Is there anybody out there?

[pensnest]

I've been reading comments to this post on Why Evolution Is True, and thinking my own thoughts.

Before you go to read them for yourself, tell me—do you think there is life elsewhere in the Universe? Or are we on Earth all there is? And, why?


My own feeling is that yes, there is life elsewhere. I'd put money on it, but it's the sort of bet that can only be proved in one direction. The way I see it is that the universe is so beyond-imagination huge that even if Life is pretty damn unlikely, there are an awful lot of dice-throws available. A million-to-one shot really does become a certainty. If this is really the only place in the whole mighty universe where life has ever happened, the *odds* against life become another one of those mind-bogglingly large numbers that I cannot get my head around. I admit, I don't actually *want* to believe that—but since we can't tell what the statistics are, I'm not denying any facts by choosing not to.

Anyway. We can't hope to look everywhere and everywhen in the universe, so we'll never know for sure that there is *no* life elsewhere. If life's a very rare occurrence, chances are it'll occur far beyond our scope. If, on the other hand, it's comparatively simple for Not-Life to start self-replicating and turn into Life, we might find proof. We might find it locally. We might find it on Mars, or on one of the moons of Jupiter or Saturn. And if there turns out to be Life, most likely in the form of teeny tiny bacteria-like organisms, elsewhere in our solar system—assuming it turns out to be Life that isn't related to Life on Earth—then the odds of there being *intelligent* life shoot right up. Which is exciting!

Comments

[sperrywink]

I just started reading "The Hidden Reality" by Brian Greene which is all about alternate universes or multiverses and one of the first arguments for not just other life in the universe, but near-duplicates of *our* life is just that statistical argument. With finite mass/energy in an infinite universe, for every quadrant of space it can only be shuffled in a limited number of finite combinations which leads to copies of the same stuff over and over again. Some identical, some differing by small amounts (what if I went left instead of right?), some drastically different happening over and over again across the infinite universe.

Totally cool thought!

[pensnest]

Hmm. I haven't read that particular book. It's an interesting argument... but when we look at the history of life on Earth, some of what has evolved is due to particular chance events happening at particular times. I'm thinking of the mass extinctions which have been attributed to meteorites (the dinosaurs, and possibly the Cambrian variations). If the dinosaurs hadn't gone, would mammals have become what they are? We might be living in a world of birds and extremely sophisticated lizards! And indeed, we still have no idea whether it's easy for Not-life to become Life; could be Life emerges with almost routine regularity, could be we're on the only planet where it has. And the biomass on this planet could be non-bio, or in an incredible number of different varieties. Perhaps it depends on what the author means by 'near-duplicates'.

I get too boggled by the possible variations between shades of this universe—which is itself far too big for me to get my head around. Alternatives are too much for me to handle!

[nopseud]

I don't think we have anywhere near enough data to make even a very bad guess.

[pensnest]

True, and I boggle at the possible variations on probabilities and numbers involved. (I'm quite surprised at scientists who do try to put numbers on it.)

I suspect that all the SF I've read inclines me to the belief that life isn't exclusive to Earth—although I don't think we'll find intelligent, able-to-communicate-with-us life; the universe is too big. But at least it's a question that we might be able to answer in the affirmative.

[bettina]

I do very much believe that there's life elsewhere. The universe is so incredibly big with billions and billions of stars and just in the past few years they've found so many stars with their own planets. I think, chances are pretty good that on some of those planets there's life. :)

[pensnest]

That's pretty much exactly how I feel about it. Even if Not-life becoming Life is *really rare*, there are so many opportunities out there.

[ephemera]

I think it's unthinkably unlikely that somewhere in a near-infinite universe throughout the whole of time we're the only planet that evolved life, and various forms of intelligent life forms, therefore I assume that somewhere, somewhen, there are / have been / will be other intelligent life forms. Not sure how likely it is that we'll ever find each other, or if would be desirable to...

[pensnest]

That's how I feel about it, too. It would be such a *shame* if life has only ever evolved the once! And I'd like to think that life, in its most primitive forms, turns up every five minutes, intergalactically speaking.

[solariana.livejournal.com]

With all the billions of galaxies, stars, planets out there, I would be surprised if there wasn't some sort of life out there. I was watching a science show once where they stated even if only one planet in a million had life, there would still be life on over one million planets! Inteligent life is, of course, a different question.

I absolutely believe there is some sort of life somewhere out there, but probably so far away and so shortlived that we would never meet. As far as intelligent life, who knows. But if there is, it probably is a speicies that looks differently from us and probably speaks a totally different language (so much for Star Trek!). And again, probably so far away and with such a short lifespan we would never meet.

But who knows? I keep my mind open to such things.