Billions of Habitable Planets?

cbv writes: "MSNBC has an interesting article about new calculations by Charly Lineweaver and Daniel Grether, both of the University of New South Wales in Australia, which provides an interesting answer to the question on how many potentially habitable planets exist in our galaxy."

Comments

Did they remember to subtract 1?

[blair1q]

Because by the time we can find another one that is, this one won't be.

--Blair
"Keeping up with the Gbrtlrxzes."

Re:Did they remember to subtract 1?

[Restil]

Actually, we'll probably FIND one in less than 20 years. It'll probably take just as long again to confirm that its actually habitable and to what extent it might already be inhabited.

Its the next leg of evolution, where we actually manage to amble our way across lightyears to get there. THAT... may take a significant fraction of the rest of civilization as we know it. And while it may take thousands of years to make that next huge step, the planet will be around for billions more yet.

-Restil

Re:Did they remember to subtract 1?

[ryusen]

Its the next leg of evolution, where we actually manage to amble our way across lightyears to get there. THAT... may take a significant fraction of the rest of civilization as we know it. And while it may take thousands of years to make that next huge step, the planet will be around for billions more yet.
travel all those lightyears, ten thousand years to get there and about 10 or 20 more years to utterly devistate the indiginous peoples, and another 500 years to pollute the kaka out of it?
heck by then maybe we'll have terraforming or dyson spheres and we can just make new places to live

Re:Did they remember to subtract 1?

[Doppler00]

I think it is more likely that we will be able to MAKE another planet habitable before we ever find one. I wish NASA would stop spending so much money looking for life on other planets and instead focus on putting life on other planets. We could eventually colonize Mars if they would focus on missions to it.

Re:Did they remember to subtract 1?

[stph]

More fatalistic...? Hmm, how about: "Woo Hoo, billions more planets to despoile!"

It would be cool

[Mr.Sharpy]

if we could actually see these smaller planets.

Re:It would be cool

[cmpalmer]

Well, I'm no expert (I'm not even an amateur), but I have heard that an array of optical telescopes (particularly if they could be placed on a solid airless body like the moon) could have the ability to optically resolve planets around other stars.

This would be an expensive undertaking, but it would resolve the issue pretty quickly. I think that positive confirmation of extrasolar Earth-like planets would be an amazing, culture changing phenomena, right up there with actually discovering extraterrestrial life.

PI think my info on optical telescope arrays came from Entering Space by Zubrin.

Re:It would be cool

[arashi sohaku]

In the current Discover magazine (March '02 dead tree version), there is an article talking about something similar, and actually developing a technology that could filter out the starlight (1000 billion times brighter than the earthlike planet) and enable a ground-based telescope armed with this tech to "see" a planet.

Fairly interesting, and I hope these guys get their plan adopted.

Thunder

Re:It would be cool

[Mondrames]

As some people have already pointed out, they are makint telescopes that not only are better than hubble, but one that uses to mirrors (like binoculars) to create an intereference pattern with the observered star's light, causing it to "dim" to the point where you can see its planets.

There is one currently in the works that will use an array (4,6?) in orbit to do the same thing.

Discovery Science had a program with Jonathan Frakes narrating the other night on this. They also cover the Jupiter/Protector theory.

Re:It would be cool

[Ariane 6]

What you're referring to is space-based interferometry. I was talking to my astro prof a few months ago, and he showed me calculations that absolutely blew my mind.

An optical interferometric array on the far side of the moon, would have resolution sufficent to give us maps of earth-size planets -out to 100 light years, IIRC.

I was so impressed, that I even asked another faculty member, who concurred.

The BIG question

[Spamalamadingdong]

What will it take to get a program going to actually send people out to them?

Re:The BIG question

[Scaba]

I think only telelphone sanitizers, hairdressers and middle management will get to go, if I remember correctly.

Re:The BIG question

[medcalf]

What will it take to get a program going to actually send people out to them?

We appear to be waiting for a crisis, wherein the surface of Earth is sterilized by a marauding enemy. We'll then live underground long enough to retrofit the Yamato as a space battleship, and send her and her brave crew out as the last hope of mankind.

Re:The BIG question

[KingKire64]

Earth Being Destoryed to make room for an intergalactic highway? Maybe the Vogals will help us...

Re:The BIG question

[cmpalmer]

As I mentioned in a previous comment, I think a nice high resolution picture of a cloudswept blue and green plant around, relatively, nearby star would probably be enough -- I just hate that I probably won't be around to find out what it discovers.

Re:The BIG question

[s20451]

Manned interstellar spaceflight would require:

• A multi-trillion-dollar committment from the industrialized nations, complete with the political support for a project that could take centuries to implement
• Propulsion technologies (large-scale solar sails, nuclear / anti-matter propulsion, etc.) and life support technologies that are currently only imagined
• Orbital construction of a 10-100 thousand ton spacecraft - including shielding, centrifugal gravity, recycling, fuel ... possibly more than one spacecraft, for the sake of redundancy
• Extensive space infrastructure -- you might want to construct the craft from lunar materials, since it would be easier to launch
• A few dozen (or more) highly skilled, highly motivated people to operate the spacecraft, are willing to assume the risks of a 20-50 year journey in an untested spacecraft, who would be able to work together in extremely difficult conditions over decades without killing each other, and who would be willing to never return to Earth (maybe even willing to die before seeing the destination, with only their children arriving)

Some have observed that the level of committment this would require of humanity would be like nothing ever seen before, and which would require devotion that has historically only been commanded by religious quests.

Re:The BIG question

[AndroidCat]

"So when they drive an Information Bypass through the Electronic Global Village, what I want to know is: How do you lie in front of a cyberspace bulldozer?" - Ron Sharp.

Re:The BIG question

[Winged Cat]

And the quest to establish humanity among the stars, or at least off of this rock, does not invoke fervor similar to what religions have in the past?

How about a small, gradual exploitation of the Moon and other resources in space to develop the propulsion and life support technologies, then get a bunch of people who know what they're doing and are completely sick and tired of the rest of humanity deciding to launch a colony ship? Technically, that has elements 2 through 5 of what you proposed, but no need for trillions of dollars from several countries.

Re:The BIG question

[rworne]

OK. We need to start digging in the desert to find an old buried ship and use the discovered lost technology to build a new one in orbit and go off to find our "Homeworld"?

Or scour Japan looking for Noriko to pilot the Gunbuster?

It's great now that there's more Sci-Fi to hope will come true. 2001 was such a disappointment.

Re:The BIG question

[AMuse]

Some have observed that the level of committment this would require of humanity would be like nothing ever seen before, and which would
require devotion that has historically only been commanded by religious quests.

Fortunately, there's a "religion" with the right kind of funding to do so!

Who would ever think something good would come out of Scientology? :>

Re:The BIG question

[notsoanonymouscoward]

Lets just see how funny this can get

Re:The BIG question

[shd99004]

What it will take? I think huge steps forward in technology and science. We know it's possible to use anti-matter as fuel for interstellar journeys, however it's an extremely expensive and slow process... and then we need more experience of living and travelling through outer space - so far we've gone to the moon only. It's a huge step to do that, but nothing to what we need to accomplish. And even if we reach near speed of light, that will cause problems as well, in a speed that high, even the smallest dust particle (let alone a huge meteorite) is dangerous. I'm sad to say that we wont be going to any stars for the next 100 years... maybe not for another 500 years, unless some new Einstein or Hawkings makes a crucial discovery, making production of antimatter a piece of cake, or to find out how to travel through worm holes or whatever. I know that we will go to the stars, no doubt about it. Question is only when.

you mean...

[youngerpants]

N = R* × fp × ne × fl × fi × fc × L

Where,

N = The number of communicative civilizations
The number of civilizations in the Milky Way Galaxy whose radio emissions are detectable.

R* = The rate of formation of suitable stars
The rate of formation of stars with a large enough "habitable zone" and long enough lifetime to be suitable for the development of intelligent life.

fp = The fraction of those stars with planets
The fraction of Sun-like stars with planets is currently unknown, but evidence indicates that planetary systems may be common for stars like the Sun. more info

ne = The number of "earths" per planetary system
All stars have a habitable zone where a planet would be able to maintain a temperature that would allow liquid water. A planet in the habitable zone could have the basic conditions for life as we know it. more info

fl = The fraction of those planets where life develops
Although a planet orbits in the habitable zone of a suitable star, other factors are necessary for life to arise. Thus, only a fraction of suitable planets will actually develop life.

fi = The fraction life sites where intelligence develops
Life on Earth began over 3.5 billion years ago. Intelligence took a long time to develop. On other life-bearing planets it may happen faster, it may take longer, or it may not develop at all. For more information, please visit Dr. William Calvin's "The Drake Equation's fi"

fc = The fraction of planets where technology develops
The fraction of planets with intelligent life that develop technological civilizations, i.e., technology that releases detectable signs of their existence into space.

L = The "Lifetime" of communicating civilizations
The length of time such civilizations release detectable signals into space.

Re:you mean...

[LordNimon]

For those who don't know, the above equation is known as the Drake Equation. What a lot of people don't realize is that the equation itself is more interesting than the answer, because no one can truly know what values to use for the seven unknowns. To quote the above link:

The real value of the Drake Equation is not in the answer itself, but the questions that are prompted when attempting to come up with an answer. Obviously there is a tremendous amount of guess work involved when filling in the variables. As we learn more from astronomy, biology, and other sciences, we'll be able to better estimate the answers to the above questions.

Re:you mean...

[LordNimon]

BTW, my biggest complaint about the Drake equation is that it's too simple. We need similar equations for the unknowns "fl" and "fi" before we can even begin to use it.

Re:you mean...

[mikec]

I think "L" is the problematic one. The term "Lifetime" is deceptive, because it isn't the lifetime of the civilization, it's the span of time that the civilization wastes huge amounts of power broadcasting into space.

It may well be that most civilizations go through a brief broadcast period and then learn to use point-to-point methods of communication that aren't easily detectable. One reason is simple economics: dumping energy into space is wasteful. But it may also be that successful civilizations actively avoid broadcasting their presence to avoid hostile encounters.

Here's a depressing thought: they may also consider it prudent to quickly destroy nearby infant civilizations quickly, perhaps by accellerating small chunks of rock to near lightspeed and aiming them at noisy planets. Such an attack could obliterate life on earth with virtually no warning at all.

Re:you mean...

[Anonymous Coward]

"Here's a depressing thought: they may also consider it prudent to quickly destroy nearby infant civilizations quickly, perhaps by accellerating small chunks of rock to near lightspeed and aiming them at noisy planets."

PALESTINIANS FROM OUTER SPACE!!

Re:you mean...

[Atreides4]

Here's a depressing thought: they may also consider it prudent to quickly destroy nearby infant civilizations quickly, perhaps by accellerating small chunks of rock to near lightspeed and aiming them at noisy planets. Such an attack could obliterate life on earth with virtually no warning at all. I don't think we really have to fear a homicidal extraterrestrial civilization because any civilization that thought like that and demonstrated that level of xenophobia would have blown itself sky high before developing the technology to do something like that. So all we really have to fear is an extraterrestrial civ that was really peaceful and then went nuts and is in all probability in its death throes.

Constantly in discussions like this people talk about "Cortez and the Aztecs" scenarios, and barring a form of hyperspace travel that's not likely. Think about the cost of colonizing another world, especially one light-years. It's trillions of dollars (or planet Xenons, or incredible expenditures of energy, however aliens measure cost) to move a very small group of individuals. In the long run its probably going to be cheaper to colonize Mars, the Kuiper Belt, etc and maybe even manufacture a Dyson sphere around the sun then to send masses of people to other stars. So if the alien civ thinks rationally its probably not going to be a problem. Another scenario might be a kind of interstellar Pilgrims, but I doubt any civ would equip people it persecutes with that level of energy producing equibment (handy weapons), or leave it on once they were gone (in case of a home-based system).

There's also the "They'd already be here" factor. If there were aliens with interstellar spacecraft and a xenophobic madness within 40 light years or so, they'd already be here. The fact taht we exist at all leads me to believe the only aliens are far away, mellow enough not to kill us or colonize Earth, or that interstellar space travel will always remain prohibitively expensive. (especially because the return on investment seems to approach zero for the people of the planet who have to bankroll a relativisic interstellar voyage) If we do communicate with aliens, it'll be through signals, a la the Qeng Ho nets in A Deepness in the Sky.

While there could be a magic increase in energy production that would make interstellar travel laughably cheap, there would be heat issues (a la Ringworld) and with that kind of tech the questions still arise of why and how they would reach such a level of tech if they thought that like that.

On the other hand, there could be crystal spheres protecting habitable worlds as in David Brin's "The Crystal Spheres."

Re:you mean...

[Theodore Logan]

I've already posted a similar comment in this thread, but since I formulated it rather bad and not too many people seemed to notice I'll make another try. And this time I'll cut and paste from this site.

One of the problems that the Drake Equation produces is that if you take reasonable (some would say optimistic) numbers for everything up to the average duration of technological civilizations, then you are left with three possibilities:

1. If such civilizations last a long time, "They" should be _here_ (leading either the the Flying Saucer hypothesis---they are here and we are seeing them, or the Zoo Hypothesis---they are here and are hiding in obedience to the Prime Directive, which they observe with far greater fiqdelity than Captain Kirk could ever muster). -or-

2. If such civilizations last a long time, and "They" are not "here" then it becomes necessary to explain why each and every technological civilization has consistently chosen not to build starships. The first civilization to build starships would spread across the entire Galaxy on a timescale that is short relative to the age of the Galaxy. Perhaps they lose interest in space flight and building starships because they are spending all their time surfing the net. (Think about it---the whole point of space flight is the proposition that there are privileged spatial locations, and the whole point of the net is that physical location is more or less irrelevant.) -or-

3. Such civilizations do not last a long time, and blow themselves up or otherwise fall apart pretty quickly (... film at 11). Thus the Drake Equation produces what is called the Fermi Paradox (i.e., "Where are They?"), in that the implications of #3 and #2 are not terribly encouraging to some folks, but the two flavors of #1 are kinda hard to come to grips with.

An alternate version of 2 is that interstellar travel is far more difficult than we think it is. Right now, it doesn't seem much beyond the boundaries of current technology to launch "generation ships," which power systems. An
alternative is robot probes with artificial intelligence; these don't seem so difficult either. The Milky Way galaxy is well under 10^5 light years in diameter and over 10^9 years old, so even travel beginning fairly recently in Galactic history and proceeding well under the speed of light ought to have filled the Galaxy by now. (Travel very near the speed of light still seems very hard, but such high speed isn't necessary to fill the Galaxy with life.) The paradox, then, is that we don't observe evidence of anybody besides us.

Re:you mean...

[Theodore Logan]

An even more elaborate discussion of the consequences of this line of reasoning can be read here.

Too bad discussions on Slashdot die so quick. This one could have been fun!

Re:you mean...

[Kazir]

O'Reilly & Associates has a great book on this very subject, Beyond Contact.

Re:you mean...

[Jeremi]

... or it could be that the reason we don't detect any alien broadcasts is because the aliens have already encased Earth in a giant spherical display screen that simulates the night sky, to keep us calm until they are ready to throw us into their dying sun.

(mod: -1, Silly ;^))

Re:you mean...

[SectoidRandom]

There was an excelent ariticle at Scientific American on exactly that, with nice diagrams etc..
It is a slightly depressing for those star trek style optimists like me. :) But of course there is an infinate number of possibilities in the Universe! Have a look at Possible Solutions to get you thinking more..

There are so many considerations though, for instance Not all habitable zones equal. but one that really peaked my interest is an article about how our moon in many made our world. (sorry cant find the link) Basically the theorised formation of our moon, ie big planetoid crashing into proto-earth, ejecting large portion of earths crust into orbit with remains of other planetoid. Basically creating the plate-tectonic's we have on earth, which i might add do not exist on any other planet/moon observered.

Meaning that the plate tectonics are extremly rare, if you'll note a big factor in the creating on mountains, continents, etc is the continual movement of the plates. Getting to the point, if we didnt have a moon (and the results of its formation) and we still had water, then Earth would be a completly water world! Because without the continual movement, creation of continents / mountains etc, water would erode any land mass's in time.

I find that so interesting (even if it's all theoretical) as it's just another very rare factor that contributed to us being here. Rather than us being whales or some such. :)

So just maybe for the optimists (like me) most worlds out there which are habitable dont have inteligence because a huge portion of them are just water with no land. Then comes the argument of why would inteligence such as ours evolve on such a world?

Re:you mean...

[nizo]

An alternate version of 2 is that interstellar travel is far more difficult than we think it is. Right now, it doesn't seem much beyond the boundaries of current technology to launch "generation ships," which power systems.

The problem isn't CAN we do it, but WILL we do it. Who knows, maybe by the time a species hits a certain technological threshold, apathy takes over. Based on our current spending in the "explore and colonize space" arena, we have been there for 20 years now, and its getting worse.

Re:you mean...

[mikec]

I don't think there's much point in fear, because there is absolutely nothing we could do about it.

However, I completely disagree with your reasoning. Xenophobia may well be the rational course. This is particularly the case if interstellar travel and trade is impractical. Destroying a nearby planet is extremely cheap. The downside is ... what? If I accept your argument, then there will never be any commerce or contact anyway. The upside is that the probability that they will destroy my planet is now zero instead of some positive value. Unless there is something to be gained by letting another civilization live (as there certainly is between civilizations on Earth), it's clearly rational to destroy them.

Re:you mean...

[Above]

Bah.

The answer is easy, 42. It's nice you finally found the question.

Re:you mean...

[spike hay]

An alien civilization would have to be more zenophobic than the Vogons to bother destroying earth. Intersteller travel is very expensive. They would have to be extremely violent to expend the amount of energy needed to reach earth and destroy us.
Intersteller distances are huge. You have to go thousands of times faster than chemical rockets to be able to practically do it. While it may not be so bad to send a 10 lb. reasearch probe at 50% of the speed of light to another star, sending a 500,000 ton Galacton Battlecruiser to 50% C and slowing it down again at Earth is a difficult proposition, for all but the most advanced type II civilizations with Dyson Spheres. If you are using Fusion, you would have to have around 99% of your vehicle mass fuel. But thats just to accelerate it. You also have to slow it down, which means, factoring in deadweight and fuel tank mass, only 1 millionth of the Galacton's shipweight is payload. The only intersteller craft that can be practically scaled up that large is a laser sail. Fusion powered craft of that size that are capable of stopping at their destination would require quintillions of tons of expensive deuterium and tritium.
To send an earth-destroying ship, you'd need a Dyson Sphere to provide around a quadrillion watts of power for a laser sail. The craft would then proceed to drop around 20,000 thermonuclear bombs on earth. Alternately, if they really wanted to "take care of" earth, they could build a dyson sphere around the sun and focus the entirety of the Sun's energy on earth.

A civilization that is interested in destroying life on earth would probably have blown itself up long before it has the capability to do so. Look at us: We are not that violent. We would certainly not wipe out E.T's. Yet even we came perilously close to ending civilization a few times during the cold war. Now a civilization so violent that it would be interested in expending the immense amount of energy to make us extinct would have most likely blown themselves up long before they had the technology for intersteller travel.

Re:you mean...

[mikec]

This is just wrong. There is no reason to send a "ship". There is no reason to slow down. Find a metallic asteroid a few hundred feet in diameter.
Accellerate it to 0.9c using any of a number of fairly crude methods of propulsion. Mount a small guidance system capable of hitting a planet the size of earth. Wait.

Re:you mean...

[kesuki]

Of course Lexx explains this pretty simply We're a type 13 planet in the middle of the darkest part of the dark universe. Meaning any other habitable planets nearby would also have been type 13 or close to a type 13 that generally blow themselves up, or dissapear (into a black hole) when attempting to create singularities to study.
Disclaimer: they didn't use that wording exactly, but I took it to mean as such.

Re:you mean...

[Soft]

There is an interesting (and somewhat depressing) answer to the Fermi paradox in Stephen Baxter's "Space": interstellar spaceflight is reasonably practical, advanced civilizations do evolve and expand, and would potentially last a long time, except that before they have time to really spread out and develop StarTrek-like gadgets such as faster than light travel, defense shields, etc., a gamma ray burst occurs inside the galaxy, sterilizing everything within, and everybody starts over. That would account for the lifetime part of the equation, I guess.

Re:you mean...

[Mark Hood]

2. If such civilizations last a long time, and "They" are not "here" then it becomes necessary to explain why each and every technological civilization has consistently chosen not to build starships

Or maybe it takes the age of the galaxy so far, to get to where we (the human race) are now... and so no-one's been able to build starships yet.

I admit it's unlikely, after all - we're out on the fringes of the Milky Way, and so it might have taken longer for iron, carbon etc to form in stars out here, leading to rocky planets and sentient beings, but maybe it takes longer than we think... In other words, might we be the most advanced civilisation within detection range?

Seems unlikely though...

Re:you mean...

[Pastor Fluff]

Of course, according to DNA, N ends up at zero.

"It is a known fact that there are an infinite number of worlds, but that not all of them are inhabited. It therefore follows that there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to zero as makes no odds, so that if the average population of each world is equal to zero, then the total population of the universe must also equal zero, and that any individuals you may meet from time to time must be the products of a deranged imagination."

Re:you mean...

[danielrose]

what is that from? the answer to the meaning of life is 42... ??? i forgot :(

I claim this planet in the name of ... ME!

[Malic]

I want my own planet. Of course, you're all invited as guests - I should have plenty room.

Re:I claim this planet in the name of ... ME!

[pyros]

Do you have a flag? No flag no planet! Those are the rules I've just made up. And I'm backing them up with this gun lent to me by the National Rifle Association.

Re:I claim this planet in the name of ... ME!

[pyros]

correct for 10 points. ;P

Re:I claim this planet in the name of ... ME!

[lain_iwakura]

"Lain could kick Neo's butt"

But... I wouldn't. Why would I do that? I'm not that way, am I?

Re:I claim this planet in the name of ... ME!

[NevDull]

Hopefully you're not claiming it in the name of Windows ME. If so, I'm sorry to say it'll be End-of-Lifed when economically advantageous to Microsoft.

Re:I claim this planet in the name of ... ME!

[Dolly_Llama]

If you want your own planet may I perhaps suggest you become a mormon?

From this website

Celestial (Heaven) - for Mormons who have kept ALL of the laws and ordinances of their church. What will the celestial heaven (kingdom) supposedly be like for a good Mormon? He will be a god, he will rule over a planet with his wives and spirit children.

laugh, its a joke

Re:I claim this planet in the name of ... ME!

[SpacePunk]

Yeah, go with him. I'm tired of you people cluttering up my planet.

-

Re:I claim this planet in the name of ... ME!

[mother_superius]

*points*

Now YOU will feel the wrath of the Slashdot Effect!

Ha .. better yet ..

[TheViffer]

we need to find them first before we can see them

:-P

Yes, and?

[govtcheez]

Billions and billions of Jupiters...

If only we could live on Jupiter

Wake me up when we find billions of Earths...

Re:Yes, and?

[infochuck]

If you had actually READ the article before scrambling to get in an early post, you'd have noticed that they said, several times, that there are likely just as many Earths...

Re:Yes, and?

[goldspider]

That's why the article is about "how many potentially habitable planets exist in our galaxy" and is titled "Billions of Earths could be out there."

Next time read more than the first sentence of the story, moron.

Re:Yes, and?

[govtcheez]

I did read the article...

My point is that just because there could be billions of Earths, sure as hell doesn't mean there are.

Slashdot's proof of this - there's billions of trolls, but that doesn't necessarily mena there's anything worth reading.

Re:Yes, and?

[Verteiron]

And for that matter, maybe even just as many Saturns and Neptunes. Uranus is probably rarer due to its bizarre axial tilt.

Re:Yes, and?

[Angry Toad]

I read the story, and the paper itself.

The whole business with "billions of earths" is just so much media noise. It was put in by the reporter to act as an attractive theme for the story.

The paper has nothing to do with terrestrial planets, and has precious little to say about them. What it is is the latest in a series of very interesting analyses of the bulk dataset of extrasolar planets collected thus far. Lineweaver argues that portions of the dataset are biased due to observational artifacts (primarily that they haven't been observed long enough yet or with sufficiently powerfull technology). When these portions are left out or are "corrected" with some very basic assumptions, there is a trend in the data which appears to indicate that low mass (ie Jupiter-sized), long period, low eccentricity planets may be very common indeed.

Nothing to say at all about terrestrials. Maybe, maybe not, but the issue is irrelevant to the science at hand.

Anyone who is really interested in extrasolar planets should go get the preprint. Some of the figures are just stunning - they look like the start of a real "Encyclopedia Galactica".

Re:Yes, and?

[Angry Toad]

Sorry to reply to my own post, but just for clarification before somebody jumps down my throat: By referring to Jupiter as low-mass I meant in relation to the large number of >2Mj planets discovered thus far.

Re:Yes, and?

[zeno_2]

I think your proof is wrong, it should be more like, "There could be billions of great minds that read slashdot, but that does not mean theres anything worth reading"

Well I don't live on this planet.

[TenPin22]

I live in a Slashdot world.

this is a WAG, nothing more, nothing less.

[Em Emalb]

"For now, no one knows whether our solar system represents a common method of formation and evolution. In fact, discoveries over the past six years seem to indicate otherwise. Most of the roughly 80 planets discovered outside our solar system are much more massive than Jupiter. They also orbit perilously close to their host stars, locations that would likely prevent rocky planets from forming in so-called habitable orbits.
But experts attribute these findings to the limitations of technology. "

Hmm, WAG anyone? Wild assed guess for those that are AC (Acronmyn-Challenged).

I would bet a terabyte of New Zealand Sheep porn that tomorrow there will be 500 stories debunking this. More "proof by way of media" sounds like to me.

I loved this comment:
'?Our solar system is Jupiter and a bunch of junk,? as Lineweaver puts it.'

Yeah baby, I live on a hurling mass of yesterdays dinner and some junk mail....wohooo.....

Re:this is a WAG, nothing more, nothing less.

[Mr_Matt]

Hmm, WAG anyone?

More properly, a SWAG. You seem to have acronyms on the brain, so you can figure that one out. :) Actually, they qualify it pretty well, I think - they state that the 80 or so planets they've discovered are far larger than Jupiter/closer to star system, yadda yadda. But they're right - the only reason they see these planets so frequently is because they're the only planets we can currently see. IIRC, the method they use to detect planetary objects is to subject the emissions of the star to very precise Fourier analysis, or other frequency analysis, and thereby detect very slight frequency shifts in detected emissions - Doppler shifts corresponding to slight motions of the star due to the influence of the planet on the star. Naturally, that influence is small, and it's only measurable above the noise floor, currently, if the planet is truly ginormous. Smaller planets don't influence stars enough that we can see it with current methods - so their statement stands, I'd say.

I think the real question is this: why the heck do you posess terabytes of sheep porn? :)

Re:this is a WAG, nothing more, nothing less.

[Em Emalb]

"I think the real question is this: why the heck do you posess terabytes of sheep porn? :)"

Why, to put up on my lego webserver of course ;)
*rim-shot*

ok, enough of me for today

Re:this is a WAG, nothing more, nothing less.

[Tackhead]

> For now, no one knows whether our solar system represents a common method of formation and evolution.

True. And as for habitability, has anyone considered the importance of plate tectonics and tides for life? Or the possibility of a causal relationship between massive collisions early in a planet's existence, and extended periods where plate tectonics continues?

Compare Earth, Venus, and Mars:

Venus: Probably no massive collision early in its life. Boring world, no way for CO2 to be recycled into a big liquid water carbon sink. Looks geologically-dead.

Mars: A mostly-geologically-dead world, too small to retain much of its original heat, and, of course, no massive collision early in its life. Had liquid water once upon a time.

Earth: Smacked by a Mars-sized impactor early in its life. Debris coalesced to form huge satellite called "the Moon". Frighteningly geologically-active. Big-ass oceans sink lots of CO2. Plate tectonics keeps it underground rather than letting it vent into the air.

A sample size of "three" is pretty slim, but to my (untrained - any exogeologist-types out there care to comment?) mind, the facts that Earth got whacked and the fact that the Earth still has a thin crust (while Mars, and more interestingly, Venus, have cooled off) appear to be more than coincidence.

Bring in an exobiologist -- perhaps "tides" (think "tidal pools" are handy for forming life. Also think about the impact that tectonic activity (and life) has in recycling CO2 on Earth.

Does anyone know if Earth's core is "too hot" to be accounted for simply by heat from 4.5 billion years of radioactive decay of its initial components?

I'm speculating that the impact that created the Moon also added a metric buttload of heat to the still-forming planet's core, while simultaneously stripping the proto-Earth of some of its lighter silicates. If the impactor came from "far enough away" in the solar system, it may have brought a metric buttload of water ice with it. The result was a glob of metal-enriched rock, water, water, everywhere, a double-planet system with tides (useful for future development of life) and recycling of crustal material via plate tectonics due to the planet's thin crust.

(jumping off the deep end into wild-ass speculation now...)

Perhaps this is another reason to go to Pluto. Perhaps the Pluto/Charon system formed in a manner similar to Earth/Moon. If we found evidence that Pluto had a metallic core, and that it was warmer than could be accounted for by radioactive decay...

If we assume (or can demonstrate) that things like plate tectonics and tides are "good" for the formation of life (at least, they seem "better" than the situations on Mars and Venus that arose from the lack thereof), it'd be nice to know that early massive impacts were common. It'd be even nicer to know that there was a correlation between such impacts and "warm" planets with lots of water.

(Sigh... still holding out for the day we see the spectrum of light reflected from a rocky planet in orbit around another star... a spectrum showing lots of oxygen that should have reacted itself away by now unless something on the planet's surface was replenishing the supply...)

Re:this is a WAG, nothing more, nothing less.

[GeekLife.com]

Yeah, no mention of the fact that the only way we've detected other planets is through their gravitational influence on the stars their orbiting. Obviously any planets we detect will have to be huge, until we have the technology to detect smaller planets. It's ridiculous logic to draw a conclusion then that most planets out their are huge.

Re:this is a WAG, nothing more, nothing less.

[Winged Cat]

Heck, even when we're inhabiting other planets (permanently, or at least for several years at a stretch) with massively expensive and sophisticated gear to sustain life, we'll have a better picture than we do now...

Re:this is a WAG, nothing more, nothing less.

[rho]

I'm more interested in that terrabyte of NZ sheep porn, myself...

Re:this is a WAG, nothing more, nothing less.

[orkysoft]

Earth: Smacked by a Mars-sized impactor early in its life. Debris coalesced to form huge satellite called "the Moon".

Then why does the moon have an entirely different mineral composition?

Re:this is a WAG, nothing more, nothing less.

[Tackhead]

> Then why does the moon have an entirely different mineral composition?

The Moon isn't a remnant of the original impactor, it coalesced from debris thrown off after impact.

D00dz with a hell of a lot more computing power than I have have done computational fluid dynamic simulations of an off-center impact of a Mars-sized impactor on a mostly-molten proto-Earth with a bunch of silicates floating on top of a more dense core.

The most common result is that the two bodies coalesce, but with a lot of crap (particularly from the upper, silicate-enriched layers of proto-Earth) thrown into orbit.

That is, what we see today, namely an Earth with lots of metals, and a silicate-rich moon.

(This makes sense -- the competing theory to the impact theory is that the Earth and Moon formed simultaneously out of the same accumulating cloud of dust. One of the reasons this theory has been deprecated in favor of the impact theory is that it doesn't account for the mineral differences between Earth and Luna.)

MSNBC has an interesting article

[ackthpt]

Hmm.. I know there are lots of dreamers and well wishers that there's friendly, intelligent life on other planets..., but I just had the thought...

What, if any, businesses are preparing to exploit that life, if possible. This shouldn't seem such a far out idea, after all, 500 years ago someone set sail with three ships across the Atlantic and look how ill-prepared they were for what they found.

Suppose M$/MSN has a plan to spread influence extraterrestrially?

Shudder.

Re:MSNBC has an interesting article

[amuro98]

Suppose M$/MSN has a plan to spread influence extraterrestrially?

Does this mean they'll discover that space is round, and not just a mostly flat (albeit "bumpy") field? :)

Why live on planets?

[Ectropy]

By the time we have the sufficent amount of technology for exploring the billions of Eaths out there, I am sure we will have plenty of technology regarding space stations. The only purpose I see in colonizing planets is for just mineral mining and for exploration. There should be no need to try and terraform or have to shape the Earth-like planets to our needs, we should just build space stations. At least then we do not have to worry about having insuitable worlds, or worlds that are unproductive. Also, a space station would be customizable for purpose and for people. There is no need to colonize many planets!

Re:Why live on planets?

[viking099]

I don't agree with this.
After all, why invest all the time and resources and everything to build a floating planet?
There's already one there, why not use it?
My money is going to be more on habitat controls than planet-sized space stations.
Here's what I see as a more likely scenario:
We find a nice planet to inhabit, pick out the most strategic locations for civilization hubs, send in teams to build the hubs, and slowly expand the hubs as people come in.

So to sum up:
We're probably going to colonize planets one at a time, and live on a solid, natural surface. We are not going to build a zillion death star type space stations and live life zipping around the cosmos.
but hey, I'm always up for a debate...:-)

Re:Why live on planets?

[orkysoft]

Maybe people like those Big Blue Rooms?

Re:Why live on planets?

[apsmith]

But we only live on the surface of the planet, which catches only a tiny fraction of the energy the sun makes available; in the long run there's a lot more room out there between the planets than on them, and I hear the view is spectacular...

Re:Why live on planets?

[_Mustang]

Why not take this the step further, and build a dyson sphere?

After all, there's not a massive tech leap between able to terraform (a la Star Trek genesis device) and building such a massive undertaking as the dyson sphere. Of course, the question then becomes one of supply. Does it really make sense to use all that material to build when it could instead be used directly for some venture or the other...

Re:Why live on planets?

[znu]

I expect by the time we have useful interstellar travel, we will have reached the point that raw materials and construction are essentially free. Building space habitats is cheap with the right tech. All you do is set a few self-replicating robots loose in an asteroid belt. Of course, teraforming planets is cheap too, with that kind of tech (plus the sort of biotech we'd probably have by then), but it still takes a really long time.

Maybe if the planet is earth-like enough that you can just land, go outside in your T-shirt, pitch a tent and stay the night, it'll get colonized. But there isn't much point if you have to do any serious work, like, say, replacing a reducing atmosphere or getting more water from somewhere.

Re:Why live on planets?

[sheetsda]

I think we'd become the nanites in the Grey Goo scenario, only we'd be able to jump from planet to planet. We humans tend not to know when to quit exploiting something for its resources. Or is there nothing wrong with doing this to an uninhabited planet? (I'd like to hear opinions on that)

Re:Why live on planets?

[delcielo]

What a drag!

Technically, I'm sure you're correct. By the time we are able to travel to other planets, they will probably not be a necessity; but what a bleak picture of life that presents.

I guess I have too much affection for sunrises, rivers, mountains, cool breezes, etc.

Re:Why live on planets?

[Bill Currie]

No, instead it will be destroyed buy some hick kid haunted by ghosts firing a torpedo down your chimney.

Re:Why live on planets?

[darkwiz]

Gravity.

There are a number of problems with space colonization, but one of the killers is gravity.

But what about oxygen, food, etc you may ask?

Gravity takes care of the containment for you. Your gravity isn't going to spring a leak and start venting air away (assuming it is great enough to hold it in place at a proper pressure).

Further, without physical stress (ie: weight) bones/muscles deteriorate requiring more maintanence to keep the human colonists functional.

Food: A planet provides a MASSIVE surface area with which to grow crops (even if the soil is unarable, large hydroponics systems could deal with it). A self sustaining station would require massive amounts of materials to make a farm large enough to feed its inhabitants. Let alone if a small asteroid came along and broke the ceiling out of your greenhouse...

Assuming you aren't eating nutritional pills by then.

Re:Why live on planets?

[Eccles]

Why not take this the step further, and build a dyson sphere?

No gravity inside a sphere. Ringworlds make more sense.

Re:Why live on planets?

[Xerithane]

Yeah man!
Space habitats want to be FREE! I think I'll start a grassroots GNN effort, 'Gnu's Not Nasa'.

Re:Why live on planets?

[roman_mir]

Asimov's Nemesis? What about the Niven's RingWorld? Doesn't it make sence to live close to a star to derive as much energy from it as possible?

Re:Why live on planets?

[Restil]

Planets are much larger than space stations.

Planets have more available resources than space stations.

Planets with a proper ecosystem naturally recycle the elements needed for life, mainly in our case, Oxygen and water.

While a 6 mile wide asteroid can cause serious damage to both space stations and planets, planets are pretty damn impervious to baseball sized rocks (of which in space there are many many more) where space stations can be quite devestated by them.

The magnetic fields and atmosphere of planets filter out a lot of dangerous radiation which space stations need to take special care with.

Planets aren't going anywhere quite yet I feel. :)

-Restil

Re:Why live on planets?

[brunes69]

Just because resources are free, does not mean they ar eunlimited. There is a finite amount of bas emetals in the earth, such as iron and soforth. Removing enough to construct the space stations you describe (enough to hold a planet's worth of people) would require the resources of more than one planet.

Re:Why live on planets?

[Pope]

you can just land, go outside in your T-shirt, pitch a tent and stay the night

Ah, so we will discover Raisa after all!

Re:Why live on planets?

[anno1602]

First, definitions:

- inhabited: A form of life (however primitive) exists on the planet
- inhabitable: The planet can theoratically sustain above-mentioned life.

Uninhabited, but inhabitable planets are out of dicussion for exploiting. Even if we choose not do inhabitate them, a different civilisation might try to do so, or life (however primitive) might still form. And remember: Before you are able to give life, don't try to take it away - even not the chance of its existing

Uninhabitable: I think it is OK to exploit uninhabitable planets for our pourposes. However, it might be very difficult what uninhabitable actually means - who might know if, against our current belief, life might still be able to form. And science isn't the answer, because a main feature of science (and its strength) is that it can be wrong.

Anno.

Re:Why live on planets?

[jx100]

Well, you could have the sphere spin fst enough for gravity

Re:Why live on planets?

[bob_jenkins]

Bingo. We can support billions of times the population of earth right in our own solar system. Terraforming planets is a waste of time.

I've been building simulators of Dyson swarms in recent days.

Re:Why live on planets?

[amuro98]

That won't provide gravity everywhere on the surface of the sphere... What you'll end up is a wide "ring" that has gravity in the middle, but as you went towards the poles, the gravity would be less and less. This is why a ringworld makes more sense, since you wouldn't have these large areas that would be somewhat uninhabitable (or at least, less desirable) due to a lack of gravity.

(actually, if you had a Dyson's Sphere, the poles would have gravity...it'd just be towards the sun in the middle, right?)

Re:Why live on planets?

[orkysoft]

Uninhabited, but inhabitable planets are out of dicussion for exploiting.

Those are probably the best planets to colonize!

Re:Why live on planets?

[mselmeci]

Yes! You're right! Not only do you need the energy to power the electronics on the space station, but sunlight is needed for photosynthesis which would be necessary in order to get a stable supply of oxygen.

Also, where would one get metals from? On Earth, there are always more metals; one just has to mine more deeply. This means that space stations will effectively be tied to a planet. No deep space living for 7 years on, sorry.

Re:Why live on planets?

[apsmith]

Planets are much larger than space stations.

So far in our experience - but planets are 3-dimensional structures with only a 2-dimensional surface we can live on, while artificial stations would presumably not generally be built to have 4000+ miles of uninhabitable basement; nor 10 miles of uninhabitable ceiling. Gaining that extra dimension of living space means space structures of admittedly large size would appear vastly bigger than planets to their inhabitants, and also to plain view if spread out two-dimensionally (which makes most sense from a solar-energy perspective), even while using only a tiny fraction of a planetary mass in construction.

Planets with a proper ecosystem naturally recycle the elements needed for life, mainly in our case, Oxygen and water.

Bring the ecosystem along - that was always the idea in O'Neill's vision, and there's nothing particularly special about a planetary surface for plant and animal life that seems impossible to duplicate in an artificial space structure.

While a 6 mile wide asteroid can cause serious damage to both space stations and planets, planets are pretty damn impervious to baseball sized rocks (of which in space there are many many more) where space stations can be quite devestated by them.

Actually, you wouldn't likely build a single monolithic station, you'd build thousands or millions of smaller "islands", each probably several miles away from the other. Even a six-mile asteroid hit would at most damage only a handful of these "islands", while it could devastate an entire planet. Think of the difference between a single mainframe and a Google-sized cluster of thousands of machines: you'll have more faults on the individual machines, but the whole structure will be far more resilient. Plus each station could be mobile enough to avoid major collisions (a lot easier than moving the asteroid itself - or the planet!) And there are lots of proposed ways of handling smaller collisions that wouldn't be terribly devastating. Cover the surface in lunar rubble/dust, for example, rather than solid metal, and you'll stop most medium-sized objects in just about the distance you need for radiation protection anyway.

Obviously all this is in reference to rather large-scale astro-engineering which we're nowhere close to right now - but maybe by the end of this century?

Re:Why live on planets?

[Hydrogenoid]

Assuming you aren't eating nutritional pills by then.

Of course not... Photosynthesis rules!
Green skin for everybody is the way to go...

Re:Why live on planets?

[danielrose]

Space habitats want to be FREE! I think I'll start a grassroots GNN effort, 'Gnu's Not Nasa'.

That's 'GNN's Not Nasa' buddy!

Backwards

[Anonymous Coward]

I think you'll find that history bears out that it was those on the American continent who were wildly ill-prepared for those who found them.

Old Hat

[stipe42]

This article doesn't present anything more than the now cliched "well if just one percent of stars have planets and one percent of those are in a habitable zone and . . ."

The only original take is that those 'one percents' are getting replaced with percentages actually based in reality.

Speculations like this used to be popular because astronomy was nowhere near the technology needed to actually see planets out there. If I remember correctly, the first true proof of planets around other stars occurred around 1995 when these first gas giants started to be detected.

With the detection methods getting better every year though, it's only a matter of time before we can directly detect terrestrial sized planets around other stars. That's the point where these statistical guesses get kind of silly.

"I bet there's a thousand planets out there!"

"Actually, there are 1422. We can just count them now."

stipe42
www.pcwatch.com

more than half

[Paradise Pete]

The most remarkable fact from the article:

We found that of all planets just reaching the dawn of their personal computing era, more than half of them have a whiney guy in glasses writing letters to magazines complaining about people not paying for his BASIC interpreter.

Re:more than half

[meadowsp]

You're alright. It's not funny.

Re:more than half

[meadowsp]

No, I do get the reference, Bill Gate's letter to hobbyists. Still doesn't make it funny.

The article did not state any such conclusions...

[RyanFenton]

Regarding earth-like planets with water and rock, the article stated:

...They may be as common as Jupiters, or they may be much less common.

Alan Boss, an expert in planetary system formation at the Carnegie Institution of Washington, said the new calculations for Jovian twins seem reasonable. Trying then to estimate the number of Earthlike planets requires "a leap of faith, but one which appears to be plausible," he said.

So the headline was a bit much in this case.

:^)

Ryan Fenton

Being out in BFE helps too...

[Maryck]

The guy is right that having Jupiter as a shield definitely has made a difference in Earth's ability to support life over the long term; however, he doesn't touch on what might the more significant fact: our solarsystem is located in the boondocks of our galaxy. What this means is there is a whole lot less debris floating around to smash into earth. The closer you move towards the galactic core, the more crap there is and the less effective a Jupiter shield would be.

Re:Being out in BFE helps too...

[gorilla]

This is true, however, as the outer layer of any shape has the largest volume, then there will be no shortage of solar systems out here in the boonies.

Re:Being out in BFE helps too...

[The Kow]

Actually, yes and no.

The stars closer to the center of the galaxy are incapable of sustaining life within their system. Most of the stars towards the center of the galaxy are far too young to even have planetary systems, yet.

The population of the universe is 0...

[Anonymous Coward]

From Douglas Adams...

Number of Planets in the Universe = infinity
Number of Populated Planets in the Universe = N

n
--------- = 0
infinity

Re:The population of the universe is 0...

[unitrcn]

The universe is not infinite, just simply unbounded, according to most modern astronomers. So the real ratio, while still likely to be small, is not so small as to be insignificant.

Re:The population of the universe is 0...

[falzer]

You just calculated that 100% of the states are populated.

Re:The population of the universe is 0...

[Skip666Kent]

I was always annoyed by the little dead bugs or bits of food I would occasionally find stuck between pages.

Oh well.

Astronomy

[Anonymous Coward]

Face it, most of astronomy is based wholey on WAGs. Even Hawking admits most of his stuff is WAG.

.

why are we always the primitive society in sci-fi?

[augros]

so the argument goes that since jupiter in some manner made life possible for earth, and total destruction for many other planets . . . this doesn't sound like a very intelligent way of going about it at all! "Hey, let's find all the giant planet destroyers because they sometimes, in very rare and complicated circumstances, factor into making possible in their own limited way!" somehow, i don't think so.

How many?

[Insightfill]

...Billions and Billions...

</sagan voice>

Boy, I'll miss that guy! One of the many people who triggered lots of tech interest in me and made me who I am!

Re:How many?

[Rude Turnip]

Are you kidding me? I'm glad that bastard is finally dead. Oh, sorry, I thought you said *Sengan*.

Re:How many?

[__aaeaks4554]

Sagan made you? He made a pass at me but I turned him down.

Mod this -1 for off topic.

High estimate...

[Arcturax]

Very high... 30 billion jupiters != 30 billion earths. Just because there is a jupiter sized world (even assuming similar orbit instead of an insanely close orbit to the star) doesn't mean anything else useful formed inside its orbit. However if even .01% of those have conditions even approaching those required for life (like Mars) then chances are good for there to be hundreds of even thousands of intelligent species out of maybe a few tens or hundreds of million worlds of most likely algae and microbes.

So in short, I think this guy is nuts to suggest billions of earths. Maybe millions (tens or hundreds) in the venus->mars range but not billions.

Re:High estimate...

[Arcturax]

Oh but before I make a fool of myself, IANAA (I am not an astrophysicist) hehe

Re:High estimate...

[praedor]

I suppose it depends on what you mean by "intelligent". Dinosaurs were intelligent, so were mastadons, so are dogs and cats and gorillas and birds. If you mean intelligent as in technologically adept as human animals are, there is no reason to assume that there are a lot of those.

If it were not for an accident 65 bya, there would be no humans and dinosaurs might well STILL have run of the planet. There is NO imperative for technological intelligence or development for that matter. If not for the Europeans coming to the North America, the native Americans would still be quite healthy and happy living as the always had - they had no technological development beyond what was necessary and useful to them. The Commanche were not technologically superior to the people of Mesa Verde/cliff dwellers simply because they came later. I am not in any way dissing native Americans but am simply making a point...if not for the Europeans with THEIR accidental technologically-based society coming to North America, the natives would most likely STILL be living as they have for hundreds of years.

So, there may well (and likely is) many habitable planets. There is likely MANY locations with some form of life. It does NOT follow that there must be lots and lots of technologically advanced societies. A few here and there, perhaps, with an unknown fraction of those killing themselves off due to war or polluting themselves out of a home, with the survivors being few and far between.

That said, there is no reason to assume a priori that they would be any better about space exploration than we are. It is COSTLY to go into space. It is especially costly to put people into space. It is EXTREMELY costly to colonize space. I would also doubt that there is any spiffy way around basic rules like lightspeed barriers, etc, so it is not even a given that their spacecraft, robotic or not, can get very far in any reasonable amount of time. There is no reason to assume that machines can ever be produced that would be so much better than living things at self repair (EVERYTHING makes mistakes and they are usually detrimental - evolution isn't as simple as saying "machines will make mistakes self-replicating in a way that will permit evolution to occur there too). So some technical society launches a probe to a nearby star. Maybe it gets there within a reasonable amount of time so that those back home are still willing and able to listen to its transmissions back. Maybe they launch it and then collapse and the whole project was moot. Maybe they go for a while, expand a little within their solar system and then slowly crap out...millenia before WE came along. We just missed them by a few thousand years.

The real possibilities are endless and at least some of what I am stating here addresses the Fermi Paradox (which is, of course, itself based on the false assumption/conceit that advanced intelligence means technology which means space travel, etc). Dinosaurs, et al, were HIGHLY intelligent and advanced compared to cyanobacteria. They were HIGHLY advanced and intelligent compared to virtually everything that came before (and many that came after).

There is NO technological imperative in biology/evolution.

Re:High estimate...

[spiro_killglance]

"There is NO technological imperative in biology/evolution."

Are you sure, given war or more gentle competition
between to cilivisions, technological advance is
a huge factor in who wins.

Now, I grant you that there is no biological
imperative to the creation of an animal with
the general inteligance need for technology.
However once a speices as general inteligance
and comminication, then there pretty much going
to try every way of living they can think of
and once that happens you get evolution (of the
Lamacken kind), appling to cilivisions. Wile
any of the intelligent speices is free to try
new things, the evolution of the cilivision to
a technology advanced form is pretty much forced, by war or competition.

Re:High estimate...

[Arcturax]

Yes there is, in a group of animals like humans, he who has the biggest rock or spear or gun wins in most cases.

Europeans were not the only ones to develop technologically. The Egyptians and some African cultures became quite sophisticated for their times. As did the Chinese, who by the way, invented the gunpowder that helped make Europe so powerful later on when they learned the secret from them.

Back when Europe was still mired in the mediocraty of the dark ages, the Arabs were the best astronomers in the world (except maybe the Chinese). See all those stars up there? A lot of the names of them are Arabic because they were studied and charted by the Arabs back then.

The Aztecs and Incas and Mayans also had some interesting advances of their own. Given time they would have developed technology on their own as well.

Oh and by the way, Europeans didn't hurt the Native Americans near as badly as the diseases the Europeans brought with them. Influenza and smallpox is what really devastated the native Americans more than the settlers ever did on their own. If that had not happened, they may have well adopted enough of the technology quickly enough to repel the Europeans eventually.

As for the dinosaurs, 65 million years is a long time. Had that asteriod not hit, who is to say that some species, likely the raptors (who were already smart enough to work in groups), would not have developed the capacity to start building and using tools and fire, ect.

I think technology is simple a next step in evolution when you get advanced enough animals. Without it, humanity would not have colonized this planet like ants the way they have now.

Re:High estimate...

[praedor]

It is irrelevant that the Chinese came upon gunpowder first.
It is irrelevant that the Vikings arrived in N. America looong before
Columbus and the other Europeans. It is irrelevant that the
Egyptions were technologically quite advanced for the day. Why?
Because it didn't carry forward.

It was the Europeans that took off and made something "special"
from gunpowder - a cultural thing. Nothing lasting came of the Viking
travails in N. America. It left no lasting historical impression. It's an
interesting footnote. The Egyptions faded away and it was the Romans
and Greeks that carried the day. After the fall of Rome, the Chinese
were the most developed (and the Japanese?) but it didn't go any farther.
It was stagnant and had no lasting impact beyond spurring trade (for
silk and later heroin) and giving the Europeans gunpowder.

It was a cultural accident that it was the Europeans that took
off technologically. The Chinese had thousands of years to go virtually
nowhere - they were "developed" but it was stagnant.

If not for a few historical and cultural accidents, the Europeans
would not have driven the world into the present technological state.
The Chinese would still be as they had been for thousands of years, and
Native Americans, never seeing/experiencing Europeans, would still
be quite happy and healthy in their technologically simple lifestyles.

The world is as it is ONLY because of a few accidents: an inopportune
comet wiping out the undisputed champions of earth mastery, the dinosaurs,
the accident of evolution that led to a runnaway brain in hominids, and the
accidents of history and culture that led to technological development
that we have today.

Accidents all.

Re:High estimate...

[Squiffy]

Just because it required a series of accidents doesn't necessarily mean that it was unlikely to happen. To prove that connection you would need to present a comprehensive, cogent analysis of all of the possible ways technology could have developed on Earth, and show that the events necessary for it to happen were altogether unlikely.

Besides, before a an organism or group of organisms becomes conscious of its own actions, *everything* it does and *everything* that happens to it is an accident (barring acts of some deity, the possibility of which we should ignore lest it render the entire discussion moot). Does that mean that the dinosaurs couldn't have developed intelligence similar to our own? Does it mean that the development of our ability to group together and plan intelligently was unlikely? Or that learning to make and control fire required some serendipitous turn of events?

Just because the Europeans became technologically ambitious first doesn't mean that no one else would have.

Re:High estimate...

[praedor]

One of the main theories on human brain evolution holds
that it came about from a biological/evolutionary self-reinforcing
feedback loop. It took ~4 billion years for something like that to
happen on earth. It didn't occur multiple times (apparently),
there's just us.

The dinosaurs had a few hundred million years for ONE species
to develop a complex brain, but the Cretacious dinos were not more
intelligent/advanced than their Jurrasic predecessors. There is no NEED
for an especially large brain. Evolution, biology, life does perfectly fine
(better than fine) without brains at all (see bacteria and fungi). It
does extraordinarily well with really basic brains (see insects). It is
a biological/evolutionary accident that we have the brains we
do and if you were to reset the clock and totally remove us from the
picture, there is absolutely no reason or assurance that something
like us would reappear ever again.

Sure, there have to be odds in favor of some species of dinosaur
taking off and developing a human-like consciousness and intelligence
but what are those odds? All we have to go on is us - and again, it took
until now, >4 billion years for it to happen and ONLY after the original
planetary dominators (dinos) were taken out.

As for Europeans and technology, it is as I said, a cultural and historical
accident that they were the ones to take technology and run with it. The
Chinese had thousands of years of history to take off, but didn't. The Native
Americans had thousands of years to take off, but they remained happily
stone-aged until Europeans brought in metals and took over. The Aztecs,
Toltecs, Mayans, Egyptions all had centuries or millenia to take off, and they did
to a point (just like China) and then...sat still and/or faded away.

It was due to the Romans and the Greeks, in particular, that Europe took off.
The Greek intellectual tradition and the practical Roman uses of that tradition and
practical use of technologies provided the Europeans with a nearby influence that
drove the Renaissance and the Age of Discovery. Without the rediscovery of
Greek writings, without the direct effect of the Roman finger in virtually all of
Europes history, the technological revolution would not have occured when and how it
did. Accident and chance, not manifest destiny.

If your people and culture are doing just fine living like x, there is no reason or need to develop ever-more advanced technology. Once one group did, however, it started a feedback loop itself and took off.

I'm certainly not saying it wouldn't have happened, though in a TOTALLY different manner and time, from somewhere else. But again, it may never have happened at all and yet humans would still be just as intelligent as they are now - just living stone-age or bronze-age, etc, lives. Native Americans were not less intelligent than Europeans just because they didn't have iron, or mining, or industry, and all else. The EARLY modern humans, caveman, were not less intelligent than humans today but they got along with life just fine (were here aren't we?).

Since there are odds for this happening, though unknown, there are odds that an alien living planet will develop a technological civilization. But what are the odds? There is no reason to assume they are high, and given the vast majority of the history of life on earth, I would say that the odds are definitely not high, but rather low.

Low odds times MANY living worlds still leads to multiple advanced alien civilizations (advanced like the Aztecs or advanced like us?) but without a real solid estimate on the habitable planet population...just guesses based on an experimental population of 1 so far.

But maybe not for that reason

[Spamalamadingdong]

Being out in BFE means a far smaller likelihood of another star passing close enough to perturb the orbits of all the planets in a system. The impact of comets can change climate briefly, but with a huge effect on life; think what a semi-permanent (until the next perturbation) change in climate could do to life which had evolved for a particular set of conditions. A few trips through an over-greenhoused state would be enough to wipe out most everything but extremophile bacteria, making it very unlikely that higher life forms (let alone intelligence) could develop.

Re:But maybe not for that reason

[j_palmucci]

See this for other reasons why the entire galaxy isn't hospitable to life.

Puh-leez!

[Cynical_Dude]

Thinking that Earth is the only inhabitable planet in the galaxy or even the universe is so last millenium.

It doesn't take a genius (just a bit of open-mindedness) to figure out that in the vast reaches of just our own galaxy (not to mention the universe) the chances are good that additional systems similar to Sol were formed.

Remember: The absence of proof is not the proof of absence.

On a lighter note, I really hope they'd hurry up and colonize another planet. Then, next time some ecologist gets on my nerves by saying: "THINK OF THE PLANET!" I can retort: Sheesh, it's not like it's the only one we've got!".

And yes, I know I stole that from Futurama ;)

Re:Puh-leez!

[mkaltner]

"It doesn't take a genius (just a bit of open-mindedness) to figure out that in the vast reaches of just our own galaxy (not to mention the universe) the chances are good that additional systems similar to Sol were formed."

I totally agree with you, but with a broader vision. Who says that the other lifeforms out there require the same environment as we do?

You never know...

- Mike

I thought it was 42

[Anonymous Coward]

maybe it's 42 billion :)

Add one more factor the the calculation

[BranMan]

I've been thinking there should be another factor to that equation. Call it fv = The fraction of civilizations that survive viral plagues.

In this century we've seen ebola and AIDS. In the previous century (IIRC) smallpox, which did a real number on the world's population at the time. We've documented the first cases of these viruses, which suggests to me that they mutated from a formerly innocuous form into one deadly to people.

What would happen today if we witnessed the first outbreak of smallpox? Or something nastier than AIDS, that only becomes deadly after an incubation period of months or years? With our current level of civilization the carriers of such diseases could infect nearly the entire planet before the first bodies started to drop. Could our civilization survive losing 90%+ of the population in every location? Could any?

Perhaps that's why we haven't found any advanced alien civilizations, or any evidence that any ever existed, yet. Perhaps they all fell victim to their own diseases.

Re:Add one more factor the the calculation

[LordNimon]

Wouldn't fv just be a factor of L? But that just goes to my other post, where I say that more work needs to be done on determining other equations for the factors of the Drake equation.

Re:Add one more factor the the calculation

[puiwah]

That seems a little too specific to me compared to the other terms in the equation. Surely viral plaques, along with other scourges such as nuclear war are factored into L, the average lifetime of a communicating civilization.

Re:Add one more factor the the calculation

[gorilla]

That's all part of "L". The lifetime of the civilization. It doesn't matter how we die, if all of humanity dies, or falls below the level of technology able to communicate, then we drop out the Drake equation.

Re:Add one more factor the the calculation

[Rupert]

That would be covered under [L]ifetime, if it happened after we started transmitting, or one of the [f]s if it happened before we became [technological | intelligent | alive]

Re:Add one more factor the the calculation

[BranMan]

I'm not sure that was actually considered when the Drake equation was put together. "L" assumes that a civilazation made it to broadcasting - or better yet colonization.

Just another factor to consider -

Re:Add one more factor the the calculation

[markmoss]

If viral plagues were capable of wiping out species or civilizations, it would be factored into L. However, diseases DO NOT kill off 100% of anything -- being too deadly is an evolutionary dead end. Smallpox and ebola are not new diseases; AIDS might be, be it's far more likely that various simian HIV viruses have been picked up by Africans who ate undercooked ape meat at various times for millenia. It was recognized as a disease in the US only when nutrition, medical care, and availability of antibiotics had eliminated so many other causes of death, and after certain sub-groups of Americans had completely abandoned traditional inhibitions about sex. There is no chance whatever of it actually bringing down our civilation. With sufficient promiscuity, AIDS or other STD's can easily wipe out a village -- but until recently most Africans didn't travel enough to make it likely to spread too far before people simply learned to stay away from those from the "sick" village, while cultures that did travel widely (Arabs, upper-class Europeans) tended to be obsessed with controlling sex...

Smallpox and the bubonic plague are real killers, but not civilation-killers. The Black Plague killed somewhere between 1/4 and 3/4 of Europeans in less than a century, but European civilation not only survived but thrived. The survivors were richer and more willing to look at new ways of doing things. Especially, the shrinking workforce forced craftsmen to look at labor-saving devices -- for instance, ironworks replaced much manpower on bellows and hammers with waterpower, and in a few decades were making more and better iron than ever before.

The early course of smallpox in Europe is not too clear, but it is clear that there were centuries when it was simply accepted that at least 50% of each generation would catch it, and over 25% would die. All it meant was that fewer peasants had to starve to death or be hanged for theft, and there were more chances for peasants to become middle class or middle class to become noble...

In north america, a whole cluster of European diseases swept through a native population with no immunities. (There may have been some deliberate attempts at germ warfare like giving away smallpox-infested blankets, but the diseases were spreading so fast on their own that it hardly mattered.) Sometimes these diseases wiped out an entire tribe in one year, when the tribe was camped in one village (and probably not eating very well either), but other (maybe better fed, or more dispersed) tribes were only lightly hit. Possibly smallpox killed up to 75% and measles, etc., brought it up to 90% on the average. That didn't end most of their cultures -- it just made it a lot easier for white men to shoot and drive off the survivors.

It is highly unlikely that any one disease will ever kill more than 75%. And a real civilization can survive that quite well. There's considerable disruption in deciding how to scale back businesses to the smaller work force and customer base, but the problems are buffered by all that inherited wealth...

Re:Add one more factor the the calculation

[Mike Monett]

" Perhaps they all fell victim to their own diseases."

Most likely they would have their own version of the FDA and pharmacutical giants. These walk a difficult line between curing someone so they no longer need doctors, or killing them through mistakes. Either way, the victim no longer contributes to company profits in a trillion-dollar business.

There are other effective ways to cure infections whether caused by bacteria or viruses. Medical science is helpless against the shingles virus, for example. But a simple circuit made with two 9-volt batteries, some distilled water, and silver electrodes cured my attack. For proof, see

http://www.geocities.com/mrmonett/shingles/0shin .h tm

Disease is not the problem. Medical science is.

Regards,

Mike Monett
mrmonett@yahoo.com

Re:Add one more factor the the calculation

[Jaysyn]

Now we just have to worry about something that we create wiping out 99% of the planet. Ever read The Stand? Captin Trip's was a real nasty virus.

Jaysyn

Re:Add one more factor the the calculation

[kmellis]

However, diseases DO NOT kill off 100% of anything -- being too deadly is an evolutionary dead end.

So? In case you haven't noticed, things become extinct all the time. The fact that being too virulent is an "evolutionary dead end" doesn't mean that a disease can't be too virulent. And you're also assuming that this host is the disease causing organism's primary reservior, which it may not be. Obviously, with a large enough host population, the chance that some will survive is almost certain. That's just probability, not due to some fanciful guiding evolutionary force that avoids a "dead end".

Re:Add one more factor the the calculation

[kcbrown]

However, diseases DO NOT kill off 100% of anything -- being too deadly is an evolutionary dead end.

Yes, but the history of the world is full of evolutionary dead ends. Just because something is an evolutionary dead end doesn't mean it won't happen. Quite the contrary: evoluationary dead ends are the norm. It's the stuff that survives evolution that is unusual, and the only reason we don't think of it that way is that the stuff that has survived evolution is generally what we find in our environment.

No, a disease that can wipe out the species is very possible, and is something that should be factored into the Drake equation.

Re:Add one more factor the the calculation

[ASM]

It is highly unlikely that any one disease will ever kill more than 75%.

Um... IIRC, Ebola Ziaire(sp) kills 90% of its victims. It's really quite nasty too. When people "Crash and bleed out" (ie die), they spew blood everywhere, along with bits of their internal organs. Inside, they tend to look like puree.

Re:Add one more factor the the calculation

[gorilla]

Fc gives the chances of an intelligent species getting to the level of technology required. L gives the lifetime of a civilization once it reachest that technology level. EVERY factor assumes that the earlier one is met, because otherwise it's just silly - you can't have intelligence if you don't have life.

Re:Add one more factor the the calculation

[markmoss]

If Ebola or any other horrific disease wipes out 90% of one village in a few days, most people from other villages will stay far away so they don't catch it... Not to mention that death rates of "up to 90%" seem to happen only when people are undernourished, overcrowded, and lack all modern medicine. "As low as" rates don't make headlines, but when WHO gets a medical team in soon enough death rates are down to 40% of those infected, and most don't get infected. In a more modern society, where it's harder to quarantine diseases, people are healthier to begin with, Ebola is somewhat treatable, and the death rate would be quite a lot lower.

When the media can't find enough real dangers, they go hysterical about Ebola. Michael Fumento
put it into perspective:

Talk about an outbreak! From the apparent inception date of the current epidemic in Uganda last October 14th to January 25th of this year, 427 Ebola cases have been reported with 173 deaths. During the same time there were over 1,900 media references to the disease on the Nexis database.

That's 11 media mentions per fatality.

...

"It's possible that someone with Ebola might leave a remote area where the disease is occurring and might even get sick here," Dr. C.J. Peters, chief of the Special Pathogens branch at the federal Centers for Disease Control told me. But, "Because our socioeconomic level allows high standards in hospitals . . . there would be a few cases but they would be controllable under our circumstances."

Ebola has as much chance of spreading in the North America as malaria does in the Arctic.

Finally, even in Africa, Ebola as an infectious disease killer is a pipsqueak.


The slow stealthy diseases can be more dangerous. Bubonic plague is exceptionally bad, because it spreads through rats without drawing much attention (most people think of piles of dead rats as a good thing), and then suddenly jumps to humans. But it's treatable with antibiotics; most Americans who catch it (a few every year, from wild rodents) survive. And at it's absolute worst, the plague didn't bring down western civilization, but probably contributed to bringing about the renaissance, the age of exploration (did the switch from galleys to sailing ships happen because of a shortage of galley slaves?), and the industrial revolution.

Re:Add one more factor the the calculation

[ASM]

hmmm. After clicking through your link, it seems that I stand quite firmly corrected. Thanks.

This has probly already been said, but...

[Eskimo Bob]

Anyone who believes that there is not an assload of planets that could possibly support sentient life is incredibly arrogant.

Anyone who believes that a "god-like being" would only create life on a singular planet is even more arrogant.

Anyone who believes that we will be able to easily find them within the next century is naive.

Anyone who thinks that people will be sent to any such planets found within the current century is a tool.

Remember, the earth is not the center of the universe (unless of course, all points in the universe are equidistant from every other point, then every point is the center of the universe, which would really mean it has no center. But what are the odds of that...).

That being said... I wouldn't mind taking a ride on a monkey fueled liquid nitrogen cooled rocket sleigh to some far off planet and get it on with alien chicks with 2 bellybuttons, like William Shatner.

Re:This has probly already been said, but...

[John Harrison]

Anyone who type like you do is simply trying to annoy me and attract attention due to visual cues rather than content.

Really, it is annoying.

Re:This has probly already been said, but...

[mashedpotatoes]

Anyone who believes that there is not an assload of planets that could possibly support sentient life is incredibly arrogant.

Anyone who assumes that because the Universe is big, there MUST be many habitable planets assumes too much.

I would like to believe that there are zillions of habitable planets and many of them host intelligent life. Unfotunately, life is pretty damned complicated and we don't have a clue how it began. We absolutely cannot predict how many habitable planets there are and how many of those support life.

Anyone who believes that a "god-like being" would only create life on a singular planet is even more arrogant.

Anyone who thinks that IF there is a "god-like being", he can KNOW that god's motivations is equally arrogant.

I don't even believe a "god-like being" exists. If such a being does exist, who can say if it made one or two or ten billion inhabited planets? At least "people of faith" have some documentation. Your assertions are pulled, presumably, from your arse.

Re:This has probly already been said, but...

[mashedpotatoes]

My point wasn't that the "documentation" is accurate. It just annoys me when someone claims to know the truth of the origin of the universe.

I don't believe in creationism, because there are more observable explanations for how the universe came to be. However, my belief system is no more proven then the creationists.

Jupiter-like planets offer 2 chances for life

[Jason Levine]

As the article says, Jupiter-like planets can act like a debris-magnet to protect Earth-like planets from comets, asteroids, and the various other junk floating around solar systems. Their immense gravity can either force and object out of the solar system entirely or force it to collide with the large gas giant. (An impact which would leave Earth near-barran for centuries is barely felt on Jupiter gas giant.)

The moons of the Jupiter-like planet offer another possibility for life. Like Europa, gravitational stresses from orbiting such a large planet can cause heat to warm up a normally frozen world. This heat might help melt ice into water (as is thought to be on Europa under the ice shell). And where there's water, life might not be far behind.

Now this isn't to say that life=intelligence. We might be talking about the ET equivalent of bacteria, here. Still, the discovery of ET-bacteria would be a huge matter.

Hadn't we better lie low?

[JThaddeus]

Another habitable planet might be a good idea but we (apparently) won't be needing it very soon (barring the actions of the Bush EPA).

Frankly, I've always wondered why the rush to find other civilizations. Unless we confidently expect to be able to do to them what Cortez did to the Aztecs, I think the best idea is to hope the Earth stays hidden from prying eyes. Afterall, we may be Aztecs to them! And since when has a lesser civilization benefitted from meeting a superior one?

Re:Hadn't we better lie low?

[Kheldarstl]

I just finished reading "The Forge of God" and "Anvil of the Stars" by Greg Bear, both of which deal with this issue. Should we on Earth broadcast radio signals like a baby crying in the woods, when we don't even know if there are any wolves loking for a quick snack? The best example I can think of from human history is th Hawaiians who were technological inferior defeating Cook who was technologically superior to them.

just my $.02 worth...

Keith

So?

[BigChigger]

Doesn't matter how many there are if we can't get them. BC

before you go bonkers about this

[Theodore Logan]

...and deduce that there are quadrillion intelligent lifeforms out there, remember what Fermi said about all these fancy equations (and that has later become known as "The Fermi Paradox"):

If there are aliens, where are they?

Sounds silly? I agree. Sounds like "The Fermi Paradox" is too fancy a name for a natural objection? I agree on this too. However, when you think about it, it becomes fairly obvious that it really is the only argument in this debate that is somewhere between strong and very strong.

Re:before you go bonkers about this

[sheetsda]

If there are aliens, where are they? ... However, when you think about it, it becomes fairly obvious that it really is the only argument in this debate that is somewhere between strong and very strong.

I don't know if there are any correlaries to this Fermi Paradox, but based solely on your post I think Fermi made waaaay too many assumptions. Lets see...

• They're not advanced enough for us to locate?
  
• They're too advanced for us to locate?
  
• They don't want to be located or at least located by us? (as in actively seeking to hide)
  
• They don't care to be located? (as in not hiding but not shouting "hey here we are!")
  
• They don't care to locate others?
  
• They have not yet been able to contact us because our ability to receive signals has only been around 100 years, and they're, oh, 500 lightyears away?
  
• We still have no idea how to receive their signals?
  
• They have no idea how to send signals?
  
• They don't believe we exist?
  
• They too have a Fermi Paradox?
  

I could go on forever. I don't consider this a strong argument. I prefer the approach of statistics, even if it can yield no answers based our on current lack of information.

Re:before you go bonkers about this

[Theodore Logan]

I can agree that all those are natural objections, as long as you presume that "they" are not too many. Otherwise, you may have a problem. The Fermi paradox could be said to be based on the following premise:

Either only Earth have a technologically advanced civilization, or many planets do.

It is, in other words, not the case that only "a few" planets have highly developed civilizations. By many is meant at least in the order of a billion or so. I'm sure you can figure out why this premise is not unreasonable for yourself. Now, the argument goes, maybe the objections you raise are valid for some of the civilizations, but it would incredibly naive to think that they (or, to be more precis, at least one) would be for all of them. Even if what you say would be the case for 99% of them, there would still be many millions left.

This is, however, an interesting debate, albeit an old one. Feel free to reply if you think something is seriously wrong with the line of reasoning outlined above.

Re:before you go bonkers about this

[_prime]

>If there are aliens, where are they?

Perhaps they are waiting for us to grow out of our infancy. I mean, do you really think we're really to handle that sort of idea? Let's take a look a high level look at our planet:

• Over 30,000 humans (mostly children) die each day of hunger when there is plenty of food for everyone.
• We poison our environment (or world) and somehow expect this to not affect us. Clean alternatives are available but they aren't used.
• We haven't learned to stop killing each other. The fact that we all really want the same basic things seems to escape us, as well as the fact that those things (happiness, peace, etc) require nothing except for our willingness to give up our deadly attachments to those things which really aren't doing us any good but that we think will make us happy (money, glamor, power over, etc).
• 
  
  It seems to me any highly evolved race would know well enough to keep their distance and wait to see if we destroy ourselves before initiating contact (especially if they knew, like a wise parent, that we have to figure these things out for ourselves).

Re:before you go bonkers about this

[maxpublic]

This is anthropomorphized Star Trek silliness with no basis in science or logic. Not only anthropomorphized, but *liberally* anthropomorphized ("oooh, you nasty humans are still killing each other!").

Puh-lease. Stow the SF 'violent human race sickens advanced cultures' shtick. It's old, it's tired, and most of all, it's ludicrous.

Max

Re:before you go bonkers about this

[T-Ranger]

Why, exactly, are you assuming that the points you make are not what alians beleive is a good thing? Prehaps there exists alians that beleive that starvation, enviromental distruction and war are good things.

But the real question...

[Champaign]

Is where Vulcan is and how we can get in touch with them without having to build some dang warp powered rocket...

Wasn't this idea pretty much done after sciam's...

[phasic]

article? It talked about the composition of the star that was needed to foster life bearing planets, and how those stars were only found in a small ring percentage of the galaxy.

... But it's really just a W.A.G.

[jnd3]

Seriously. Not to be a wet noodle, but these guys are pretty much pulling numbers from where the sun don't shine.

Anyone who believes that there is not an assload of planets that could possibly support sentient life is incredibly arrogant.

Anyone who believes that a "god-like being" would only create life on a singular planet is even more arrogant.

No personal offense intended, but isn't is also then true that anyone who dogmatically asserts the opposite is equally arrogant? Let's remember that science is (or is supposed to be) the search for knowledge (from the Latin sciens, having knowledge). These guys can make their estimates all they want. But the fact is that there is currently exactly one known planet with life: Earth. Later facts might prove them right. But they might prove them wrong, too.

Re:... But it's really just a W.A.G.

[Eskimo Bob]

You sir, are correct.

But just because we don't/can't find another planet with life doesn't mean it doesn't exist. It also doesn't mean it does exist. It just means we can't find it.

BUT... Honestly, it's damn near impossible for us, as in the human race, to find out everything about everything, seeing as how at some point it is possible that much of our current knowledge will be proven wrong. As has happened constantly through history (though at the time things seemed correct). What is right now will most likely be wrong later.

The fact isn't that there is one known planet with life, but that <i>we</i> only know of one planet with life. It's not much of a difference, but it is a difference. It does, however, rely on the fact that either past knowledge of this has been forgotten or that there are other planets with life that is sentient. Knowing what we know now, the former is probably more likely to be correct out of the two, though secret option number 3, we's alone, is even more likely to be correct.

Sure, Science is the search for knowledge, but since mathematics is a field of science, and statistics is a field of mathematics, then statistics is a field of science. And statiticians make estimates, that makes them scientists and makes their guesses "scientific calculations"... in a way. And we all know that a statiticians job is to pull numbers out of their ass.

Statistically speaking, there is a high probability that an assload of planets that can possibly support life exist besides our own.

To summarize: The only way we'll know for sure that life sustaining planets with intelligent life exist elsewhere in the universe is to find one, otherwise we can never be sure one way or the other, unless we find all planets in the universe and determine that they are all lifeless.

Honestly though, I'm just talking out of my ass.

habital in what context?

[josepha48]

If you are looking for billions of habital intelligent planets, your probably off the mark. I think that it is more likely that there are bacteria or something of that nature on some of these other planets. But that is just my opinion.

Fact is that if there was life on another planet we would not be able to get there with current technology and understanding of physics. It would take to long traveling at what scientists today call the maximum speed limit 'the speed of light'. Maybe someday when we understand space and time better but not now.

Watch Discovery channel now and then as they already went over alot of this stuff. They made a discovery a while ago and discovered how to detect the 'gas giants' as they call them (jupiter / sturn sized planets) orbiting a star by watching the stars wabble.

And for you real space fanatics http://www.spaceref.com/ and www.space.com are great sites.

Lastly I cant type and spell so don't point out my typoes and spelling errors it is really laim.

Re:habital in what context?

[klaun]

traveling at what scientists today call the maximum speed limit 'the speed of light'

I've never met any scientist, today or otherwise, who call the speed of light the maximum speed limit.

Maybe someday when we understand space and time better but not now

I think we understand space and time better everyday. But that doesn't mean that we will ever necessarily create a faster-than-light mode of transportation.

Lastly I cant type and spell so don't point out my typoes and spelling errors it is really laim.

Fair enough, but habital? This is more than simple mispelling, you missing an entire syllable!

Not being concerned enough with your post to look at a dictionary or check for typos is also pretty lame. Why share at all?

Re:habital in what context?

[josepha48]

"I've never met any scientist, today or otherwise, who call the speed of light the maximum speed limit."

To bad! According to current thoery proposed by Einstein, and many of his believers nothing can travel faster than the speed of light and that which does looses mass. The loosing mass part has been proven in lab test as a particle like an electron is accelerated to the speed of light it gets lighter. There have been many who believe that because of this, light is considered the maximum speed limit. Try watching discovery as that is where they mentioned this.

"But that doesn't mean that we will ever necessarily create a faster-than-light mode of transportation."

True, but maybe we'll find a way to bend space or warp time so that we do not need to travel faster than the speed of light, but that we can travel through time by bending space. There have been theories proposed that if you bend space and make two points that are light years apart at the same point in time then you can travel through space in a shorter period of time. It is actually confusing and better explained as if space were a sheet of paper. If you have a hole at two ends of this paper, and this piece of paper, then you fold the paper in half the holes are now much closer and the travel time is near 0 if these holes are next to each other. So the question then becomes is it possible to bend space?

"Not being concerned enough with your post to look at a dictionary or check for typos is also pretty lame."

Sorry my dictionary got stuck up your ass.

Re:habital in what context?

[mother_superius]

warp time

Even if you slowed down time, that is, made an hour "longer" (man, that's confusing... how would we know?), we would still be traveling the same miles per hour...

Re:habital in what context?

[LoseNotLooseGuy]

...and that which does looses mass. The loosing mass part has been proven in lab test...

I suspect that entities traveling near the speed of light do not actually "let loose or release" mass; that would imply that the entity is somehow capable of consciously manipulating its own mass. I believe the words you were looking for are loses and losing.

Congratulations! You have been participant #15 in my campaign to rid Slashdot of this error.

New planets?

[Hoi Polloi]

Great, as soon as they reveal their locations their going to get spammed.

Universal Sterilization program

[PaulGibson]

I saw a NOVA episode recently where the occurrance of pseudo or genuinely random bursts of radiation are visible from Earth. They (some very astute astronomers) have been figuring out what is up with them for some time. They have proven so far that they originate from a very long distance from our galaxy, and go on to say that any life that is in the beam will be immediately sterilized. The bottom line was that there may likely be other earths out there, but the likelihood that they are safe from this radiation is very small. It seems that they have discovered that we are safe enough, as the radiation is caused when massive stars collapse. The star size has to be something very much bigger than any star they have actually located in our galaxy. I can't remember the size estimation, but it was orders of magnitude larger than our sun (a medium sized star).

Our universe is probably a mere atom inside a larger universe, and these radiation bursts are simply the efforts of their Einstein trying to split us.

Re:Universal Sterilization program

[Lepruhkawn]

Our universe is probably a mere atom inside a larger universe, and these radiation bursts are simply the efforts of their Einstein trying to split us.

God is a fractal.

Each atom we can observe contains a copy of the known universe that we can observe.

Re:Universal Sterilization program

[bpd1069]

it was on the order of 30-50 times the mass of the sun would cause the star to collapse creating a blackhole. The final death cry of this star would create a radiation (gamma I believe) powerful enough to be euivelent to nuclear explosion for 300-400 lightyears in radius...

They called these things "Death Stars" as they can easily sterilize anything within its touch. They NOVA show went on to say basically there is only one or two stars that are on the mass scale of a potential "Death Star" within 500 light years of earth, but they dont think they are the "type" to implode...

I guess this makes you realize that the regions of the galaxy that life "Might" exist within our time frame would have to be along the edge of the galactic core? Possibly but who knows for sure when your talking on the order of billions of years.

I used to hold my own personal theory that if interstellar flight were possible on other planets with intelligent life it would probably occur within dense star clusters. Going to another star a mere 0.5 light years away is more attainable than 10-20 for your first leap into the unknown. But if this Death Star theory holds up then these are the LAST places that such a evolution in technology could occur. It's all a big interesting question that we will never know the answer to (our great great great great grand children perhaps but not us).

So I say create a galactic map of the galaxy. Everywhere there is a suspected "black hole" of sufficent mass, X out that reagion for 500 light years... Find a region free of blackholes and you may just have a place to aim that Arecibo radio telescope to have our SETI@Home clients busy.

Re:Universal Sterilization program

[Doctor Fishboy]

I think you've misunderstood the program slightly.

Gamma Ray Bursts are seen across the sky at a rate of a couple of bursts per day, with the current detection limits. The latest theory is that they are the last stages of a binary pulsar (two neutron stars orbiting each other) spiralling together and just before they coalesce, an intense, beamed burst of gamma rays is emitted from this system. We are seeing the bursts from many millions/billions of light years away, and for us to be detecting them over that distance, the implication is that the energy release is awesome, to say the least.

Any star system in the galaxy in the GRB's beam path is immediately sterilised. It doesn't have to be *our* star, we just have to be in the way of a burster's beam. Thankfully we don't see any binary pulsar systems in our own galaxy that look close to doing this soon.

This is used to great effect in Greg Egan's "Diaspora" which details what happens to the Earth when a GRB goes off nearby, and Stpehen Baxter uses the idea of many GRB's sterilising the galaxy every 100 million years to explain the Fermi Paradox in his great series: "Manifold: Time"

Hope this helps,

Dr Fish

Re:Why live on planets? Answer:Sex!

[Damek]

If you live in a space station, you have to keep building out the station in order to create room for more people. That's a lot of effort.

But if you colonize planets, everyone can have a lot of sex to fill the place up, and the offspring can go build their own homes!

Less work! More sex!

That's why planets are more attractive than space stations!

Metrics...

[DrCode]

Can anyone tell me the difference between a 'metric buttload' and an 'Imperial buttload'? Thanks.

Re:Metrics...

[Chelloveck]

Multiply by 2 and add 30.

Re:Metrics...

[Andrewkov]

Thanks, that was the first time I laughed out loud reading slashdot in quite a while .. Nice post!

Re:Metrics...

[FrankDrebin]

Can anyone tell me the difference between a 'metric buttload' and an 'Imperial buttload'? Thanks.

I believe the imperial buttload is based on the size of Hing Henry V's rear end. Quite large, it was.

While the metric buttload is smaller, it scales nicely. For example, there are 10 metric buttloads in a metric shitload.

QED

Re:Metrics...

[roystgnr]

The "metric buttload" is logical and has been used by just about everyone for centuries, but the "Imperial buttload" is kept alive by backwards Americans who can't bear to teach their children things they don't really understand themselves.

Answer: Not much further along than we.

[Kjella]

We've got chemical rockets. We can pretty accurately estimate what a fission rocket, fusion rocket and an anti-matter rocket can do (in order of increasing power), and frankly, it's not that damn impressive compared to the insane distances of space.

Radio signals? How should we send, what solar systems, what frequnencies, what intensity, what signal type? Likewise goes for listening. SETI is looking at one extremely small area of the sky, and yet it needs an extremely powerful signal, only the most powerful of radars aiming precisely for earth would be detected. And even then it could be put off as static, or a burst by some natural phenomen.

We could use a Warpdrive and a Sub-space communications system. But some sci-fi isn't going to be sci-fact ever, of course there's no telling which in advance.

Kjella

That depends...

[AshsZ]

Depends on what you classify as the "universe". IF you classify the expanse of space, then I'd agree with it being "unbounded". But if you classify the "universe" as the matter contained within it, there is a finite "volume" to the universe, of which is constantly changing, but not infinite. Ad nauseum, really.. :)

Mark this article as redundant?

[suso]

Shouldn't this article be marked as redunant since the fact that there are billions of habitable planets out there should be painfully obvious in the vast expanse of the universe. I think the more interesting calculation would be to determine how many doubtful people there are out there.

Only discusses HABITABLE worlds.

[Restil]

But not the worlds that have developed life or advanced civilizations. There's a big difference.

Its also fair to wonder, how many spacefaring civilizations are there? By that I don't mean, how many have launched someone into space, but how many have actually colonized worlds outside of their home solar system?

It has been shown, that given extremely slow, but reasonable travel times between stars, and assuming it would take 500 years (for an already technologically advanced society) to develop a world and the rest of the solar system, then advance on to the next one. With this in mind, such a civilization would only require about 3 million years to completely colonize the galaxy. Considering the billions of years the galaxy has existed, 3 million years is but a brief moment in time. If it was going to happen, it would have already happened.

Now consider our own situation. We're 4.3 light years from the nearest star. We're in the perfect location to drop off a few test subjects (humans with no technological knowledge) and see what happens. It would take a long time before they'd discover what really happened. And others could observe and reflect in that time.

-Restil

Re:Only discusses HABITABLE worlds.

[pyrrho]

I think it would take longer than 500 years.

And: did you know:

heavy metals are made inside stars? It takes a large number of solar generations to get heavy metals in clouds which can then form into planets around a star too small to make said metals, etc.?

Actually, I believe current thinking is that we are not far into the period of time when habitable planets could have started appearing.

Re:Only discusses HABITABLE worlds.

[Restil]

500 years with the current rate of growth isn't unreasonable. Remember, the colonists already have all the necessary technology to construct and build spaceships necessary to make the next leg of the journey. 500 years is about how long that civilization would take before making the next move. The planet may not be fully colonized by then. It wouldn't have to be. Its enough time to establish a base of operations and a thriving economy.

That doesn't mean that they always would make the next step. There's always going to be those cultures that decide to withdrawl from the rest of the galaxy and live on their own. But there's no reason it COULDN'T happen in that amount of time.

-Restil

Re:Only discusses HABITABLE worlds.

[pyrrho]

not only do you have a good point, but I went to the site in your sig and (did you make this yourself) because if so, I'm impressed. Great toy!

Re:Only discusses HABITABLE worlds.

[Paradoxish]

It has to be said: who can prove aliens have the attention span to spend 3 billion years colonizing? There seem to be two assumptions that almost everyone makes that really bug me:

1) Assuming we don't blow ourselves apart (a less likely scenario than most think, I'd say) we'll eventually spend three billion years colonizing the universe. Think about it! If humanity is still in a technological state where we even want to bother colonizing the universe three billion years from now (or even a million years from now) it'd be unbelievably pathetic. Go ahead and think this is trollish, but at least consider what I'm saying first. Technology is increasing exponentially. There was a time when technological gains couldn't be perceived over three lifetimes. And yet, in the last one hundred years, we've seen completely revolutions in warfare, travel, communications, mathematics, physics - you name it, we've done it. My parents saw these changes and they completely altered the way life is lived. In my relatively short life time I've seen life totally altered by personal computers and the internet. I expect to see medical breakthroughs before long. Just one million years is roughly 10,000 lifetimes. How can you even hope to imagine what our goals will be 100 lifetimes from now, or even 10? I'm willing to bet even a mere 10,000 years from now things like "colonizing the stars" will seem completely alien to us.

2) That intelligent aliens are similiar enough to us that they have any reason to move to the stars. Maybe they're so physically tiny that it would take them millions of years just to fully explore their own world, and the rest of the universe is too large for them to ever consider. Or maybe they are like us. Who's to say that in our TINY amount of recorded history we'd just happen to be lucky enough to see them. If it really is impossible to move at the speed of light then how do you know they didn't eventually give up? What makes you think that they're going to spend 3 billion years colonizing? Maybe what we consider to be habitable is totally inhospitable to 99.99999% of the life in the universe, so our system holds absolutely no value to them. There are a million reasons why they wouldn't be here, why they'll never be here, and why we'll probably never be there.

(Heh, this turned out to be a pretty logical post. Too bad I posted too late for anyone to see it)

Safety and Security.

[Talinom]

I don't care how many worlds there are in the Galaxy. I'm NOT going to wear a red shirt when I beam down to one of them.

Other factors

[jafac]

Don't forget that the degree of axial tilt AND periodicity of axial tilt oscillation are thought to play a huge role in climate change cycles, and therefore the formation and evolution of life.

How many planets of the right size, right consitution, right size and distance and periodicity of large satellites, right distance from sun, right periodicity of solar orbit, right periodicity of rotation, right frequency of asteroid collisions, right strength of magnetic field, right type of sun, right stage of solar lifecycle, right stellar neighborhood (no local supernovae). . .

Seems pretty farfetched to me.

Re:Other factors

[PineHall]

Good points! I have heard that some astrophysists are promoting the "Rare Earth" Hypothesis. They say that there are many factors required to create an earth-like planet and that conditions have to be just right with the right elements being formed by the right stars in the vinicity of a planet to form that is capable of life.

It makes one wonder if SETI will be sucessful.

.com flashback

[TheLastUser]

The reasoning reminds me .com marketing.

How many people surf the web?

If only 1% of those people come to our site, WomenWithoutBras.com, then, at a $10cpm, we will make 42 billion dollars a month, wow!

Want to buy some stock?

Eventually, when we stop sending astronauts into orbit to monitor mice having sex, and put up some decent astonomical instruments, we will be able to image some Earth sized worlds, and then we will forget all about the statistics.

Butt-head astronomer

[artemis67]

Boy, I'll miss that guy! One of the many people who triggered lots of tech interest in me and made me who I am!

Tech interest? This is the guy who, when he found out that Apple had a project with an INTERNAL code name of "Sagan," had his lawyer write Apple some nasty letters.

Apple complied by renaming the project to "BHA," the meaning of which you could guess from the subject line of this message.

Space.com Article

[G00F]

30 Billion Earths? New Estimate of Exoplanets in Our Galaxy http://www.space.com/scienceastronomy/astronomy/ju piter_typical_020128.html

Re:Space.com Article

[spike hay]

I submitted an article to slashdot that had that same Space.com article that you linked to in it FOUR DAYS AGO. I'm very bitter that they rejected it, and put an identical one on a few days later.

Re:Space.com Article

[G00F]

and even worse, its an MS based one they used!

Follow-up question

[Spamalamadingdong]

How many of these technologies would be worthwhile for other purposes and could be developed for scientific or even profit-making purposes in the mean time?

(Of course, I'm asking this because nobody is going to devote such resources and focus on one far-off goal long enough to accomplish it; anyone who does will lose other competitions to groups which do not. On the other hand, if the goal can be accomplished via a number of short-term projects each of which is useful and even profitable in its own right, the grand goal follows almost inevitably.)

Probabilities

[Therin]

Let's see... there are 20 amino acids, 19 of those are stereoisomeric (have a mirror image). Outside of living organisms there is no way to isolate l-alanine from r-alanine, for example. So there are 20 amino acids useful to life, 19 that are not.

Now take a small protein, say 250 amino acids long. Do some probability calculations, and see how likely the first protein is. Then remember that it's supposed to generate itself in an aqueous (water) solution; but amino acids rapidly dissociate in water. So if it forms, it won't be around for long.

Assume we have a high density, a vast over-sufficiency from somewhere, of all the amino acids on hand. Further assume they never degrade. Further assume that once a bond is made that helps build the protein we want, it stays around. None of those are really valid, but let's use them to see where we can get to.

So the odds are, for a given 250-element protein, 1 out of 39 (1/39) to the 250th power.

That works out to 1.7x10^398 tries to get one protein. The lowest guesses for how many are needed for the simplest cell are 200-300 of those. As a calibration, the known universe is less than 10^30 inches across.

So how likely is this to have happened by chance? Use your brains, folks, think!!!

Just rationally, isn't it clear that chance had nothing to do with it?

Re:Probabilities

[dhogaza]

Since scientists are obviously idiots, they never thought about this until you (or was that Fred Hoyle?) brought it to their attention, right?

Bah. The problem with simplistic explanations as to why "abiogenesis is impossible" is that scientists have very good answers such so-called proof of impossibility.

The short story: you can prove anything if you start with a false premise. And unfortunately, the premise underlying your supposed proof of impossibility is false.

Those who are actually interested in the science of biology rather than creationist dogma might be interested in this page.

Re:Probabilities

[cruachan]

It just doesn't work like that. You don't need to assemble everything in one go - all you need to do is assemble a set of building blocks that have a sufficent advantage so that some form of evolution can do the rest.

There's lots of literature on this stretching back to the 50s. Among things you might like to consider is that short sequences of amino acid - 10 or 15 - can show catalytic behaviour. The proteins we have nowdays are the finely tuned results of 3.5 billion years of evolution. When life started out it got along much more crudely.

Of even more interest is that you don't need proteins at all. Single strand RNA can also act as a catalyst all by itself. And you don't need DNA either - RNA will pass along genetic information as well. True it makes a lot more mistakes - but the systems are cruder so it doesn't matter so much.

At base all you need for some form of life is a membrane system (lipids assemble these automatically), catalytic molecules and a crude genetic system - RNA will handle these two functions. Once you have that biological evolution kicks in and does the rest.

Personally I think the most biggest stumbling block for earth, and human, like life is not creating life in the first place at all. Our earliest micro-fossils indicate there was life on earth just about as soon as it had cooled down sufficiently to support liquid water. The stumbling blocks instead seem to be evolving, eukaryotes, multi-celled organisms and intelligence.

Multicelled eukaryotic creatures only appeared less than a billion years ago - that's after over 2.5 billion years of single celled creatures only. Similarly self-concious intelligence only arose in the last 10 million years - after many hundred of millions of years of land animals. Both traits would appear to be only very weakly selected for.

Personally I'm betting on finding a lot of planets covered in slime out there.

Re:Probabilities

[cruachan]

See my previous post. If you had to assemble life as he says (and doing the math) then he's correct.

But you don't.

Re:Probabilities

[cruachan]

>toxic environment

What, like oxygen? :-)

One of the most nasty, reactive toxic chemicals know. Good job there wasn't much about back then.

Re:Probabilities

[cruachan]

And when modern cells synthesis proteins they don't just create the energy needed to assemble the chain out of nowhere. Enzymes don't *do* anything magical to the chemical reactions going on - they're *just* catalysts. Proteins nowdays get assembled because of special circumstances in the interior environment of the cell.

Back on the primitive earth same thing would have happened - but in a much more primitive way

Besides this concentration on proteins is missing the point. Primitive life was more probably a lipid/rna combination. The wonderful thing about self-replicating systems and evolution is that all you have to do is assemble a basic replicating system - and you've got hundreds of thousands of years to do that across the whole surface of a planet - and once you have something that can grow and replicate then your on your way.

Proteins probably came later - assembled within the internal environment of your proto-cell. There's some interesting indications that tRNA molecules have a basic chemical affinity with the amino acids they code for - not needed now but a vestige of early evolution

The worst thing about this 'can't assemble a 250 amino acid protein in one go' red-herring is that it ignores the evidence about only needing simpler systems to get started. I've already mentioned the 'protenoids' where short amino acid sequences have catalytic properties. Further along in evolution we developed the ribosome and the whole protein assembly mechanism. Nowdays it's a massive molecular assembly visible through an EM, but over 20 years ago it was shown you could strip this back to a 1/100 of it's current size and still have a working, albeit less efficiently, process.

Finally I can't resist the one about other things boinding to amino acids - err that's half the point! Amino acid chains are often useful because they can bond other molecules. To bring two things together here one of the short 'protenoids' I mentioned was a 30 amino acid chain bonded to a porphoryn - and guess what - it carries oxygen reversably just like haemoglobin! Crude - but effective.

Re:Probabilities

[jfryer]

Fascinating, truly fascinating reading. Both sides of the argument have faults and seemling solid details, but lets just throw a wobbly into the equation.

If, according to the original equation, it was impossible for life to begin by chance, then how did it start? and more importantly when?
Lets go with the "Christian" theory of God creating man, great theory (no proof though, for proof denies faith and without faith I am nothing).

According to this theory life has not been on this planet long, God created the seas, the fish, the birds etc in 6 days. He must have found time to create fossils also, since that is the only way to explain all these fossilized bones that are being found everywhere. Nor does it explain the fact that life has been PROVEN to have been on earth longer then the Bible would have you believe.

Nor does it say that He created Dinosaurs, which since they have been proven to exist he must have done (lucky Adam wasn't eaten by a Raptor), something as big as Dinosaurs are hardly likely to be left out of the bible if God created them, I mean its not as if you would be able to miss them.

But hey we are getting of the topic somewhat aren't we. Lets just settle for the fact that nothing is impossible. Surely if it is possible for a surpreme being to control/alter/guide life on earth, it is equally possible for life on Earth to start all by itself. Either option is just as impossible and replies on the faith of the believer in a large part.

However science will never be able to prove there is a God, but it is pretty darn good at dating millions upon millions of year old fossils.

Who do you think has the upper hand there?

Re:Probabilities

[spike hay]

No offense, but you must not have a very good understanding of Poymerase Chains, also called proteins. They form fairly easily by themselves, even in water.
I may point you to the example of protocells. I you take five amino acids(i dont remember which) mix them together, heat them, and then cool them, they will form protocells. These are DNA-less organisms that use ATP, have a cell membrane, metabolize, bud just like yeast, and do quite a few other things associated with cells.
In early earth, amino acids such as these would be easily formed by lightning or the more intense UV-light that they had back then. These would be formed from dissolved atmospheric gases in tidal pools such as hydrogen, ammonia, methane, CO2, and water.(the atmosphere was much different back then). Amino acids would be formed quite easily in early earth. Amino acids form so easy that they have even been found in meteorites.
Anyway, the combination of a few easily formed amino acids would produce protocells quite easily. Also, these same organic cocktails produce DNA and RNA. Maybe a few hundred million years down the road after protocells are created, a protocell forms around an RNA strand. It's just evolution from there.

Re:Probabilities

[cruachan]

The problem with your argument is your working a priori to establish life cannot have arisen on earth naturally. Then to promote this argument you insist that life must have arrisen in one go in the form that we now see it. Rather like inisisting the first flight was taken in a jumbo jet.

This is totally specious. We've got a whole planet surface and half a million years in which to work. There's all sorts of conditions - from black smokers at the bottom of the oceans to sundried pools to the deep rock in the earths crust.

All we have to do is create a self-replicating system. Proteins are not required from the word go - we need a membrane an information store and a process to replicate the information. Once we have that natural evolution does the rest for us.

I have no problem with religion itself, but your creationism is an insult to God is He exists. Let's ignore the fossil record - you have too many trite answers for that. Consider instead Woese and other's work on 16s RNA sequences from the 80's forward.

16s RNA is a highly conserved part of ribosomes. However is does show variation between species with changes in it's sequence. Most interesting if you analyse variation in 16s RNA across a range of species (and it's now been done for thousands) you can come up with an evolutionary tree which fits our evolutionary model remarkably well. Incidently this doesn't just include animals and plants but bacteria of all shapes and sizes too.

In other words we have good evidence of the evolutionary process completely independently of fossils - and unlike fossils 16s RNA analysis is pure number crunching.

Now for God to have set us up like this - with a world stuffed with evidence that directly supports evolution - but to have created us in a biblical fashion with the evidence put there just to test us reeks of a twisted mind. Positively malevolent in fact.

I wouldn't be suprised if God (should He exist) isn't positively insulted.

Re:Probabilities

[cruachan]

Self-replicating systems are a cute phrase. Seen any outside living organisms lately? Wouldn't there still be a whole bunch of these around if they were likely to occur? What would make the old ones go away when new ones came along? Why are there none today?

Competition. Survival of the fittest. Out-bred by new more evolved efficient species.

Frog in Blender

Jeez. What a phenominally desperate argument. In what way are the post-blender conditions for a frog anyway similar to any conditions on the early earth?

Re:Probabilities

[jfryer]

Hey, I am more then happy to consider the possiblities that life didn't start billions of years ago. Are you?
While I am happy to admit I may be "blindly" following a belief system based around science, are you not just as blindly following a belief system based around a being no one has ever proven exists?
Or can't you admit that since your version on the truth "must" be right?

"I'm glad you love it, but frankly it seems very clear to me that I'm the one fighting the textbooks" maybe this is true, but aren't you following your own textbook, which has been editted, censored and changed to suit popular taste (just like school text books are [see http://www.straightdope.com/mailbag/mbible1.html]) called the bible? Your entire belief system is based around one single book (technically one single collection of books I admit), how does that make your beliefs any more valid then my own?

I cannot comprehesibly (sp?) prove that life started billions of years ago, nor can you prove that it did not. To use your own words against you "open your mind - be willing to consider alternatives" The question is, can you take your own advise and consider alternatives also?

Re:Probabilities

[jfryer]

One more thing which I must add to my last post, something which I cannot let past.

Your quote "Now remember that scientific orthodoxy is a vicious and cruel tyrant" and "Look at the history of science - Pasteur was a victim of it" and finally "yet were drummed out of their professions by the tyranny of the orthodoxy" All true, all totally 100% true, I couldnt agree more with you. But to be fair, to be even handled, to be balanced, perhaps I should mention the tryanny of the christians. Can there be a greater tryanny that the world has seen (short of Hitler)? How many crusades were sent into the Muslim lands? How many innocents where slaughtered, men, woman and children, just for not believing in God? How many people were tortured in confessing they were heretics and then murdered for that confession?
Most of western history is a case of 'believe in God or be slaughtered and go to hell', it is only in recent years (last 200 maybe) that that attitude has been toned down somewhat. And thats only because we have been too busy slaughtering each other for geo-political reasons.
It seems to me that Pasteur got off lightly when we was drummed out of his profession. Leonardo Da Vinci was in fear for his life becuase of his scientific discoverys and inventions, but not from other scientists, from the church.

But, believe it or not, after everthing I have said I am still a christian, I am just not a fanatic believer, I am willing to belive more then one possibilty and consider more then one option.

Oh, and I am not afrid to post this under my own name either.

Re:Probabilities

[cruachan]

"Yes horrible things were done (Crusades, Inquisition) by the Catholics (who many argue are not Christians). "

Oh wow. Catholics not Christians. Are they going to burn in hell then?

And which particular split of the xian church do you belong to then? Guess the one that just *happens* to have a direct line to the truth.

Jeez, zelots like you positively dangerous. The worst attrocities are committed by people who think they have a direct line to the truth. What, really is the difference between a xian and a muslim fundementalist - except you of course are saved ;-)

It's you who have to open your eyes. You've been brainwashed by a cult.

Re:Probabilities

[spike hay]

I'm sorry!!!! I got a few facts mixed up. I got polymerase and polypeptide mixed up. I always do.

Rare Earth

[artemis67]

Personally, I have to say that I lean towards the conclusions found in Rare Earth by Peter Ward and Donald Brownlee. I think they make a very compelling argument for there being far fewer earth-like planets than all of these starry-eyed astronomers are predicting.

hmm

[frostern]

how can u be so sure about that, for all we know we might find a planet fast.. the only thing that is between us and sutch a planet right now is technology/ science.. so all we need to is get smarter and learn, and break those barriers down. (the only thing that will slow stuff like this down is bureaucracy..)

The Problem with Space Travel

[rudy_wayne]

Science Fiction has clouded our vision of reality. Consider:

Nearest star is just over 3 light years away, so, traveling at 1/10 the speed of light, it would take you 30 years to get there.

1/10 speed of light = 66.9 Million Miles per Hour

Therefore, the problem becomes:

You must somehow build a spacecraft that can travel at 66.9 Million Miles per hour, non-stop for 30 years, and can accomodate a crew for that same 30 years.

Re:The Problem with Space Travel

[roman_mir]

Read Nemesis (Isaac Asimov). BTW. by the time a large spaceship like that goes half way to the star we would have developed technologies allowing us to go back and forward to and from the star 100 times a day. Poor crew of that ship would have arrived to the star only to visit McDonald restaurant!

Re:The Problem with Space Travel

[asincero]

> Nearest star is just over 3 light years away

Actually, the nearest star is just (on average) 93 million miles away!

- Arcadio

Re:The Problem with Space Travel

[fence]

Actually, the nearest star is just 8.3 light minutes away.

I'm fairly confident that it has at least one Jupiter-like planet and at least one Earth-like planet orbiting it.

Re:The Problem with Space Travel

[spiro_killglance]

But only if you travel slowly, if you can
uniformly accelerate at one-G, then i a little
less than a year, nothing not even light will
be able to catch up with you.

Re:The Problem with Space Travel

[JohnC3]

That is why Drake (author of Drake eqn, now director of SETI) is searching for ET in the radio and optical rather than proposing to develop technology to travel there. Sagan's proposal to go to Mars, etc was for purely scientific exploration, not as a prelude to spread our seed across the galaxy. Virtually all astronomers believe that ET will NOT drive up in a spaceship; he/she/it/? will send us a signal (hence SETI), IF he chooses. The signal will have to be deliberate, powerful and carefully planned; a TV broadcast (a la Contact) won't do it. Even Arecibo Observatory doing ionospheric/planetary radar probably wouldn't do it (too sporadic) even though AO could easily communicate with a comparable facility a good fraction of the distance across the Milky Way (IF we knew it was there; hence SETI). But even a round-trip "hello/how are you?" to the nearest star would take 6+ years.... Drake's estimate from his eqn a year ago was either about 1K or 10K (I forget which). I wonder how far he would reduce the estimate after Sept 11? (former radio astronomer at AO)

the technical article

[awhoward]

here's the technical article (on the preprint servers):

http://xxx.lanl.gov/abs/astro-ph/0201003

You forgot a couple

[Guitarzan]

It would also require:

Antigravity technology
Replicators
Warp speed (or hyperspace, I don't care which)
and especially, Captain Kirk

Re:You forgot a couple

[zeno_2]

Oh please, with what 'Captain Kirk' has been up to lately, I say we built a rocketship and send him off in it, we could tell him its one last mission for the Federation =)

The universe isn't a very friendly place...

[danro]

Ever heard of a little something called binary black holes?

This little thingies has two tightly focused, _really_ hot jetstreams of radiation going out in opposite directions, but doesn't emitt much in other directions (They're black holes after all, so they suck up pretty much everything that could make them detectable).

Well, now imagine a spinning binary black hole.
It'll be almost undetectable... until it happens to spin so that one of the jetstreams hit a planet and fry it to a crisp.

We _could_ have things like this just around the corner (astronomically speaking) and not be aware of it.

I don't know how common this type of celestial bodies are, but for life, they are definitly a Bad Thing, since they could effectivly "reset" a planet and life would have to start all over again...

Re:It's almost as hard as you say it is...

[danro]

You must somehow build a spacecraft that can travel at 66.9 Million Miles per hour, non-stop for 30 years, and can accomodate a crew for that same 30 years.

No, you dont. You must build a spacecraft that can _accelerate to 66.9 Million Miles per hour, and deccellerate a few decades later.
Once you have picked up speed in space there is no additional effort to keep it, since there is very little friction in the near-emptyness of space.

You are right about one thing though.
Interplanetarry travel is a lot harder than most people think...

Actualy, I thin kthe real porblem would be

[G00F]

How would you see where your going in time to react to things ahead of you at that speed. (or faster)

I think it is more than posible to creat a shuttle that could go that fast. Mind you, it would take a few years to get to that speed, and a few more years to slow down.

But still, my first question remainds, at 1/10 the speed of light, I don't know of any good way to see arround you.

this is Asimov's universe

[peter303]

Asimov has many life-capable planets out there in this Foundation universe (and several other stories). However, none have developed intelligent life. 90% of earths history was like
that. You'd just see deserts and a little bit of scum in the water. Worms and such developed in the last 12% of the earth's age. Fishes and plants in the final 6%.

We just need to find ourselves a good Avatar

[kaladorn]

I just wonder where we'll recruit a crew of gung-ho fighters with the classic Big Eyes, Small Mouth syndrome....

What about the Moon?

[roman_mir]

Do we have all the facts to say for sure that the Moon had nothing to do with formation of life and maybe even of intelligent life on this planet? Our closest neighbour is only 300,000km away from us and it is also a HUGE satellite for our planet. It has a profound effect on this planet, an effect that Deimos and Phobos of Mars can only dream about. How about tides that Moon enforces on our largest pools of water? It is possible that life was created specifically because of these tides, in the puddles of water that were left behind a tide (well that's a theory anyway).

So, how many of those planets have comparable Moons around them?

Re:What about the Moon?

[mperrin]

Tides aren't a substantial argument. The sun's gravity produces tides on the Earth as well. The amplitude of solar tides is about half that of lunar tides, so even the complete absence of the moon doesn't imply there would be no tides. They'd just be somewhat smaller.

Beyond that, there's an increasing body of evidence that early life was highly extremophilic and more likely formed deep underground or near a deep-sea hydrothermal vent. I don't know of -any- hard evidence that tidal pools played a large role in biogenesis; it's all speculation as far as I know, though I'm admittedly only an astronomer, not an astrobiologist.

Re:What about the Moon?

[Corgha]

[I'm no planetary scientist, so you'll have to forgive any inaccuracies, and maybe someone who knows a little more will correct me.] One possible reason for the importance of the Moon (if one believes it originated in an impact) is that it may contain a great deal of light outer-crust rock that would normally be on Earth.

Earth has these little continents that leave the thin tectonic plates (made of denser rock and covered with vast oceans) free to move around. Imagine how different Earth would be if all the rock that currently orbits us were instead filling the ocean basins and keeping the plates from moving around.

A few back-of-the-envelope (containing some stupid coupon from AT&T Broadband) calculations gives about 2x10^19 m^3 for the volume of the Moon, 5 x 10^14 m^2 for the surface area of the Earth, so, spreading the moon out evenly (and neglecting curvature), a layer 4 x 10^4 m thick. Granted, it might not all be silicate, but it's a lot of rock, especially considering that the average depth of the oceans is around 4 x 10^3 m, and the plates under the oceans are around 5 x 10^3 m thick (results of random web searches).

Something to think about the next time you look up at the Moon.

Re:What about the Moon?

[wytcld]

Read an argument like that just a couple years back, that one claiming specifically that without the stabilization of the Moon's orbit the Earth would itself be less regular (in just what way I can't remember, but it seemed sensible at the time). If that argument's right, then to get a planet stable enough for an ecology of Earth's complexity you might just about need to be a binary planet like we are. Then you might also need to have relative giants in outer orbits to sweep the crap out of your way.

They do seem to be saying the planets they see or deduce elsewhere tend to be on wilder orbits than ours too - more like Pluto than the rest of our planets. That again would throw off the stability that helps as a base for ecological richness.

Of course, now that we're throwing out our ecological richness we might as well explode the Moon as the fastest way to free up its natural mineral resources. It's not like there are caribou running _on_ it or anything. And its effect on lovers in its present form is a significant secondary contributor to disease vectors.

So that's what happens. Advancing civilizations arise only on worlds like ours with Moons, which they proceed to exploit, which finishes off their ecologies, so they turn the husks of their worlds into spaceships. Then, already being on spaceships, the romantic lure of building other spaceships to be on loses its attraction. Especially after they learned that every advanced ecology develops pathogens which are entirely effective against all lifeforms evolved on other worlds. Evolutionarily, worlds which can't do this get overwhelmed by invasive weeds, and their ecologies stay as relatively primitive as the grass field by a truck stop in Kansas. Since worlds featuring organisms entirely evolved for those worlds' own unique niches produce the strongest ecologies, new worlds which are able to seed from the morphogenic "spore" of such rich planets win the evolutionary battle because of coming from richer, stronger, more successful morphogenes.

And that's all you need to know, people of Earth, at this stage of your progression to the Dyson sphere.

I hate this part!

[2Bits]

As soon as I start being dreamy about space travel, there's gotta be someone on /. to pull me back into reality.

Great offer!!!

[Futurepower(tm)]

I will give you half of my share of the planets if you can tell me how to get there and back, safely and for a reasonable price.

You're not in the clique.

[Blaede]

Sad but true

Cute, but false.

[Nindalf]

No matter how badly we mistreat this world, it won't be worse than anything we find out there, unless one happens to have extremely Earth-like life on it already, the kind of place they find all the time on Star Trek, with lumpy-foreheaded humans and grass and spruce trees (foam boulders optional).

By "habitable" they mean planets like Mars and Venus. Places you can live on in extremely well made air-tight shelters, and maybe eventually terraform.

We could have a sustained nuclear war (presumably sustained from off-planet), stripping the planet of sophisticated lifeforms and blowing off half of its atmosphere, and it would still be a nicer place to live than anywhere else in our solar system or anything we're likely to find orbiting another star.

In terms of human habitability, we're taking pretty good care of this one. Wiping out the wilds is sad, but a choice of farms or forests is easy for hungry people. Where it appears unnecessary, done too casually for convenience rather than survival, that is just staying ahead of what the population growth will demand in a generation or two. The pollution looks bad, but it's a feature of short-lived transitional technology, and will tail off before intolerable damage is done.

On the whole, human effort is greatly increasing human habitability of Earth, not decreasing it. The pristine, wild world of a hundred centuries ago couldn't support half a billion humans, while today it supports well over 6 billion, and the way is being made for 10. Even one century ago, it probably couldn't have sustained half our current population. Things probably won't get tight here on Earth's surface until at least 100 billion, by which time we'll be seriously working on these other places to live. As it is, we haven't seriously dented the resources of our planet, just dug around a little at the choice bits on the surface.

Re:Cute, but false.

[maxpublic]

One small correction: Venus isn't terraformable. Why? because Venus is almost tidelocked to the sun. Even if you could alter the atmosphere the 'day' and 'night' would last months, resulting in temperatures of hundreds of degrees F to minus hundreds of degrees F. While the right size and (possibly) the right composition, a planet that's tidelocked or nearly tidelocked isn't in any way, shape, or form terraformable.

Max

Re:Cute, but false.

[spiro_killglance]

very good point. However this is one way to
get around this. So that we can terroform venus:

1. Build a huge (but thin) sun shield to block out any direct sunlight.

2. Build a large number of huge but thin,
rotateble mirrors in orbit around venus to direct
sunlight at choosen parts of the planet at choosen times.

Thus the sunlight received by any part of venus
at any time is now controllible, and we can
set the climate and weather of venus to our
desire.

Although this would requires a lot of engineering and work, it doesn't require anything out of the
ordinary in technology or physics.

Re:Cute, but false.

[ASM]

Let us hope you are right.

Re:Cute, but false.

[Malcontent]

"As it is, we haven't seriously dented the resources of our planet, just dug around a little at the choice bits on the surface."

I don't know where you got this bit of information but even if it was true we are just now starting. remember the human population is growing at a pretty geometric rate. The amount of natural resources used last year probably equal the amount used for the first ten thousand years of human existance.

Having said that I just read today that the native American forest is down to 5%. Over 95% of the forested land in America is gone and turned into farms and shopping malls. I would say that is a pretty significant number (aside from the fact that it hasn't eliminated hunger or starvation from the US let alone the rest of the world).

Re:Cute, but false.

[sql*kitten]

Wiping out the wilds is sad, but a choice of farms or forests is easy for hungry people

This argument is almost exactly backwards, because you are food. By this I mean you are quite literally what you eat, every molecule your body is made of is there because at one point or another it was food, and then it was eaten.

On the whole, human effort is greatly increasing human habitability of Earth, not decreasing it. The pristine, wild world of a hundred centuries ago couldn't support half a billion humans, while today it supports well over 6 billion, and the way is being made for 10.

Increasing populations don't lead to a higher demand for food; rather a higher availability of food results in population growth.

For this reason, increasing the food production capacity of our planet - of any planet - is inherently unsustainable. Eventually, you will get to the point where resources are exhausted, and the population will be abruptly adjusted by famine - which is just as nature intended. But since humans are intelligent, we should be capable of regulating ourselves, and on the whole the Western nations are, to manage supply and demand.

Things probably won't get tight here on Earth's surface until at least 100 billion, by which time we'll be seriously working on these other places to live

A planet that was nothing but farms and dormitories would be a pretty miserable place.

Re:Cute, but false.

[sql*kitten]

While the right size and (possibly) the right composition, a planet that's tidelocked or nearly tidelocked isn't in any way, shape, or form terraformable.

I don't think it's unreasonable to assume that by the time that terraforming is actually feasible, there will be a technique for altering the orbit of a planet. I mean, how hard could it be? :0)

Re:Cute, but false.

[Benjamin Shniper]

Use engineering to give venus a large moon.

set it up to rotate close to venus, and farther away over time. This will
1. Strip off most of the atmostphere.
and
2. Cause Venus to rotate.

Two problems solved at once, plus you get very interesting fireworks when you set of the nuclear bombs to move the asteroid.

-Ben

Re:Cute, but false.

[Azghoul]

You might want to check on that number (95% gone).

Maybe 95% of 'old growth' forest is gone, but who cares, really... they're plants, they grow back.

In terms of real forested area, over 65% of NY state is forested, more than there was 150 years ago.

Re:Cute, but false.

[ek_adam]

There is more forest in the United States now than there was in 1800.

Cities used to need large farms with a few days travel. Now your food is likely to travel several hundred miles before it reaches the supermarket. Nothern New England is covered with forests that used to be farms.

Re:Cute, but false.

[bpowell423]

First off, I think your 95% of forest is gone is incorrect, as others have pointed out. But more to the point, the poster you quoted appears, at least to me, to be talking more about the resources of the earth itself, under the surface...metals, fossil fuels, what-have-you. The earth is thousands of miles in diameter, and we've only scratched the top mile or two.

Not that we shouldn't be careful. I dislike smog and appreciate trees as much as the next guy. We need to be conservative of our resources, but we're by no means close to exhausting the earth's resources.

Re:Cute, but false.

[RogerWilco]

>As it is, we haven't seriously dented the >resources of our planet, just dug around a >little at the choice bits on the surface.

I can not agree with you on this.

You should check out the research started by King Hubbert. A summary is given on (after a short google search):

http://www.oilcrisis.com/hubbert/

His basic point is that for most resources it takes more energy to mine/produce them, as the
energy we can produce with them.
I think his predictions are rather scary, as they still hold after 50 years.
I could elaborate a lot, but I invite you to check this out for yourself.

Re:Cute, but false.

[ShooterNeo]

We have had the technology for essentially unlimited energy for about, oh, at least 30 years. Its called nuclear reprocessing (i.e. the "choice" stuff we have to run out reactors will run out but its fairly simple to make more). True, it isn't being used out of fear, but if we ever get close to running out of other energy sources everyone will happily go to nuclear, cause it would be cheaper (and by that time, the waste and safety issues should have fairly solid solutions. Waste can be reprocessed, plants can be made much more foolproof with different reactor designs)

Re:Cute, but false.

[Malcontent]

"There is more forest in the United States now than there was in 1800."

Does anybody actually believe that?

Re:Cute, but false.

[Malcontent]

Everything that sustains human life on this planet is in those first three feet. Take away the top three feet of soil and we all die.

Re:Cute, but false.

[Malcontent]

"In terms of real forested area, over 65% of NY state is forested, more than there was 150 years ago."

Ah yes the fine art of lying, you practice it very well my friend. Yes what you say is the truth but it's not the whole truth or nothing but the thruth. as This report shows there is less forest in NY then there was in 1600 and 1700. Not only that but the rate of reforestation has leveled off and is possibly dropping again. Again that's just in the north.
As the report I mentioned also makes clear the forests elsewhere are being cut down to make up for the offset.

That's just America though. Of course we stripped the northwest first and then replanted some of it as we started logging the west.
Worldwide the picture is a whole lot different. Right now for example it's cheaper to buy logs from canada then to log them here. We will probably stabilize and the canadians will cut more. In other places they are going to run out trees withing a hundred years.

Re:Cute, but false.

[marcus]

>Everything that sustains human life on this
>planet is in those first three feet.

Sorry, but this is simply incorrect.

Fish come from near the surface, all the way to the bottom of the sea. We only harvest from the upper "few hundred feet" of the sea.

Oil and coal come from thousands of feet below the surface and believe it or not, energy sources are very important to our survival.

In the context of the thread, even if the top 3 feet of the Earth were removed, along with the resident ecologies, this planet would still be far more habitable to humans than any other in the solar system.

Re:Cute, but false.

[Malcontent]

"Sorry, but this is simply incorrect. "

I am afraid it is you who is rather misinformed.

"Fish come from near the surface, all the way to the bottom of the sea. We only harvest from the upper "few hundred feet" of the sea."

All the life in the ocean depends on plankton which live in the first few feet. Considering the fact that plankton also produce a significant percentage of the oxygen in the atmosphere eliminating the life on the top three feet of ocean could kill everything not just the fish.

"Oil and coal come from thousands of feet below the surface and believe it or not, energy sources are very important to our survival."

the first few feet of soil contain just about all the bacteria, microbes, worms etc that enable plants to grow and flourish. Although to your typical economist (or republican) these things are worthless they enable us to live. Without them we won't need the oil, gas, coal or other things.

"even if the top 3 feet of the Earth were removed, along with the resident ecologies, this planet would still be far more habitable to humans than any other in the solar system."

That statement carries no meaning. It may be "more habitable" but I doubt it will be actually habitable. Without the first three feet you have no fish, and almost no vegetation. Maybe a few thousand humans could scrape a living but I doubt even that because we have no idea what kind of athmospheric and oceanographic effects the disappearance of sea life would have. It could very well ice over the planet or burn it. The carbon balance is a tricky thing.

I saw something like this once...

[Anonymous Coward]

it's an equation where you plug three variables in to get the number of inhabited (not just habitable, I believe) planets in the universe; of course you pull the three values out of your ass and end up with anything between 0 and one hundred billion kadgillion (or whatever) quite easily.

Re:It's almost as hard as you say it is...

[pinkj]

There's also the problem of cosmic radiation which is fatal to humans if exposed to it for too long. If I remember correctly, a simple journey to Mars would be impossible to achieve unless there was a way to shield the craft from cosmic radiation. Does anyone know if there has already been a methode developed to deflect the radiation?

This is what we should do:

[rice_burners_suck]

Combine this discovery with technologies such as global computer networks, advanced robotics designed for many purposes, the ability to genetically engineer any kind of living creature and terraforming technology, and we'll be able to create entire ecosystems that produce some intended results. Call it a computer--or more accurately, a machine--the size of a planet, with its output being anything from mined materials to manufactured consumer and business products to medicines and chemicals that are hard or impossible to produce on Earth. Nobody said the atmosphere on those distant planets need to contain oxygen--they could be saturated mostly in carbon-dioxide so that genetically engineered plant life could thrive, making unbelievable things possible. Imagine... on a distant planet, where plants grow extremely fast, robots cut down millions of trees every day and ship them to Earth. No longer would it be necessary to kill trees on Earth for houses, furniture, or even paper! Materials could be mined from distant planets. Why use up our own oil, metals, minerals and whatnot, when we can mine and retreive it from another planet? Why pollute our own atmosphere to manufacture things if we can manufacture them on other planets and let those planets get polluted? If designed correctly, those planets won't even get polluted! But who cares if they do?! Garbage crisis? No problem! Put it on another planet. The beauty of it is that no human being would actually have to set foot there! The robots could fix each other when they break down, and could be remote controlled from Earth, just like the Mars lander. It would be very beneficial to all of mankind, and would open up unbelievable multitrillion dollar international businesses that deal in interplanetary sales and distribution.

Re:This is what we should do:

[guiding_knight]

Pretty good idea, except for one thing: accountability.
If people are not actually on the planet, they will not care about it. Entire planets would be destroyed, or at least ravaged. Since all thats there is robots anyway, this wouldn't immediately affect us, but just imagine the effect when an alien civilization comes along and sees what we've done to countless worlds.

Also, what happens if something goes wrong with Earth? Where will we go if our ecosystem crashes? No one really wants to live on a planet that's been used to store garbage for a decade or two.

Basically, we shouldn't try to solve our problems by putting them in someone else's back yard.

Re:This is what we should do:

[Graymalkin]

That is a waste of energy. To mine something from a planet and get it to another planet requires massive amounts of energy and very long periods of time (much longer periods of time than societies on Earth last). By the time any materials mined from other planets got back to Earth the society that deemed it a good idea would be long gone. Not only would that society be gone but by the time the technology to make a lumber planet or oil planet existed there'd be no need for oil or lumber on such a massive scale. It takes alot of energy to get something from a planet into space. What you're saying would require an economy based around energy (in whatever form) thus shipping anything from the surface of a planet to the surface of another planet (scores of light years away) would cost absurb amounts of money (energy). You're trying to solve problems of 1890 by importing materials from space. Doesn't that seem a bit silly?

THOUGHT POLICE

[masterkool]

Just keep in mind that there are no difinitive answers, theories or results to this idea. Anything can happen, we coulkd find a billion, and we could find none. The whole idea is onle inductively conclusive.

All planets great and small.

[MyMarty]

I'm not in the field of astronomy, but i'm going to attempt to express and intelligent opinion anyway. Tell me how i go.

I don't think the fact that a large proportion of planets discovered by us so far are massive indicates that a large proportion of ALL planets are massive. Of course, this is one possibility. I would say, however, that our methods and technology are quite primitive for the task at hand. The resolution of our view of the universe if low and finite (but getting higher). As our surveilance resolution gets higher we might start discovering smaller planets.

Re:All planets great and small.

[CodeMonkey555]

In fact, you are absolutely correct. There are two methods to find planets in another solar system: wobble and occlusion. The wobble method detects minute movements of the star as the two objects orbit each other. Only when the planet(s) are of significant mass will the wobble be detected by our current means. The occlusion method looks for an object to move between the star and the Earth and decrease the intensity of the star's light. Again, this can only be detected for large planets.

If the aliens are intelegent

[Fembot]

aliens with any sense would try to avoid us for as long as possible given our (humans) extreme desire to destroy each other and well if they happen to find a copy of mars attacks then i think were completly doomed never to meet aliens ever

and given that the universe is infinite for all we know that would imply that there are an infinite number of planets and thus an infinte number of habitable planets

O btw my name is Ford Prefect :-)

Assload of planets?

[Pope]

Is that metric or imperial?

Why are we wasting our time?

[Berserker76]

..why don't these scientists spend their time, money and intelligence on solving the problems we have here on this planet before we completely destroy it. And how is an Earth like planet that is thousands/millions of light years away going to help us? Oh great....there is a planet with purple algae on it, WE ARE SAVED! =)

Re:Why are we wasting our time?

[cyber-vandal]

Most of the problems on this planet have been solved, it's the willingness of humans to actually apply the solutions that is the problem.

the next question would be ...

[PaganRitual]

... out of all these 'billions' of habitable planets ... how many of them are filled with beings who believe in ancient myths which tell them that they are the only life in the universe as specially chosen by a mythical deity?

Related News

[nihilogos]

Australian immigration minister Phillip Ruddock is reported to have asked scientists to submit a viability report on sending asylum seekers to these planets.

Billions of Habitable Planets

[NeuroManson]

!= Inhabited planets...

Recall that a couple of decades ago, Carl Sagan hypothesized that planets that could spawn intelligent life could have equal potential to self destruction to Earth... Chances are, if we manage to visit some of these planets, we'll find some ancient broken down probes, and maybe some nuked out cities, devoid of life...

Re:Billions of Habitable Planets

[Razzak]

Or, billions of machines using us as batteries!

What are the Odds That We're Alone?

[reallocate]

Seems to me that there's always been a lot of hominid hubris involved in this business of postulating our uniqueness or lack thereof as the bastion of intelligence life in the universe.

Isn't the basic problem that we are too far away from the next neighborhood to visit it so we can find out if anyone really lives there? The fact that we can't yet, get, or talk, to the next neighborhood has nothing to do with whether or not someone lives there. It just means we don't have the ability to determine that.

So, until Captain Cook managed to get to Australia, did it make sense for Europeans to assume that "there's no life down there"? Probably not, but the point is that whatever Europeans thought or knew had nothing at all to do with the reality of all those people walking around what Europeans decided to call Australia. p? If you support the uniqueness of Earth in the universe, it seems to me that the burden is on you to produce a cogent argument explaining why it is Just Us Humans.

Hmmmmm, variety of humanoids, yummm!

[Com2Kid]

CatGirls, elves, fae, oh yah! The more planets there are the better the odds are that we may find some sapient humanoids who resemble characters from modern fantasy! Kicking.

Hell if necessary we can colonize a few billion planets, and if THEY don't have the 'desired' females on them, we can start going into parallel dimensions until we eventually do find the 'desired' 'results'. w00t!

This species (homo sapiens) is /SOOO/ going to rock the galaxy(metaverse? Kickin!) in another few hundred years!

Re:Hmmmmm, variety of humanoids, yummm!

[Com2Kid]

Somebody is OBVIOUSLY not a hentai fan. ^_^

(sorry, just got done playing an Anime Based RPG that has a large amount of people with catear headbands on. Catgirls rock!)

Just try and tell me these are not cool.

Interesting!

[orkysoft]

Thanks for your well-informed explanation.

Re:Interesting!

[orkysoft]

Uhh, yeah, and don't forget to imagine a Beowulf cluster of space probes while you're at it! :-)

Re:It's almost as hard as you say it is...

[mother_superius]

that's what that poster implied... of course you'd have to accelerate to that speed! Do you expect it to be easy?

Re:Interesting! {2}

[orkysoft]

As long as you're not talking about etching the picture of the Goatse man onto a gold plate, and send it on the probe, I'm okay with it ;-)

Journal Article

[Witchblade]

Wow. That may well have been the least informative popular science article I've read in a few years.

If anyone is interested in the results and the technique they used an abstract and the preprint of their results are available here

Yeah but what about moons?

[Robber Baron]

That's no moon, it's a space station!

Short lived civilizations could be good, not bad

[FreeUser]

3. Such civilizations do not last a long time, and blow themselves up or otherwise fall apart pretty quickly

Or alternatively, civilizations progress at a geometric rate, transcending themselves in a few short generations, so that by the time intersteller travel becomes feasable they have lost interest and moved on to more compelling possibilities (perhaps departing this frame of reference entirely).

Once one hypothesizes a civilization significantly more advanced than our own it becomes difficult to even imagine the technologies they may have, much less what interests they would find compelling, or what goals they might set for themselves. For all we know they are all around us, unrecognized because they operate at levels as far beyond us as we are beyond the simple microbe.

Most of it could be done by colonising the planets

[Goonie]

Space infrastructure, research into long-term life support/closed-cycle ecosystems, fusion power, light sails, etc. etc, would presumably be developed to colonise the solar system (Mars, the Moon, asteroids, etc.). Given a solar-system wide economy hundreds of times bigger than our present global economy, it might be feasible one day.

As to the crew issues, you'd probably first build a frickin' huge telescope, big enough to image nearby terrestrial planets. You'd then build an unmanned probe with some snappy AI technologies to investigate promising candidates for colonisation. Then, once you've found somewhere good (it might take several lifetimes, but what's the hurry), you build your starship and the crew goes off to colonise the planet.

Would people go? Looking at our history, I don't see why you couldn't find plenty of people who would. Just imagine it, the chance to own a significant fraction of *an entire star system* :)

Re:That dang msid.msn.com

[Jeremy Erwin]

It's a space.com article anyway. I can't imagine why msnbc has so many slashdot fans.

Re:Short lived civilizations could be good, not ba

[maxpublic]

And as odd and new-age Boomerish this sounds, it's also the most likely explanation. That is, those civilizations which reach the technological level required to colonize the galaxy lose interest in such pursuits because such things no longer intrigue them - and in fact they shortly thereafter 'disappear', at least to our limited wetware perspective. It's the only logical explanation that accounts for both the lack of current non-human residents here on Earth and the galactic 'silence' we run into at every turn.

Any other hypothesis runs into a host of other unsolvable problems which essentially boil down to 'where is everyone?'. No matter how rare intelligent life is all you need is *one* successful species to fill the galaxy over a relative short time frame - the fact that this hasn't happened requires that you either admit the human race is the *only* intelligence to arise in this galaxy (uh huh), invent a rather lame excuse for why *everyone* has failed, subscribe to some sort of X-Files/Star Trek silliness, or embrace the above explanation knowing that you can't explain what happens to everyone, only that *something* does.

Guess we'll find out in a century or two, assuming we survive the next couple hundred years.

Max

Weird

[boky]

I've been going through the comments and still haven't come accross 42.

Links to spend a day on

[ynotds]

I can't imagine why this and the post immediately below didn't score some "insightful" mods while I've been off acquainting myself with their relevant and useful links.

Beyond the importance and improbability of our moon, I see the Drake equation putting a bit too much reliance on a single estimate of getting from life to intelligent life.

The fossil record makes it plain that bacterial life is relatively easy (or the product of spanspermia, which doesn't change the implications) but that metazoa is hard, one might suspect because the bacteria don't give up easily, being blind to the potential of flourishing as intestinal symbiots.

Even metazoa to intelligence took well over half a billion years, if we equate intelligence for this purpose to the posession of recursive language, whereas we breezed through intelligence to technological in under 100K years, if not without some flirting with self destruction.

The Fermi alternative that we are indeed first still needs to be considered against the possibility that the first may have been less influenced by a cultural duty to subdue the world and instead, when they realised they were unlikely to meet anybody else for a hundred million years (the tail on the probability distribution) have settled for something less than galactic domination.

Beautifully Said.

[Bob_Robertson]

I couldn't have said it better myself. In fact, I couldn't have said it half as well.

Bravo.

Bob-

I couldn't disagree more.

[Bob_Robertson]

Manned interstellar exploration will require exactly what manned intercontinental exploration did: Time and opportunity.

As long as governments have a monopoly on space, we as individuals have no opportunity.

Get government out of the way, and someone will try it. Then it's just a matter of time.

Remember how much hostility NASA reacted with when told that the Russians were going to let a paying customer go into space? That's a hint.

I suggest you read Kings of the High Frontier by Viktor Komen for a good discussion of the matter.

Bob-

Re:I couldn't disagree more.

[cyber-vandal]

And how would a CEO sell that one to the shareholders/venture capitalists. 'We're going to spend several billion dollars on a mission that might not succeed, trying to establish if there's any way of making money out there'. Much easier to just be a NASA contractor and get paid, regardless of the mission's success.

Re:I couldn't disagree more.

[Bob_Robertson]

It doesn't cost several billion dollars to get into space, just a few million. Many times that was spent on silly speculative dot-com ventures.

Of course it's easier to be a government program, look at how much money and lives you get to waste and keep your job.

I really do recomend you read Kings of the High Frontier.

Bob-

Re:I couldn't disagree more.

[sql*kitten]

And how would a CEO sell that one to the shareholders/venture capitalists. 'We're going to spend several billion dollars on a mission that might not succeed, trying to establish if there's any way of making money out there'.

Columbus made a pitch like that, and he didn't even have an MBA!

Re:I couldn't disagree more.

[Geezle2]

"As long as governments have a monopoly on space, we as individuals have no opportunity." Well, I hate to intrude upon your fantasy here but governments have a monopoly on space exploration/exploitation because they are the only entities on the planet with the capital and . . .well. . .scope of vision to make it a reality. Corporations must show a profit each quarter, or at least the potential to make a profit in the near term or investors will lose interest (or should I say dividends? heheh!) and move their capital elsewhere.Corporations don't have the staying power to invest trillions in a project that could take decades to show any returns. The first step to serious industry in space is the development of some heavy lift to orbit infrastructure. We are not talking competition with that AMC Pacer of the sky, the shuttle. . .here we're talking the spaceworthy equivalent of a 40,000 ton container ship. This, I am quite sure, is well beyond the means of any individuals on Earth and few corporation would be capable of it even if they devoted all of their resources to the task for a few decades. On the other hand, the US government thinks nothing of slapping a few $trillion on the table for such items as Trident submarines and stealth bombers. A heavy lift to orbit infrastructure is well withing the abilities of governments. . .Get government out of the way and no one will do it. . . "Remember how much hostility NASA reacted with when told that the Russians were going to let a paying customer go into space?" Just because someone can pay you for the gas doesn't mean that they have the means to buy the car! This in no way what so ever indicates that private citizens (or even corporations for that matter) are willing or able to take on the task of off-planet infrastructure development. BTW, were there a commercial space station. . .say . . .like a novelty orbiting hotel built by Hilton. . .the price for a weekend there would be an order of magnitude greater than what our intrepid "paying customer" shelled out. . .In this latter case, the ticket price would have to cover things other than the cost of fuel to haul your carcass up to orbit. . .things like construction costs, crew and employee payroll, oh yeah, and profit. . . NASA was upset by the RSA's plan because the International Space Station is being built with taxpayer dollars to coonduct serious research, not to be a playground for the rich and famous . .now if the rich and famous were willing to foot a substantial portion of the cost of construction, I'm sure that NASA would reconsider their position. . . Face it. . .It is because of governments that we have done anything at all in space. If it hadn't been for the Soviets forcing the issue, we would still be wondering what the Earth looked like from more than a few thousand feet away. If the human race has a future in space, it will be governments that get us there. . . Don't take my word on it though! Prove me wrong! Go ahead. . .build a starship. . .no one will stop you. . .If you are afraid of the US government intervening, just build your starship in the Dominican Republic. . .or Mexico. . .or Haiti. . .a few thousand dollars in bribes and you won't be hassled.

Re:I couldn't disagree more.

[cyber-vandal]

Yes, but Columbus was funded by the government. Queen Isabella of Spain was the one that funded his voyage.

Re:Short lived civilizations could be good, not ba

[spiro_killglance]

These basicly two chooses:

1. something unexpected kills all of them,e.g. Trying to measure the mass of the Higg Boson, squashes the planet down to the size of a pea, (lexx)

2. They find an easier way to expand and grow
than travelling through the galaxy. e.g.
Knowledge of Quantum Gravity allows them to build
basement universes, creating space-time, energy
and matter to order. In which case filling the
galaxy becomes pointless. They still might be
a reason to talk to other cilivisions through, and
that is to trade stories and culture.

Re:Short lived civilizations could be good, not ba

[Saeger]

This is the theory I've adopted as well--it just makes the most sense to me.

We'll eventually be able to create our own "virtual" universes, which are infinitly more interesting, since WE'RE effectively Gods there.

If I had a choice between a) slowly trekking through one boring physical universe, or b) freeing my mind from its limited primordial wetware brain, and moving into my own universe(s), I'd choose the latter.

--

Hmm �

[da5idnetlimit.com]

"the only thing that is between us and sutch a planet right now is technology/ science."

To put it another way, I always thought that what separated us were Gazillions Kilometers and that the first travellers would have to use cosmic winds...

Best to work on protonics right now than putting work in the Warp Drive 8)

Also some string

[da5idnetlimit.com]

a few thousand miles, so you can spin the planet a wee bit more 8)

Re:Short lived civilizations could be good, not ba

[at_18]

Mod parent to +5! Where are my mod points when I need them?

Sagan never said such a thing or so he said.

[Schwarzchild]

I think he only said "Billions..." and people just tacked on the extra billions, of course, him saying that he never said that means he actually said it! ;)

Re:Sagan never said such a thing or so he said.

[Insightfill]

Yeah, I remember hearing about that once and had a chance to go through a few of the old "Cosmos" tapes from the local rental shop - the "billions per sentence" ratio never got above one.

On the other hand, he did release a book called "Billions and Billions" that seemed to cover all sorts of topics.

Johnny Carson's impersonation of Carl Sagan used it, and Sagan eventually said it years later. After a while, he was reported to have grown to hate the phrase and tried to refrain from even using the word "billions" in public. At a Planetary Society meeting in 1981, his speech eventually had to use the word "billions" (just once), and giggling broke out in the audience, and then he just glared.

Still, quite a few people have gotten fame (or more fame) for things they never said. I get that all the time at home...

Check out "They Never Said It: A Book of Fake Quotes, Misquotes, and Mis-Leading Attributions" on your favorite book/search site. (I'm not supplying a link because you're all grown-ups and know how to search!)

Re:Sagan never said such a thing or so he said.

[Schwarzchild]

At a Planetary Society meeting in 1981, his speech eventually had to use the word "billions" (just once), and giggling broke out in the audience, and then he just glared.

He should have just said "one-thousand million..." and he could have avoided saying billion!

You know what this means...

[Graabein]

You know what this means, in 2-300 years the title "Miss Universe" will actually mean something.

Expert in planetary system formation?

[Graabein]

Quote from the article:

"Alan Boss, an expert in planetary system formation at the Carnegie Institution of Washington"

Now I'm sure Mr. Boss knows more about the subject than most people, but can anyone really call themselves an expert in a process we know to be happening all over the Galaxy (and most likely Universe), but for which we have only one observable study object? (And even that is 5 billion years after the fact, so much of what we "know" is conjecture.)

I mean, expert on our own solar system, yes, but planetary system formation in general?

A defined number of planets

[cra]

Recent events and research reports concidered, I'd say the number of inhabitable planets is zero. None. 0.

Re:Short lived civilizations could be good, not ba

[ChristTrekker]

Seems to me that's just self-delusion. Who says the physical universe is boring? Your own universe will be limited by your intelligence and creativity. We are no where near figuring out everything in the real universe yet. That goes to show that a personal universe would be less interesting than the real one. If one thinks that the universe he creates is more interesting, doesn't that imply he thinks the universe should cater to his whims? Seems egotistically arrogant.

I value other people and the interactions I have with them. I wouldn't get that in a personal universe, or if I did, those people would necessarily be less than I am. Only an infinite God (which you and I are not) could create an "interesting" universe.

Moon lacks hydrogen

[peter303]

Most of life and our civilization burns hydrogen compounds for energy. This is water or hydrocarbons. The moon appears to outgassed most of its water and hydrocarbons eons ago. Might be a bit ice in some the perpetually dark polar craters- but not a whole lot. We'd need to import hydrogen from earth or a capture a comet. Comets have lots of water and hydrocarbons.

Re:Short lived civilizations could be good, not ba

[leifb]

We'll eventually be able to create our own "virtual" universes, which are infinitly more interesting, since WE'RE effectively Gods there.

Perhaps this is presumptuous on my part, but as someone who has played with religion, lucid dreaming, deep hypnosis, and biofeedback, I find the world around me to be far more challenging, entertaining, varied and surprising than anything my nervous system can put together on its own.

Did I mention meaningful?

The prospect of a virtual apotheosis bores me.

Give me real problems to solve, real experiences to explore, real tools to use in implementing solutions.

I'll make my own apotheosis.

There's another darker prospect that doesn't require a robot holocaust to come into being: maybe the effective Gods have been plugged into their realities involuntarily, as a means of pacification. Maybe a population that can wire their pleasure centers for constant activity doesn't feel the need to explore.

Re:Short lived civilizations could be good, not ba

[BorosAttila]

all you need is *one* successful species to fill the galaxy over a relative short time frame The fact that humans and any other life form on Earth fills the available space for it doesn't mean that alien life forms have the same behavior. Maybe they are not as expansionists as we are.

On the other side they would need a huge amount of energy to fill the galaxy, and if they have such an energy source and the appropiate technology, they could make anything they need.

Rare Earth. Very VERY Rare Earth.

[hackus]

There are some seemingly odd probabilities at play here, one of those that I am interested personally in is due to the fact that, we human beings, intelligent life, are really RARE. Even on a world that has had a very nurturing Sun, and very ULTRA stable periods of time with regards to ideal conditions for life to evolve.

I am using the Earth as a model, but out of the billions of years, and the millions of species, only one became intelligent, to be using slashdot today. I think that speaks VOLUMES about the probability of intelligent life out there in the Galaxy.

We are talking about galactic time, as well in terms of intelligent life and its probability on a very very nurturing planet, which I think the Earth is an ideal model of.

If intelligent life is so common, it would seem to me you can't make the same argument about given enough time (Billions of years) and simply because there are "so many" of those possibilities, doesn't make it common. Intelligent life isn't common on earth, only one species has it. It is very very VERY uncommon.

There was huge amounts of time, Galactic time, on earth and only ONE intelligent life form evolved. I think that speaks volumes about what we can expect out there we we explore space. We may very well be alone, or if we are not, the other race is so far advanced I would think we would have very little in common to initiate communication.
(All this thinking about lasers, and radio waves is so quaint. SETI and the people who run it are pretty naive about research into these sorts of areas. Nobody in thier right mind would use radio waves to communicate, or any sort of electro magnetic wave. The distances that a space faring race would have to cover, would solve the problem using a form and method of communcation that doesn't have these issues. You can bet it is a science far beyond our understanding, and methods to detect.)

If we are to use the Earth as a model, and assume it represents the normal progression of life, if given the right conditions, habitable earth like planets are probably very rare.

If we use the Earth as a model, intelligent life takes galactic time to come about. That would mean there may be only 1 or two other intelligent races in our galaxy.

I don't buy into the belief that habitable earths are common place. We have 9 planets in our solar system, only one is habitable, not all nine. We also know that life zones around stars are very fragile, and stable computable orbits in these zones only allow at most one planet during the lifetime of a star. Please note. Life zones around stars change as they go through stellar evolution.

We also know our sun is not an "ordinary star" as we are lead to believe in our physics text books only published 5 years ago. It is FAR too stable as far as its output goes. Most stars observed are NOT AS stable in stellar output as our sun, but go through cycles of instability, or are just unstable due to thier composition as they evolve.

It requires, many many MANY things to come together to make a habitable planet, and just counting stars that have similair stellar output as our sun doesn't equal large numbers of habitable planets out there.

In fact, you may even need a certain CONFIGURATION of a solar system for life, let alone intelligent life too come about otherwise, you have impact events that snuff it out totally. Jupitor reduces the large impact bodies in our solar system for example, because of its large gravity. Sucking up big rocks that would otherwise destroy all life on earth in an instant of galacitc time should they impact earth. Solar systems without large planets like Juptitor, life probably won't get the chance to take root because there is nothing to stop large impact events from frequenting the planet in the habitable zone.

It is clear you need galactic time spans of stability to bring about intelligent life.

There are so many unique, and very unlikely things about our solar system that the more systems we look at, I would be willing to bet, probably seem very alien too our own solar system configuration, but probably represent the statistical average "Joe" solar system.

-hack

Re:Short lived civilizations could be good, not ba

[maxpublic]

Only an infinite God (which you and I are not) could create an "interesting" universe.

Evidence to support this assumption? None.

Max

Re:Short lived civilizations could be good, not ba

[maxpublic]

On the flip side, there's absolutely no reason to believe that over the lifetime of the entire galaxy that no species has arisen which doesn't want to expand. All you need is curiosity and an appreciation for different scenery.

And you don't need a huge amount of energy to fill the galaxy. Using ramscoop ships you could ship tens of thousands of colonists in leapfrog from one system to another in relatively short order, effectively colonizing all habitable planets within a speedy (galactic) time frame. It wouldn't matter at all if the civilization remained coherent so long as a *single* one of these colonies developed successfully and continued the chain.

Max

Re:Short lived civilizations could be good, not ba

[BorosAttila]

On the flip side, there's absolutely no reason to believe that over the lifetime of the entire galaxy that no species has arisen which doesn't want to expand

OK, I must admint I'm a little pessimistic about how many *intelligent* species could arise. The fundamental requirement for intelligent life to evolve is an extended period of almost perfectly stable conditions. It took life 3.5 billion years to produce us, on other planets evolution may be slower. We know what happened to dinosaurs, even Jupiter could not save them, and it could be worse.

Suppose there are "humanoid" species, willing to expand. The article says there are about 30 billion Earth-like planets in our galaxy, but it is just about 16 billion years old. Then "filling the galaxy" means filling 2 planets every year. This is highly unlikely...

"Why they aren't here?"

"They are here, just hiding" - FALSE! If they are willing to expand and fill the galaxy, they would simply blow us off the planet. Anytime in our history a superior civilization met an inferior one, that was catastrophy for the latter. And they was both humans. Expansionist aliens would treat us as we treat animals, or worse.

Maybe they are not here, because they are fighting each other in an endless war, or have destroyed each other.

Maybe interstellar flight is much more difficult than we think it is. What about navigation close to light speed? "Generation ships" are possible but maybe only a few individuals would accept it. They won't ever see their destination, only their chlidren will (IF the mission succeeds). And they literally have to put their lives on it.

They found better places to go.

They can terraform any planet, and don't need to travel so far.

They don't live on planets.

Re:Short lived civilizations could be good, not ba

[ChristTrekker]

infinite God (which you and I are not)

Self-evident. No assumption. If you disagree, you have some serious delusions of grandeur.

an "interesting" universe

I suppose if you're so self-absorbed that you're only interested in what you yourself can imagine, then I suppose such a universe might be interesting. Personally I find it more interesting to be challenged by the things I could not have imagined for myself.

Live in the terminator

[GPS Pilot]

If a planet is exactly tidelocked, there would be a small habitable strip of land near the terminator (the boundary between the freezing night side and the roasting sunward side). It used to be thought that Mercury was exactly tidelocked, and I remember an interesting piece of science fiction about the inhabitants of Mercury's terminator.

Possibility #3...

[GPS Pilot]

Such civilizations do not last a long time, and blow themselves up

The most energetic events in the universe -- far more energetic than supernovae -- are gamma-ray bursts, and they're quite a mystery to astrophysicists trying to figure out how a natural process can give rise to them.

I think I've figured it out. They're not a natural phenomenon, they are advanced weapons, used to take out entire solar systems. (The shock wave probably destroys all life in neighboring solar systems as well.) Sadly, this weapon has been re-invented over and over again in different parts of the universe. We see gamma-ray bursts in all directions of the sky. From the distance in light-years, we know that some of them happened billions of years ago, and some of them happened less than a billion years ago.

Or maybe they're not weapons. Maybe they are accidents that occur when a civilization performs very high-energy physics experiments.

Slowboat to Zarton

[Tablizer]

(* An alternate version of 2 is that interstellar travel is far more difficult than we think it is. Right now, it doesn't seem much beyond the boundaries of current technology to launch "generation ships," which power systems. *)

If we don't care how long it takes, we could build such ships right now. It would require a Jupiter-sized budget and a lot of plutonium, but do-able.

It would be a multi-generational colony(s). Sort of like Mormons In Space.

The number of people terrorists can kill doubles every few decades or so. At this pace we better start thinking of putting our eggs in other baskets. One of these days Osama's will be able to easily build nukes. The ability crawls down the feedchain surely. And don't even start about bioterrorism or nanoterrorism, etc.

Were doomed! Let's get building!