In the 1950’s, Nobel Laureate Enrico Fermi proposed a paradox by asking, where is everyone? His reasoning was simple, given the sheer size of the universe, what are the chances we’re alone? If we’re not, where is everyone else? We should look out into space and see signs of intelligent life around other stars.
Conservative estimates put the number of galaxies in the visible universe at around a hundred billion, and the number of stars at 10^24. The problem with both of these numbers is we have no way to appreciate them in every day life. They’re simply too large to hold any meaning. But hold a grain of sand out at arm’s length, and you’re blocking the light from 10,000 galaxies!
Astronomer Frank Drake came up with the first methodical way of estimating the possibility of life elsewhere in our galaxy (remembering ours is just one of at least a hundred billion). He arrived at the conservative figure of 10,000 other civilizations, while Carl Sagan thought the number could be as high as a million.
Some estimates for the entire universe end up with absurdly large numbers like “ten million billion” alien civilizations! The bigger the numbers being spit out of our estimates, the more perplexing it seems that we don’t see evidence for any other intelligent life in outer space. Fermi’s Paradox is a head scratcher. Or is it?
There’s a problem with Fermi’s Paradox. We’re not actually sure it’s a paradox.
Think back to the numbers we just looked at—10,000 galaxies, containing trillions of stars, all obscured behind a single grain of sand. If just one of those galaxies contained life, we wouldn’t know it. We can’t see any of those galaxies with any clarity.
There’s a case to be made that WITHIN our galaxy we don’t see any other intelligent life, but beyond our galaxy, our ability to look for life is non-existent. It’s a bit like someone standing on the shores of Greece saying, “I see no evidence for Egypt.”
Fermi’s observation isn’t really a paradox. Look at how little we’ve actually searched. Even our most advanced planet-hunting space telescope has only focused on a tiny patch of our own galaxy. It’s no surprise we haven’t found life. Honestly, it would be a surprise if we had.
Remember, there are roughly a hundred billion stars in our galaxy alone, but again, numbers like this are meaningless without context.
Ah, that really doesn’t help.
Just how big is a hundred billion? Well, a million seconds pass in 12 days, a billion seconds in 34 years, a hundred billion seconds pass in well over three millennia.
Is there life in outer space? Yes. Earth itself is proof of that.
Is there any other life in outer space? Well, we’ve just started looking. We really cannot say one way or the other, but we have no reason to think there isn’t. Fermi’s got us looking, and that’s a good thing, but don’t underestimate the magnitude of the challenge.