May
09
2008

I think we're alone now*

Is anybody out there?: If not, it'd be fine by me!
Is anybody out there?: If not, it'd be fine by me!Courtesy NASA

Is there intelligent life elsewhere in the Universe? That’s a hot topic, both among astronomers and right here on Science Buzz. The argument goes like this:
• There are about 100 billion galaxies in the known Universe
• Each galaxy has about 100 billion stars.
• Even if only a small fraction of them have planets, that’s still an awful lot. Ya gotta figure at least some of them developed intelligent life.

And thus we go looking for signs of life in outer space: probes to Mars, searches for organic molecules, even scanning the skies for radio signals. So far… nothing.

Nick Bostrom is glad. This Oxford professor argues that finding life on other planets would be bad news for us here on Earth.

The way he sees it is this:
• The Universe is about 14.5 billion years old.
• Earth is about 4.5 billion years old.
• That’s plenty of time for intelligent life anywhere else in our galaxy, or even a nearby galaxy, to come pay a visit.
• They haven’t.

This convinces Bostrom that interstellar travel must be impossible – if it wasn’t, someone would have stopped in by now, if only to ask for directions.

What makes interstellar travel impossible? Bostrom and economist Robin Hanson theorize (or “theorise” – they are British, after all) the existence of one or more “Great Filters.” The evolution of life, from primordial ooze to galactic explorer, requires a vast number of steps, some so complicated as to be virtually impossible. Obviously, one of those steps has been preventing interstellar travel for the past 14.5 billion years, so it must be pretty good.

What does all this have to do with life here on Earth? Simply this: the identity of this filter, and whether it lies ahead of us or behind us, may very well determine the fate of all humanity.

If the filter lies behind us—especially if the filter lies wayyyy behind us—then we’re in good shape. We’ve passed the barrier that has stopped everybody else. But if the filter lies close to us—or, worse yet, ahead of us—then it spells big trouble. For example, perhaps the only way to travel the stars is to harness some great energy source: nuclear power, or perhaps something we haven’t discovered yet. And perhaps every civilization in the history of the Universe that discovered this power ended up blowing themselves up. It’s unlikely that we would be any different.

Bostrom’s conclusion is counter-intuitive but compelling. If, as we explore the Universe, we find life is rare, then that’s good news—Earth succeeded where every other planet failed. But if we find that life, especially complex, intelligent life, is common, then that doesn’t bode well at all. Whatever stopped those planets is likely going to stop us, too.

*(PS: The answer is, Tommy James and the Shondells, later covered by Tiffany -- both proof that intelligent life is exceedingly rare, even here on Earth.)

Your Comments, Thoughts, Questions, Ideas

JGordon's picture
JGordon says:

For some reason I find this story totally depressing, and yet totally awesome.

Like, super-advanced Kryptonians were out there, and the last thing their planet heard was "Well, I'll just press this button, and that should do the trick----" Hilarious.

Or humans are the most advanced beings in the universe, and we watch Top Model and don't even wear metallic clothing. Hilarious.

Or Earth is like the "weird table" in the high school lunchroom of the universe, and we're the kid picking his nose and wondering why no one wants to sit by him. Oh ho ho.

posted on Fri, 05/09/2008 - 11:33am
Kunicki24's picture
Kunicki24 says:

Thats rather interesting, depressing yes but Bostrom makes a point. If there was life out there why haven't they tried to make contact with us, but then again they couldn't even know we are here and be searching in the same way we are.... hmmm..... something to think about....

posted on Thu, 05/15/2008 - 10:13am

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