptions. by Hatta · · Score: 1

      We're both wrong. The sphere isn't stable, in that there's no net force correcting it from a perturbation. But it's not unstable either, because there's no net force amplifying a perturbation.

      If you think about a sphere that has been slightly perturbed, you're right in that part of the sphere would be closer to the star and those gravitational forces would be higher. But at the same time, more than half of the sphere would be on the opposite side of the star, pulling in the opposite direction. These effects cancel each other out.

      I guess this is called "passive stability".

      --
      Give me Classic Slashdot or give me death!
    95. Re:Flawed assumptions. by maxwell+demon · · Score: 1

      You know, living at the north pole, he eats fish 264 day a year. So it's very understandable that he wants to eat something different at that one day.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    96. Re:Flawed assumptions. by Hatta · · Score: 1

      You miss one of the biggest points of having a Dyson sphere. That is, a truly enormous surface area with which to collect all that energy.

      --
      Give me Classic Slashdot or give me death!
    97. Re:Flawed assumptions. by maxwell+demon · · Score: 5, Insightful

      The "power of prayer" goes not only against science, it even goes against true faith. If god is all-knowing and good, then he must know what is best for the people even without the people praying for it. If he needs to be told what to do, he's not all-knowing. If he does the good only if someone prays for it, he's not good. And if he does something which is not good because someone prays for it, he's even less good. Therefore we find that an all-knowing and good god cannot be influenced by prayers, and therefore the believe that prayers have objective effects (other than the normal psychological effects) shows a lack of faith.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    98. Re:Flawed assumptions. by maxwell+demon · · Score: 1

      Well, some of our power (nuclear fission) comes from different stars.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    99. Re:Flawed assumptions. by ShanghaiBill · · Score: 1

      The poles are like the key stone in an arch.

      Not unless you can find a material a few quadrillion times stronger than steel.

      Saturns rings aren't solid rings.

      But they would still be stable even if they were solid. I mean each narrow individual ring, not the whole disk of rings (that would not be stable since the inner rings would rotate faster than the outer rings).

    100. Re:Flawed assumptions. by DRJlaw · · Score: 4, Interesting

      And don't get me started on Santa Claus. How does he deliver toys to over a billion homes in one night? Science offers no plausible explanation for that.

      Relative velocity time dilation has been understood for years. Please leave your geek card at the door on the way out.

      Reltive velocity time dilation only theoretically solves the time aspect of the problem, and only if you neglect the fact that at least the delivered presents have to STOP in my frame of reference..

      I don't care how damn amazing a Wii U is supposed to be, when 1.5 kg of mass rips to a halt under my Christmas tree from, let's be generous here, 0.9c, the resulting vaporization of my house (k.e. ~ 0.5mv^2, or 1.09*10^17 joules, or 26.06 Mt of TNT) is going to result in a very unhappy Christmas.

    101. Re:Flawed assumptions. by pastafazou · · Score: 4, Funny

      that's easy. His requirements to make the "good" list are so unrealistic, he doesn't have to make any deliveries. Guilty parents then buy gifts for their brats, and Santa collects the glory!

    102. Re:Flawed assumptions. by Hatta · · Score: 1

      But they would still be stable even if they were solid.

      No they wouldn't. The geometry in 2d doesn't cancel out the way it does in 3d.

      I mean each narrow individual ring, not the whole disk of rings (that would not be stable since the inner rings would rotate faster than the outer rings).

      This is not a problem. Ever seen a record player?

      --
      Give me Classic Slashdot or give me death!
    103. Re:Flawed assumptions. by maxwell+demon · · Score: 1

      When you look for Dyson spheres you consider the possibility that an advanced civilisation would need such an amount of energy in a relatively small location. Now if, after not having found Dyson spheres, someone would claim that this proved there are no advanced civilizations, then you could complain about people assuming that Dyson spheres are inevitable. The mere search for them does not presuppose they are inevitable. It only presupposes they are possible.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    104. Re:Flawed assumptions. by Anonymous Coward · · Score: 1

      Dammit, where's the Facebook "Like" button? LIKE. Science explains reality. There's a lot out there that's imagination that science will never explain because it doesn't exist. Doesn't mean it won't be talked about, used by religious groups for profit, child-fondling, and personal gain, or other such. But belief doesn't make it any more real. Even if everyone believes in the Flying Spaghetti Monster it doesn't make it real. So science will never explain certain things. And that doesn't make science or the scientific method any less valid or any less valued.

    105. Re:Flawed assumptions. by maxwell+demon · · Score: 1

      Of course you also have to radiate away the energy from that energy source.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    106. Re:Flawed assumptions. by freeze128 · · Score: 1

      Who says they have to realize anything? Maybe the aliens are a bacteria, or fungus. They could still construct a structure around a star. Bees make pretty good builders... They could be insects.

    107. Re:Flawed assumptions. by maxwell+demon · · Score: 1

      There is no such thing as energy consumption. Energy doesn't get consumed. Energy gets used, and then the used energy gets radiated away as heat.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    108. Re:Flawed assumptions. by tftp · · Score: 1

      Well, the point of my argument is that you either learn how to make matter out of the collected energy, or that energy will cook you :-) Most of the energy will eventually transition into heat, except the energy that you intentionally blast into space.

      The easiest solution to this problem is in building the sphere at 1AU and moving there. But there isn't enough material in this Solar system to build it and fill with enough oxygen and water. Another possibility is to use that energy to heat outer planets of the Solar system... but unfortunately they would be already gone by the time you have the sphere built.

      Either way, the real question is not about the energy but about the matter. If you know how to synthesize one, good for you. Then the sphere can build itself. You need its energy only if you have enough surface to use that energy on. Otherwise it would be like living in a furnace.

    109. Re:Flawed assumptions. by XxtraLarGe · · Score: 5, Insightful

      i can think of at least 1 scenario where 1+1=10

      Yes, but that's still 2.

      --
      Taking guns away from the 99% gives the 1% 100% of the power.
    110. Re:Flawed assumptions. by Omega996 · · Score: 1

      AC, if I had mod points, I'd give them all to you. I like science fiction as much as any fan, but christ, it's fiction. The amount of fantastical speculation outside of fiction circles about endless energy, faster than light travel, 100% thermodynamic efficiency, alternate realities, and so forth really demonstrates the fundamental ignorance of science by the majority of people. The amount of ignorance is astounding.

    111. Re:Flawed assumptions. by jeffmeden · · Score: 1

      Well you don't technically need volume you just need a sphere that is somehow self-stable and you need to built it in-situ... What does google think?

      mass of the earth / (1 astronomical unit ^ 2 * pi * 4) = 22 kg/m^2

      Given the density of the material (without refining) that's about 4cm thick. Not too bad, right?

    112. Re:Flawed assumptions. by WrongMonkey · · Score: 1
      That doesn't refute my point at all. You have an implied assumption that some reproduction strategies are normal, but others are "imposed". Ants, bees and termites have adapted a successful reproductive strategy based on the selection factors of their environment. One of those factors was this parasite. Their strategy was not "imposed" upon them any more than sexual reproduction has been imposed.

      Who knows what environmental factors an alien species might encounter? Who knows what reproduction strategies they might evolve in their environment? We cannot assume that our behavior is representative of all life in the universe when it isn't even representative of life on our globe.

    113. Re:Flawed assumptions. by Selfbain · · Score: 1

      I would imagine a species that is capable of building a Dyson Sphere would have left their evolutionary heritage behind a long time ago.

      --
      Well, it has never been successfully tested.
    114. Re:Flawed assumptions. by slashmojo · · Score: 1

      Science also fails to explain unicorns. And don't get me started on Santa Claus. How does he deliver toys to over a billion homes in one night? Science offers no plausible explanation for that.

      Schroedinger's Reindeer.

    115. Re:Flawed assumptions. by firecode · · Score: 1

      Another way technology could advance is that we will become more and more efficient at using energy. Instead of having huge Dyson sphere, a super-advanced alien race could exist only inside huge computer simulation meaning that each individual would take only small amount of memory and watts to "exist" (something like Matrix) and number of "real" individuals outside this simulation would be rather limited.

    116. Re:Flawed assumptions. by bazmonkey · · Score: 1
      I can't quote directly while at work, but I recall a TED talk mentioning that humans and the animals we raise (chickens, cats, dogs, sheep, cattle, etc.) now represent 98% of the world's terrestrial, vertebrate animals by mass. There's far more individual creatures in the wild than in domestication, but by weight we have overwhelmed the system.

      IOW, the world is essentially running to support us. That's overpopulation. In the struggle to survive against nature, we're the first creatures to have essentially won.

      What do you base that on? Humanity may have overpopulated Calcutta, or Sao Paulo. We haven't overpopulated Wyoming.

      Overpopulation isn't just about space to put people. Think about the food you eat and products you consume. The space required to support you is far, far larger than the area of your apartment.

    117. Re:Flawed assumptions. by The+Grim+Reefer · · Score: 1

      I know Santa's big, but he ain't big enough to bend space time!!!

      That's just what he looks like when you can see him.

    118. Re:Flawed assumptions. by Genda · · Score: 1

      He doesn't like milk and cookies, the Tardis does.

    119. Re:Flawed assumptions. by ranpel · · Score: 2

      Actually, I've met Santa and he's nice. It's a common misconception that he's lugging a humongous satchel filled with toys and the truth will surprise you. He's got this delightfully nifty contraption that actually uses the same power that you believe, rightfully so, would squish a toy under these same conditions. What happens is that he, this contraption that is, produces what is basically a tiny marble with the tiniest pinpoint of light within it that sort of flits around and such. You can actually fit several thousand in the palm of the average adult hand. Anyway, the weird part, these tiny marbles are "delivered" and it's this delivery process that taps the "heat" of the destined human's spirit so that when combined with the phenomenal forces of velocity and pressure they intrinsically form the resulting toy, gadget, craft or any other "gift" you can think of. The delivery "shapes" the gift solely and wholly for the destined individual and its formation is completed only when the delivery comes to a complete stop. It's quite fascinating, and fast. Now, "What about the wrapping?" you might ask and to this I will only say that it's a clever little trick that one certain little elf discovered during early experimentation with hopper loading of these tiny marbles (they're actually called bullion, if you were wondering, and they make billions a year. They're nicknamed "bb's". Clever, I know.). Essentially it was discovered via a series of unexpected in-flight hopper test failures that when the bullion slows it can "glue together" its surrounding particles of, well, anything and what Santa actually does when he twinkles his nose is "color" the wrapping and bow. The elves call this part "skid marking" in honor of that one elf that released that one fateful hopper load attempt. The elf's name was Zee but that has very little relevance. Zee's skid marked bullion piece still sits prominently at the controls of the hopper station though none are allowed to touch it.

      There, I do hope I've cleared some things up but, as it is, we must have our traditions and stories, I know.

      And to all a good night!

      --
      \r
    120. Re:Flawed assumptions. by Genda · · Score: 1

      Yeah, I love how the Marketing guys take something like DOW Chemical, make it warm and fuzzy and lollipops and teddy bears. I still wanna see how they spin Bhopal, India...

      DOW, addressing the horrors of over population one Asian town at a time!

    121. Re:Flawed assumptions. by JDevers · · Score: 1

      Why do you assume they are 1 kilometer in solid thickness? I would imagine a suitable structure MUCH thinner would suffice. Obviously if you are building a ringworld type structure with habitat on the inside, that is a different matter...but as far as a basic collector it would not need to be nearly that thick nor would it be solid.

    122. Re:Flawed assumptions. by alexo · · Score: 1

      the power of prayer?

      What "power of prayer"?

      The energy of the prayer divided by its duration, obviously.

    123. Re:Flawed assumptions. by pscottdv · · Score: 2

      You're right. The integral cancels out no matter where you put mass inside the shell.

      --

      this signature has been removed due to a DMCA takedown notice

    124. Re:Flawed assumptions. by NatasRevol · · Score: 1

      Helping the starving?

      --
      There are two types of people in the world: Those who crave closure
    125. Re:Flawed assumptions. by wierd_w · · Score: 1

      This kind of argument is semantically identical to saying the evolution of the wolf into the chihuaha is perfectly natural.

      While the mechanism is natural, the outcome is not. The host has no reproductive advantage from being infected with the parasite, and instead suffers extreme (up to 90% mortality of offspring in infected male to uninfected female pairings) reproductive deficits, coupled with direct stimulation and parasite supplied biochemistry to procreate differently.

      The mechanism for parthenogenesis in these organisms comes directly from the parasite.

      Analogously, this would be like asserting that artificial insemination performed by humans is a perfectly natural reproductive strategy, when coupled with routine castration in farm animals. Nevermind that the pressures imposed on said animals are in no fashion "natural", and result in individuals that outside of that practice, would be unable to sustain themselves due to being evolutionarily unfit.

      The parent said that such species are dominated by more aggressively replicating species. This is conserved in both models; cattle and social insects.

      The cattle are dominated by the meddling humans, and the insects are dominated by biochemically meddling protozoans.

    126. Re:Flawed assumptions. by TrailerTrash · · Score: 1

      Can any excess heat be concentrated and sent back into the central star, rendering it indistinguishable from natural fusion energy release? Apologies in advance if that's a hopelessly noob question.

    127. Re:Flawed assumptions. by s.petry · · Score: 1

      Dark Energy is real? Oh come now. Are you one of the first in line to bash a "believer" too? Dark energy is a fairy tale created to back the Big Bang Theory, which would not have been possible without fairy tales like that, and dark matter.

      The latest quantum physics has shown that the Big Bang is indeed just a fairy tale. Guess what that makes the 2 fairy tales required to support it?

      There is a lot we don't know, but when the fairy tales are exposed why continue pretending they are real? Did your parents make you put out milk and cookies for Santa for years after you learned it was a good hoax?

      --

      -The wise argue that there are few absolutes, the fool argues that there are no probabilities.

    128. Re:Flawed assumptions. by s.petry · · Score: 1

      Thanks, I was worried I was the only one that thought that this is a staggeringly foolish endeavor.

      --

      -The wise argue that there are few absolutes, the fool argues that there are no probabilities.

    129. Re:Flawed assumptions. by TeknoHog · · Score: 4, Funny

      And that's why it's called Rudolf the Redshift Reindeer.

      --
      Escher was the first MC and Giger invented the HR department.
    130. Re:Flawed assumptions. by TheRealMindChild · · Score: 1

      If something COULD be more than 100% efficient, somewhere in the universe it would be created and the net energy of the universe would increase. Seeing as that isn't observed, at least for now, we can assume with confidence that it just isn't possible.

      --

      "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
    131. Re:Flawed assumptions. by TheRealMindChild · · Score: 1

      Like I have stated previously, logic dictates if the law of thermodynamics is defeated, the net amount of energy in the universe would constantly increase.

      --

      "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
    132. Re:Flawed assumptions. by s.petry · · Score: 1

      Currently this is a very real set of limits. Until we set up asteroid mining stations, colonize other planets and moons, and can permanently inhabit space, we are very limited to the resources we have here or what gets dropped here from outside (materials and energy).

      I believe that you are confusing myopic with realistic. Your optimism is fine, and hopefully one day we will extend our reach but reality has to trump your optimism.

      As the old saying goes:

      The optimist claims the glass is half full. The pessimist claims the glass is half empty. The realist claims that the glass is twice as large as it needs to be.

      --

      -The wise argue that there are few absolutes, the fool argues that there are no probabilities.

    133. Re:Flawed assumptions. by Nadaka · · Score: 1

      Reading comprehension motherfucker. Do you have it? Reread what I wrote. Don't just skim it for key words that set off whatever bullshit mental health problems you have. Then reply in a way that actually considers the content that I wrote.

    134. Re:Flawed assumptions. by HeckRuler · · Score: 3, Insightful

      Sorry, but while chemistry is involved, it isn't even approximately the same as love.

      It's a subset. The chemicals would be the building blocks. Like how the elements of a turning complete language (if, loop, set) are the building blocks that compose the most advance artificial intelligence system. So AI is a subset of software. Likewise love is a subset of chemistry.
      There's all sorts of subjects that are tied into software that pertain to AI, like documentation, feedback loops, unit testing, etc. And there are all sorts of subjects that are tied into chemistry that pertain to love: biology, neuroscience, sociology, porn.

      So rather than saying computation requires an abacus, you should be saying computation requires math. Which it does.

      If I were to say that love is nothing but a bunch of chemicals bumping around, it would be perfectly true.
      The economy is nothing but a bunch of wealth shuffling about.
      AI programs are nothing but a bunch of bits being flipped.

      This view is pertinent here because the woo-woo crowd is trying to claim that there's some mystical magical additional force/quality/aspect to it which is beyond our ken. There is not. It really does boil down to something that simple.

    135. Re:Flawed assumptions. by HeckRuler · · Score: 1

      My GOD! It's like they'd have to trade some of their delicious coal (they're our number one producer) in exchange for some of this corn I've got over here in Iowa. We've got, like, tons of it. No really, we've got so much food, we feed our food food, just so our food tastes a little better. Ok, a LOT better. mmmmm Steak.

    136. Re:Flawed assumptions. by Nethemas+the+Great · · Score: 1

      The OP framed it as generally stupid, whereas you frame it specifically--to the capacity of present technology. I am not in disagreement with you, but I am with the OP.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    137. Re:Flawed assumptions. by WrongMonkey · · Score: 1

      "This kind of argument is semantically identical to saying the evolution of the wolf into the chihuaha is perfectly natural." You almost get it. From an evolutionary stand-point, there is no difference between natural and unnatural. How many chihuahuas are in the world? How many wolves are left in the world? If the world's wolf population is wiped-out due to loss of habitat and chihuahuas survive because they are more suited to co-existing with humans, then chihuahuas are the more successful species. Their genes will be passed on and the wolves' will not; that's all that matters in evolution. The only objective view is to recognize that humans and chihuahuas have a symbiotic relationship. Just like cattle and humans. Just like protozoans in insects. You can't apply anthropomorphic values, like "impose" and "domination", on natural processes.

    138. Re:Flawed assumptions. by WrongMonkey · · Score: 1

      You've moved the goal post. You are no longer talking about whether Wyoming is overcrowded, but whether Central North America is overcrowded. My point was that the the concept of "overcrowded" doesn't necessarily mean that people are packed in shoulder-to-shoulder. It's relative to the resources available to a given region.

    139. Re:Flawed assumptions. by lightknight · · Score: 1

      Need to build one != will build one.

      --
      I am John Hurt.
    140. Re:Flawed assumptions. by martas · · Score: 1

      Don't forget about that pesky accelerated dilation thing. Infinite energy doesn't to you much good if you're being torn apart as a sub-nuclear level.

    141. Re:Flawed assumptions. by lightknight · · Score: 1

      Heh. Then perhaps we should look into getting an ammonia-based atmospheric cooling system, like some of our outer planet neighbors.

      --
      I am John Hurt.
    142. Re:Flawed assumptions. by wierd_w · · Score: 1

      Under you definition, there is no such thing as an unnatural process, making the distinction moot.

      That is the point you are trying to make, but it opens huge cans of worms. Carried to its full and logical conclusion, nothing unnatural exists, thus something clearly artificial, like a computer system, is a "natural phenomenon."

      The imposition of the implied distinction betwee natural (if left alone) and unnatural (influenced directly by the actions of another agency) are not mine, but are products of human cognition, intended to deal with this cognitative foulup.

    143. Re:Flawed assumptions. by Lehk228 · · Score: 1

      26 megatons multiplied by the number of Christmas observing households

      i suspect that a lightspeed santa would obliterate the earth's surface

      --
      Snowden and Manning are heroes.
    144. Re:Flawed assumptions. by tftp · · Score: 1

      Fusion reactors (which you seem to think is the foreseeable endgame, as you mention it twice) may be great and all

      I only want to remain within boundaries of what is imaginable today. If we go beyond then we suddenly get zero point energy, and then everyone can have all the energy of all the Universes in his pocket (which also will make Dyson spheres useless.) Magic is not a good answer in this discussion. We either deal with facts and science, or we deal in fantasies.

      the sun (which is of course a fusion reactor itself, with more fuel then you could possibly acquire otherwise.)

      Why can't I get some Helium from the Sun? If you are powerful enough to build an object that is comparable in size to the Solar system then you certainly can teleport or something a few million tons of stellar mass for your pocket expenses.

      The whole point of building a Dyson sphere is because local sources of energy are no longer sufficient.

      And as I said, local sources of energy may be not necessary. You would want remote sources of energy. But if you intend to use the Dyson sphere to charge your portable batteries then you can do it near any star - not just at your homeworld. A young blue star would be far more profitable in this regard, and you can waste its planets without a thought. Do that in your own Solar system and watch other planets change their orbits. Including your homeworld. Fun, isn't it?

      Or if you want to leave your original planet in place, you can easily build it *inside* it's orbit. That' be much more efficient use of material anyway.

      Yes, limited by the strength and thermal resistance of the material. You also lose the "hiding" factor, if you care about that. A classical Dyson sphere is outside, so that nothing escapes except the black body radiation.

      Just leave a window to illuminate your planet as before

      I'll have to leave it to better cosmic engineers than myself to synchronize orbits of those two objects...

      or use an extremely tiny fraction of the prodigious energy collected in order to artificially illuminate it.

      Well, I guess people can get used to eternal night and artificial light. Progress demands sacrifices, as they say.

      if you're already imagining a civilization capable of such hyperstructures, it's not hard to also include nanometer thin film that can do the energy capture

      I can imagine construction of a Dyson sphere using only traditional technologies. However the current science does not easily allow existence of nanometer thick stable hyperstructures that are sufficiently strong. Your sphere will be under tension from the sunlight, and it has to be spun or otherwise stabilized in space - and that has to be done very accurately, or else any deviations from the ideal sphere (as long as the Sun is an ideal sphere itself, mass-wise) will tear it apart. A segment of the sphere that is closer to the Sun will move faster, eventually folding onto other segments and unraveling the whole thing. Blow a soap bubble and look how wobbly it is. Your bubble of a nanometer thin film will be just as wobbly, influenced by coronal mass ejections, by passing planets, and punctured by many comets and asteroids that just happen to fly by. The sphere either needs to be sturdy enough to survive impacts (like the Ringworld - with footnotes) or it has to be able to heal itself. However the latter is doubtful because a sphere under tension tends to rip like a balloon; it is unstable by definition. Solutions to that involve thicker threads that carry the load - but those threads can become severed too, ad infinitum. Ideally you want a force field to hold the sphere together, especially considering that the sphere needs to be pushed by correction engines if you want it to not drift into the Sun. If the sphere is spinning then we are looking at even more forces that try to flatten it into a disk.

      Some people mention that the sphere does not need to be solid. In such a

    145. Re:Flawed assumptions. by s.petry · · Score: 1

      I'll see your request to read, and raise you your own statement.

      Dark Energy? we don't even know what it actually is, if it is energy, or if it can do anything useful.

      Nothing there indicates that it's hypothetical. In fact, claiming we don't know what it is, or if we can find use for it, both require it existing first correct? If I said "We don't know if Santa has a beard or not" it would obviously indicate that I know some dude named Santa right?

      Your last paragraph could be taken one of two ways. First that the energy types are hypothetical, second that we just lack the science to know much about them. Since the first conflicted with what you previously stated, I had to go with the latter.

      So back at you, reading comprehension motherfucker. If you write something you don't mean, it's not a problem with the recipient when you are taken literally.

      --

      -The wise argue that there are few absolutes, the fool argues that there are no probabilities.

    146. Re:Flawed assumptions. by s.petry · · Score: 1

      I did not take their statement the same, I took it as a bit paradoxical perhaps to be humorous.

      --

      -The wise argue that there are few absolutes, the fool argues that there are no probabilities.

    147. Re:Flawed assumptions. by Migraineman · · Score: 1

      Gotta have a thickness to calculate overall mass. If you'd prefer to have a thinner spherical shell, feel free to re-calcualte the required mass. Me? I'm not going to get hung-up on the details, though I was surprised to find the resources required to be "reasonable."

      Personally, considering that the sphere is 150e6 km in radius, I'm thinking that a 1km shell is pretty damned thin.

    148. Re:Flawed assumptions. by jwhitener · · Score: 1

      Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth, much like humanity.

      It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic if we possessed them. Our assumptions are limited by our current understanding. In the next thousand years we could see all kinds of advancements that render building a Dyson sphere completely unnecessary.

      Just to counter-balance the point that we might have enormous energy production advancements, we might also have tremendous energy requirements if we make breakthroughs in things like warp drives, opening wormholes, etc..

    149. Re:Flawed assumptions. by scdeimos · · Score: 1

      I think alvinrod's point was that if we were to come up with a way to make energy, say from gravity, we wouldn't need a big, complex Dyson sphere to live in. We could just spread among the planets (and stars) and setup power supplies wherever we land.

    150. Re:Flawed assumptions. by Drinking+Bleach · · Score: 1

      Zoidberg made the list.

    151. Re:Flawed assumptions. by aNonnyMouseCowered · · Score: 1

      No need to bring advanced physics into the picture. Seeing the danger of relying on a discontented population of underpaid elves to ramp up production, Santa invented a droid army of Santas. These both produce the toys and deliver them on Christmas. The elves you see burning up are the occasional terrorist saboteurs.

    152. Re:Flawed assumptions. by tbird81 · · Score: 1

      How does science explain psychics? Auras, the afterlife, the power of prayer?

      Or even more easily.

    153. Re:Flawed assumptions. by toddestan · · Score: 1

      How so? It's not like there would be any time for you to be unhappy before being vaporized.

    154. Re:Flawed assumptions. by toddestan · · Score: 1

      There are also other problems. First, a Dyson sphere is not a stable system. Left to its own devices, eventually the sphere will crash into the star (or the star will crash into the sphere, depending on your point of view). So you're going to need some kind of active system to get the thing positioned. Granted, that's probably not a big deal for someone advanced enough to build it.

      The second thing is gravity, if you desire such a thing. Barring some artificial gravity machine, the only way to get gravity (well, simulate it) would be the way we already know how - by spinning the sphere. This would of course only leave you with a band that has the desired gravity characteristics (granted, this band would still be huge), surrounded by a progressively steeper hill that has less and less gravity as you climb it. And I would recommend putting some spin on it, otherwise you could not stand on the inside of the sphere as the star's gravity would pull you towards the center, as a sphere of equal thickness and density will impart no force on any mass inside of it. And you would have to spin it at a considerable rate to simulate a planet's gravity - much faster than a planet orbiting at the same distance (however, this would be an advantage for intergalactic space travel as starships would leave the system with a considerable speed boost and wouldn't have to slow down nearly as much to land on the sphere so you do have that going for you).

    155. Re:Flawed assumptions. by khallow · · Score: 1

      Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth, much like humanity.

      I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

      Nonsense. A Dyson sphere is an efficient use of what you have, namely a star, not some futile chase after infinity.

    156. Re:Flawed assumptions. by khallow · · Score: 1

      Basic laws of reality? Isn't science about increasing our understanding of reality? Many theories and ideas have come and gone and been replaced by more refined ones. We would be extremely naive to think our current understanding is even remotely close to all there is to know and completely correct. There is much to learn my friend.

      We already know of basic limits on any civilization, no matter how advanced. I think it is foolish to assume that things like the laws of thermodynamics or the speed of light can be overcome, no matter how advanced the civilization, because if it could, it probably would have already transformed the universe in an obvious way.

      Even in such restrictions, one can see a lot of room for some pretty wild stuff. For example, imagine a universe where a kilogram of arbitrary matter is roughly as intelligent as a large university. That's possible with sufficient technological advance and a long enough time frame. It doesn't take FTL, ESP, or some other exotic discovery, but something that could be developed within today's restrictions, starting with today's techologies, and developed over a long enough time period, say a billion years.

    157. Re:Flawed assumptions. by tftp · · Score: 1

      So you're going to need some kind of active system to get the thing positioned.

      This would require the sphere to be rigid - and not only rigid but sufficiently strong to impart the force from the motor to the adjacent elements. This will result in oscillations, and it will not be a trivial task to energize those motors, or to stop them. Failure of one motor, with other engines running, can lead to destruction of the links between sections of the sphere (or to destruction of the solid sphere, if it is contiguous.) Given the size of the sphere (several AU in diameter) the very concept of "simultaneous" will have relativistic effects involved. It will be an extremely fragile construct; all your operations must be flawless, and any single mistake, ever, will destroy the sphere.

      And I would recommend putting some spin on it [...] at a considerable rate

      The centipetal force of the center band (at the latitude 0) will be provided by the gravitational attraction of the Sun. However the same attraction will be applied to the stationary poles (at the latitude of 90 degrees.) The poles have zero velocity; therefore, they will be falling toward the Sun. The only thing that prevents such a collapse is the rigidity of the rest of the sphere. This will result in various forces that, at first blush, would be astronomical. The sphere, if it is ideally flexible, will be squeezed into a disk, and then into a ring (because different bands of the disk would want to spin at different angular speeds, that's what forms bands in planetary rings.) If that's not what you want then you need to compensate the squishing forces.

      A rotating sphere will also present interesting challenges if you want to beam energy from the sphere to inner planets or ships. This would be doubly interesting if the beam must be accurately aimed, lest it becomes a death ray.

      The spinning sphere will be a gyroscope. Impacts from comets, asteroids and spaceships will be translated into precession which is capable of eventually making the trajectory of the axis hard to calculate. I cannot say much about the tensile forces that will be present within the sphere.

      this would be an advantage for intergalactic space travel as starships would leave the system with a considerable speed boost and wouldn't have to slow down nearly as much to land on the sphere so you do have that going for you

      This is true only if you only fly within the equatorial plane of the sphere. Approach in any other plane would present a nontrivial problem. An accident near the sphere has a chance to completely destroy the fragile structure, just as a single needle can explode a rubber balloon. Even if you are very careful, you can't do anything about an asteroid that can travel fast and be large. Perhaps the sphere can survive until you send repairmen; but if not you will have big problems.

    158. Re:Flawed assumptions. by hierofalcon · · Score: 1

      I'm sure if it came down to it, that could happen. Just don't mix it with the gas - they need all the gas mileage they can get to get from one city to another without a refill.

    159. Re:Flawed assumptions. by gottabeme · · Score: 1

      The point is that, to one who didn't understand the concept of binary, or even of counting, it would seem impossible. It makes perfect sense that a civilization so advanced that it could completely harness the power of a star would have technology so far advanced beyond our own that it would be beyond our current understanding.

      It's good that people are thinking beyond what we can see--but this is surely not a good use of money. SETI is bad enough, but this is worse.

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    160. Re:Flawed assumptions. by gottabeme · · Score: 1

      Where did you obtain your data?

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    161. Re:Flawed assumptions. by gottabeme · · Score: 1

      The reason people in the third world have so many children is because of infant mortality and the need for large families to work and make a living. Telling them to have fewer kids would be like telling them to commit suicide.

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    162. Re:Flawed assumptions. by KDR_11k · · Score: 1

      And when you've got a dyson sphere do you really NEED to hide?

      --
      Justice is the sheep getting arrested while an impartial judge declares the vote void.
    163. Re:Flawed assumptions. by MrL0G1C · · Score: 1

      There is no reason to believe that the second law of thermodynamics can be violated

      Other than certain instances of the Casimir effect you mean.
      http://en.wikipedia.org/wiki/Casimir_effect#Repulsive_forces

      Filter error: That's an awful long string of letters there, the slashdot filter is fucking retarded, it can't even handle a couple of links, but anyway this link should read - The Dynamical and Static Casimir Effects and the Thermodynamic Instability

      The Casimir Effect and Thermodynamic Instability

      I'm no physics expert but that last paper seems to say that black hole theories also break the second law of thermodynamics.

      --
      Waterfox - a Firefox fork with legacy extension support, security updates and better privacy by default.
    164. Re:Flawed assumptions. by Lord+Bitman · · Score: 1

      and we'd need every one of them in order to build a dyson sphere, too

      --
      -- 'The' Lord and Master Bitman On High, Master Of All
    165. Re:Flawed assumptions. by Curunir_wolf · · Score: 1

      Well according to the linked WIki article, theories typically use thicknesses from 8 cm to 3 m, so significantly thinner. But even at that thickness, the "solid shell" variant of the Dyson sphere is considered and extremely implausible construct, for a number of reasons. Not least of which is the huge amount of pressure on the shell, ability to keep it in place, large objects flying in from the outer solar system, etc.

      So I'm a little curious why they are actually doing a search like this? Because from the description it sounds like they are hunting for Dyson shells. Dyson spheres deployed as swarms or bubbles are much more feasible (and thus likely), but that wouldn't block all the light from the star, just alter it some.

      --
      "Somebody has to do something. It's just incredibly pathetic it has to be us."
      --- Jerry Garcia
    166. Re:Flawed assumptions. by Patch86 · · Score: 1

      One fundamental problem with Dyson Spheres (or "space energy" of any variety) is global warming. No, not the greenhouse gas kind, but the thermodynamic kind. If you capture energy that was destined to radiate out into deep space, beam it to earth, and use it to do any work, you'll raise the planet's temperature. If you're capturing a significant proportion of the Sun's energy and utilising it in futuristic devices on Earth, you'll be doing something not terribly unlike increasing Earth's temperature by the entire output of the Sun.

      The same objection has been levelled at nuclear power (particularly in relation to futuristic cold fusion).

      Obviously, you can discount this if all your energy is going to be used powering spaceships and whatnot.

    167. Re:Flawed assumptions. by leonardluen · · Score: 1

      This project may not ever actually find a Dyson sphere, but developing the technologies and processing techniques to actually run the search will still help advance or technology. and what happens if they find something that we weren't expecting, that we never would have found because no one was previously looking for heat sources without emitting visible light?

      i would say SETI also is not a waste. the data they are gathering can still be useful to other people. and occasionally they find a strange signal that is worth re-checking out, even if it has never been contributed to an alien yet. also they need to think about how to detect an alien signal and so need to refine our signal processing techniques, this itself helps advance our technology and knowledge, and this knowledge may eventually be applied to how we broadcast our own signals such as for use with cell phones or wifi.

      a great many discoveries were made while searching for something completely different.

    168. Re:Flawed assumptions. by LordVader717 · · Score: 1

      The amount of thermal emission depends on the temperature and surface area.
      A civilization would presumably require a minimum temperature and have a small (in stellar terms) amount of material available. Using known characteristics of stellar radiation and plugging in some sensible values you could work out the peak wavelength. The far limit would be the CMBR wavelength, as you can't cool off any more than your surroundings.

    169. Re:Flawed assumptions. by leonardluen · · Score: 1

      one more note a big technology to come out of SETI is techniques for distributed computing, which is now used for folding@home and other applications that could potentially directly benefit us.

    170. Re:Flawed assumptions. by HiThere · · Score: 1

      Well, if "chemistry" includes electronics, I'll agree. Otherwise it's sounding like robots can't love, which while currently true, I doubt is forever true. In fact, I would class "love", etc., as basicly alogrithmic in nature, even though we don't currently know what the algorithm is. So saying it's chemistry is identifying the implementation with the algorithm.

      OK, I guess that's a bit closer to what I really meant.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    171. Re:Flawed assumptions. by b4dc0d3r · · Score: 1

      I'm not sure if my reply to someone else applies, or if I should just ask you to either not steal what other people wrote or at least credit it.

      Either way I am jeopardizing my karma in the hopes of improving online discussion one person at a time. Obviously I hope that means something to you, and at the same time it is just as obvious that I should check myself into some sort of institution for wasting such time as I have for it is clearly in the realm of utter madness.

    172. Re:Flawed assumptions. by b4dc0d3r · · Score: 1

      What if the same chemicals in different circumstances could produce different emotions? What if I said that the difference between love and fear is simply context?

      That your awareness on a conscious level of your surroundings colors the chemical stimulation to feel like a different emotion, invalidating the entire concept of emotion and whittling it down to a slightly-less-than-conscious decision tree which makes you feel love, or fear, or anger, or any number of emotions?

      What if emotion is simply a state machine which, given predictable inputs of chemical and situational nature, results in what we in our self-importance as humans refer to as the inexplicable and ethereal state called "love"?

      This is the most clear explanation I could find on the subject given 2 minutes of searching, and you will find that the reported sensations in stage 2 (attraction) are the same as trepidation. There's even a picture of a roller coaster. The chemical basis of a sustained, devoted relationship are further explained.

      Wait till you get to the experiment at the bottom, it should blow your mind.

      "The science of love"
      http://www.youramazingbrain.org/lovesex/sciencelove.htm

      And screw this Dyson Sphere nonsense - just hook your bed up to the grid and send energy nightly to your house or the creation of energy surplus. Don't use a bed? harvest the trapeze, back seat of the car, or repetitive one-armed motions. Energy problem solved. Now, everyone go screw.

    173. Re:Flawed assumptions. by b4dc0d3r · · Score: 1

      You missed the point of prayer completely. You don't pray solely to ask for things. It is supposed to be a time of personal meditation if you wish to so define it, also known as personal time which you dedicate solely for your deity of choice.

      Psalm 23 is frequently used as a group prayer. It is a simple affirmation which requests nothing, not even acknowledgement, of the Christian god. Instead of requesting goodness and mercy, it says Surely goodness and mercy shall follow me all the days of my life.

      Similar conditions apply to the prescribed Salah, in which Muslims recite parts of the Qur'an. It would be strange for such a ritual to contain personal requests which a deity could choose to fulfill or reject.

      The power of prayer is a brief period of affirmation and meditation, which has proven benefits if you exclude requests for financial gain, and balance out the apparently miraculous restoration of health with the passing away despite continuous, devoted prayer for another's health.

      It is founded in true faith in the sense that you don't know if your request will be fulfilled. You have faith that either you will get what you asked for, or that somehow in not getting it you are playing a part in the plan set out for you by your chosen deity.

      Repeatedly praying for something and not getting it can actually increase a person's faith, as they hold out for that one prayer that gets through, in the same way playing the slot machines all night without much more than a pittance in winnings makes people believe that the machine is "about to pay out".

    174. Re:Flawed assumptions. by Carewolf · · Score: 1

      My point was that a ring world can almost be made from the matter of a single solar system. A dyson sphere would require moving in all the planets and all their mass in from hundreds of nearby solar systems.

    175. Re:Flawed assumptions. by Anonymous Coward · · Score: 1

      And 2+2=5, for large values of 2.

    176. Re:Flawed assumptions. by mike4ty4 · · Score: 1

      Doesn't *completely* solve the problem, however -- it only takes *one* civilization who does believe that way. Unless, of course, *all* such civilizations are doomed to failure -- in which case, we'd better heed the lesson implicit in that one.

    177. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      You make a good point and follow sensible logic, but I'm not sure you realise your starting assumptions, particularly those about God's motivations - what if God's intention in people praying (and, perhaps, in creating the universe in the first place) is more about training up said people rather than making the world "good" by our subjective measure? What if reality as we know it is only a training ground? (For what, I have no idea, but it's an interesting concept). As a parent, I'm more concerned about the development of my kids' character than the specific temporal goal at hand (occasionally, them learning consequences is of more importance than getting a little hurt in the process).

      My 2 cents anyway. :-)

    178. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      Agreed - there is a limit to the usefulness of energy you get out of a collection system. Also, I note that everyone here is assuming that a civilization would *want* to extract all available energy? What's to say you actually have a use for it all and don't want to dump some? Also, what of the waste heat from whatever (presumably very considerable) industry you have in place to use said energy?

      So yeah, it's probably a waste of time looking for Dyson spheres, but hey, we might learn something else from the data. And, if we do happen to actually find something...?

    179. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      Yes - all of our energy sources are ultimately solar (e.g. oil: solar --> plants --> buried and degrades to oil). The only arguable exception is nuclear, but even then, if you follow current ideas on where higher elements are formed, it's still from a star...

    180. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      And here I suggest you go hear Sir Richard Attenborough: http://www.youtube.com/watch?v=dN06tLRE4WE

      Depends on resource use: if you live like the average American, theoretically Earth can support about 1 billion. If you live like the average Indian, about 10 billion, like the average Rwandan, about 12 billion. Being that most of the world is trying to live more like America than Rwanda, at 7 billion, we have a big problem.

      Overpopulation is not just about the area you physically occupy, but the land use required to support your living - do your grow your own food, mine your own metals, produce your own energy?

    181. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      Average assumption on replacement level is 2.1 live births per fertile female. http://en.wikipedia.org/wiki/Total_fertility_rate

      Still not sure how to get 0.1 of a kid and have it a live birth though...

    182. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      This is actually a good point, as the tend is for a society's fertility rates to drop as it becomes more developed (specifically, as women become more educated), and may Western nations are either in decline, or only growing because of immigration. Realistically - and somewhat surprisingly - if we want to solve global overpopulation, our best bet is to educate women (which also means: fix poverty first...) I'm happy to stop at 2 kids though.

    183. Re:Flawed assumptions. by BevanFindlay · · Score: 1

      You are correct in thinking that the population should stabilise somewhere (cf. this), as the second differential of population growth has been negative for some time (i.e. population is growing, but the rate of growth is steadily decreasing). But, there is also a high likelihood that we are going to hit the Earth's population carrying capacity well before then - some argue that we're already at it, only propped up by artificially increasing crop yields etc by fossil-fuel-derived fertilisers etc - when those fuels run out (which they will), most of humanity stops eating...

      So, we will slow down at some point, but possibly not soon enough.

      Also, note the similarity of the (mid-estimate) graph on that Wikipedia page to an S-curve (typical of populations with an imposed limit).

    184. Re:Flawed assumptions. by gzuckier · · Score: 1

      It's not at all obvious that advanced civilizations will be on the pathway to harness greater and greater energies via more complex technologies, unless you define advanced to mean harnessing greater energies. We're souped up monkeys; we do things monkeys would do and think like monkeys would. Frankly, the beginnings of human technology lay in banging rocks together.

      I venture to say that a civilization derived from cetaceans would be quite different, given that they don't have hands, vision underwater isn't a major sense, there isn't a lot of stuff around to bang together, and they would never encounter fire.

      --
      Star Trek transporters are just 3d printers.
    185. Re:Flawed assumptions. by thesupraman · · Score: 1

      Asia the meat and America the tech.

      I can only assume you accidentally got those two the wrong way around?

    186. Re:Flawed assumptions. by HiThere · · Score: 1

      A note of general agreement, plus a few other consideration:

      Well, assuming you want to ability to extract as much energy as you can from the system isn't unreasonable. It's just that there are always costs to efficiently collecting energy, and at some level those costs will exceed the benefits. That said, if we assume nano-machinery, etc. the limit may well be very high.

      One question may be whether or not they have (mainly) uploaded. If they haven't, then some appropriate temperature will need to be maintained for the non-uploaded...but possibly only over a small area, and outside the shell...so that may well be undetectable. But if you assume that it's *not* an upload civilization, then temperatures will be affected over a wide area, and should be detectable. (The kind of civilization that builds a Dyson sphere doesn't have a small population.) Since colder temperatures slow chemical reactions, it may well be reasonable to conclude that the ones that are currently present are based on liquid water, or something even hotter. But I think that before one builds a Dyson sphere, one will generally become an upload civilization, which means that the temperature only needs to satisfy the needs of computers...and that can be a lot more flexible.

      So I don't think they'll find what they're looking for. But by looking for something, they may well find something, even if it isn't what they're looking for.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    187. Re:Flawed assumptions. by busybox · · Score: 1

      Tell this to believers, and they will tell you that their prayer only consists of "thanking God for all the great things the God has done".

    188. Re:Flawed assumptions. by AmigaMMC · · Score: 1

      Three letters: Z P M

    189. Re:Flawed assumptions. by HeckRuler · · Score: 1

      No, I'm trying to say that the "carrying capacity" of Wyoming depends on external factors, like how much food they can buy. You could measure a place by how much of one vital resource they have, (ignoring their ability to trade one resource for another) and that would be interesting, but it wouldn't dictate whether or not Wyoming is overcrowded. If you've got tunnel vision on water and food, EVERY CITY is horribly overcrowded, while rural areas have a ludicrous abundance.

      My point is that you can't selectively look at a specific region when talking about resource scarcity. Cause, you know, we trade things.

    190. Re:Flawed assumptions. by Lando · · Score: 1

      No, 2 is a lie, it does not exist.

      --
      /* TODO: Spawn child process, interest child in technology, have child write a new sig */
    191. Re:Flawed assumptions. by gottabeme · · Score: 1

      It may be true that some good has come from SETI and may come from this project. But IMO the money would be better spent in other areas of research.

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
  3. what about nuclear fusion? by alen · · Score: 2

    i'm sure an advanced civilization will master Star Trek type fusion tech before doing something ridiculous like building a starlight collector.

    the earth compared to the sun is like a grain of sand to a beachball. where would you get enough matter to build something around a star if the same or similar size ratio will exist in other star systems?

    1. Re:what about nuclear fusion? by Anonymous Coward · · Score: 5, Funny

      where would you get enough matter

      Obviously harvested from the home planets of other civilizations they've destroyed. What a silly question.

    2. Re:what about nuclear fusion? by nschubach · · Score: 1

      I'm also sure that if a civilization was so advanced they could make a dyson sphere that they' be able to "hide" from a civilization barely scraping space from a planet they haven't fully explored.

      Though, the "tailpipe" conjectures being made are fun to read about... it just screams of movie plots.

      --
      Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
    3. Re:what about nuclear fusion? by Shrike82 · · Score: 4, Insightful

      The energy output of a star is going to be many orders of magnitude higher than what you'd get from fusion technology. The sun is a giant fusion plant itself! A sufficiently advanced technological civilisation may very well find itself bound only by the amount of energy it could produce or harness, and getting every last scrap of energy from a star is a massive boost to an energy based economy.

      --
      You can advertise in this sig from as little as £99.99 a month!
    4. Re:what about nuclear fusion? by Nemyst · · Score: 3, Interesting

      A star is a fusion reactor. In fact, if you need the kind of power that's given out by a Dyson sphere, then a Dyson sphere is by and large the most efficient method for generating it, especially for long periods of time.

      The question should be whether any civilization would require so much power in such a static and concentrated way (as opposed to dispersed across hundreds of planets across thousands of lightyears), and where they'd find the materials required to build it (we're speaking about transforming entire planets from crust to core, or harvesting dozens more in a less destructive fashion).

    5. Re:what about nuclear fusion? by confused+one · · Score: 1

      OK, there are two issues here to discuss...

      You could certainly build fusion power plants. Lots of them. As your power requirements go up as a society, you just build more. Except... The waste heat. No power generation process is 100% efficient. In fact, 30% may be a reasonable number for a nuclear plant. The remaining 70% becomes waste heat dumped into the environment. Now, what happens to the electrical energy you made -- the 30%? Some of that will get turned into "stuff" or into forms of potential energy. A substantial fraction will likely get converted into heat. So, as you build more and more power plants, you put more and more heat into the environment. You can already see this in localized heating of rivers where power plants draw water for cooling. If society becomes orders of magnitude more energy intensive than we are now, the heating of the environment could become a significant problem; and, the same would apply to any hypothetical advanced alien society.

      As to where you get the material to build a Dyson sphere... To begin with that's a misnomer. No one would build a sphere -- they'd build a ring or a large number of orbiting platforms. As you pointed out, the solar system is vast. If your society is becoming advanced enough, large enough and energy intensive enough that you might consider a Dyson sphere, then you're probably going to have (or be able to develop) the ability to mine the non-habitable planets, asteroids, etc. for the raw materials you need.

    6. Re:what about nuclear fusion? by ShanghaiBill · · Score: 1

      where would you get enough matter to build something around a star

      The Earth has a radius of about 6000km. That is about 10^11 cubic km, mostly iron.
      The surface area of a sphere at one AU (150M km) would be about 2.8e17 km^2.
      If my math is right, you could use that iron to build a Dyson Sphere about 0.35 mm thick.
      0.35mm of steel is plenty strong enough to support a solar collector suspended in space.
      If you need more material, just dismantle some more planets.

    7. Re:what about nuclear fusion? by 0xdeadbeef · · Score: 4, Insightful

      For fuck's sake, people, read a god damn book. Star Trek is make-believe bullshit.

      If you're completely ignorant about a subject, is it too much to ask that you remedy the situation before farting an opinion? There are four links in the post for your education!

      I mean, sure, the Templeton Foundation are a bunch of religious loons, but do you actually think you know better than Freeman Dyson and the actual physicists, astronomers, and engineers who consider the idea plausible? If so, you'd better tell them why it can't work, before they waste all that money! Your paper on the subject will make you famous!

    8. Re:what about nuclear fusion? by seven+of+five · · Score: 3, Interesting

      Although a star has a large net output, it's only because it's so big. Proton-proton fusion has a very low energy density. Though barely conceivable by today's technology, you could theoretically produce the Sun's output in a powerplant a few km across going to D-D or P-11B fusion fuel. No stars are therefore necessary. Matter-antimatter reactions would be orders of magnitude better still.

    9. Re:what about nuclear fusion? by uigrad_2000 · · Score: 1

      Are you familiar with rubble piles? When you get a lot of mass together in one place in space, rubble piles end up being the result.

      There really is no way to build a 0.35mm steel plate in space for more than 500 miles without it collapsing into a rubble pile. We think of steel as being strong, but when you start talking about astronomical-type distances, even the strongest materials we have begin acting more like liquids. It would be easier to make a cellphone tower out of tapioca pudding.

      --
      Free unix account: freeshell.org
    10. Re:what about nuclear fusion? by rhsanborn · · Score: 1

      Matter-antimatter would be much more efficient, except that it takes a lot of energy to make the anti-matter.

    11. Re:what about nuclear fusion? by Grishnakh · · Score: 1

      I thought TFA already covered that: they could "hide" if they wanted to, sure, but that would require extra engineering work and compromises, and why would they bother with it? Why would they care about hiding from us or anyone else? If there's some aggressive interstellar species out there, it's defenseless civilizations like ours that would need to worry about it, not some civilization so advanced they can build a Dyson sphere.

    12. Re:what about nuclear fusion? by rufty_tufty · · Score: 2

      Actually I'd argue that if you have the tech to build a Dyson sphere you've the technology to dismantle the star and make much more efficient use of the matter than merely burning it to helium.
      You'd want to dismantle the star and use it as a matter source for fuel and construction, the alternative is to leave it wastefully burning and then eventually exploding. What a waste when there's all that entropy there that can be used.

      --
      "The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
    13. Re:what about nuclear fusion? by TheMathemagician · · Score: 1

      What "resources" would you need that you couldn't just synthesise? Well apart from Earth women of course.

    14. Re:what about nuclear fusion? by tnk1 · · Score: 1

      The density of the solar collectors would not need to be very high, which means that you could probably build a very, very thin shell of individual collectors around the star in question. The available materials may still be an issue, but maybe not.

      Indeed, if you were able to engineer tiny nano machines of the right sort that can redirect solar energy predictably, the "sphere" might just look like a thin dust cloud around the star that grows thicker as more of the star's energy is redirected.

      What a Dyson Sphere will probably *not* look like is a monumentally large metal sphere. Maintaining such a shell in a stable orbit around a star is extremely hard. The most likely sort of megastructures would probably be large "plates" in interlocking orbits, but even then, that's a lot of structure to keep in a stable orbit.

    15. Re:what about nuclear fusion? by tnk1 · · Score: 1

      Usually because planets would possibly not usually contain enough energy to run the civilizations in question by that point. And just like using oil to make gasoline to burn up is a lot less efficient than using it to make plastics, we'd probably want the planets in question for the exploitation of their existing heavy elements, not their energy itself.

    16. Re:what about nuclear fusion? by ShanghaiBill · · Score: 4, Informative

      There really is no way to build a 0.35mm steel plate in space for more than 500 miles without it collapsing into a rubble pile.

      Dyson was well aware of that. A Dyson Sphere is not a connected solid sphere. It can consist of billions or trillions of independently orbiting structures, such as O'Neill Cylinders.

      A solid structure would be a Ringworld, which is impossible to construct with our current understanding of reality.

    17. Re:what about nuclear fusion? by tnk1 · · Score: 1

      Even if you could find enough matter, where are you going to get the energy needed to move it all into place

      From the star itself? It's likely that any project would assign all or most of its initial energy output to itself to complete the project. These spheres would likely not be built all at once, they'd be built in phases over long periods of time. They might even start off as initial "lesser" projects where there are a few solar collector satellites of a tech level we could probably construct today, which then slowly over time, multiply until they are effectively a shell around the star.

    18. Re:what about nuclear fusion? by Grishnakh · · Score: 4, Interesting

      Matter-antimatter reactions may have extremely high power density, but there's a big problem: where do you get the antimatter from? It's unlikely there's large naturally-occurring deposits of it available anywhere, since it annihilates itself when it contacts matter. M-A energy sources really only make sense as a way of storing energy, not producing it. Even Star Trek takes this position: the starships use antimatter for propulsion, but only because of the energy/power density it offers, and it's produced artificially specifically for this purpose, probably using solar energy production.

      Energy is a primary need of any civilization. Every civilization has to get it somewhere. Back in the early days, we got our energy from the sun solely: we used it to grow crops (for food) and feed our animals (for transportation), and to power our ships (for water-based transportation; we used the sun to produce wind to power these ships; luckily, we didn't have to produce the wind ourselves, as natural processes had already done this for us, but we took advantage of it). These days, we largely get our energy from hydrocarbons created millions of years ago by solar-fueled processes, though we're getting some power from nuclear fission (where we break apart large atoms that were created in stars long ago). In short, we get energy where we can find it naturally-occurring. A more advanced civilization will probably be no different: though it may convert energy from one form to another, it'll have to mine that energy from somewhere, and the most obvious source is a nearby star which is giving off lots of energy for free already. Of course, if they figure out how to get energy directly from quantum fluctuations, or by mining antimatter from a parallel universe or something, then they might not need stars any more, but that sounds even more advanced than a Kardashev Class II civilization which we're talking about here.

    19. Re:what about nuclear fusion? by Grishnakh · · Score: 1

      Not quite so mind-boggling; there was an article recently saying the calculations for an Albuierre warp drive were wrong, and they determined that instead of needing the mass-energy of Jupiter for such a spacecraft, they only needed the mass-energy of a Voyager probe. That's still a lot of energy (think a whole bunch of H-bombs), but for a Class II civilization harnessing the entire energy output of a star, it's probably not that big a deal.

    20. Re:what about nuclear fusion? by DigiShaman · · Score: 2

      I've read about Dyson Sphere's being equipped with stellar engines. Basically, it's now a giant starship (in the true meaning of the word) built around a core source of power. A star.

      If you though taking an international flight from halfway around the world was a bitch, imagine taking a trip from one side of the starship to the other. Perhaps they will have the whole teleportation thing figured out by then.

      --
      Life is not for the lazy.
    21. Re:what about nuclear fusion? by tnk1 · · Score: 2

      Constructing a massive shell of computing substrate around a star to contain the uploaded consciousnesses of a whole civilization might be a very good reason to have a static fusion plant at the center. Such a shell could make an efficient use of what solar energy it gets in its local area without having to transmit that energy to other sections of the shell. You just have to make sure that the individuals do not clump in a small area or if they do, they clump infrequently in a a relatively few zones which have been specially designed to receive redirected power from other sectors of the sphere.

    22. Re:what about nuclear fusion? by flappinbooger · · Score: 1

      i'm sure an advanced civilization will master Star Trek type fusion tech before doing something ridiculous like building a starlight collector.

      the earth compared to the sun is like a grain of sand to a beachball. where would you get enough matter to build something around a star if the same or similar size ratio will exist in other star systems?

      This is being done by a civilization that isn't worried about the logistics of such trivial concerns as the raw materials...

      --
      Flappinbooger isn't my real name
    23. Re:what about nuclear fusion? by Grishnakh · · Score: 1

      >> i'm sure an advanced civilization will master Star Trek type fusion tech before doing something ridiculous like building a starlight collector.
      For fuck's sake, people, read a god damn book. Star Trek is make-believe bullshit.

      Wrong. He (and you) should probably read more Star Trek. Star Trek doesn't use fusion tech, it uses matter-antimatter reactions to power starships. Now, where do you think they get this antimatter from? It's not like there's likely to be antimatter mines anywhere in a matter-based universe. It comes from starlight collection (they use solar energy collection for all planet-based power needs, and for artificially producing antimatter to fuel starships). They even mention this here and there in ST fiction, though ST does tend to gloss over a lot of details about exactly how their advanced civilization and societies work outside of paramilitary starships (like how they can't seem to decide whether money exists or not in the Federation).

      FTL may or may not be possible, but antimatter-based power generation certainly is for an advanced civilization, but since there's likely no natural sources of the material, it would have to be artificially produced (to be used as a highly concentrated energy source for places where plentiful star-based energy isn't available), so the obvious answer is get the energy from stars. Star Trek got this part right: the most likely ultimate energy source for an advanced civilization is stars.

    24. Re:what about nuclear fusion? by Nethemas+the+Great · · Score: 1

      Actually the more desirable targets (contrary to science fiction) would be the uninhabited worlds closer by. Why travel tens, hundreds, thousands of light-years when you can harvest the resources of your neighboring star systems. Further, whose to say their biological requirements are our own?

      --
      Two of my imaginary friends reproduced once ... with negative results.
    25. Re:what about nuclear fusion? by Anonymous Coward · · Score: 1

      | If you though taking an international flight from halfway around the world was a bitch, imagine taking a trip from one side of the starship to the other

      I make that round trip every year.

    26. Re:what about nuclear fusion? by citizenr · · Score: 1

      Magog World Ship from Andromeda
      http://andromeda.wikia.com/wiki/Magog_World_Ship

      --
      Who logs in to gdm? Not I, said the duck.
    27. Re:what about nuclear fusion? by Grishnakh · · Score: 1

      If you're asking why any interstellar species would be aggressive and want to invade, basically you hit the nail on the head. Any species advanced enough to travel between stars is likely able to get or make whatever they need nearby without having to travel long distances and then exterminate some native population and steal their world, and probably wouldn't have the same biological requirements anyway.

      This again reinforces my position that any Dyson-sphere-building civilization isn't going to feel the need to bother cloaking themselves from detection.

    28. Re:what about nuclear fusion? by mrsquid0 · · Score: 2

      So their Americans?

      I doubt that other planets have their own Americans.

      --
      Just because you are paranoid does not mean that no-one is out to get you.
    29. Re:what about nuclear fusion? by mrsquid0 · · Score: 1

      Not quite so mind-boggling; there was an article recently saying the calculations for an Albuierre warp drive were wrong, and they determined that instead of needing the mass-energy of Jupiter for such a spacecraft, they only needed the mass-energy of a Voyager probe. That's still a lot of energy (think a whole bunch of H-bombs), but for a Class II civilization harnessing the entire energy output of a star, it's probably not that big a deal.

      The energy requirements may be plausible, but the energy density needs to be negative, which means that you need exotic matter to make the Alcubierre drive work.

      --
      Just because you are paranoid does not mean that no-one is out to get you.
    30. Re:what about nuclear fusion? by amRadioHed · · Score: 1

      The energy requirements of a warp drive are only have the problem. The much bigger problem is that it relies on physics which doesn't exist and we have no reason to believe ever will. Sure exotic matter could be possible, but I wouldn't bet on it.

      --
      We hope your rules and wisdom choke you / Now we are one in everlasting peace
    31. Re:what about nuclear fusion? by Nethemas+the+Great · · Score: 1

      Actually within the Star Trek universe the use of fusion technology is wide-spread. The use of matter-antimatter reactions is primarily with warp/primary power on most (but not all, see Romulans) star ships and weapon systems. I would recommend adhering to your own advice.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    32. Re:what about nuclear fusion? by amRadioHed · · Score: 1

      If they aren't concerned about resources, why do they need to build a Dyson sphere?

      --
      We hope your rules and wisdom choke you / Now we are one in everlasting peace
    33. Re:what about nuclear fusion? by magarity · · Score: 1

      This again reinforces my position that any Dyson-sphere-building civilization isn't going to feel the need to bother cloaking themselves from detection.

      Exactly; and never mind the needs and desires of the invaders; what would it take to invade something that far away from whereever the invaders come from? Look what a giant logistical feat it was to invade Europe from England in WW2. That was just across a few miles of ocean. And then there's the size. Invading a sphere around a star would take the term "theatre-wide operations" to a whole new level.

    34. Re:what about nuclear fusion? by HiThere · · Score: 2

      Yes. And in that case, why not use them in situ.

      I think MacroLife is a much more reasonable concept than a Dyson sphere. Or a Topopolis. Or both. Or maybe you could find a way to solve the problems of a ringworld.

      P.S.: A Dyson sphere doesn't have the dynamic instability problem of a ringworld, but it has a static version of the same thing. There's NOTHING to keep the sun in the center. Unlike the ringworld it isn't pulled off a peak of unstable equlibrium, but it's also not held at the center by anything. So ANYTHING that imparts momentum to the shell will tend to cause it to drift off center. This is less commonly realized than the problem of how to hold the air in place.

      P.P.S.: I was addressing the most common form of Dyson sphere imagined. Engineers don't usually design it that way, but rather design lots and lots of habitats that can link at the edges. The solar cells have nearly complete coverage, but the habitats don't need that. That's much more practical for several reasons (e.g., you can build it in pieces). But note that this is closer to the concept of a Topopolis. And a Topopolis doesn't start with the intention of intercepting all solar radiation, though it could expand to do so, in which case it would be an implementation of a Dyson sphere. It could also extend "tentacles" intoo the Oort cloud, to facilitate the harvesting of comets...but I think MacroLife is a more appropriate way to do that.

      N.B.: Topopolis doesn't require controlled fusion. MacroLife probably does. (I don't think fission is energetic enough, though one could certainly build small & slow versions using fission.) But note that even the "fast" versions of MacroLife would probably never get faster than 0.01c unless there are DRAMATIC improvements in several areas of technology. Guarding against meteor impacts is only one. And energy production is only one. It might required controlled generation of something analogous to gravity, i.e., something that could impart momentum over the entire structure without stressing the parts unevenly. My current idea is an ion engine that could exert several hundred pounds of thrust. This is probably better seen as a panel of ion engines, some of which eject electrons, and others of which eject protons at .99c or higher. I have no idea how practical this would be, but it doesn't seem totally out of the question. Clearly with this kind of motive power, you DON'T want to come in close to something heavy. But comet heads, etc. should be reasonable, and even Pluto, if you were careful. Don't think of it as a ship, but rather as a city. It may be slightly mobile, but even an ocean liner would be a marvel of acrobatic grace next to it (except, of course, that it would be mobile in three dimensions).

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    35. Re:what about nuclear fusion? by maxwell+demon · · Score: 1

      What "resources" would you need that you couldn't just synthesise?

      Gold-pressed latinum, of course.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    36. Re:what about nuclear fusion? by Grishnakh · · Score: 1

      Plus, if your civilization is advanced enough to travel to another star system and successfully defeat a civilization that's built a Dyson sphere, then you're surely advanced enough to just build your own Dyson sphere and not need to undertake an invasion far from home.

    37. Re:what about nuclear fusion? by maxwell+demon · · Score: 1

      Actually I'd argue that if you have the tech to build a Dyson sphere you've the technology to dismantle the star and make much more efficient use of the matter than merely burning it to helium.
      You'd want to dismantle the star and use it as a matter source for fuel and construction, the alternative is to leave it wastefully burning and then eventually exploding. What a waste when there's all that entropy there that can be used.

      The problem is that hydrogen isn't the ideal material to build structures from, to say the least. And while it could be burned with oxygen to get enery, that energy would be nowhere near the energy you'd get from fusing the same amount of hydrogen. Which the sun does for free.

      Now if the sun is almost burned out, then it may make sense to dismantle it in order to prevent a destruction. However, it probably is a better idea to move to another star because your current primary energy source will go away one one way or the other.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    38. Re:what about nuclear fusion? by Thud457 · · Score: 1

      Exhibit A apparently the Earth's magnetic field traps anti-protons from the Sun. We just have to go collect them. If you can't be bothered to get up off your collective asses, well, you deserve to go extinct. Oh, and they're a renewable resource (at least for a few billion years) since they are constantly replenished from the Sun.


      Exhibit B and Exhibit C -- harvest solar power, generate more antimatter. Yeah, kind of wasteful, but you fucking monkeys aren't fully utilizing Sol's bounty anyhow. I'm sure you'll figure out ways to improve efficiency with experience.


      Honestly, you're all a bunch of lazy whiners, content to prey upon each other with arbitrage rather than applying yourself to actual productive work that would generate real wealth. The galaxy doesn't need the likes of you.

      --

      the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff

    39. Re:what about nuclear fusion? by nschubach · · Score: 1

      But isn't that getting back to the resource issue (ie: needing an ass ton of material for a huge sphere)? Relying on the laws of conservation; The only reason you'd wipe out a species is for the rock they claim home. You'd likely claim up all neighboring systems until you had the resources you needed. This would create a void of empty star systems in the immediate vicinity. In that case, wouldn't it be far saner to just look for a group of stars in a cluster with no planets? Maybe they also found a way to claim the stars themselves which gets back to the point of them just being able to fuse atoms to generate the material they need.

      --
      Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
    40. Re:what about nuclear fusion? by 0xdeadbeef · · Score: 1

      Except it "educated" them to the point of believing they know better about the subject than the very people who have studied it. Look at the dolt I replied to above. If he'd actually read the fucking article, or even the Wikipedia page on Dyson spheres, he'd see

      "Even though there is enough mass in our solar system to construct a solid sphere, such a structure would not be mechanically feasible," Wright told me. "It would probably have to be more like a swarm of collectors."

      and

      Dyson replied, "A solid shell or ring surrounding a star is mechanically impossible. The form of 'biosphere' which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star."

      This is a vastly more efficient and logical approach to SETI than listening for modulated radio. It's the difference between finding a city in the wilderness by its waste light versus finding it because someone is shining a laser beacon at random points along the horizon and you just happen to be there when it splashes in your eye. Traditional SETI assumes of the alien civilization an extremely wasteful energy expenditure for an altruistic purpose, while this approach assumes a very efficient use of resources without any desire to educate the savages.

      And while there are always a few morons who shit in SETI threads, I suspect most of the naysayers in this thread actually love SETI because it caters to their science fiction fantasies. And yet they have just enough incredulity to dismiss Dyson spheres without actually understanding the reasoning behind this search because they saw an episode of Star Trek that had a solid sphere several million times more massive than its enclosed star.

    41. Re:what about nuclear fusion? by 0xdeadbeef · · Score: 1

      That's an astonishingly good idea you have there. We could fuse the hydrogen into ever more useful elements, whilst simultaneously using the waste heat to drive the industry that uses them. Though, of course, there is the sticky problem of getting that matter into orbit, which would require more energy than can be sustained in a controlled fashion.

      So, gentlemen, I think we're agreed: For the good of human race, we're going to blow up the sun.

    42. Re:what about nuclear fusion? by furbearntrout · · Score: 1

      From the star itself. Smaller stars last longer anyway.

      --
      Crap. What did the new CSS do with the "Post anonymously" option??
    43. Re:what about nuclear fusion? by oreiasecaman · · Score: 1

      I doubt that other planets have their own Americans.

      What a relief... :)

      --
      This is a UDP joke, I don't care if you get it or not...
    44. Re:what about nuclear fusion? by lightknight · · Score: 1

      Huh, I thought they discovered an asymmetric process a little while back.

      --
      I am John Hurt.
    45. Re:what about nuclear fusion? by martas · · Score: 1

      Why exactly would a ringworld be more impossible to construct than a Dyson Ring? It could be built piece by piece, so that at fist each piece orbits the star independently, and then joined...

    46. Re:what about nuclear fusion? by jez9999 · · Score: 1

      Of course, if they figure out how to get energy directly from quantum fluctuations, or by mining antimatter from a parallel universe or something

      By the time you get to that level, you're called Q.

    47. Re:what about nuclear fusion? by jez9999 · · Score: 1

      and where they'd find the materials required to build it

      Aren't energy and matter interchangeable? You could start building the Dyson sphere, and then it could sustain its own building by using the energy it's getting from the star to generate more matter for more Dyson sphere.

    48. Re:what about nuclear fusion? by WildBlueYonder · · Score: 1

      In this Astrophysicists professional opinion it is unlikely (and probably impossible) to construct a rigid "shell" structure which is able to hold itself over the sun, or even hold itself apart from it's own gravity field before collapsing into rubble (as another poster stated). If you did construct such a structure it would also be unstable and prone to falling into the sun, ala Ringworld, but if you could construct such a structure in the first place that may not be an issue.

      The simple fact is that the stiffness/density ratio to withstand the gravity of a sun is enormous, probably impossibly so. Also, that sort of structure would probably have an enormous mass.

      A very popular way of solving this is the "Dyson Swarm", which other posters have mentioned. Just keep building and launching normal satellites until they literally block the sun. An alternative (one which is not mutually exclusive to the swarm approach) is to build a structure that does not need to withstand gravity. Instead of a shell build a thin membrane that surrounds the sun, light enough that the solar radiation pressure that object feels is slightly larger than the gravitational pressure. Instead of tending to fall into the sun the entire balloon would inflate out from the sun until it was taut. The structure would then only have to withstand the tensile force of the excess solar radiation pressure, so lets say 1% of the gravitational force, and tensile force can be withstood with lighter materials than compressive force to boot.

      So what would the areal density of such a membrane have to be?:

      Pressure * MembraneArea = MembraneMass * Gravity

      MembraneMass/MembraneArea = ArealDensity = Pressure / Gravity

      Gravity = SunMass * GravitationalConstant / radius^2

      Pressure = FluxDensity / c (assuming that our membrane is perfectly absorptive, also note that we don't need to take into account the pressure of the photons leaving the membrane, as they will be split evenly between the inner and outer surfaces and cancel each other out.)

      FluxDensity = SolarLuminosity / MembraneArea (//*The SolarLuminosity is the total power output of the sun.)

      MembraneArea = 4 * pi * radius^2

      so: ArealDensity = (TotalPowerOutputOfSun / (4 * pi * radius^2) / c) / (SunMass * GravitationalConstant / radius^2)

      The radius cancels out! That means that the same membrane (barring heat constraints) can be used anywhere in the solar system!

      ArealDensity = (TotalPowerOutputOfSun) / (4 * pi * SunMass * GravitationalConstant * c)

      ArealDensity = (3.839E26 Watts (kg*m^2/s^3)) / (4 * pi * 1.9891E30 kg * 6.673E-11 m^3/kg/s^2 * 3E8 m/s)

      ArealDensity = 7.67E-4 kg/m^2

      So all we need to do is make a very thin structural membrane, line it with incredibly efficient solar cells, as well as efficient transmission to the laser stations studded every few tens of thousands of square kilometers, into a sheet of membrane that masses around 7 grams a square meter! (safety factor, as well as extra to hold up those laser installations) Easy peasy, that's just an order of magnitude less than a sheet of ordinary paper! For an even more relevant example this paper references a current deployed solar array areal density of 80 g per square meter. Coincedentally enough that's actually exactly the areal density of a sheet of paper, so an order of magnitude of improvement is actually what we are trying to achieve.

      As far as the total mass of this system, that's ArealDensity * 4 * pi * radius^2. Let's think really grand and build it 10% past Saturn. .0007 * 4 * pi * (1.1 * 1.43E9)^2 = 2.18E16 kg. That's only 3.6E-9 the mass of our planet, or 2.3E-5 the mass of Ceres, so once we get Asteroid mining started up that'll be no problem. Heck, if you wanted to be lame and build it at 1.1 times Earth's maximum distance from the sun you could make it more than 100 times lighter than the Saturn variant.

    49. Re:what about nuclear fusion? by painandgreed · · Score: 1

      i'm sure an advanced civilization will master Star Trek type fusion tech before doing something ridiculous like building a starlight collector.

      the earth compared to the sun is like a grain of sand to a beachball. where would you get enough matter to build something around a star if the same or similar size ratio will exist in other star systems?

      How about the same place you got all the matter for that "fusion tech" that allows you to produce enough energy to dwarf the energy output of the sun? The sun is a very nice, already built fusion reactor that keeps us from having to build our own miniature "starlight collectors" as that's pretty much all that fusion tech is.

    50. Re:what about nuclear fusion? by toddestan · · Score: 1

      It's the tremendous stress that would be involved once you spin it up to simulate gravity on the inside (and to hold the atmosphere in if it is not sealed). You need a material strong enough so that it doesn't fly apart. If it rotated at orbital velocity (in other words it took a year to complete one rotation) then it is possible to build it using materials we have access to.

    51. Re:what about nuclear fusion? by Sardaukar86 · · Score: 1

      i'm sure an advanced civilization will master Star Trek type fusion tech before doing something ridiculous like building a starlight collector.

      the earth compared to the sun is like a grain of sand to a beachball. where would you get enough matter to build something around a star if the same or similar size ratio will exist in other star systems?

      I read a good book (The Time Ships by Stephen Baxter I think, as a sequel to The Time Machine by H.G. Wells) that had the Morlocks evolving into a highly technically-advanced society that eventually put Dyson spheres around most of the visible stars in the galaxy

      Their method involved manipulating gravity (from memory) to force matter away from the star itself. Their clever tech manipulated this matter as it cooled to become an energy-collection device that we'd probably call a Dyson shell and internally a gigantic living space for the Morlocks themselves. The book described this as taking tens of thousands of years to build.

      I don't know how feasible this is but it made for a great sci-fi read IMHO.

      --
      ..Mullah or Pope, Preacher or Poet, who was it wrote: "Give any one species too much rope and they'll fuck it up"?
    52. Re:what about nuclear fusion? by Maritz · · Score: 1

      I've heard anti-protons could potentially be found in usable amounts in field lines of a strong magnetic field such as Jupiter's. So it mightn't be out of the question to get usable amounts from nature.

      --
      I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
    53. Re:what about nuclear fusion? by martas · · Score: 1

      Ah, right, I forgot it would have to rotate faster than orbital so things like people and atmosphere stick to it...

    54. Re:what about nuclear fusion? by BevanFindlay · · Score: 1

      In theory, you could probably do this by simply opening one end of the sphere. It would be horribly slow to accelerate, but should work (making bold assumptions about sphere stability etc...) If you had something a bit more like half a sphere that was somewhat reflective,* you'd probably get yourself a good bit of speed up after a while (not human-lifetime timescales though, but neither is building one).

      *Getting it to balance pressure from solar wind and pull from gravity and blah blah and stay on one side the whole time would be a mind-bending exercise, but probably not much more difficult than actually making a functioning Dyson Sphere in the first place. A bunch of heliostats could work though.

      Oh, and you wouldn't want to get too close to whatever star system you were planning on visiting, either!

  4. Let me predict.... by slashping · · Score: 5, Insightful

    They'll find nothing.

    1. Re:Let me predict.... by Tablizer · · Score: 5, Interesting

      They'll find nothing.

      Probably, but the issue is whether it's worth looking. If there was a detectable civilization in our range, and it later was discovered that we could have detected it much earlier via a relatively small expenditure, we'd be kicking ourselves in the ass.

      Plus, it may lead to the discovery of a new unexpected natural phenomenon.

      - Sara N. Dipity.

    2. Re:Let me predict.... by zlives · · Score: 1

      o they will find it... just before they find a giant cube closing in on it :)

    3. Re:Let me predict.... by Half-pint+HAL · · Score: 1

      They'll find nothing.

      Probably, but the issue is whether it's worth looking.

      ...and the answer is "probably not". A single purpose two-year search is stupid. The proper answer is to shove the signature into the list of things that computers automatically search for when analysing the skies and let the computer search from now until Type II civilisation kingdom come.

      --
      Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
    4. Re:Let me predict.... by interval1066 · · Score: 3, Insightful

      Perhaps. You seem to be making an assumption that many naysayers make, that is we've made a huge effort in detecting exo-planetary intelligence and come up with nothing. Let me add that our efforts so far have been miniscule when campared to the real relative distances involved in the search. Meaning that a real search effort with the given technology may be a bit beyond our current economic and technical ability.

      --
      Python: 'And then suddenly you have a language which says "we're all stuck with whatever the whiniest coder wants".'
    5. Re:Let me predict.... by ShanghaiBill · · Score: 4, Insightful

      They'll find nothing.

      Which would be an interesting result.

      Experiments don't have to be "successful" to have an impact. Michelson and Morley failed to detect ether, yet their failed experiment revolutionized physics.

      If the search finds nothing, does that mean the Rare Earth Hypothesis is correct? Or maybe advanced civilizations find a way to hide their energy consumption, or maybe they don't grow or don't need the levels of energy that we think they do. A null result from this search leads to many interesting questions.

    6. Re:Let me predict.... by slashping · · Score: 1

      How about a much simpler hypothesis: life in the universe is abundant, but just never generates enough energy to be noticeable at the distances involved. For instance, genocide is a much simpler solution to deal with growing energy needs on a planet.

    7. Re:Let me predict.... by ThorGod · · Score: 2

      A single purpose two-year search is stupid.

      Progress isn't progress unless it's 100% devoted, perfect, without any possible critiques?

      This is interesting progress, it shouldn't be called "stupid". Not even if you were Edwin Hubble himself.

      --
      PS: I don't reply to ACs.
    8. Re:Let me predict.... by jpyeck · · Score: 1

      And that is the likely goal!

      Remember, it is the Templeton Foundation (they of the Templeton Prize) funding this research. This is just a wild-goose-chase that will add another pseudo-argument to the quiver: "See, Intelligent Design it is plausible. "Science" has looked for Dyson Spheres and didn't find any! Therefore we must be alone in the universe and therefore we must be the special unique creations of God."

      They even get to pretend to be impartial because they funded it. Ugh!

    9. Re:Let me predict.... by DysonSphere · · Score: 1

      Well, maybe not..

      --
      Mommy. What's a karma whore?
    10. Re:Let me predict.... by wile_e_wonka · · Score: 1

      If the search finds nothing, does that mean the Rare Earth Hypothesis is correct? Or maybe advanced civilizations find a way to hide their energy consumption, or maybe they don't grow or don't need the levels of energy that we think they do. A null result from this search leads to many interesting questions.

      A null result wouldn't tell us any of those things, because a null result doesn't even mean that there are no Dyson Spheres out there. Instead a null result would just be inconclusive.

    11. Re:Let me predict.... by ShanghaiBill · · Score: 1

      Therefore we must be alone in the universe and therefore we must be the special unique creations of God."

      This makes no sense to me. My religious friends and relatives are far more likely to believe in aliens, UFOs, etc., than my atheist/agnostic friends. Mormons used to believe there were people living on the Moon. I fail to see how evidence of alien life would either support or diminish anyone's religious beliefs.

    12. Re:Let me predict.... by Nethemas+the+Great · · Score: 1

      Have you never heard of a "pretext"?

      --
      Two of my imaginary friends reproduced once ... with negative results.
    13. Re:Let me predict.... by MartinSchou · · Score: 1

      A search finding no IR indications of a Dyson Sphere could tell us a few things, but neither of them conclusively, and we won't know which one(s) is correct.

      1) There are no Dyson Spheres
      2) There are no IR detectable Dyson Spheres (as per your hiding one)
      3) There are Dyson Spheres, but their signatures haven't reached us yet. I.e. a star 700 light years away may have just finished a Dyson Sphere, but we won't know until the signature reaches us.
      4) There have been Dyson Spheres, but their stars have died, leaving the sphere with no more energy to radiate/having been blown to bits in a nova/having strayed too close to a black hole/something else
      5) Some other equally or more likely explanation.

      Now, I haven't read the article (surprise), but I'm surprised they aren't checking for solar mass gravitational anomalies with no visible star. It seems to me, that even if you managed to hide the IR signature, or change the configuration of the sphere such that it will radiate dark energy, the sphere and star themselves cannot avoid having an impact on spacetime (i.e. creating a gravity well). As far as I understood, that's part of how we've concluded that 96% of the universe is made up of non-baryonic matter and energy.

      It seems to me that this study will really only tell us something interesting about Dyson Sphere civilizations, if they manage to detect one. They may find something completely different and just as meaningful and interesting, but this seems to be a kind of experiment, where a negative finding doesn't help us in any way.

      No, sadly I'm not a physicist, but I wouldn't mind studying to become one.

    14. Re:Let me predict.... by BevanFindlay · · Score: 1

      This goes both ways: yes, belief in one area of the "paranormal" is more likely to mean belief in others whereas a more "scientific" mind is less likely to believe in any of them, but at the same time, there are theological implications of finding life outside Earth that get tricky (e.g. if Jesus died for all humanity, did he also die for all alien life? Did Jesus appear as an alien as well, but if so, then creation isn't totally under the effect of Adam's sin... etc). They're not intractable problems, but it gets complex (if we found aliens tomorrow, a lot of monotheistic religions would empty out somewhat, but others would shrug and go, "Huh, God created aliens as well - weird but cool.") Most Christians I know don't believe in aliens.

      As a Christian (and an engineer) myself, I'm of the opinion, "I doubt there's aliens out there, but I'm not going to lose my faith if there are. Means I made a couple of wrong assumptions, but it's irrelevant to the core of what I believe."

      Of course, one of the first things I would be interested to see would be the range of spiritual beliefs of an alien race - if they believed a direct translation into their culture of (say) the Christian God, then atheists could have a big problem on their hands. :-)

  5. Oh please... by Anonymous Coward · · Score: 1

    > Astrologers Search For Dyson Spheres of Alien Civilizations

  6. Planet-based solar? by GameboyRMH · · Score: 1

    Wouldn't planet-based solar be far more affordable and efficient, and produce more than enough energy for a planet with population controlled at a reasonable level, which should be expected from any advanced civilization? Seems like it would be unlikely for an advanced civilization to build one of these given the other options (including fusion power)...

    --
    "When information is power, privacy is freedom" - Jah-Wren Ryel
    1. Re:Planet-based solar? by ByOhTek · · Score: 2

      Actually, depending on the level of respect for freedom, population control may not be expected.

      The desire of the individual and of the civilization are often in conflict, and procreation tends to be one of the areas of conflict.

      --
      Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
    2. Re:Planet-based solar? by GameboyRMH · · Score: 1

      With too much respect for freedom (aka FYGM attitude) and an insufficient sense of egalitarianism they just wouldn't reach that level of advancement. The individuals would need to accept a certain level of moderation/sacrifice for the greater good of the society.

      The other possibility is that they're all a bunch of nutjobs and will be looking for a fresh planet to colonize:

      http://science.slashdot.org/comments.pl?sid=3166045&cid=41559185

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    3. Re:Planet-based solar? by Anonymous Coward · · Score: 3, Informative

      Further, in the traditionally-envisioned model of the Dyson Sphere (hollow sphere around a star; not Dyson's actual theory), the livable surface area of the sphere would come out to something on the order of millions of Earth-sized planets. Population control at that scale, for a society with that kind of capability, is essentially a non-issue for any reasonable length of time.

    4. Re:Planet-based solar? by Baloroth · · Score: 2

      Wouldn't planet-based solar be far more affordable and efficient, and produce more than enough energy for a planet with population controlled at a reasonable level, which should be expected from any advanced civilization? Seems like it would be unlikely for an advanced civilization to build one of these given the other options (including fusion power)...

      Define "reasonable level." You'll find it depends entirely on your resources. If you build a Dyson sphere, your available power resources are vastly greater (physical material such as food and water can, theoretically, by recycled with 100% efficiency given sufficient power). And it greatly benefits a society to have a larger population: faster evolution, more smart people to make advances, more culture and art are produced, and a vastly greater chance to survive any catastrophe.

      In other words, you are thinking of the limitations a more advanced society would face from the perspective of our society. They are not the same, and doing so is a grave mistake. Our current population would have been completely and totally unsustainable for more than a few days 100 years ago (whether it is sustainable in the long term is irrelevant, my point is literally 1/2+ of the population would die in a week if we didn't have modern food production), it is foolish to think a population 100x our current couldn't be sustainable in 1000 years. In fact, we already know how we could do exactly that, in theory (hydroponics and similar). But you'd need a lot of energy to do that: hence, build a Dyson Sphere. Of course, that in itself assumes we don't discover a better way of getting energy in the next 1000 years, which is itself something of a major assumption.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
    5. Re:Planet-based solar? by WrongMonkey · · Score: 1

      Your concept of "individual freedom" is based on species bias. Not all successful species have a individual drive to procreate: ants, bees, and termites for example.

    6. Re:Planet-based solar? by tnk1 · · Score: 1

      Some civilizations might take the philosophical viewpoint that more of themselves is a good thing and that the fact that they will overwhelm the current environment is merely a problem that needs to be solved.

      In the sense of overall species survival in the long run, they're probably right. Any species caught on one planet is at risk of some sort of catastrophic event that could end that civilization, up to and including the end of their star. Although that is a very long time, it is also a finite time which is a hard end for a civilization that has decided on a static position of not spreading out.

      Further, within that time period of a couple billion years, something like their system passing through a particularly inhospitable region of the galaxy in its orbit or even two galaxies colliding and their system being disrupted in some way is possible.

      Even thinking about these threats is assuming that they have enough ability to defend against relatively more common threats like asteroid or cometary impacts, which they may or may not have the ability to actually do, especially if they cannot generate energy beyond a certain level.

      Over time, staying still is death. It sounds all nice and pretty to have a stable population and "live in harmony" with nature, but the reality is that nature wants you dead. Living in harmony with nature sounds nice in the sort term, but it is pure death in the long term.

    7. Re:Planet-based solar? by CCarrot · · Score: 1

      If you build a Dyson sphere, your available power resources are vastly greater (physical material such as food and water can, theoretically, by recycled with 100% efficiency given sufficient power).

      Okay, ew.

      I know that's basically how mother nature does it too (with lesser efficiency)...but still. Ew.

      --
      "I love animals! Some are cute, others are tasty, what's not to like?" - Betsy Schroeder, Jeopardy contestant
    8. Re:Planet-based solar? by DamnStupidElf · · Score: 1

      By "essentially a non-issue for any reasonable length of time", I'm assuming you mean for e^rt = "millions", which is only about e^13.8 for a million. So after a million of years of living on the Dyson sphere the yearly population growth would have to be tiny (less than 0.00138%) to not fill up the entire surface.

    9. Re:Planet-based solar? by ByOhTek · · Score: 1

      No it isn't reasonable. The human population at current tech levels can double every 35-50 years (we peaked at 30, I think we are down to 50).

      Say tech is up, so carrying capacity is 10billion/earth, and the sphere is initially stocked with 10,000 people.
      Lets also say the star is similar to the sun, and for heat dissipation reasons, it's actually better to have the sphere about 1.5 AU in radius (that is, the radius is now 225*10^6km)

      The surface area of one side of the sphere is 1.590 * 10^17km^2
      The surface area of the earth is 5.1 * 10^8 km^2
      The sphere can hold ~312 million earth surfaces on a side, or a carrying capacity of 3.12*10^18 people... ~61 doublings from 2 people.
      2 people with proper medical care could bring the sphere to capacity in ~3050 years.
      10000 people in closer to 2400.

      --
      Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
    10. Re:Planet-based solar? by ByOhTek · · Score: 1

      all successful species have an individual drive to procreate at a higher than replacement amount. However, what you are describing is that not all individuals of those species share this desire. It is safe to say, however, that for all known species, the at least the limiting reproductive members (and often the non-limiting members) have a drive to produce a greater-than-replacement number of reproductive offspring.

      --
      Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
  7. Genuine excitement by Shrike82 · · Score: 1

    This is the first time in a very long while that I've read a /. story that's gotten me excited. The idea that we could find evidence of a Dyson sphere is quite crotch-tingling for a fan of science fiction like myself!

    Of course there's the problem of how we can be sure any evidence we see is actually a constructed sphere and not a freak natural occurrence, or something that we simply don't understand or haven't envisaged at this point. Still, any data that showed a "should-be-visible" star radiating heat but not light is something of note. Hell, it would give us something to start beaming signals at like mad in the hope of a return at the very least. Lets just hope it's within X light years, where X is less than half my remaining lifespan so I can catch the "Hello? Who the fuck are you!?" signal from the big blue people on Pandora.

    --
    You can advertise in this sig from as little as £99.99 a month!
    1. Re:Genuine excitement by confused+one · · Score: 1

      Hell, it would give us something to start beaming signals at like mad in the hope of a return at the very least.

      You should be careful what you ask for. There are things you really shouldn't poke with a stick -- Bears for one, large cats, wasp nests, hives of locusts... Aliens advanced and hungry enough for raw energy (and materials) to build Dyson spheres.

    2. Re:Genuine excitement by FatLittleMonkey · · Score: 1

      More than that, if we can detect their Dyson sphere, but can't hear any RF between the millions of habs in their Dyson sphere, then they are deliberately being very quiet. A civilisation old enough and advanced enough to build a fucking Dyson Sphere is being very quiet.

      So maybe we should take the hint.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
    3. Re:Genuine excitement by DysonSphere · · Score: 1

      "crotch-tingling"? *blushes*

      --
      Mommy. What's a karma whore?
    4. Re:Genuine excitement by spire3661 · · Score: 1

      "If you can't take a little bloody nose, maybe you ought to go back home and crawl under your bed. It's not safe out here. It's wondrous, with treasures to satiate desires both subtle and gross. But it's not for the timid." -Q

      --
      Good-bye
    5. Re:Genuine excitement by camperdave · · Score: 1

      Hell, it would give us something to start beaming signals at like mad in the hope of a return at the very least.

      You should be careful what you ask for. There are things you really shouldn't poke with a stick -- Bears for one, large cats, wasp nests, hives of locusts... Aliens advanced and hungry enough for raw energy (and materials) to build Dyson spheres.

      Every book, movie, TV show, and comic book I've read says that we'll defeat the alien menace, so I say poke away.

      --
      When our name is on the back of your car, we're behind you all the way!
    6. Re:Genuine excitement by readin · · Score: 1

      Hell, it would give us something to start beaming signals at like mad in the hope of a return at the very least.

      You should be careful what you ask for. There are things you really shouldn't poke with a stick -- Bears for one, large cats, wasp nests, hives of locusts... Aliens advanced and hungry enough for raw energy (and materials) to build Dyson spheres.

      Usually I'm with the crowd that says we ought to be careful about how we contact alients, but in this case I think your reason is wrong: why would any aliens advanced and hungry enough for raw energy to build Dyson spheres want to bother us? Certainly not for our energy. There is nothing on earth that has the energy to compare with what they could get from any random star. Nor for our raw materials - again we're nothing special in terms of raw materials and if they're capable of manufacturing a Dyson sphere then there is nothing in terms of improved materials we could offer them either.

      Probably the bigger danger is that they would want to send scientists to put us in cages and study us or worse, get rid of us before we become as advanced as they are (admittedly that would take a long time, but if the aliens were far away they would know the round trip time for our signal to reach them and for their killing squads to reach would be long enough to allow us a lot of advancement).

      --
      I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
    7. Re:Genuine excitement by BevanFindlay · · Score: 1

      Bahahaha.

      Err, you were going for the comedy angle, yeah?

      If not, go read up on the "Prisoner's Dilemma", or in this case: "If alien civilisation exists that could potentially wipe me out, then I should wipe them out first, thoroughly and completely, or make sure I have something off-planet than can wipe them out in case they target Earth." (Also note: any civilisation who can go interstellar can by definition wipe out whatever planet is at the other end - it's actually a lot easier than a friendly visit).

      There are some other interesting answers to the "planetary prisoner's dilemma" that don't necessarily end in genocide (e.g. whether one or other side has alternative colonial bases, whether one thinks that the other might have alternative bases, whether one has hidden weapons waiting closer to the target system, whether an alien civilisation has utterly alien concepts of value and ethics that lead to totally different conclusions, cultural vs biological preservation as paramount...) Generally, if we found something, I would be wanting to get off-planet as soon as possible, and being as friendly as possible in the mean time. Considering that an "answer" to us saying hello would be on the order of decades at the closest, establishing an offworld presence in that time isn't so unlikely (just in case they decide to answer with a stellar-magnitude directed burst of gamma rays).

      It's a little hard to fight off something like a directed burst of energy from your planet, or a relativistic kill vehicle.

    8. Re:Genuine excitement by camperdave · · Score: 1

      Well, we've been broadcasting to the stars for well over a century. If you're going to hide offworld, you'd best hurry.

      --
      When our name is on the back of your car, we're behind you all the way!
  8. Runs out of energy? by Rik+Sweeney · · Score: 1

    I thought energy couldn't be created or destroyed, so the energy on this planet is pretty much constant?

    1. Re:Runs out of energy? by Errol+backfiring · · Score: 5, Informative

      Eventually, the energy is converted to heat, which can leak out into space. Our planet is not a closed system. The good thing is that there is also energy coming in into our system (solar energy, for example).

      --
      Nae king! Nae laird! Nae yurrupiean pressedent! We willna be fooled again!
    2. Re:Runs out of energy? by Half-pint+HAL · · Score: 1

      Energy and matter are interchangable. The plan is constantly gaining matter and energy from space (sunlight, starlight, cosmic rays, meteorites) and is also constantly losing matter and energy to space (evaporation of the upper atmosphere, radiated heat, leaked radio waves). The amount of energy+matter in the universe is constant, but the amount on any given planet is constantly changing.

      --
      Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
    3. Re:Runs out of energy? by Daniel_Staal · · Score: 1

      That's over the entire universe. It's quite possible for any subset of the universe to gain or loose energy, by sending it outside the subset.

      Also, just because the energy exists doesn't mean you can use it.

      --
      'Sensible' is a curse word.
    4. Re:Runs out of energy? by i+kan+reed · · Score: 1

      Logical failure on your part: "On this planet"

      Usable energy like fossil fuels are used, the energy goes to higher entropy state: i.e. heat.

      Heat in the atmosphere radiates out. Total energy on the planet: lower.

    5. Re:Runs out of energy? by prefec2 · · Score: 1

      It can be created (sort of) by fusion or fission. However, the matter + energy are fixed. So you can convert mass to energy causing to be more energy in the unsivers and less matter. However, energy cannot be destroyed or created as such, it is converted to or from matter.

    6. Re:Runs out of energy? by ShanghaiBill · · Score: 1

      I thought energy couldn't be created or destroyed, so the energy on this planet is pretty much constant?

      Correct. But the type of energy will be different. A bright star emits visible light, which is a low entropy form of energy, that can be converted to electricity or other useful forms. Once that energy is used by a civilization, it is low quality, high entropy energy, in the form of heat. That heat must be disposed of by radiating it into space as infrared radiation.

      So if we can detect something that emits as much energy as our sun, but emits that energy in the infrared spectrum, there is no other explanation for it. At the current age of the universe, there is just no way for a star that big to be that cool naturally.

    7. Re:Runs out of energy? by Translation+Error · · Score: 3, Funny

      Eventually, the energy is converted to heat, which can leak out into space.

      Don't worry; we're working on that.

      --
      When someone says, "Any fool can see ..." they're usually exactly right.
    8. Re:Runs out of energy? by cellocgw · · Score: 1

      I thought energy couldn't be created or destroyed, so the energy on this planet is pretty much constant?
      Gosh I must be getting trolled, but just in case not: didja ever hear of a really simple equation this guy Einstein came up with? Just three variables.

      --
      https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
  9. So why can't we do it? by jtseng · · Score: 1, Interesting

    I suspect at this point humanity, as a collective whole, is still too small-minded to consider such an endeavor. Our politicians are narcissistic/sociopathic, and private industry would want it to be profitable.

    *sigh*

    --

    Sanity.html - Error 404 not found

    1. Re:So why can't we do it? by Zontar_Thing_From_Ve · · Score: 4, Insightful

      I think you are 100% correct, but it's not just politicians who are small minded. Here's an example. I work in IT as a Linux System Administrator. One of my colleagues is not only extremely smart and one of the most knowledgeable IT guys I've ever worked with (he is like a living set of man pages), he is into sci fi. He feels very strongly that we have more pressing needs at home in the USA than to spend almost any money on NASA. I mean, he is the exact kind of guy who I would expect to be in favor of building a moon base. When guys like him won't even back NASA, there's really no hope for the USA to ever do anything useful in space in our lifetime unless it becomes a national security concern. But in direct response to your suggestion, I want to see a moon base first and a manned expedition to Mars before we try something massive like this. It's a "walk before you run" kind of thing.

    2. Re:So why can't we do it? by Intrepid+imaginaut · · Score: 1

      Build a Dyson sphere? We haven't anywhere near the technical, scientific, or engineering capability to even begin contemplating that scale of ultraconstruction. Maybe in fifty thousand years or so. Which is fortunate since we have no need to build anything of the sort. Lets start small and pave over Saturn. Seriously. :D

      From what I can tell the astronomers are looking for heat sources without a corresponding light source. I have my doubts but they would be purely speculative, if such a sphere is found what a spectacle it would be.

    3. Re:So why can't we do it? by Daniel_Staal · · Score: 2

      It probably would be profitable, in small sections. (The original 'Dyson Fleet' version.) If you have the tech to put up orbital solar at reasonable cost, it's probably profitable to put up more and more orbital solar plants as your race grows.

      --
      'Sensible' is a curse word.
    4. Re:So why can't we do it? by prefec2 · · Score: 1

      Because it is totally insane to build such thing. It is much more reasonable to build collectors for sunlight based on earth. There is plenty of energy available based on that technology, which will fuel us for the next million years. Beside that, building a Dyson sphere in the right size so that we could live on the inside must be almost as big as Earth orbit. The sphere surface size is approx. 281176811992656000 km even if the collector would require only a millimeter think foil to be useful, you must provide 2811768119926.56 km of material. Total Earth volume is 1083002572572 km. So you need 2.6 Earth size planets to build it. Considering that we required quite some time to dig up some parts of the upper km of our planet (ca. 100 years), I assume it is completely impossible with present technology to even try to do it.

    5. Re:So why can't we do it? by Half-pint+HAL · · Score: 1

      It's not that we feel profit is evil, but that profit-centric capitalism devalues all social goods that offer no profit. EG. I wouldn't mind hospitals profiting from treatment if it didn't mean that unprofitable patients end up dieing of easily treatable diseases.

      --
      Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
    6. Re:So why can't we do it? by SecurityGuy · · Score: 1

      On a planet where we can't bother to feed people starving on one side with the excess output of the other, yeah, I'd say you're right. We create fat, narcissistic 6-year-olds named Honey Boo Boo while parents elsewhere watch their kids starve.

      This civilization thing...we're doing it wrong.

    7. Re:So why can't we do it? by MickyTheIdiot · · Score: 2

      you win the false choice fallacy of the day award.

      No one said profit is evil. What was said that some things worth doing might not be profitable.

    8. Re:So why can't we do it? by MozeeToby · · Score: 1

      Well, in a small way we have considered this endeavor already and in a very, very small way we've already begun. See, Dyson spheres aren't giant shells of rigid matter, that would be virtually impossible (not to mention gravitationally unstable), they're swarms of solar arrays all in different orbits carefully calculated so that all the output from the sun is always being collected. So, every time you hear about space based solar, that's step 1 of building a Dyson sphere. And you can look at every solar powered device we put in space, especially those in solar orbits, as step .5 if you really wanted to.

    9. Re:So why can't we do it? by Hatta · · Score: 2

      He feels very strongly that we have more pressing needs at home in the USA than to spend almost any money on NASA. I mean, he is the exact kind of guy who I would expect to be in favor of building a moon base.

      And he's right. We shouldn't go to Mars because we want to brag about putting men on Mars. We should go to Mars because investing in high tech domestic industry is an excellent solution to our economic problems. It's a good reason to invest in education, it's a good reason to pay highly educated people good salaries. A manned mission to Mars is exactly the kind of stimulus program this country needs.

      --
      Give me Classic Slashdot or give me death!
    10. Re:So why can't we do it? by tnk1 · · Score: 2

      I am not like your colleague, but it may be that there is a time and a place for those sorts of expenditures. I don't think you would argue that you shouldn't be building telescopes when your family is starving, so the question becomes at what point do we have to take care of our own to the exclusion of all else. I don't think that this is the time for it, but you could argue that the US may well have been in a better place to put a man on the moon, economically, in 1969 than we are now.

      So, his position can be a consistent one. He wants a moon base. Maybe he really, really wants a moon base, but he doesn't want that moon base if someone had to starve for him to get that moon base.

      I can't argue with his viewpoint, I only might argue with his perception of how bad the problem is, and just how much we gain from *not* building that moon base. We can't shut down research every time we see a homeless person. At no point in history has there ever been a time where no one was poor. There's a lot of reasons for people being homeless, unemployed or hungry, those reasons often not being directly related to how much money you throw at them.

      Sometimes, the reason they are homeless or unemployed is because we've made things so efficient that we need new things for humans to work at until we have mastered those things as well. Research is one of the only ways to truly create new jobs that move an economy forward. Just spending money on more government bureaucratic jobs or welfare programs can't do that because it is just maintenance overhead, not actual economic growth. In the end, you need research and moon bases to keep the level of poverty down and even to simply keep people optimistic and willing to work for a better future.

    11. Re:So why can't we do it? by ArsonSmith · · Score: 1

      Not just private industry, I'd want it to be profitable too. If it's not profitable what would the use be? If we were able to make one but then nobody could afford to eat I don't think it would be very useful. If one was made and everyone got to live better because of it then everyone profits.

      --
      Paying taxes to buy civilization is like paying a hooker to buy love.
    12. Re:So why can't we do it? by Maritz · · Score: 1

      Kinda makes me wonder how many potential Newtons, Da Vincis and Einseins are dying of malnutrition and preventable diseases as the decades roll on.

      --
      I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
    13. Re:So why can't we do it? by BevanFindlay · · Score: 1

      Interestingly, finding a Dyson Sphere would suddenly make getting into space a global security concern - see my post above about the Prisoner's Dilemma, but basically: if they can build that, they can wipe a planet, so getting off-planet becomes a big priority. It might actually be one of the best things for Humanity - get us all outwardly-focused and forced to co-operate.

    14. Re:So why can't we do it? by BevanFindlay · · Score: 1

      So, what are you (personally) doing to fix it? :-)

  10. massive amounts of deliberate engineering by Anonymous Coward · · Score: 1

    'If a civilization wants to hide, it's certainly possible to hide,' says Wright, 'but it requires massive amounts of deliberate engineering across an entire civilization.'"

    You mean, similar to what would be required to build a Dyson sphere?

    What would you get from a massive amount of accidental engineering?

    1. Re:massive amounts of deliberate engineering by adonoman · · Score: 1

      You mean, similar to what would be required to build a Dyson sphere?

      Similar, but orders of magnitude more - the summary cites

      a hundred times larger than necessary

      What would you get from a massive amount of accidental engineering?

      You get cities.

    2. Re:massive amounts of deliberate engineering by Jeng · · Score: 1

      What would you get from a massive amount of accidental engineering?

      Usually a spectacular failure.

      --
      Don't know something? Look it up. Still don't know? Then ask.
    3. Re:massive amounts of deliberate engineering by Talderas · · Score: 1

      Penis enlargement pills.

      --
      "Lack of speed can be overcome. In the worst case by patience." --Znork
    4. Re:massive amounts of deliberate engineering by Artifakt · · Score: 1

      What would you get from a massive amount of accidental engineering?

      On a dyson sphere? Minecraft, with a 'shared creative' server and no anti-griefing mods emplaced.

      --
      Who is John Cabal?
  11. If they have the tech to build it, do they need to by Koreantoast · · Score: 2, Interesting

    Wouldn't a civilization advanced enough to pull off an engineering feat like a Dyson Sphere also have advanced their engineering sufficiently to find more efficient power sources?

  12. That is a big if. by jellomizer · · Score: 1

    The Dyson sphere is a massive engineering project. It would take a very very advanced civilization to complete it, using a lot of energy just to build it, taking a long time to do such work. Chances are they will kill each other off before they did such a project.

    --
    If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    1. Re:That is a big if. by tnk1 · · Score: 1

      It also misses the obvious point that while there might be killing, no one has killed off *everybody* yet. It could happen, but there is reason to believe that just as humanity has not seen the end of war, war will not necessarily be the end of humanity.

  13. Earth alone has a perpetual energy supply. by goombah99 · · Score: 1, Interesting

    moreover, the earth is a collector of solar and lunar energy. We call it wind and sunshine and tides, there's even solar "wind" if one goes a bit outside the atmosphere. Together these have more than enough energy to power all of the earths needs. Harvesting these may not be simple, but it would be a lot simpler than a dyson sphere. ergo, no dyson spheres will ever be built unless the planet is too far from the sun to collect enough solar energy on its crossection.

    What the earth lacks is a perpertual supply of transportation fuels or a means to adequately replace them. But replacing them is forseable and we don't absolutely need them--we just over exploit them now because we can.

    --
    Some drink at the fountain of knowledge. Others just gargle.
    1. Re:Earth alone has a perpetual energy supply. by Grishnakh · · Score: 1

      Sure, there's enough energy out there for one earth, but what if your species expands, and one planet isn't big enough for them all? By building a Dyson sphere, you get millions (billions?) of times the surface area of one planet, or you can create lots of independent artificial habitats, and have room for much more population, which of course would need much more energy.

    2. Re:Earth alone has a perpetual energy supply. by Nethemas+the+Great · · Score: 1

      Us "science types" are not the ones "using" atom bombs to destroy. Society's politicians, it's leaders are responsible for the utilization of such technology in detrimental ways. Us science types simply wish to expand the capability of humanity, to explore, to create, to improve. What a sad world we live in if we must condescend the rest of its inhabitants and treat them as naive children that shouldn't play with knives, fire, power tools.

      --
      Two of my imaginary friends reproduced once ... with negative results.
    3. Re:Earth alone has a perpetual energy supply. by BevanFindlay · · Score: 1

      Offtopic, but why are us "science types" not the ones going for leadership positions? I think engineers and scientists should be the ones getting into positions of power and making big decisions.

  14. Blocking light by Kjella · · Score: 1

    'If a civilization wants to hide, it's certainly possible to hide,' says Wright, 'but it requires massive amounts of deliberate engineering across an entire civilization.'"

    If a civilization with a Dyson sphere has any reason to hide, it's probably for a civilization with interstellar flight and then I'd think you'd quite easily find the black spot. Unless you assume they got a system to route or absorb/emit starlight from one side of the sphere to the other. But since we're far into science fiction land already, why not...

    --
    Live today, because you never know what tomorrow brings
    1. Re:Blocking light by jovius · · Score: 1

      More likely some other civilisation is hidden beyond our observable bubble of universe of about 14 billion light years in their own bubble - which can be billions of billions of light years away and practically unreachable.

    2. Re:Blocking light by sinij · · Score: 1

      "If a civilization wants to hide" is on itself a very interesting question.

      Assuming that superluminal is ether impossible or impractical due to high energy costs, why would a civilization want to hide?

      Well, hiding could be byproduct of efficiency, after all, radiating energy into space in any way is not a good way to reach high efficiency.

      They can also be concerned about hostile action from other civilizations, but then they need to have some evidence that other civilizations exist. This in turn tells me that not every civilization would hide, and this in turn would falsify this argument in light of "can we find someone".

    3. Re:Blocking light by dywolf · · Score: 2

      Most engineers already think a total dyson sphere is absurd, at least for a first or even 10th effort. The task of fulling enclosing a star?
      Instead most likely what you would see would be a network of solar arrays, mssive though they be, but also most likely out of the orbital plane ("polar" caps being the most logical and simplest logitically), so that the majority of the star's light still radiates normally.

      --
      The guy who said the election was rigged won the presidency with the second-most votes.
    4. Re:Blocking light by tnk1 · · Score: 1

      Well... it doesn't even have to be that far away. We're not going to be able to pick out a Dyson sphere in even a neighboring galaxy unless we know exactly what to look for, and even then, it can't give off more energy than the originating star, so it will be very difficult to pinpoint. That means that there could be Dyson Spheres all over Andromeda or the Magellanic Clouds, and we're not likely to be able to make them out at this distance.

    5. Re:Blocking light by BevanFindlay · · Score: 1

      Why would you want to hide? Look up "relativistic kill vehicles" - in space, a big target is very, very easy to destroy. Basically, you just point a big engine at it.

      Having said that, "wasting" heat energy is often more efficient than building something to use it - your returns diminish to the point that eventually it takes more energy to build the collector than you're getting out of it. Look at cars or any other industry of ours (a nuclear power plant is an ideal example - they create lots of waste heat, and if we could use it, we would). Law of diminishing returns and all that.

      Ergo, the only reason you would build near 100% efficient heat collection was if hiding was very valuable to you (in energy cost), but at that point, you'd be better off using the energy to expand your civilisation to another star system - i.e. create a "backup". :-) Ergo, if Dyson Spheres/Structures exist (debatable, even presupposing advanced civs), then they'll be visible.

  15. First space-faring race = a bunch of nutjobs by GameboyRMH · · Score: 3, Insightful

    I was watching that Riddick movie with the Necromongers the other day and I realized that the concept was actually very realistic. What kind of society would get into space first? The ones that put a high priority on space exploration. And what kind of civilization would do that just for the heck of it before any others? The ones that have some irrational reason to do it driven by some kind of religious fervor. While the "Star Trek like" science-driven societies pace themselves in a sensible manner, the religious nutjobs would throw every single resource their entire civilization could at getting into space to please their space deity or whatever. If there's an advanced space-faring race out there you probably want to steer clear of them.

    See also: The Irkens from Invader Zim

    --
    "When information is power, privacy is freedom" - Jah-Wren Ryel
    1. Re:First space-faring race = a bunch of nutjobs by PPalmgren · · Score: 4, Interesting

      That's only given all civilizations started at roughly the same time. However, this isn't Civilization V. A space-faring race could have formed a contigous civilization several hundred thousands or millions of years ago, not a couple thousand years like ours. It might be the natural evolution of things at that point.

    2. Re:First space-faring race = a bunch of nutjobs by SmurfButcher+Bob · · Score: 2

      So you're saying that at least one alien theology states that their deity will be found in a human's anal cavity?

      --

      help me i've cloned myself and can't remember which one I am

    3. Re:First space-faring race = a bunch of nutjobs by GameboyRMH · · Score: 1

      True it's possible that the Starfleet Federation could get a big head start on the Necromongers/Irkens, but the reverse is also true...all up to chance really, and calling it 50/50 is probably optimistic given the huge time penalty of "reasonableness" or worse yet "hesitance and bickering."

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    4. Re:First space-faring race = a bunch of nutjobs by Mike+Buddha · · Score: 2

      Yeah, that makes sense, until you look at reality. The European drive to colonize paid a lot of lip service to religion, but in the end it was the almighty gold piece that drove the conquest. How do we justify the cost of putting a person on the moon? By the economic benefits of the scientific discoveries and the resulting technology created.

      Economics drives our pushes forward, not religion. Scarcity is the underlying force.

      --
      by Mike Buddha -- Someday the mountain might get him, but the law never will.
    5. Re:First space-faring race = a bunch of nutjobs by GameboyRMH · · Score: 2

      Hey who knows :-P

      "Go forth and insert the blessed rods of Glarznaks into the primary solid waste excretion orifice of the beings in the sky, for it is good and will save them from damnation."

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    6. Re:First space-faring race = a bunch of nutjobs by swb · · Score: 1

      IMHO, the major problem with much science fiction seems to be the assumption that alien civilizations would be rational, organized and technically sophisticated.

      It strikes me that Earth, at its current general level of technical evolution, could have manned bases on the moon and probably be well on our way to building bases on Mars if we had the typical science fictional level of social cohesion and if all the resources we spent on developing weapons and fighting wars were spent on outer space development.

      For example, the US aircraft carrier fleet with planes alone is roughly a 90 billion dollar investment, and I would guess that when you factor in labor, training, and other resources you're looking at a 200 billion dollar outlay. And that's just for aircraft carriers.

      Contrast that with NASA's 18 billion dollar budget and the defense departments 700 billion dollar overall budget, and you can see how if the world alone was spending on space instead of war we'd easily have Moon and Mars capability developed and deployed.

      I would assume that other worlds would have the same problems we have the lead us to believe we're better off with a huge military than the ability to colonize Mars. And who's to say that other worlds would even get as far as we did?

      It's almost an accident that we're as developed as we are, most of modernity worldwide owes its roots to Europe and the Enlightenment. If that doesn't happen -- the plague doesn't wipe out the population of Europe with all the social and demographic changes this brings, if the church crushes Luther and protestantism, we could be still living hand-to-mouth and dreaming of the luxury of Rome.

    7. Re:First space-faring race = a bunch of nutjobs by GameboyRMH · · Score: 1

      You're only right if there's a demand for something that can be brought back from space profitably (which may not be possible or may only exist in fringe cases). The Europeans had a demand for more gold and spices and had a pretty good idea that they could bring them back profitably. It's a much bigger hurdle to develop interstellar travel than ocean-crossing ships.

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    8. Re:First space-faring race = a bunch of nutjobs by confused+one · · Score: 1

      Aliens from Independance Day. Essentially swarms of inter-stellar locust, consuming all natural resources on a planet, then moving on...

    9. Re:First space-faring race = a bunch of nutjobs by sinij · · Score: 3, Interesting

      Actually, chances are that not only civilizations started and finished at different times, but also that

      Assuming current predictors of life-supporting planets are at least within ballpark, each space-faring civilization existed, prospered and dyed off before running into any other civilization.

      What more reasonable assumption is that WE are product of such advanced civilization, that is some form of life-seeding DNA-based life that originated on some planet elsewhere produced advanced civilization and they realized that due to scale of our universe they will never get to explore most of it and just seeded universe with life.

    10. Re:First space-faring race = a bunch of nutjobs by Anonyme+Connard · · Score: 1

      How do we justify the cost of putting a person on the moon?

      If I remember well it was justified by a political competition, which is not very far from religion.

    11. Re:First space-faring race = a bunch of nutjobs by mcmonkey · · Score: 2

      While the "Star Trek like" science-driven societies pace themselves in a sensible manner, the religious nutjobs would throw every single resource their entire civilization could at getting into space to please their space deity or whatever. If there's an advanced space-faring race out there you probably want to steer clear of them.

      What makes you think "Star Trek like" societies are science-driven? Remember the Enterprise, in all its incarnations, is a military vessel.

      One of the revolutionary aspects of TOS is the purely scientific nature of their mission--they're not looking for a new home, they're not on the run from the law or some other force, they're out there just to see what's out there. But they (the crew from TOS and most every recurring character from all the other series) are members of the military.

    12. Re:First space-faring race = a bunch of nutjobs by cyberchondriac · · Score: 1

      See also: The Irkens from Invader Zim

      My Tallest!
      I'd do anything for them.

      --

      Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
    13. Re:First space-faring race = a bunch of nutjobs by tnk1 · · Score: 1

      And a Federation would need to have a good head start on an Imperialistic civilization because although it may well be more advanced and stable technically, it cares a little too much for the comfort of its own citizens to be able to match the single-minded approach of a civilization with a truly religious fervor to conquer. It would literally come down to hoping the imperialists became unstable as a society before they trashed the Federation.

      Hell, the only real threats to the Federation are usually put far, far away and they are only protected from their contact with them because the writers only throw one ship at them at a time, or the invaders are constrained to pass through a single, easily defensible wormhole. Even the writers are aware of this, because they show quite clearly that the Borg have run over many civilizations that are just as advanced as (or more so than) the Federation is, but they had the very bad luck to be the direct neighbors of the Borg.

    14. Re:First space-faring race = a bunch of nutjobs by tnk1 · · Score: 1

      There are always what-if situations, but I'd say that considering the current situation, Luther might have been worse for science than Rome ever was. The creationists are for instance, almost completely Protestants who believe in the literal interpretation of the Bible. The Catholic Church has always taken a much less literal, and much more sophisticated view of its own doctrine. The roots of science and humanism come, in part, from the Catholic recognition of the value of scholastic achievement and their care for the documents of the ancient world. A fundamentalist Protestant would be much, much more likely to state that the Bible is the only book you ever need to read, while Catholics like St. Augustine and Tomas Aquinas were trained in Classical learning, and were very receptive to Greek and Latin texts which represented the state of the art at the time.

      While there were incidents like that with Galileo, you will find people who oppose progress for just about any reason. Indeed, a chief reason that the Catholic Church was so sensitive to possible heresy was the very existence of a vigorous Protestant movement at that time. In short, its politics. There's nothing I have ever seen in the Bible or even Catholic doctrine that required that Galileo or Copernicus was wrong. Instead, it was the Church's love of the Greeks like Aristotle which informed their incorrect views on things like celestial spheres and the geocentric theory of the solar system.

      As far as defense goes, defense built the space program. Actually, to be honest, warmongering built the space program. Rocketry existed before WWII, but do you think you would have large, payload capable liquid-fueled ballistic rockets as soon as we did without Hitler wanting to bomb London? The defense program has actually turned over two Hubble telescopes to NASA recently. Yes, there is war and killing and 30,000 dollar toilet seats, but there is real money being put into space by the military as well. Possibly more than what is being budgeted by NASA. Defense may have a bigger budget than NASA, but part of that's because it is running its own space program in the defense department.

      What I don't think is that our development was an accident. The facts of nature are manifest. You can suppress people individually, even oppose ideas, but ideas that work will eventually be accepted simply because they are self-evident. Indeed, it may be a good idea in the long run, for even good ideas to have to fight for their very survival because that means that other, less useful ideas will as well. The good ideas will, eventually, win out, while the bad ones will fall into disuse by dint their own uselessness.

      Point being, don't take a black and white view of your bogeymen. You may not like the Catholics for their views on some issues, but the Enlightenment didn't appear out of nowhere and the place it hatched from was from Catholic Europe. Similarly, money spent on "defense" is hardly lost to research. Indeed, we might well have had a cure for baldness before we landed a man on the moon, if we didn't put ourselves in competition with Germany, Japan, and then the USSR militarily.

    15. Re:First space-faring race = a bunch of nutjobs by Mike+Buddha · · Score: 1

      Not true. We brought a bunch of rock back from the moon. That's not where the greatest benefits from that expedition came from. I'd surmise that insterstellar travel will give us some from column A, some from column B. Particularly if we find Eridium.

      --
      by Mike Buddha -- Someday the mountain might get him, but the law never will.
    16. Re:First space-faring race = a bunch of nutjobs by Mike+Buddha · · Score: 1

      When you see NASA asking for more funds to build a rocket to Mars, they don't say anything about how we embarrased the Reds, they talk about Velcro, Tang, and MRI machines.

      --
      by Mike Buddha -- Someday the mountain might get him, but the law never will.
  16. Re:You ain't seen me, right? by ByOhTek · · Score: 1

    Yeah, but remaining in a shroud of folded space-time that you couldn't enter, without the allowance of those inside, or be destroyed at the subatomic level, would be a much better solution, I think.

    --
    Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
  17. Efficiency by Anonymous Coward · · Score: 1

    If the civilization has achieved 100% energy efficiency, there would be no radiated heat, as that is simply wasteful.

    1. Re:Efficiency by confused+one · · Score: 3, Informative

      If the civilization has achieved 100% energy efficiency, there would be no radiated heat, as that is simply wasteful.

      Fundamental laws of physics apply, even if you're a technologically advanced civilization.

    2. Re:Efficiency by PerMolestiasEruditio · · Score: 1

      In this universe we obey the laws of thermodynamics, including the 2nd Law. There is no, and can be no 100% efficiency.

    3. Re:Efficiency by maxwell+demon · · Score: 1

      In this universe we obey the laws of thermodynamics, including the 2nd Law.

      I don't. :-)

      --
      The Tao of math: The numbers you can count are not the real numbers.
  18. Population growth by Tablizer · · Score: 1

    with population controlled at a reasonable level, which should be expected from any advanced civilization?

    It may not be politically "popular" for a given civilization to limit population growth. Imagine what the Republicans and Tea Party would do and say if somebody proposed government-enforced limits in the USA. And incentive programs are criticized as "poverty eugenics" by some on the left and "socialistic engineering" by some on the right.

    Thus, expansion via space colonies may be more palatable to such civilizations.

    1. Re:Population growth by the+gnat · · Score: 4, Insightful

      Imagine what the Republicans and Tea Party would do and say if somebody proposed government-enforced limits in the USA.

      Why pick on the Republicans here? I'm relatively liberal, and I know plenty of other liberals who would be just as outraged.

    2. Re:Population growth by GameboyRMH · · Score: 1

      I contend (above) that such a civilization would never reach the level of advancement necessary. They'll destroy themselves (either in one big spectacular event or by wasting resources/political will on war over the long term and "die in their cradle"), or deplete their planet's resources with no backup plan.

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    3. Re:Population growth by zlives · · Score: 1

      "expected from any advanced civilization"... we are not there yet

    4. Re:Population growth by GameboyRMH · · Score: 1

      Nope we sure aren't.

      --
      "When information is power, privacy is freedom" - Jah-Wren Ryel
    5. Re:Population growth by operagost · · Score: 1

      Who says that population has to be controlled by government? Population is controlled by other factors. "Control" just implies that the population size is steady; this could come about for biological or social reasons.

      --

      Gamingmuseum.com: Give your 3D accelerator a rest.
    6. Re:Population growth by tnk1 · · Score: 1

      A great deal of civilizations would have to all die and never reach that level of advancement, if we assume that alien civilizations are out there and relatively common. While it is impossible to know how many alien civilizations are out there, if there are any significant number, in billions of years, at least one has probably figured out a way to not destroy itself unless there was an extremely compelling reason why they would by default.

      This pessimistic viewpoint is based on our experience with nuclear weapons, climate change and resource shortages, but the reality is, even we haven't yet destroyed ourselves, or even come close, so assuming that all civilizations destroy themselves isn't even really based on any empirical data. Optimism is something that we do have the liberty of having at this point, at least until we come across the charred remains of hundreds and thousands of alien civilizations buried under piles of plastic.

    7. Re:Population growth by Quiet_Desperation · · Score: 1

      Yet we don't lack for people who feel comfortable psychologically profiling theoretical advanced civilizations. ;-)

      The moment someone says "An advanced alien civilization would..." I tune out.

      Unless it's Intended to be a work of fiction, of course.

    8. Re:Population growth by sycodon · · Score: 1

      I think that any reasonable person would recognize any imitative to limit population growth as an unjustifiable intrusion on the rights of the individual. Any successful program would require the State to employ armed force.

      See China.

      --
      When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
    9. Re:Population growth by readin · · Score: 1

      He wasn't picking on Republicans and the Tea Party, he was complimenting them. I'm glad to here there are some liberals who favor freedom too.

      --
      I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
    10. Re:Population growth by Tablizer · · Score: 1

      I wasn't complimenting them. I was just stating their likely reaction, without a value judgement attached to it.

    11. Re:Population growth by Tablizer · · Score: 1

      Natural selection will guarantee it will eventually grow if unchecked by either disaster/starvation or regulations.

  19. TFA is educated stupid by Thud457 · · Score: 4, Funny

    Dyson doesn't have spheres, Dyson has balls !

    But nothing sucks like an Elecrolux.

    --

    the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff

    1. Re:TFA is educated stupid by sociocapitalist · · Score: 1

      Balls are spheres...

      --
      blindly antisocialist = antisocial
  20. energy leakeage by demonbug · · Score: 3, Insightful

    If Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to see through our infrared telescopes. 'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright.

    Right, because there's no way a civilization advanced enough to build 282743338860000000 square kilometers of solar panels is going to be able to build solar panels capable of absorbing and using mid-infrared light (heat). If the supposition is that they inevitably build Dyson spheres to capture all of the available energy coming off their star, why would they let a whole bunch of it escape as heat?

    Seems like a giant waste of time and money, but I suppose they will be generating useful data while they look. Still, their chances of finding one are likely ludicrously close to zero even if one does exist. I also find the whole premise to be rather poorly thought out, I have to admit; even if a civilization is capable of building a Dyson sphere, I'm not sure it makes any sense to actually do it.

    1. Re:energy leakeage by Hentes · · Score: 4, Informative

      Energy can't be used for work, only energy difference can. If they didn't radiate away the captured sunlight they would overheat very quickly.

    2. Re:energy leakeage by Anonymous Coward · · Score: 1

      For us, this is true. For a civilization with the 50k years of scientific and engineering experience necessary to realistically embark on such a lofty project as a Dyson Sphere, probably not. Without some very fundamental refinements in our understanding of energy and the universe at large, a Dyson Sphere is simply impractical in every conceivable way.

    3. Re:energy leakeage by 0xdeadbeef · · Score: 1

      If the supposition is that they inevitably build Dyson spheres to capture all of the available energy coming off their star, why would they let a whole bunch of it escape as heat?

      Where does energy go after you've used it? You think that shit disappears?

      I also find the whole premise to be rather poorly thought out

      Well, then, write a paper on it. You'll have shown Freeman Dyson to be completely wrong, you'll be famous!

    4. Re:energy leakeage by LateArthurDent · · Score: 1

      Energy can't be used for work, only energy difference can. If they didn't radiate away the captured sunlight they would overheat very quickly.

      For us, this is true. For a civilization with the 50k years of scientific and engineering experience necessary to realistically embark on such a lofty project as a Dyson Sphere, probably not.

      Incorrect. It doesn't matter how advanced a civilization gets, they're not breaking the laws of physics. And this is one of those laws of physics that we are 100% sure we are correct. There is no way around thermodynamics, we are not wrong about it.

    5. Re:energy leakeage by LateArthurDent · · Score: 1

      Based on our observations of our very specific corner of the universe, over what amounts to an insignificant speck of time, viewing through a limited scope of technology that has been built in a hierarchical fashion upon possibly flawed assumptions about our reality. We've only been at this whole science thing, relative to modern physics, for a couple hundred years. It's presumptuous beyond reason to presume that we have a firm and unwavering grasp of the nature of energy that even fifty-thousand years of testing will not budge. To assert such is to sound like a flat-Earther.

      To be clear: it is entirely possible that we know everything there is to know about the nature of energy to the extent that our assumptions herein are effectively true, and all of our observations to date support that, but it is absurd to assume, given the historical record of science in general, that further refinements will not be made over a period of time orders of magnitude greater than we've even had this cute thing called "civilization" -- never mind "science".

      If you want to tell me that a sufficiently advanced civilization has faster than light drives and is capable of time-travel, I'm going to tell you, "that's highly unlikely, but possible." But no civilization absolutely anywhere regardless of how wondrous their science is has beaten the Carnot cycle. It's not arrogance or presumption. It's simple evidence. And to deny evidence is what a flat-Earther does.

      You can pull the whole, "we couldn't possibly have connected enough evidence card", but that's the equivalent of religion. Sure, I might not be able to prove your particular religion is wrong. But considering there's no evidence for it, to assume otherwise isn't scientific. Once I have evidence to the contrary, I'll change my mind on anything, but the evidence needs to come first.

    6. Re:energy leakeage by Nemyst · · Score: 1

      There are ways around our current vision, however. For instance, you could use a parallel universe as a giant heat tank, effectively nullifying the need to radiate it away.

      I know it sounds far-fetched, and that's because it is, but bear in mind quantum mechanics sounded positively insane when first introduced. Einstein worked for decades to show it was wrong (despite actually helping lay down its foundations), and he's one of the most brilliant scientists the world has ever known.

  21. Re:You ain't seen me, right? by Half-pint+HAL · · Score: 1

    I'm also confused as to how you can judge the likely frequency of light when you don't know what their building the friggin' thing out of. I mean, if they're advanced enough to collect and build the materials to make an inconceivably large solar array in space, maybe they'll be able to work out an even more efficient means of gathering light and reabsorbing any waste heat -- ie no leakage. (Heck, even a Sterling engine would be pretty efficient when there's a massive solar collector on one side and cold, black vacuum on the other.)

    --
    Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
  22. Pretty much impossible, IMHO by Khyber · · Score: 1

    Dyson Spheres are practically an impossible thing to build. First off, you'd need the energy to build such a system around the star. Secondly, you would need the MATERIALS (and even with Energy-Matter conversion tech, the issue again is energy.) Thirdly, you'd need the TIME.

    These three things have been against us for pretty much any project our species has ever attempted, and I would readily assume the same constraints would apply to other civilizations attempting a Dyson Sphere. Given the sheer scale of the project, I would have to say it is nigh impossible.

    --
    Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
    1. Re:Pretty much impossible, IMHO by Reschekle · · Score: 1

      Regarding time: I don't think you have to build the entire thing all at once. You could construct it over the course of centuries or millennia while still benefiting from the incremental energy output gains you achieve as the build is in progress.

    2. Re:Pretty much impossible, IMHO by wonkey_monkey · · Score: 1

      Given the sheer scale of the project, I would have to say it is nigh impossible.

      Which is exactly the sort of thing people would have said in the past of the Hoover Dam, or the Great Wall of China, or putting a man on the moon.

      These three things have been against us for pretty much any project our species has ever attempted

      And we overcome them all the time.

      --
      systemd is Roko's Basilisk.
    3. Re:Pretty much impossible, IMHO by FatLittleMonkey · · Score: 1

      A Dyson sphere (as opposed to a Dyson Shell) is a collection of free orbiting habitats. They can accumulate slowly, each one being immediately useful. You don't have to build the whole sphere at once.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
  23. Star Trek covered this by Anonymous Coward · · Score: 1

    If a civilization has the ability to construct a Dyson's Sphere they are probably so advanced they wouldn't need to construct it in the first place. (From Star Trek TNG, not a direct quote)

    1. Re:Star Trek covered this by WillAdams · · Score: 2

      Still didn't keep them from featuring one (see TNG:Relics w/ the James Doohan appearance):

      http://www.tor.com/blogs/2012/09/star-trek-the-next-generation-qrelicsq

      I still don't find the idea of a sphere workable:

        - you need to have artificial gravity to make it work or everything not bolted down falls into the sun
        - where do you get the material from? Dismantle several (dozen, hundred, thousand, million?) star systems?
        - what material could it be constructed of?

      Even a ringworld is pretty far-fetched (though it could be spun).

      The most believable space habitat I've seen in fiction thus far is Varley's Gaea (from his Titan/Wizard/Demon trilogy).

      --
      Sphinx of black quartz, judge my vow.
    2. Re:Star Trek covered this by catmistake · · Score: 1
  24. Errmmm... by Nevynxxx · · Score: 1

    'but it requires massive amounts of deliberate engineering across an entire civilization.'

    And a Dyson Sphere doesn't?

  25. Food for thought... by Troyusrex · · Score: 2
    The Templeton Foundation that funded this research is often highly criticized for religious bias. It's kind of like oil companies providing money for research. It might be good in that it provides research funding but there's always a worry that the money from an organization with a particular point of view might skew the science.

    I'm not saying that this invalidates the research, but it does cast some doubt on it and the reasons it is being done.

    1. Re:Food for thought... by MartinSchou · · Score: 1

      It's kind of like oil companies providing money for research. It might be good in that it provides research funding but there's always a worry that the money from an organization with a particular point of view might skew the science.

      Wouldn't it be cool, if there was a way for people and companies to donate money to a publicly run research fund, that any scientist can request funds from?

      No strings attached as to what they want to fund - just the ability to make a donation (possibly for a minor tax break?) along with a certificate of the date and size of the donation?

      Companies (and industry groups) can still do their own research, but they'll have a way to help fund fundamental research into things that aren't going to result in short term profits. Like CERN or stuff like that.

      Btw, just to put CERN into perspective, money wise.
      CERN's 2012 budget: 970 million Euro
      Expected cost of US 2012 presidential election: 4.6 billion Euro
      Total budget of the LHC: 7.5 billion Euro
      2012 Summer Olympics budget: 11.5 billion Euro
      Authorized TARP expenditure: 360 billion Euro

      Think about it.
      You could build 0.6 LHCs in the for the money poured into one single election.
      Or 1.5 LHCs for the cost of two weeks worth of sports entertainment.
      Or 48 LHCs for 1 TARP program. I'm pretty sure that if you were to start building something like that, you'd kick start the US economy like crazy! Seriously.

      Yes, I'm a bit of a fan of more funding for fundamental sciences, like what's being done at CERN - had you noticed? ;)

    2. Re:Food for thought... by kenorland · · Score: 1

      Funny, when right wing activists criticize research funding (oh, say, on climate change) as having a socialist and progressive bias, people call the people making the criticism anti-scientific. When left-wing activists criticize research funding as having a religious bias, the research funded by that is then itself called into question.

  26. Re:You ain't seen me, right? by h4rr4r · · Score: 2

    The cold black vacuum is not going to take a lot of heat. There are few particles for that heat to go to.

    While space itself is cold, it makes a very good insulator. So you might want to rethink that sterling engine.

  27. Re:If they have the tech to build it, do they need by Anonymous Coward · · Score: 1

    On a cosmological scale, there aren't power sources that are more efficient than a star. Maybe a different type of star, if so.

    OTOH many things are pretty inefficient on a cosmological scale. The suns energy outbut per cubic meter (Or cubic feet.) is on the same level as a compost. It's just so much larger. We can already build power sources way more efficient than the sun. We just can't do it on the same scale.

  28. Fusion Reactor by RichMan · · Score: 1

    Why wrap your world around a giant fusion reactor that requires a massive clearance space if you can make smaller more portable more mobile units?

  29. obviously they don't unstand TIMECUBE by Thud457 · · Score: 5, Insightful

    Against Stupidity, even the gods themselves labor in vain.


    lets see how many mods perceive the relevance to the reference

    --

    the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff

    1. Re:obviously they don't unstand TIMECUBE by Genda · · Score: 1

      Precisely the quote I was about to use. In the "Gods Themselves" Asimov speaks about an endless source of energy utilizing the flow of energy between a proto-universe at a higher energy state than ours and another ancient universe near heat death. There must be endless possible ways to step outside limits imposed by our presumptions of a closed universe. Each would present opportunities to harness immense energy.

      The presumption that an advanced civilization would emit energy anywhere but perhaps microwave seems unlikely. We are just now creating new materials capable of converting infrared into electricity. One would have to presume that an advances society would have designed the means to harness virtually every watt of useable power from its star.

      I'm not certain what civilization would mean to a society capable of a Dyson Sphere. As has been mentioned, there might only be one persona/identity. It might be very hard to distinguish a Dyson Sphere from a single stellar mass black hole. Perhaps the low energy emissions plus absorption spectra in a nebula? That little black body might just be visible in an emission nebula. Try looking there!

    2. Re:obviously they don't unstand TIMECUBE by b4dc0d3r · · Score: 1

      Too bad I can't moderate you "-1 Condescending Bag of Arseholes".

      You even admit to tossing out an oblique reference which people will most likely either recognize (and therefore it is redundant) or ignore (and therefore proves free of value).

      I would not have even bothered to mouse-over the link had Genda not summarize the relevant bits. I assume there are 3 or 4 people who both had mod points available and also are familiar with that work, and also enjoy being coy with answers just to see how many people understand what is effectively an inside joke, a shared secret about which you can maintain your smugness.

      Feel free to actually contribute next time, and find a circle of friends with whom you can play the game of who can find the most deceptively irrelevant comment.

  30. That Dyson is something else by Anonymous Coward · · Score: 1

    Never thought he could top that fan with no moving blades, but harnessing all of a star's energy output? Very cool.

    1. Re:That Dyson is something else by Overzeetop · · Score: 1

      If you think his vacuums are expensive, this is going to blow your mind.

      --
      Is it just my observation, or are there way too many stupid people in the world?
  31. Interesting, but for other reasons by larry+bagina · · Score: 2

    Dyson spheres are an interesting thought experiment but fairly stupid when you think about the logistics (as mentioned in previous comments, so I won't get into it). At least on our scale. Just as elctrons orbit the nucleus, moons orbit planets, planets order stars, stars orbit the galaxy center, galaxies orbit the giant turtle and form supergalxy clusters... There's no reason to say intelligent life composed of cells composed of molecules and atoms couldn't also exist at a larger scale. (Ask the symbiotic bacteria in your gut sometime). And intelligent life at a larger scale certainly could biuld a dyson sphere. Hell, maybe we are part of the dyson sphere.

    --
    Do you even lift?

    These aren't the 'roids you're looking for.

  32. Dyson Sphere: How useful is it? by scorp1us · · Score: 2

    Ok so somehow you get enough materials and energy to shape it into a sphere. That's an impossible task, but then it's somehow even more impossible that they use radiators to disperse the heat? I mean when you're talking about impossibility, it doesn't matter if it's squared or cubed. Then once you have this shell of solar collectors, how do you get the energy inside of it? You basically have a Faraday cage.

    Also, why the fuck? Any significantly advanced civilization would use gravitational engines. That is either under direct or natural control, they would set up a oscillation system between multiple orbiting bodies where they can harvest energy without needing fusion. Instead of lighting up the solar system, they'd go invisible, detectible only via gravity waves which to date, are impossible to detect. At a minimum, significantly harder to detect.

    --
    Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
    1. Re:Dyson Sphere: How useful is it? by Nethemas+the+Great · · Score: 1

      Have you not considered that the shell itself is an inhabitable surface and if such a surface were inhabited that that population would have the same or similar energy per-capita requirements as us peons hanging out on our ball of mud?

      --
      Two of my imaginary friends reproduced once ... with negative results.
  33. Silly waste of time. by Lumpy · · Score: 3, Interesting

    First off a dyson sphere does not take into account the MASSIVE amount of praticle energy that is coming off the star. the Stellar wind on that scale would be immense. Secondly, Orbits are not magical. a dyson sphere is unstable and will either wobble and start to collapse into the star, or rip apart due to the uneven gravity well. Just the technology to even be able to have the ability to think of building a Ringworld, something far, far, FAR easier than a Dyson sphere is so mind bogglingly compex that it collapses in upon it's self.

    Sorry but it's a waste of time we might as well look for civilizations that are harvesting black holes to power their space ships.

    --
    Do not look at laser with remaining good eye.
    1. Re:Silly waste of time. by camperdave · · Score: 1

      You just answered the second part of your question with the first part. The math tells us that the star would pull on the Dyson sphere equally no matter where it was within the sphere, so it would drift. However, the stellar wind would be pushing out on all parts of the sphere and would thus keep it centered around the star.

      --
      When our name is on the back of your car, we're behind you all the way!
    2. Re:Silly waste of time. by Ugmo · · Score: 1

      Even though shows like Star Trek show Dyson spheres to be a solid objects, Dyson originally meant it to be more like a sphericle cloud of technology that surrounds a star. The cloud could be made up of hollowed out asteroids or spacestations or nano-bots. All of these would intercept the energy from the local sun.If some leaked through between two space stations someone else would build a space station further out and intercept the overflow. There might be a high probability of collision, but the cloud will not fall into the sun in one piece.

    3. Re:Silly waste of time. by Lumpy · · Score: 1

      " The math tells us that the star would pull on the Dyson sphere equally"

      The math is wrong. Because no star is a perfectly symmetrical gravity well.

      --
      Do not look at laser with remaining good eye.
    4. Re:Silly waste of time. by Lumpy · · Score: 1

      "Are you assuming the sonar panels have to be continuous and connected?"

      Yes, because you have to constantly ping the enemy ships so their space torpedoes wont get us.

      --
      Do not look at laser with remaining good eye.
    5. Re:Silly waste of time. by Lumpy · · Score: 1

      There is not enough raw materials in a solar system to make a dyson sphere. Even if you completely consumed every planet, asteroid, comet, etc... so in order to build a dyson sphere you will need the tech for interstellar travel AND be able to cart back whole planets.

      Still think it's plausable?

      --
      Do not look at laser with remaining good eye.
    6. Re:Silly waste of time. by camperdave · · Score: 1

      No doubt the SphereBuilders would be able to compensate for any minor irregularities - perhaps even using the solar wind to do station keeping.

      --
      When our name is on the back of your car, we're behind you all the way!
    7. Re:Silly waste of time. by Nemyst · · Score: 1

      Harnessing the power of the atom was also mind-boggingly complex. Harnessing fusion power still is.

      That it is hard is no reason to avoid it, and people who make absolute predictions about the future tend to be absolutely wrong.

    8. Re:Silly waste of time. by BevanFindlay · · Score: 1

      It's been said, though this is Slashdot so why read before posting, :-) that Dyson's concept was more of a Dyson Swarm than a rigid sphere. A swarm of discrete orbitals is far more plausible than either a ring or a sphere.

  34. Disruptive bluffing by cellocgw · · Score: 4, Funny

    Quick! Let's build a giant IR emitter w/ some filters to produce the same spectral curve as a Dyson sphere. All those not-quite-advanced societies out there will detect it and run screaming from our perceived galactic-overlordishness.

    --
    https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
  35. Didn't someone run the numbers on this? by jayhawk88 · · Score: 1

    ...and determine that the energy requirement for building and maintaining even a partial Dyson Sphere was so astronomically high that even assuming 100% energy collection from the star, it would never be feasible to build?

    1. Re:Didn't someone run the numbers on this? by scorp1us · · Score: 1

      Someone needs to. This idea is ridiculous. From material availability to just figuring out that hey it's easier to go somewhere else, the idea is pure mental masturbation and not indicated by logic.

      --
      Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
  36. Still see light... by beaverdownunder · · Score: 1

    If we can assume that such a civilisation would still want sunlight to hit their planet, then any Dyson "sphere" would need to have a 'gap' around the plane of the inhabited planet. This wouldn't be perfect, and there would still be a bleed that would at distance be observable from any angle.

    Wouldn't this money be better served feeding starving kids in Africa? (Just sayin'...)

    1. Re:Still see light... by scarboni888 · · Score: 1

      I think the sphere would be larger than the orbit of the planet meaning the both the planet and the sun it orbits are inside that sphere.

      Therefore no gap is required unless there's some need to see stars or the outer plaents.

      Basically just a big door to let out the space ships now and again would do, I'm sure.

    2. Re:Still see light... by BevanFindlay · · Score: 1

      I have wondered: a Dyson "sphere" is more likely going to be a swarm, with lots of gaps, but gaps that change with time as they orbit. Seeing as this is how we usually detect exoplanets, I wonder what the resulting starlight would look like? Maybe we'd be better looking for that, or would it show up with current analysis of planet-finding data, or would the brightness changes be too small to detect?

      Also, there's no reason why you would leave the original planet intact - more reasons against than for, I would say (unless you're nostalgic).

  37. Dyson Sphere by Anonymous Coward · · Score: 3, Funny

    I don't understand this nonsense of astronomers searching the galaxy for Dyson Spheres. I had no trouble finding and buying one off Amazon. The design is revolutionary, and it's very powerful. It gets pet hairs out of my carpet with ease. Highly recommended!

  38. Re:If they have the tech to build it, do they need by Half-pint+HAL · · Score: 1

    Yes there are. Local fusion, because you collect it close to source, and at a controlled rate. You can't slow your star, and you're setting up the collectors a quarter of a light hour away.

    --
    Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
  39. Re:If they have the tech to build it, do they need by confused+one · · Score: 1

    Maybe. But maybe it takes so much energy to bring the other power sources to fruition that you need a massive source of energy to begin with; and, it's only worth the effort to power things like ships that need more compact energy sources.

    Taking a cue from science fiction: If I remember right, in Star Trek lore, the Federation gets it's supply of anti-matter from a particle accelerator built on a platform in close orbit of Sol. It extracts the energy necessary to run the process from the star. It's not efficient; so, the only place it's worth using is to power starships. They use more mundane methods to generate power for use on the planet surface.

  40. Why hiding? by gmuslera · · Score: 1

    IF what we already know about universe, in particular about speed limit, is true, they should not need to hide. The danger from inside their own solar system is far greater than the danger of invasion from outside it, in practice forever, unless you are talking about natural processes (i.e. a big asteroid/rogue star/whatever in collision course or a supernova close enough)

    IF there is one out there, then instead of hiding they probably will make it very evident, at the very least to tell us all "we did it, bitches"

  41. Re:If they have the tech to build it, do they need by PerMolestiasEruditio · · Score: 3, Interesting

    Small black holes are basically 100% efficient at turning mass into energy via Hawking Radiation, which is nearly two orders of magnitude more efficient than Stars powered by fusion.

    There are some serious suggestions as to how to go about making them (ultra powerful converging gamma ray lasers, as photons aren't subject to Pauli Exclusion Principle). While it probably requires a moon-sized machine to do it, it is probably feasible for a civilisation capable of building a Dyson sphere, and once you have that technology you don't need stars or the gravitational hassles that they create anymore.

  42. Wasted energy by morcego · · Score: 1

    So, let me get this straight. Said civilization is technologically advanced enough to build a Dyson sphere, but not to avoid energy leakage in heat form ? Sorry, I don't buy it. If they are starving for energy and have that kind of technology, why not convert that heat "exhaust" into thermal energy ?
     

    --
    morcego
  43. Re:You ain't seen me, right? by h4rr4r · · Score: 2

    That is why.
    Space is such a good insulator, that dissipating the heat from the crew and sunlight requires it.

  44. Why should a Dyson sphere be hard to build? by PeterM+from+Berkeley · · Score: 2

    Once you have self-replicating, "intelligent" machines to do the job?
    Assuming you could keep them interested in building your sphere, of course!

    You just create your first self-replicating solar-powered Dyson-sphere builder, and then sit back and watch it and its scions build for the next hundred million years or whatever. Or maybe nowhere near that long, assuming exponential growth (to some limit) of the builder-bots.

    Another example of the power of the Singularity?

    --PM

    1. Re:Why should a Dyson sphere be hard to build? by scorp1us · · Score: 1

      Rock is rare. Gas is common. You'll need to either gather materials from several other "nearby" solar systems, or use fusion to generate the materials yourself. Either way, it's energy intensive. Next calculate the energy required to process and shape the materials Of course there is a speed/energy tradeoff. Efficiency would say you process the materials near the sun then let it push the panels into position. A more energy intensive approach would be some other artificial source of energy, but if you have that, why bother?

      Even if you have to bother, why wouldn't you just go to another solar system and transform that. I'm going to say that terraforming is loads less energy intensive than building a shell around a solar system.

      I have no idea why Dyson Spheres get the traction they do. It's rather inefficient.

      --
      Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
  45. Manipulating energy instead of matter by Guru80 · · Score: 2

    What if at a certain point in evolution and understanding the world around you and the universe you discover that instead of manipulating matter, which consumes vast amounts of energy, that it's possible to manipulate energy itself which (theoretically) would require no more energy than what is already present around us. Instead of building vast energy gathering complexes you can for all intents and purposes manipulate what's already in abundance for civilizations advantage. All of a sudden faster than light travel isn't an impossibility but likely and taken for granted in as much as we take hoping on an airplane.

  46. Re:If they have the tech to build it, do they need by thereitis · · Score: 1
    What would all that energy even be used for? I would think that 'getting somewhere else' would be in the top 5, but how would you even store that kind of energy if not in the form of the star itself?

    On a different note, is it conceivable that the energy could be simply deflected (instead of harnessed into electricity) and be useful?

  47. Dyson Spheres? by Beorytis · · Score: 1

    That's a relief. At first I thought you meant they were searching for alien Dyson Balls.

  48. Dyson signals by WaffleMonster · · Score: 1

    Or maybe they all have Mr Fusions and are quite happy to scoop up hydrogen by splitting water, mineing other planets, asteroids... or sucking it out of the ISM.

    With all this talk about energy what if instead of a sphere of solar collectors it were an array of gyro mirrors which could be controlled in such a way apparent luminocity changes slightly yet enough for a signal to be broadcasted over massive distances?

    This seems like a more pluasable and exciting idea to me than having to deal with collection and distribution of energy. After all Mr Fusion may prove to be much more convinent than solar arrays especially if there is any significant interplanetary traffic between terraformed worlds.

  49. Do you mean that up till now by joeflies · · Score: 1

    Astronomers weren't lookin for large sources of energy?

  50. Re:If they have the tech to build it, do they need by thereitis · · Score: 1

    It's huge but look at the difference in density (from Wikipedia):

    Average density of the Sun: 1.408×10^3 kg/m^3

    Average density of YV Canis Majoris: 0.000005 to 0.000010 kg/m^3, the star is a thousand times less dense than the atmosphere of the Earth (air) at sea level.

  51. Re:You ain't seen me, right? by jamstar7 · · Score: 3, Interesting

    Been written about. Course, Zahn didn't come up with any conclusions why the Spinneret aliens were hiding, just that they were.

    Makes me wonder if some civilisations are hiding, and what they're hiding from.

    --
    Understanding the scope of the problem is the first step on the path to true panic.
  52. Other civilisation may not be mamals by aepervius · · Score: 1

    Or even if they are mamals they may not be organised around individuals. See if you have a colony with a central queen/king as reproducing organs and a lot of worker, then reproduction limitation are much much easier. A civilisation with such a central reproduction would not need to go for a dyson sphere, it could simply limit itself in population , redirect project in a much better way we individual do, and not need all the distraction we need.

    --
    C. Sagan : A demon haunted world:
    http://www.amazon.com/gp/product/0345409469/
    visit randi.org
    1. Re:Other civilisation may not be mamals by Lord+Lode · · Score: 1

      They won't mammals, but also not reptiles, insects, birds, amphibia, fishes or anything else we know. Because, those are the things that happened to evolve on our particular planet, but what would evolve on another planet could be anything randomly different and probably would have a completely different path where different terminology than "mammal" and "reptile" would be needed.

  53. Counterpoint by aepervius · · Score: 1

    The energy investment for a dyson spehre is many order of magnitude above a fusion reactor, and you can make up as many reactor as you may need. How much energy do an individual need to live in comfort ? At some point you do not need much more. So the only factor really requiring a lot of energy is that they may not be able to stop reproduction. But at least our ci shows that when people go live in comfort they don't need to procreate that much.

    --
    C. Sagan : A demon haunted world:
    http://www.amazon.com/gp/product/0345409469/
    visit randi.org
    1. Re:Counterpoint by HeckRuler · · Score: 1

      Ok, as long as I have more comfort than the next guy.

  54. Materials by gerardrj · · Score: 1

    Where would all the material come from?

    That's a lot of "stuff" to build a structure to basically encircle a star. I've venture to say it would take more physical material than comprises most habitable planets.

    --
    Article X: The powers not delegated... by the Constitution...are reserved...to the people
  55. Has anyone bothered to.. by Paracelcus · · Score: 1

    Has anyone bothered to calculate + or - X the mass of a Dyson sphere? Even a ringworld would require the consumption (IMHO) of a solar system (or two).

    The idea makes for fun scifi but it's just rediculous to think that anything like this could exist.

    Very, very advanced civilizations may have FTL travel, but they also may live in log cabins and ride horse analogs.

    --
    I killed da wabbit -Elmer Fudd
  56. The Templeton Foundation by Forty+Two+Tenfold · · Score: 2

    The Templeton Foundation rewards answers that involve religion. I don't trust who funds this search, I don't trust the results.

    --
    Upward mobility is a slippery slope - the higher you climb the more you show your ass.
    1. Re:The Templeton Foundation by gandhi_2 · · Score: 5, Insightful

      The Nazis got us into space. The military industrial complex got us the internet. War gave us most of our trama medicine.

      But you take issue with this one, huh?

    2. Re:The Templeton Foundation by trooper9 · · Score: 1

      Damn. I wish I had mod points.

      --
      blah
    3. Re:The Templeton Foundation by Holmwood · · Score: 1

      /boggle. Well, no, they don't. You might try reading about them. But leaving that aside, irrational skepticism is your privilege, but the beauty of real science is that it's replicable and falsifiable. In the highly unlikely event that these scientists lie about a discovery, anyone with access to decent mid-infrared instrumentation will be able to verify it's false.

    4. Re:The Templeton Foundation by Forty+Two+Tenfold · · Score: 1

      Well, yes, they do. You might try reading about their signature program, the Templeton Prize, who gets it and for what. And think for a bit, why are they supporting this useless search.

      --
      Upward mobility is a slippery slope - the higher you climb the more you show your ass.
    5. Re:The Templeton Foundation by Forty+Two+Tenfold · · Score: 1

      The Nazis got us into space. The military industrial complex got us the internet. War gave us most of our trama medicine.

      But you take issue with this one, huh?

      Exactly. Look what the worst things in the world got us - useful things and discoveries. The Templeton F. wants to get us - what?

      --
      Upward mobility is a slippery slope - the higher you climb the more you show your ass.
  57. Re:You ain't seen me, right? by Artifakt · · Score: 1

    99% of Dyson sphere builders build a normal model and within a few aeons get eaten by the uberborg/guardians of the inorganic/hounds of tindalos. 1% of dyson sphere builders are paranoids from the beginning and devot trememdous extra resources to hiding their emissions, and so live. And then, since they are paranoids fron the beginning, invent their own species of world harvesters to wipe out the potential threat of new dyson sphere level cultures. Space constantly gets more dangerous with wave after wave of new harvesters being released, for anyone will tell you, paranoids lash out at their perceived threats.

    --
    Who is John Cabal?
  58. Fleet of Worlds by ThatsNotPudding · · Score: 1

    I hope they also keep a look out for Rosettes http://en.wikipedia.org/wiki/Klemperer_rosette too.

  59. Wouldn't they radiate to some hilbert space? by gestalt_n_pepper · · Score: 1

    To get more bang for the buck via a higher energy differential? We might not see any infrared at all. We might as well look for a circular area of complete absence or radiation of any sort.

    --
    Please do not read this sig. Thank you.
  60. First space-faring race = a bunch of locusts by FatLittleMonkey · · Score: 1

    The first colonies of the first civilisation will develop at various rates, some faster and some slower. If those colonies eventually colonise another wave, it will be the fastest, most aggressive developers that get the prime destinations. And of the second wave, it will be the fastest most aggressive colonies that seed the third wave, with the slower developers falling further and further behind as the waves of colonisation expand.

    After ten of so generations of colonies, the things will be expanding as fast as technology allows, burning through the galaxy like a wildfire.

    [This is the plot that ID4 should have used to explain the "locusts". Both making a stupid story more logical (coz it also explains the weak security), and ending the movie on a more poignant note, as Goldblum's character pisses on their celebrations by explaining that this is just the first wave, in a decade or a century there will be another ship, and another after that, arriving faster and faster, and they will never stop coming.]

    --
    Science is all about firing a drunk pig out of a cannon just to see what happens.
  61. Why not a RingWorld by rossdee · · Score: 2

    A ringworld is a lot easier to build than a Dyson Sphere, you could do it with the material from one solar system. And you can spin it for gravity.
    For a dydson sphere you need to invent some sort of artificial gravity (even a sphere made of a thin layer of neutronium isnt going to work

    Books to read:
    Orbitsville , Orbitsville Deoarture by Bob Shaw

    Ringworkd , Ringworld Engineers, Ringworld Throne by Larry Niven

    Anyway a Dyson Sphere is an example of a type 2 civilization (one that utilizes the entire resources of its star
    A type 1 civilization utilizes the entire resources of its planet and we have only scratched the surface of this one - just think how many zigawatt millenia of energy lies in the molten rock just a hundred km below your feet and all the way to the core

  62. Re:If they have the tech to build it, do they need by Hatta · · Score: 1

    Vacuum energy? Apparently about 3/4 of the energy of the universe is vacuum energy. If you could consume space itself to produce energy, you might even be able to delay the heat death of the expanding universe.

    --
    Give me Classic Slashdot or give me death!
  63. Re:If they have the tech to build it, do they need by camperdave · · Score: 3, Insightful

    We build taller and taller skyscrapers. Why? There are more efficient structures, and it's not like they are there to harvest resources unavailable at ground level. Besides, some peasant can build a mountainside hut that is at a higher altitude than the highest skyscraper. So, maybe it's not about the energy. Maybe it's a statement of prowess, or art.

    --
    When our name is on the back of your car, we're behind you all the way!
  64. sustainability by Chirs · · Score: 3, Insightful

    We cannot (given current understanding and resource consumption patters) maintain the current population of the planet indefinitely.

    1. Re:sustainability by svick · · Score: 2

      Why not? What's the limiting factor (assuming sufficiently advanced technology)? Energy? Certainly not, with fusion. Freshwater? That's not it either, because with cheap fusion energy you can make it out of seawater. Food? I don't think so, making food doesn't have to deplete any resources.

      Is using fossil fuels, depleting aquifers and salinizating soil sustainable? No, but that's not the only way. I don't see why having something like 10 billion people shouldn't be sustainable for a very long time.

    2. Re:sustainability by gottabeme · · Score: 2

      From where did you obtain your data?

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
  65. Re:You ain't seen me, right? by codesmithe · · Score: 1

    Actually, my "Dyson Animal" gets pretty warm after a a while. And it's more purple than black.

  66. Advances Civs will be Virtual by Baron+von+Daren · · Score: 1

    A Dyson Sphere is a largely ludicrous concept, and it did not anticipate virtual reality. By the time a civilization has the wide array of capabilities required to create anything approaching a Dyson Sphere, such a construct would long since be superfluous. I won’t go into all the reasons a Dyson Sphere is logistically unrealistic, other have already done this.

    The most realistic trajectory for any species is to eventual stop expanding into real space and transition to virtual space. Most advanced species will eventually evolve from biological organisms into technological organisms. Computational capability does require a high power density, but the power efficiency gains realized by the transition from real space to virtual space are staggering. In other words, the amount of raw power needed to sustain a highly advanced virtual civilization, with relatively limitless ‘space’ to expand is minuscule compared to the raw power needs of a civilization that needs lots of physical space, atmosphere, food, clothing, houses, leisure space, large scale transportation, etc, etc., etc. etc.

    Any truly advanced civ will have a very limited physical footprint because they will be largely virtual. Even if a virtual civ wishes to continue exploring the 'real' world, the amount of power needed to move a computational system and some robotic or android 'physical avatars' around and sustain them is, again, minuscule compared to sustaining biological bodies and moving them around. Power needs will still be high, due to the power density of computation, but it will be very manageable. Couple these lower power needs with advances in efficacy (which have generally followed Moore’s Law) and you simply do not need to expend the tremendous effort required to construct a monstrosity like a Dyson Sphere.

    Sure, there may be something that prevents civs from going virtual (like the soul), but as yet there is no empirical reason to believe this is the case.

  67. Re:If they have the tech to build it, do they need by MobyDisk · · Score: 1

    I wish people would stop debating speculative statements like "If someone knows a thousand times what I know, and is a billion times more advanced, having technology I could not imagine, then ..." The premise of the statement prevents any possible conclusion.

    The best we can do is say "Given the limitations that we believe apply to the universe, what would we do?"

  68. Get over it by Snaller · · Score: 1

    WE are the first ones, sad but true - now stop wasting money looking at the stars and build a ship instead.

    --
    If Google really cared they would fix Android Chrome to reflow text, instead of discriminating
  69. Think outside the box by Roger+W+Moore · · Score: 1

    There is no reason to believe that the second law of thermodynamics can be violated, and overwhelming evidence that it cannot.

    True but within what we already know it is entirely possible to imagine that you could dump your low grade heat "invisibly" without violating thermodynamics. For example suppose you dump it into neutrinos or perhaps Dark Matter or Dark Energy if you want to be more exotic. I don't see any reason why this would be forbidden but equally I see no way that we could achieve it because the neutrino coupling to matter is incredibly small unless you go to extremely high energy. So I would rate it as highly improbable (given our current understanding) but by no means impossible.

  70. Spheres are not practical at that scale by nurb432 · · Score: 1

    However, a ribbon ( or a ring, if you like ) would be.

    --
    ---- Booth was a patriot ----
    1. Re:Spheres are not practical at that scale by iggymanz · · Score: 1

      That really would be included in the notion of a "dyson sphere", not a literal solid sphere but many many orbiting things that effectively catch most the energy of the system's star

  71. basic laws of reality will still apply by nurb432 · · Score: 1

    Who's laws? Ours? Theirs? Some humanoid caveman? A dolphin?

    To think we know all of reality is absurd. We only know a small part of what is going on in the universe. Not only that we could easily be running on a false assumption/observation that would completely break down every law of physics we think we know.

    We have not been around all that long, we are NOT experts.

    --
    ---- Booth was a patriot ----
  72. Let me hope.... by alexo · · Score: 1

    They'll find nothing.

    I'd rather not be exterminated just yet.

  73. Star Trek TNG by Laebshade · · Score: 1

    First thing I thought of: http://www.youtube.com/watch?v=ECLvFLkvY7Y

  74. Best quote from a scientist evah! by braindrainbahrain · · Score: 1

    "It's strange to write a serious research proposal and have half of your bibliography be science fiction."

  75. Sci-Fi vs. Sci-Fact by Laserfuzz · · Score: 1

    If they had the technology to build Dyson Sphere they would also know that their parent star won't last forever making the build a complete waste of time and resources. As someone else stated if they follow Darwinian evolution and wanted to grow and spread out then they would simple leave their system for another one. Again if they had the tech to build it they could leave way easier and cheaper. (Time and resource wise)

    1. Re:Sci-Fi vs. Sci-Fact by DirtyLiar · · Score: 1

      If they had the technology to build Dyson Sphere they would also know that their parent star won't last forever making the build a complete waste of time and resources. As someone else stated if they follow Darwinian evolution and wanted to grow and spread out then they would simple leave their system for another one. Again if they had the tech to build it they could leave way easier and cheaper. (Time and resource wise)

      Actually, just because they built a Dyson Sphere, does not necessarily mean that they have turned their back on the Universe. Maybe they are just "hive" based, and prefer to be in close proximity to their "homeworld".

      Besides, they could always build multiple sphere's, and / or use their sphere to channel, redirect and amplify the solar-wind (or use some other unknown technology, since that's what we're dealing with here) to create thrust, allowing them to move their spheres.

      In my "experience" (reading copious amounts of sci-fi), sphere dwellers are ancient civilizations that actually have turned their backs on the greater universe, despite my earlier comment, and are no longer interested in spacial expansion, preferring to contemplate what they have already learned and accomplished.

      --

      THINK! It's patriotic

  76. nonsense by kenorland · · Score: 1

    At its heart, thermodynamics is nothing more than the assumption that certain processes are fundamentally random and unpredictable, an assumption about symmetry. These symmetries may well turn out to be broken by processes that we haven't observed yet, for example on a cosmic scale.

    Even with existing physics, there are lots of things they could potentially do that would look like a violation of thermodynamics to us (even though it isn't): use a black hole, use a wormhole, radiate the heat in a tight beam, use neutrino cooling, or maybe even cool with dark matter.

  77. Dyson ran the numbers by kenorland · · Score: 1

    Dyson ran the numbers:

    A solid shell or ring surrounding a star is mechanically impossible. The form of 'biosphere' which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star

    Such a "Dyson sphere" would grow naturally and incrementally, and it doesn't require any unusual materials.

  78. Presuppositions by gottabeme · · Score: 3, Insightful

    You build a box and try to fit God inside it. When he doesn't fit, you conclude he doesn't exist. The irony is that God created the one who created the box in which God does not fit. I find that you are not even aware of your own presuppositions, therefore you cannot reach a reasonable conclusion. You have been so heavily influenced by atheists and scientism (which is practically worshipped as a religion unto itself) that you have confined your own thinking to a box which you are unwilling to exit, and perhaps even unaware of.

    1. You presuppose that if God acts on a prayer, it indicates that he was previously unaware of something.
    2. You presuppose that if God is all-knowing and good that he must necessarily enforce what is best for people.
    3. You presuppose that, as a finite, relatively insignificant human being, you could possibly know whether and when God intercedes in our world and to what ends.
    4. You presuppose that you could even know what is "good" or "best" from the perspective of an all-knowing, all-powerful, universe-creating, life-breathing entity beyond our comprehension.

    Your conclusion ("Therefore we find that an all-knowing and good god cannot be influenced by prayers...") is a non sequitur. It's not even a logical conclusion from your assertions. And your assertions are unsubstantiated, anyway.

    The very nature of an omnipotent, omniscient entity who exists outside of our plane of existence means that we cannot completely comprehend him; we may only do so to the extent he chooses to reveal himself to us. What you have done is set forth arbitrary specifications for God, and if it seems to you that he does not meet your criteria, you conclude that he must not exist. This is nothing short of absurd. If God exists outside of or above our universe, if he created you and the universe and the very nature of our existence, how could you possibly define the means by which he may exist?

    N.B. I am not even arguing that God does exist--I'm simply arguing that your logic is fundamentally flawed because of your presuppositions. Either God is an all-powerful, all-knowing entity--and therefore beyond our comprehension--or he is finite, like us, but with advanced technology--and therefore, presumably, ultimately understandable--or he does not exist at all. If you are arguing based on the presupposition that he is all-powerful and all-knowing, then you must argue that he is far beyond any of your reasoning or standards, and therefore you cannot logically define criteria for proving his existence.

    The argument boils down to whether anything can exist beyond our understanding or comprehension: if we can comprehend God, then nothing is ultimately beyond our understanding, and--eventually, perhaps far beyond our lifetimes--we can "find" him, understand him, and even possess similar powers (note that this implies being able to create an entire universe of our own, from nothing). In this case, it's simply a matter of time until he is "discovered"--until then, he either does not exist or we have yet to find him (a conclusion which does not answer the questions, "How?", "Why?", and "From what?"). But on the other hand, if things may exist beyond our understanding, then we can never expect to meet God on our terms, and trying to do so is naive and futile.

    I like the fishbowl analogy. (It's not perfect, of course.) The fish's entire universe is inside his fishbowl. He knows nothing outside of it (perhaps it would be useful to declare the fishbowl to be opaque, or at least barely translucent). Now and then something from outside his universe seems to interact with his world--perhaps a hand reaches in, but he cannot discern the source of the hand. The fish cannot comprehend existence outside of his bowl, or outside of water, the very fabric of his existence. Therefore, to him, nothing must exist outside of his world, and nothing must exist outside of water--which, to him, isn't even water, just reality as he knows it. But to the human, clearly the fish is limited

    --
    "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    1. Re:Presuppositions by gottabeme · · Score: 2

      You're really going to play it like that? After what you said--which certainly does imply that you believe God doesn't exist--you expect me to believe that you do believe in God? What god do you believe in?

      Or are you just using the "you can't even comprehend what I say" excuse to avoid having a discussion? (The condescension was a nice touch, by the way.)

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    2. Re:Presuppositions by maxwell+demon · · Score: 1

      No, what I wrote neither implies that god exists nor that god doesn't exist. It does not make any statement about the existence or non-existence of god. I don't want you tho think that I believe in god, nor do I want you to think that I don't believe in god. Indeed, I don't care whether you think that I believe in god.

      But given that you are obviously not able to understand what I write, I guess it doesn't make any sense to add any further explanations.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    3. Re:Presuppositions by b4dc0d3r · · Score: 3, Informative

      You did not read the post before asking gottabeme to read yours. The post began with an illustration of assumptions being made, then listed your assumptions.

      If I pray for something and it does not happen, that does not mean my prayers were not answered. Or if I think about something without praying and my non-prayer does not appear to be answered, that does not mean it wasn't. My prayer, combined with that of others, may result in a situation in which it is not obvious to me that my prayer, or non-prayer, was even considered.

      A kid finds a lamp, rubs it to shine it up a bit, and out pops the Genie.
      The genie grants him one wish.
      The kid says "I want to be Batman." So the Genie kills the kid's parents.

      Was his request granted, and does the kid see that his request was granted?

      We don't have the first clue what an alien civilization might do. We may have found one which is desperately trying to communicate with us but we just don't know it. We have a thought experiment by Dyson which is attempting to solve the problem by extrapolating from a string of assumptions which statistically speaking are probably increasingly invalid. The same flaw you made in your post. We may never find aliens, because they may not want to be found, and we almost certainly will never find God because he requires faith, not proof.

    4. Re:Presuppositions by gottabeme · · Score: 2

      No, what I wrote neither implies that god exists nor that god doesn't exist. It does not make any statement about the existence or non-existence of god.

      I can read between the lines. If I'm wrong, please enlighten me. Or are you simply unwilling to admit that you're more transparent than you like?

      I don't want you tho think that I believe in god, nor do I want you to think that I don't believe in god. Indeed, I don't care whether you think that I believe in god.

      What you're trying to say is, "I don't want to talk about it." What I don't understand is why you don't simply say that. And I'm curious as to why not. But the fact that you literally don't care simply reveals again that you don't believe in God. So why not just say so? Why the games?

      But given that you are obviously not able to understand what I write, I guess it doesn't make any sense to add any further explanations.

      I understand the literal meaning of your words just fine. But that's not as interesting or meaningful--or as important--as what lies behind them. You're not as mysterious as you'd like to think.

      It's a bit ironic, though: you claim I don't understand you, but you clearly don't understand the points I'm trying to make.

      --
      "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
    5. Re:Presuppositions by steppedleader · · Score: 1

      1. You presuppose that if God acts on a prayer, it indicates that he was previously unaware of something.

      Umm, no, he didn't. He simply said if God is unaware of something until someone prays, he is not all knowing. If God is ever unaware of anything, he is not omniscient. That seems pretty basic. To say otherwise is to render the words all-knowing and omniscient meaningless.

      2. You presuppose that if God is all-knowing and good that he must necessarily enforce what is best for people.

      Where did he imply any such thing? If God is all-good, he must only do good, whether or not anyone asks him to. How such actions relate to people isn't necessarily relevant to whether or not they are good.

      3. You presuppose that, as a finite, relatively insignificant human being, you could possibly know whether and when God intercedes in our world and to what ends.

      No, he just used basic logic. If God is not bound by that, he is incomprehensible in a way that would leave us unable to know anything at all about him, so any argument about God would be as silly as an argument about whether or not 1 is the same as 2. Also, if God is not bound by logic, I'm curious how you resolve the question of whether or not God can create a mountain so heavy that he cannot move it. The traditional resolution of that paradox is to say that such a thing is logically impossible, and while omnipotence would allow God to do anything that is possible, it would not allow him to do the impossible. Do you have a resolution every other philosopher and theologian has missed?

      4. You presuppose that you could even know what is "good" or "best" from the perspective of an all-knowing, all-powerful, universe-creating, life-breathing entity beyond our comprehension.

      Once again, he neither said nor implied any such thing.

      The GP poster never claimed his argument disproved the existence of God in general, just a God with very specific characteristics. He didn't even imply that prayer was useless -- he explicitly allowed for the possibility of it having psychological effects on the person praying, a la meditation.

      His argument showed one thing, and one thing only: That if God is all-knowing and all-good then his will and his actions cannot be influenced by prayer. That doesn't mean God is nonexistent, and it doesn't mean prayer can't have effects on the person praying, it just means that if someone can influence God's actions via prayer, either God is not all-knowing, or he is not all-good. His point was this: Since religions such as Christianity teach that God is, in fact, both all-knowing and all-good, people who believe that such a God both has those characteristics and can be influenced by prayer are misunderstanding their own religion.

    6. Re:Presuppositions by steppedleader · · Score: 1

      A small addendum: There is actually one logical way that an all-knowing, all-good God could be influenced by prayer: If what is prayed for is strictly neutral morally. I don't know if many prayers asking for things fit that criteria, though.

  79. What is love? by gottabeme · · Score: 1

    The emotional feeling is one thing. But what about this kind of love?

    "For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous personâ"though perhaps for a good person one would dare even to dieâ"but God shows his love for us in that while we were still sinners, Christ died for us."

    "By this we know love, that he laid down his life for us, and we ought to lay down our lives for the brothers."

    That kind of love doesn't propagate any genes. It makes no sense from a Darwinian perspective.

    --
    "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
  80. Mod parent up by gottabeme · · Score: 1

    This deserves to be modded up.

    --
    "Those who consume the bulk of goods are those who make them. We must never forget this secret of our prosperity."
  81. Re:That may be inordinately difficult by Altus · · Score: 1

    By the effect of a huge amount of matter on the light around it.

    Distingishing it from a black hole is an exercise for better physicists than I.

    --

    "In America, first you get the sugar, then you get the power, then you get the women..." -H. Simpson

  82. Re:You ain't seen me, right? by Half-pint+HAL · · Score: 1

    Have you not heard of subatomic thermo-fissional macro theory? Thermal concretisation by quantum friandisation of bendy quark string polarisation? Heat-induced temporal flux? Well neither have I, but the aliens may well have.

    --
    Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
  83. Flawed Premise by DirtyLiar · · Score: 1

    'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright.

    Any engineer will tell you that waste heat is energy lost.

    I can't imagine that a civilization with the technology to tear enough solar systems apart, move all the material to one location, and build a Dyson Sphere would find it impossible or inconvenient to capture that waste heat and turn it back into energy before it escapes into space. (Any sphere that does not capture all of the central sun's radiant energy is inefficient.)

    As as we have found out, there is always something you can use more electricity on.

    --

    THINK! It's patriotic

  84. intergalactic civilizations by Cristian+Chidesa · · Score: 1

    It is extremely difficult to imagine how it would look a civilization far more technologically advanced than our own. Such an advanced civilization could produce its own energy from nuclear fusion or might be able to extract energy from the vacuum, they would have total control of gravity (they could create artificial gravity), so they could build artificial worlds not related to a solar system, artificial worlds that would perfectly "work" in the vast space between galaxies where there is no danger of cosmic collisions, black holes, supernovae, etc.

  85. Unstable by szo · · Score: 1

    When I was a physics student, we had a joke about this:
    - How do recognise a Dyson Sphere?
    - It has a star-sized hole on the side.

    --
    Red Leader Standing By!
  86. But then we would.... by hesaigo999ca · · Score: 1

    Bu t then we would have proof we are no longer alone in the universe and all religions that base God to be centered around the earth and no where else, might have to perish, no?

  87. Ah assumption by RubberDogBone · · Score: 1

    The problem with the Dyson Sphere concept is that it assumes there is no other sufficient source of energy, largely because humans haven't invented one.

    Barely over a hundred years ago, we hadn't invented the airplane or helicopter or nuclear power plants in Tsunami zones, or iPads. Yet these things exist now and humans invented them.

    By assuming that we know best and there is no other possible better source of energy, we're basically saying it cannot be done. The problem is we have a really bad track record in that area of not know what the hell we are talking about, much less what aliens might do.

    We invent. We should assume aliens will also invent.

    Now, it will be interesting someday if humans and aliens finally do meet up and we find out they have invented something we also have. The iPad of that era, just for example. We don't have any room for such a thing in our IP laws so the standard lawsuits would fly. And it would be fun to watch the first human IP lawyer try to serve G'Gurat with a suit over bezel design and rows of icons. Especially if G'Gurat is hungry that cycle.

    --
    Sig for hire.