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

[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!