MacGougan at Large

Notes on Paradoxes - 5

Fermi Paradox

Back in 1950, Enrico Fermi asked, “Why aren’t there any aliens?” This wasn’t a reference to immigration. He was asking about the real aliens - extraterrestrials. 

Given the enormous size of the observable universe and all that had been done up to that point to observe and explore it, why was there no sign yet of any intelligent life - or, frankly, any life, period - beyond our little pebble-grain of a planet?

This was taken as a paradox because of notions about probability. Even if intelligent life is a one-in-a-million shot, there are billions and billions of possible sites out there where it could arise. If we had that many monkeys randomly typing, a few thousand of them would have produced Hamlet by now. Why don’t we see signs of intelligent life anywhere else in the universe?

(I am setting aside, for the moment, the question of whether or not we see signs of intelligent life on Earth.)

The paradox has only become more striking in the years since Fermi asked his question. Our knowledge of the universe grows and grows, and still there is no evidence of alien life.

There are various schools of thought on this, most of them depressing. We’re alone in the universe. Intelligent life inevitably destroys itself. Intelligent life is out there, but it’s paranoid and hiding from us. Intelligent life is out there, but it’s malevolent and sneaking up on us.

My personal favorite theory starts with a thought experiment. Imagine you are parachuted onto a random point on the Earth. How long would it take you to find people? You might come down in the middle of a city and find them right away. It’s more likely that you’ll come down out in the country somewhere, and it might take you days or weeks of walking to find anyone. It’s even more likely that you’ll come down in the middle of an ocean, and it might take you months or years to row your dinghy to someplace where you can see people.

That is, maybe the unfathomable vastness of the currently-known universe is just a sparsely populated corner of the actual universe. We just happen to have parachuted into the celestial boondocks. In which case, we’ll take the good with the bad. There aren’t any other civilizations nearby to learn from, but real estate is inexpensive and there aren’t a lot of zoning restrictions.