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Far Future Will See No Evidence of Universe's Origin

Posted by Zonk on from the man-that-is-a-cheery-thought dept.

Dr. Eggman writes "According to an article on Ars Technica and its accompanying General Relativity and Gravitation journal article 'The Return of a Static Universe and the End of Cosmology', in the far future of the universe all evidence of the origin of the universe will be gone. Intelligences alive 100-billion-years from now will observe a universe that appears much the way our early 1900s view of the universe was: Static, had always been there, and consisted of little more than our own galaxy and a islands of matter. 'The cosmic microwave background, which has provided our most detailed understanding of the Big Bang, will also be gone. Its wavelength will have been shifted to a full meter, and its intensity will drop by 12 orders of magnitude. Even before then, however, the frequency will reach that of the interstellar plasma and be buried in the noise--the stuff of the universe itself will mask the evidence of its origin. Other evidence for the Big Bang comes from the amount of deuterium and helium isotopes in the universe.'"

50 of 340 comments (clear)

  1. But even worse by catbutt · · Score: 5, Funny

    by then, we'll be dead, which seems like the bigger problem.

    1. Re:But even worse by ushering05401 · · Score: 5, Insightful

      Nah, the bigger problem would seem to be that as far as we know we are the only sentients capable of taking advantage of the information currently available... which places a huge responsiblity on our shoulders.

      If the far future will see an absence of this information then we have a responsibility to persist the data beyond the demise of our culture, whether or not another civilization will arise that can interpret the data. The information we can gather now would appear to be a limited resource given our current understanding of cosmology, and we who have access should derive what we can and pass the value on as others will not be able to do so.

      Can you imagine the ID vs Evolution argument in an apparently static universe? Oh wait.. just pick up a history book and check out the executions, exiles, pariahs, and all the other fun stuff that happened to/became of our scientific forefathers back when the Earth was considered the center of a static universe.

      Regards.

    2. Re:But even worse by Anonymous Coward · · Score: 2, Funny

      At that point you must subscribe to the "We are all gods" view of human potential.

      Maybe he's a Mormon? :-)

    3. Re:But even worse by The+One+and+Only · · Score: 5, Insightful

      But here's an interesting question--if documents were discovered from some ancient civilization that had a completely different cosmology, describing that cosmology, would you take those documents at face value? Suppose they contained measurements and recorded observations, as well as a prediction that future observations would differ in a certain way. I'm not sure the far future would believe us, so we would have some convincing to do.

      The upside is, the people of the future can believe in a static universe, and insofar as their universe is compatible with that hypothesis, they're no worse off for not knowing the truth. If it turns out that the universe's origin does make a difference to them, there will no doubt be some observations that don't correspond with their static universe hypothesis, forcing them to adopt a hypothesis similar to ours. So by preserving our data and our theory we are indeed providing a possible solution to a future scientific problem.

      --
      In Repressive Burma, it's not just your connection that dies. slashdot.org/comments.pl?sid=314547&cid=20819199
    4. Re:But even worse by ushering05401 · · Score: 2, Interesting

      Funniest thing about these possibilities is that our descendants may still persist in some form.. and in that case, rediscovering the little cache of info their ancestors left behind could easily (and correctly) be interpreted as communication from an ancient alien race with a poor (perhaps doomed?) comprehension of cosmology.

      I can see it now.. the philosophical debates about who these ancient creatures might have been... about how they were doomed from the get-go by their flawed and quaint interpretations of the cosmos.

      *sigh*

      I am only middle aged, but I miss the future already.

      Regards.

    5. Re:But even worse by catbutt · · Score: 2, Insightful

      Why again is that our responsibility?

      I mean, given that we've probably got another, say, 20 billion years till the information goes away, I guess I don't really feel the need to mark it as high priority on my to-do list.

    6. Re:But even worse by nomadic · · Score: 4, Funny

      by then, we'll be dead, which seems like the bigger problem.

      Well, let's narrow it down; the bigger problem is -I'll- be dead. That I think is something we all can agree is the biggest problem.

    7. Re:But even worse by maxwell+demon · · Score: 2, Insightful

      The upside is, the people of the future can believe in a static universe, and insofar as their universe is compatible with that hypothesis, they're no worse off for not knowing the truth.

      Do we know the truth? Maybe there's another important factor in the equation which is as invisible for as now as dark energy domination would have been earlier in the universe's history. Or maybe there's something interesting in the universe's history of which all traces are already invisible now, just as the expansion of the universe will (probably) be invisible to the future people.

      And BTW, who knows what they will be able to measure? We don't know the nature of dark matter and dark energy. Thus how do we know that examination of those (which might follow finding it e.g. in advanced accelerator experiments, independent from any astronomic observations) wouldn't reveal other signs of the origin of the universe, signs which are currently hidden from us (because we miss the required knowledge to observe them), and which would tell those future observers about the history of the universe anyway?
      --
      The Tao of math: The numbers you can count are not the real numbers.
    8. Re:But even worse by lord_sarpedon · · Score: 2, Funny

      A China full of Qs huh? I can just imagine the untapped potential for humanity that would spring forth at that point.

      I can see it now -- penis enlargement then just a snap of the fingers away...

      Finally, a solution to spam! 100 billion years!

      --
      "Strangers have the best candy" -Me
    9. Re:But even worse by The+One+and+Only · · Score: 2, Insightful

      The ancient Stoics believed the universe was born out of fire, and will return to fire. The reason we don't believe this is because they apparently made this up instead of making observations like we do and applying a scientific method. I'm sure that a future civilization with our data, along with their data, will come closer to an accurate theory so long as (a) our data are accurate, (b) they accept our data as accurate, and (c) their data are also accurate. We would of course be better off with data from before now, but unless ancient Atlantis had radio telescopes and teams of physicists studying cosmology, we're pretty much stuck with what we've got. You're right--we can never be omniscient anyway.

      --
      In Repressive Burma, it's not just your connection that dies. slashdot.org/comments.pl?sid=314547&cid=20819199
    10. Re:But even worse by Short+Circuit · · Score: 2, Interesting

      While I have no problem archiving information for future intelligences, I really don't think intelligences 100 billion years from now will have any more difficult a time understanding their universe as we do now. (I am assuming, of course, that those intelligences are of a similar nature intellectually to our own. This may not be the case...)

      Look at it this way: What if intelligences similar to ourselves were alive five billion years ago? Would they have any easier or more difficult understanding their universe as we do ours? How do we know that there weren't signals and information sources available then that have petered out today?

      What it all boils down to is the sensory nature of the intelligence. Our understanding of the universe is framed in how we understand our environment. Astrophysics is merely an application of our own interpretation of things which we have only limited tools to understand. If we could personally sense neutrinos or gravity waves, for example, wouldn't our understanding of the universe be much different? It's conceivable that, if life existed in a sufficiently early period of the universe, sensory details such as these could be vital for life, while things like visible-spectrum EM pictures would be useless.

      Who's to say that, 100 billion years from now, life will exist whose sensory perception takes advantage of physics that we can't? Astrophysics or quantum physics, there are things we don't understand. Perhaps the underlying causes would be more clear to life in 100 billion years than today.

      --
      tasks(723) drafts(105) languages(484) examples(29106)
    11. Re:But even worse by eu_virtual · · Score: 5, Interesting

      Theres a cool little story about these same questions here, for anyone that wants to read it: http://www.365tomorrows.com/06/23/37-hands/ Just a sneak peak: "He couldn't believe this debate was still going on. For years they had assumed that the Manhattan Inflation Trial in 4838 had put the lid on the silly notion that the universe contained billions of galaxies. Billions! Zed looked out the window at the smooth black plane of the night sky. One-two-three-four-five-six. Six galaxies. There they were. It was so basic, so obvious. Any kid with a neutron telescope could make the observation for themselves!"

    12. Re:But even worse by rho · · Score: 2, Funny

      Here's what's always annoyed me about astronomers/cosmologists/telescope jockeys of all stripes. They love to talk about how what they do is science, and to the extent that they apply the scientific method to their work, they are right. But simply because they are applying the scientific method does not make what they produce a fact. After crunching some numbers, the space geeks come back to us and let us know that the Universe is 4 billion years old, not 5 billion years old like we thought.

      What? Only an idiot would say that. But "according to current theories, if all our observations are correct, and not accounting for things that we don't know and/or don't understand, we put a date of 4 billion years on the age of the Universe" doesn't really sync with how NOVA likes the TV show to flow. And of course coming out with a hard "fact" like that will totally piss off Vladimir Boroshitz who really ticked you off at the last astronomy convention when he hoarked the last Zima from the cash bar.

      It has always seemed to me that the further out into space you go, the more positive the starfags get. The composition and likelihood of a galaxy 200 million light-years away to contain life? "Pretty good!" Closer to home, they're all "we don't know this, we don't know that", because that means research money to send Lego to Europa to dig for microbes.

      --
      Potato chips are a by-yourself food.
    13. Re:But even worse by The+One+and+Only · · Score: 2, Insightful

      What? Only an idiot would say that. But "according to current theories, if all our observations are correct, and not accounting for things that we don't know and/or don't understand, we put a date of 4 billion years on the age of the Universe" doesn't really sync with how NOVA likes the TV show to flow.

      That's pretty much implicit for everything we claim to know. You could just as well say, "according to current theories, if all observations are correct, and not accounting for things that we don't know and/or don't understand, force is the derivative of momentum with respect to time, while momentum is mass times velocity divided by a factor that converges to 1 unless you are traveling at very high rates of speed." Or, "according to current theories, if all observations are correct, and not accounting for things that we don't know and/or don't understand, energy cannot be created nor destroyed." Or, "according to current theories, if all observations are correct, and not accounting for things that we don't know and/or don't understand, this comment will appear on Slashdot if I click 'submit'."

      --
      In Repressive Burma, it's not just your connection that dies. slashdot.org/comments.pl?sid=314547&cid=20819199
  2. This really makes you wonder... by Bacon+Bits · · Score: 5, Insightful

    I really wonder what we've missed simply because the evidence is long gone.

    --
    The road to tyranny has always been paved with claims of necessity.
    1. Re:This really makes you wonder... by Anonymous Coward · · Score: 3, Funny

      What you mean like His blueprints? It's amazing what can disappear in 6000 years...

  3. Well, maybe not with current methods, but... by Slashboo · · Score: 2, Interesting

    Sure, maybe the evidence we have now to back up our theories on the beginning of the universe will not exist in the far future, but what makes people think that this is the only evidence there is? I'm sure that by the time current evidence become unavailable, future scientists will already find other evidence to replace it.

    --
    Reality is the original Rorschach.
    1. Re:Well, maybe not with current methods, but... by kebes · · Score: 2, Interesting

      I was at a physics conference a few years ago and one of the plenary lectures was on this topic. The speaker basically put forth all the various cosmological models (expanding universe with slowing expansion, universe that eventually collapses back on itself, etc.) and concluded that: "Based on our current understanding, we live in the worst possible universe."

      This is because, according to our best measurements, the universe it not only expanding, but the rate of expansion is increasing with time. Thus the universe's expansion is accelerating (this is the indirect evidence for "Dark Energy").

      This is "the worst possible scenario" because it can easily be shown (in a mathematically rigorous way) that as expansion occurs, the universe will become isolated islands of matter, which are flying away from each other so fast that they cannot hope to communicate with one another. This means that ultimately no information from one region of the universe can ever reach another region, which makes it impossible to reconstruct what happened in the distant past. Worse still, it can be shown that this leads to "Heat Death", where the universe becomes very very cold (because, for example, objects radiate energy that is lost into space and never comes back, nor is replaced by any influx of energy). The end result is that there is not enough energy density to sustain life or any organized constructs. So the end state is one of extremely high entropy, with no usable information content.

      This is not just a matter of not having good enough technology. The problem is that the universe will expand and local regions will irrevocably lose the ability to probe the past. Information will be inaccessible. No matter how good your technology is, the evidence will simply be locally nonexistent (because information can't travel faster than the speed of light).

      Now, having said all that, it's entirely possible that new measurements will point to something previously unknown (e.g. perhaps the explanation for dark energy changes the conclusions entirely). However if current models are mostly correct, then a progression towards locally isolated regions of space, who have no access to cosmological history, is inevitable.

  4. The authors make some questionable assumptions by Daniel+Dvorkin · · Score: 4, Insightful

    - The current model of the universe's origin is essentially correct. What if we're the ones living in a "post-cosmology universe," and the evidence for what really happened has faded so much that we can't detect it?

    - Currently observable stars, background radiation, etc., are all we or anyone else will ever be able to observe. Almost surely, we'll come up with better technology to observe the stuff we already know to look for; quite possibly, we'll discover entirely new things (different forms of radiation, etc.) to use in forming a more complete picture. The same goes for our hypothetical observers in the far future.

    - Human perception is as good as it gets. Anything living 100 billon years from now will be so different from us that it may perceive the world around it in completely different ways, and will accordingly have different technology for astronomy and everything else.

    --
    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
    1. Re:The authors make some questionable assumptions by ChronosWS · · Score: 2, Interesting

      I'm no biologist, but it's not that quadratic configurations are superior to other forms, but rather than they are sufficiently adapted to allow propogation of the genes. It could be that there are several possible morphologies, but this one was the first one which evolved which was well-enough suited. WIth competition for resources, other kinds may have evolved later but could not compete. On a hypothetical alternate world, a different morphology may have been initially evolved which was suitable, and provided a different template for evolution there, beating out a late-coming quadratic configuration.

      But generally it does seem to me we have, at least in gross physiology, pretty much just what we need and not much more, so your theory seems reasonable.

  5. Re:Perhaps by jshriverWVU · · Score: 2, Interesting
    Just off the top of my head, I'm not a physicist but I like to read. If the universe is expanding then it must be a finite area. If it's a finite area it must have a finite amount of energy. So if movement and expansion uses energy, then since there is finite energy it can not extend to infinity, thus it will stop growing at some point. Also in a near or perfect vacuum even small objects have a gravitational pull so they will begin to attract each other, so the universe will more than likely come back together.

    The way I think of it is like taking a pot of boiling water and adding vegetable oil. Let turn off the fire and all those tiny bubbles of oil will start to come together. So if the universe works like that, it might be possible it wont come back together as a single singularity, but if there is enough distance that the gravitational forces don't attract the larger groups, it's possible we could end up with many pin-point size singularities and perhaps multiple big bangs.

    Again I'm not a physicist, so take it with a grain of salt and add noodles :)

  6. A brief glimpse by n3tcat · · Score: 2, Interesting

    We have a very brief glimpse in the overall timeline of the universe. For all we know, the universe will switch directions of movement sooner than we expect. It could be that what we know of as the universe is actually just crap floating in the lungs of a huge beast and the universe shifts back and forth with each breath.

    Honestly I never understood what gave scientists the idea that they would ever have enough of a clue to know what was going on with the universe. I'm not saying it's wrong to do. Perhaps some awesome realization will come from it. I just really hope that there aren't any scientists that truly believe beyond a shadow of a doubt that this is exactly what is happening out there.

  7. Re:Assuming of course... by Timesprout · · Score: 4, Funny

    Please, if you want to contribute to the conversation then make sure your science is grounded in Star Trek, anything else will just confuse us.

    --
    Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
    What truth?
    There is no dupe
  8. Re:I'm sure by tomhudson · · Score: 5, Funny

    "that this article will be relevant in 100 billion years."

    Nah, it'll have experienced the "dupe death" as its reposted countless times, each time increasing its entrophy, losing a few letters here, having a few more arranged there ..

    Today:

    The cosmic microwave background, which has provided our most detailed understanding of the Big Bang, will also be gone. Its wavelength will have been shifted to a full meter, and its intensity will drop by 12 orders of magnitude. Even before then, however, the frequency will reach that of the interstellar plasma and be buried in the noise--the stuff of the universe itself will mask the evidence of its origin. Other evidence for the Big Bang comes from the amount of deuterium and helium isotopes in the universe.'"
    Today + n dupes:

    detailed understanding will also be gone.
    a full meter,
    the frequency will reach that of the interstellar plasma and be buried in
    the noise--the stuff of the universe itself
    evidence for the Big Bang comes from the isotopes in the universe.'"

    Today + n * x dupes:

    le t
    the r e
    b e
    the Big Bang
    !

    Time zero

    *

    Time zero +1

    \ | /
    -- * --
    / | \

    Time zero + z

    The cosmic microwave background, which has provided our most detailed understanding of the Big Bang, will also be gone. Its wavelength will have been shifted to a full meter, and its intensity will drop by 12 orders of magnitude. Even before then, however, the frequency will reach that of the interstellar plasma and be buried in the noise--the stuff of the universe itself will mask the evidence of its origin. Other evidence for the Big Bang comes from the amount of deuterium and helium isotopes in the universe.'"

    Because we all know, what goes around, comes around.

  9. Re:Perhaps by 644bd346996 · · Score: 2, Informative

    Just off the top of my head, I'm not a physicist but I like to read. If the universe is expanding then it must be a finite area. Nope. The rest of your logic is sound, but unfortunately it depends on that false assumption. The standard analogy is to imagine a 2d universe existing on the surface of a balloon. As you inflate the balloon, all points on the surface move away from each other. Now, realize that this is completely independent of the volume of the balloon, and it does not even require a finite surface area. Then extrapolate to three dimensions.
  10. Copyright? by geoff+lane · · Score: 5, Funny
    I found this hidden within the value of Pi expressed in base 11...

    Copyright: Year Dot God. All rights reserved.

    This universe represents copyrighted material and may only be reproduced in whole for personal or classroom use. It may not be edited, altered, or otherwise modified, except with the express permission of God.

  11. Re:Perhaps by Timesprout · · Score: 2, Funny

    Personally I was very disappointed by the Big Boing theory, I found it bounced around with the main issues and tended to dampen my interest.

    --
    Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
    What truth?
    There is no dupe
  12. Re:Perhaps by beyondkaoru · · Score: 3, Informative

    well, regardless of the acceleration observations (which might be caused by other junk pulling on us, unknown phenomena, whatever), it is possible that our galaxy and others were given enough oomph to reach escape velocity relative to everyone else; since space could go on forever (that is to say, the stuff in it might only cover a small portion of it), the oil in a pot analogy doesn't work.

    i know it might be a little counterintuitive, the concept of escape velocity (getting enough energy that you'll go fast enough to never have to be pulled back) might apply here. having finite energy does not mean that something can only go a finite distance.

    i think the confusion arises from the definition of 'universe' -- people often use it to refer to spacetime or also the stuff in it. in terms of the expansion, we're usually referring to how we notice that we're getting further away from most other things we can see.

    of course, all this speculation could get thrown out once we discover something tomorrow...

    --
    the privacy of one's mind is important.
    you do have something to hide.
  13. Re:How much has already been lost? by Admiral+Ag · · Score: 4, Funny

    No. In ancient Hebrew he would have written "YH DD T" or more likely "YHWH WS HR LLZ!"

    --
    "by that I mean people who don't sit on slashdot all day wondering why everyone else isn't building robots" DECS
  14. No it doesn't. by Colin+Smith · · Score: 2, Insightful

    Nah, the bigger problem would seem to be that as far as we know we are the only sentients capable of taking advantage of the information currently available... which places a huge responsiblity on our shoulders. Christ, stars don't last that long, what chances do you think there are for information we can store? We can barely archive it for 20 years never mind 100 billion. Then there's the issue of finding a way of transmitting it or making it available.

    Basically we have no responsibility to anyone but ourselves. Any species which exist in 100 billion years can go and get stuffed.

    --
    Deleted
    1. Re:No it doesn't. by Short+Circuit · · Score: 2, Interesting

      Christ, stars don't last that long, what chances do you think there are for information we can store? We can barely archive it for 20 years never mind 100 billion. Then there's the issue of finding a way of transmitting it or making it available. But it's insanely simple...Just transmit the entire archive using some encoding using EM radiation. Your "archive" is thus stored in a volume of space as a media stream. As long as it can be intercepted and eventually decoded by whoever "finds it", you're good.

      The difficulty lies in transmitting it at a high enough power to still have a workable signal elsewhere in the galaxy. To this end, one could build a Dyson sphere around a sun, then block or transmit the star's light according to your signal.

      Yeah, building a Dyson sphere is hard...but it has so many uses. :-)

      Basically we have no responsibility to anyone but ourselves. Any species which exist in 100 billion years can go and get stuffed. This sounds like a generalization of Ayn Rand's "You have no responsibility to anyone but yourself" philosophy, and makes me wonder how much of human "civilization" comes from culture, and how much comes from human nature.

      Not that there's necessarily anything wrong with your point of view...
      --
      tasks(723) drafts(105) languages(484) examples(29106)
  15. Y100B Compliant by Ryunosuke · · Score: 5, Funny

    How can I tell if my computer is Y100B compliant? I want to be able to read about this on slashdot in 100B years

  16. Finally, I got it. by MrCopilot · · Score: 3, Funny
    1. Take polaroids.
    2. wait 100 billion years.
    3 profit.

    Seriously this implies all information from now will be lost. Pretty Dim view.

    --
    OSGGFG - Open Source Gamers Guide to Free Games
  17. What Do We *Already* See No Evidence Of? by mkcmkc · · Score: 3, Interesting
    Turning this around, could it be that we already cannot see crucial pieces of evidence about the origin of the universe, life as we know it, or whatever?

    Just as an example, current thinking is that we're the first technically advanced society on earth, because we see no archaeological traces of previous societies. But, what if the previous society (or societies) had advanced technology that (a) was used to scrub the earth of their low-tech origins, and (b) left no traces when the society vanished, much as ice sculptures leave no traces when they melt?

    Is there any real evidence against this sort of thing? (Occam's Razor, I know. But that's an incredibly pitiful rebuttal...)

    --
    "Not an actor, but he plays one on TV."
    1. Re:What Do We *Already* See No Evidence Of? by QuoteMstr · · Score: 2, Insightful

      Any previous advanced civilization on earth would have depleted its mineral resources in its rise to high technology, just as we have. That we have (or had, anyway) oil, coal and natural gas in abundance indicates that we are indeed the first civilization to arise on this planet. These resources take hundreds of millions of years to form, and complex life hasn't been around long enough for that to have happened twice.

      Not only are we the first civilization, but we are likely to be the last. Any future society is unlikely to progress beyond an agrarian feudal society due to dearth of natural resources. We can't screw this one up!

    2. Re:What Do We *Already* See No Evidence Of? by Kjella · · Score: 2, Interesting

      Not only are we the first civilization, but we are likely to be the last. Any future society is unlikely to progress beyond an agrarian feudal society due to dearth of natural resources. We can't screw this one up!

      That a civilization which has an abundance of oil, coal and natural gas would use it, doesn't imply that it is necessary. Water wheels and wind mills have been in use for a long time, and could be used to generate electricty once someone invented the generator. The steam engine only relies on a boiler than can be powered by wood. They could skip right past fossil fuels and discover biodiesel, fuel cells, solar cells and other modern forms of energy.

      The biggest question to ask would be why it would vanish. Yes, civilization come and go but very rarely have we abandoned anything of consequence unless the whole city was founded on a natural resource that ran out or something like that. If a second crivilization was to araise, I think the biggest clue would be the nuclear waste, toxins and pollutants, destroyed ecosystem and traces of an infiniately large disaster which could possibly cause our abandoment or extinction.

      --
      Live today, because you never know what tomorrow brings
    3. Re:What Do We *Already* See No Evidence Of? by DirePickle · · Score: 2, Insightful

      Future societies wouldn't have much oil, coal, and gas to work with, perhaps, but a lot of other natural resources will be buried in our landfills.

  18. Re:Perhaps by glesga_kiss · · Score: 4, Interesting

    unless it starts to shrink back into itself and form a singularity before the next Big Bang.

    That theory has always appealed to me as it solves once of the major questions of the universe. What led up to the big bang? The idea that the universe expands and collapse suggests that before the big bang there was another universe.

    To me, the idea that there needs to be a start-point for the universe seems a little too human. We have the start of our lives, the start of the day and ultimately it all ends for each of us. But the life of an inanimate object isn't quite like that. Why can't the universe have always existed? What is time anyway, other than an abstraction of counting how often something vibrates? Isn't the idea that "it's always been there" far easier to grasp than "once there was nothing, now there is everything"?

  19. You'll be dead anyway. Here's why by Moraelin · · Score: 5, Interesting

    Let's put things in perspective a bit:

    The universe itself is 13.7 billion of years old. Our Sun is only about 5 billion years old.

    In this interval, the universe already burned a heck of a lot of Hydrogen to Helium, and even a lot of Helium to Carbon and so on until iron. You can't really have a star powered by fusing anything heavier, because fusing heavier stuff actually takes energy.

    (Anything higher than that is formed in a supernova blast. Basically some of the immense energy of the supernova is used to fuse some of the ejected elements into even higher density stuff.)

    Hydrogen is really the low hanging fruit of star fuel. It's for stars what the coal mines were for the industrial revolution. It's damn easy to start fusing hydrogen. (Easier if you have some heavier elements as catalysts to start the reaction, but the hydrogen will be the fuel anyway.) It's damn hard to start fusing anything else.

    Even helium is tricky. It requires some _immense_ pressures and temperatures, and a state that's already degenerate matter. It even starts to happen somewhere between 100 and 200 million Kelvin. It's also a bloody unstable process. The released power is proportional IIRC to the temperature raised to the _30th_ power, so it's easy for it to run away: more power released rises the temperature some more, which rises the power some more (and rather abruptly at that), which rises temperature, etc. A star the size of our sun would just blow itself up almost instantly if it was made of Helium and actually ignited Helium fusion.

    Where I'm getting is that the universe has a finite budget of hydrogen and keeps using it fast. (Well, "fast" by cosmic scales.) And then some of it gets buried in black holes and the like too. So planning to have main sequence stars in 100 billion years, is sorta like planning to still be using the oil in the middle east by then: chances are it will have run horribly thin, long time before that.

    In 100 billion years, probably the best you could get is a brown dwarf, a.k.a., a star that doesn't actually fuse anything, but it heated up when collapsing into a star, and will need a horribly long time to cool down. And hopefully a planet that's close enough to it, to be just warm enough.

    They'll be few and far in between though, so no telling if one will be close enough to move to it.

    Also, lemme say: the only chance of life there will be that someone moves to it. If you look at long time Earth history, the Sun started a lot cooler when the Earth atmosphere was made of methane, so the massive greenhouse effect just helped keep temperature in the right band for life to appear. Then as the Sun heated up, life switched atmosphere to oxygen. We've been walking a tightrope on the border between turning into Venus (if life appeared just a little later) or turning into a deep-frozen snowball that kills everything (if photosynthesis started just a little earlier.) And we actually had a damn close shave with complete extinction, the planet-sized snowball kind.

    A brown dwarf just doesn't follow that pattern. It doesn't gradually warm up, it actually starts (very very slowly) cooling down as soon as it formed. But you can pretty much approximate it as constant temperature, for the purpose of this discussion. And therein lies the problem: if it's cool enough for a methane-atmosphere planet to evolve life, that will turn into a permanent deep-frozen wasteland as soon as it evolves photosynthesis. And if it would be warm enough for an oxygen-atmosphere planet, then it's way too hot early when that planet is still methane-based. That planet will turn into Venus before it has half a chance to evolve life.

    So pretty much in 100 billion years we're looking at a dead or dying universe anyway. Worrying that they'll have witch hunts is kinda silly, when, you know, there won't be anyone alive there.

    --
    A polar bear is a cartesian bear after a coordinate transform.
    1. Re:You'll be dead anyway. Here's why by Moraelin · · Score: 2, Insightful

      Fair point, indeed, but somehow I'm not betting on it.

      1. Yes, energy indeed cannot be destroyed. It does, however, get trapped in the mass of the heavier nuclei synthetised during a supernova blast (E = mc^2) or, basically, lost as photons traveling around an ever increasing universe. Especially the latter is, really, the whole point in this topic. There'll be increasingly more photons which are (A) traveling the ever increasing space between galaxies, and never getting anywhere, and (B) getting red-shifted to such ridiculous wave lengths that they will _not_ be doing anything to any nucleus they encounter.

      Basically the incoming power decreases with the square of the distance, and the whole point is that the distance is increasing. Accelerating even. So even as more energy piles up, there's more and more space (and red-shift) for it to go through and never hit anything. If you pointed a flashlight upwards outside, only an infinitesimally tiny fraction (or more likely none at all) of the photons will ever hit _anything_, because there's simply an incredible amount of empty space out there.

      And if it does hit another star, chances are it'll be infrared or even microwave, so don't expect it to split any nuclei.

      2. Yes, technology will continue to advance, but I'm not sure what it's going to do about it. Unless it discovers a way to produce energy out of _nothing_ whatsoever, it's still stuck at the same point we are. To create a main-sequence star at that point, it would have to split trillions of tonnes of heavier elements into hydrogen. Where is it going to get the energy for that? Solar is out, fusion _and_ fission are out (most nuclei will be iron at that point, so neither yields an energy gain), fossil fuels aren't _nearly_ packing enough energy, etc. Where's that energy going to come from?

      Basically to build a main-sequence star, you're looking at needing as much energy as that star will produce during its billions of years of lifetime. Where are you going to get that, in an universe that's already running out of energy? How are you going to get that in a burst? Even if we were talking about building a sun in 10 million years (which is already an ludicriously large interval: humans never stuck to a plan for 0.01% of that time), you're looking at needing 1000 times the sun's raw power output, and that's at 100% efficiency and 0% losses (a.k.a., never gonna happen.) Where are you going to get that in an universe that, really, is running out of fuel?

      3. At any rate, for all we know now, there'll be noone alive at that point. If technology ever gets better, let them worry about that then, not now.

      4. Finally, we're talking about a freakin' _huge_ interval. The Homo Sapiens species is only 200 million years old. Worrying about what happens in in 100 _billion_ years is just nuts. Whole empires rose and fell in a _billionth_ of that time. Whole social models or indeed whole civilizations disappeared in a tiny fraction of that, and great libraries turned to ashes in what's really just a tiny blip on that scale. Planning what to do for the next 100 billion years is just nuts.

      --
      A polar bear is a cartesian bear after a coordinate transform.
    2. Re:You'll be dead anyway. Here's why by Genda · · Score: 2, Interesting

      All of this is moot if there the latest ideas involving the "Big Rip" turn out to be correct.

      In this scenario, Dark Energy continues to cause accelerating inflation of the universe until that inflation begins to effect objects of smaller and smaller scale. At first the galaxies will all go away, too far away to see. Later, nearer the end stars will be flung beyong our view. Very near the end, the sun will suddenly shrink out of existance and the space between the earth and the sun grows infinitely. At the very end the moon will fly away, layers of earth will peel away and blow off into space, ultimately our bodies would explode into their consituent atoms, and even those would be ripped apart into there constituents as space-time itself unraveled.

      Personally I'm looking forward to femtotechnology, and making a warm and comfy home in the nice big blackhole, after mastering technologies based on manipulating gravity... That or finding a friendlier universe.

  20. Further Reading: End of the Universe by CheeseburgerBrown · · Score: 2, Interesting

    Scifi short story that takes place at the heat-death of our universe.

    Topical? Yes!

    Tipping encouraged. I'll be here all week.

    --
    These stories are free but worth money.
  21. Peak hydrogen by benhocking · · Score: 5, Funny

    Where I'm getting is that the universe has a finite budget of hydrogen and keeps using it fast. (Well, "fast" by cosmic scales.) And then some of it gets buried in black holes and the like too. So planning to have main sequence stars in 100 billion years, is sorta like planning to still be using the oil in the middle east by then: chances are it will have run horribly thin, long time before that.
    Bah, you Alpha Centaurians and your "peak hydrogen" alarmism! But seriously, we're not burning through Hydrogen fast even by cosmic scales. The universe still has 75% of its original hydrogen left. Presumably, the rate at which we'll use it will decrease as we use it up. However, you have a valid point that by 100 billion years (~8x the current age), there's a good chance that the 75% figure might be more like 7.5%. (I'm completely making up that last figure.)
    --
    Ben Hocking
    Need a professional organizer?
    1. Re:Peak hydrogen by Moraelin · · Score: 2, Insightful

      Well, that's really the thing. 25% gone in 13.7 billion years is a _lot_, when you're talking 100 billion years.

      Will usage decrease? Well, that wouldn't make it that horribly much better, because that means, in a nutshell, less main-sequence stars.

      It will also mean more hydrogen which technically still exists, but is going nowhere: it's trapped in brown dwarfs that never start fusion, Jupiters, black holes, etc. Those things don't blow up, so basically short of some cataclismic event like head-on star collisions, it won't end up in a star. So expect the number of main-sequence stars to drop even faster. If the hydrogen use is, say, roughly 1/t past a point, then expect the main sequence stars to drop like 1/t^2. (Also pulled out of the arse, I don't have the time or inclination to do proper research at 1:30 AM ;)

      So, basically increasingly less places where life can evolve or move to. We might end up with the next inhabitable place being on the other end of the galaxy before the 100 billion years are up.

      Also, going by the number in your example, 7.5% hydrogen means you're pretty much screwed. It's like getting your gasoline 7.5% in <insert inert liquid of the same density>: your engine won't work on it any more, a long time before that. A star with 7.5% hydrogen just won't produce any significant amount of hydrogen fusion. Stars die, one way or another, a long time before they get anywhere _near_ that kind of a composition.

      So basically at that point, to get a main sequence star, you're betting on some _incredibly_ low odds of getting a freak fluctuation where you had a big pocket of hydrogen that somehow didn't accrete into a star earlier. We're talking odds akin to winning every single lottery on Earth on the same day. Repeatedly. There won't be many of them around.

      One within close enough range to evacuate humanity to? Heh. I wouldn't bet on that.

      --
      A polar bear is a cartesian bear after a coordinate transform.
    2. Re:Peak hydrogen by Hewligan · · Score: 4, Informative

      While 25% of the universe's hydrogen may have been converted to heavier elements, about 24% was converted in the first second or so, and then about 1% in the ensuing 13.7 billion years. At that rate, there will be plenty left in 100 billion years time.

      --

      "If God created us in his own image, we have more than reciprocated"

  22. Makes me wonder by localman · · Score: 2, Interesting

    How much information about our universe that was obvious to civilizations that rose and fell a few billion years ago is lost forever as well?

  23. Oh no, I agree by benhocking · · Score: 2, Interesting

    I just wouldn't call that "fast", even by (currently) cosmic scales. For example, I'm 37. If you told me I could get to some destination in 74 years (for example), I wouldn't call that "fast".

    Now, here's a real calculation, albeit one that's still based on completely unfounded assumptions: if the decay is exponential, then 100 billion years from now (when the universe is apprxomately 114 billion years old), there will be approximately 0.75^(114/14) or 9.6% of the hydrogen left.

    On the other hand, if the decay is linear, we'll have -104% hydrogen left, so we'll have to fuse anti-hydrogen! (Yes, that's just a joke.)

    --
    Ben Hocking
    Need a professional organizer?
  24. Scientific idea becomes non-scientific by TrnsltLife · · Score: 3, Insightful

    What is interesting to me about this scenario is that a currently scientific idea will become unscientific over time. What is now a scientific theory, testable and supported by empirical data, will become nothing more than the ancestors *claims* of empirical data.

    Can the claims of the ancestors be trusted, when they suggest such preposterous experiential data as a "sky full of galaxies" and "background radiation"?

    If they can, then science is not the only valid way to learn about the universe. We can also learn from the experiences of those who came before us, even if we cannot experience the same thing they did.

    Science is a useful way to pursue truth, but it is not the only way. I think people need to see that, and this is a good example of how that is true.

  25. Forgot that little detail by benhocking · · Score: 2, Interesting

    However, that 25% figure ignores the hydrogen that gets trapped in black holes, etc. Still, I think you're right that we will still have plenty of hydrogen in 100 billion years. (I don't know, but I think the black hole absorption of hydrogen to be less than the consumption of hydrogen due to fusion.) Peak hydrogen indeed!

    --
    Ben Hocking
    Need a professional organizer?
  26. Re:Perhaps - Information from the near-future by Proudrooster · · Score: 2, Funny
    According to my friend from the near-distant future, this is how it all works:

    1. 1. Space in the universe must be conserved and can not be expanded or contracted, i.e. the universe is not a ballon, but the way we percieve it changes, just like in Einstein's Relativity.
      2. Space is a field which is created by matter/energy.
      3. The space field has multiple properties included time, gravity, electromagnetism, and magnetism.
      4. The equation which unifies what we percieve as space-time, gravity, and electromagnetism is called the McMinnis equation and looks very similar to Maxwell's equations and has six pieces.
      5. The amount of energy in the universe is not constant as we currently believe and points to a source outside the universe. Some existentialists have theorized this is the evidence of a creator influencing outcomes.


    We also discover that the graviton and virtual massless photons (which we believe make up magnetic fields) do not exist and are merely properties of the space field which surrounds energy.

    As far as future energy sources go, ethanol dies a horrific death after totally screwing up the food supply. The nanotech guys develop new batteries which can be charged as fast as capacitors and hold 5000 times the amount of energy in the same package size. The future is primarily powered by geothermal wells which generate electricity and fusion is never fully perfected but does produce about 35% of the global electricity supply. There is a debate that the geothermal wells are cooling the core of the planet which will have disastrous consequences and descendant of Al Gore makes a documentary about it. In other news: The US/China start a colony on the moon, but something about moon dust causes lung cancer (like asbestos). Even though it is attempted 10 times, iNASA is never successful in establishing a base on Mars, but dooms many astronauts. The war in Iraq lasts for nearly 20 years.

    Hope that helps and please keep this information to yourself.