Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:
THE FERMI PARADOX
Enrico Fermi was an Italian physicist, one of the many great scientists who immigrated to the United States right before the outbreak of World War II. He is most noted for creating the first nuclear reactor and the role he played in the development of the atomic bomb.
But that’s not what we’re going to talk about today. Today we’re talking about something Fermi said half-jokingly over lunch.
Where Is Everybody?
Based on some historical detective work, we can say this probably happened in the summer of 1950. Fermi was visiting the Los Alamos National Laboratory. He and a few colleagues were having a lunchtime conversation about flying saucers. Apparently there had been an amusing cartoon about little green men in a recent edition of the New Yorker.
The conversation got serious (sort of) when Fermi suddenly asked: “but where is everybody?” Everyone at the table laughed, but Fermi’s question and the not-entirely-serious discussion that followed would become the basis of what we now call the Fermi paradox.
As a matter of statistics and probability, it seems like advanced alien civilizations should be out there somewhere. There are over 100 billion stars in our galaxy. Many (if not most) of these stars have planets orbiting them. Some of these planets must surely support life, and in at least a few cases intelligent life—life capable of developing interstellar travel.
Even without faster-than-light technology, one or more of these space-faring civilizations could conceivably spread across the whole galaxy in just a few million years. The galaxy is far, far older than that. There’s been plenty of time for the aliens to do it. So where is everybody? Shouldn’t we have heard from somebody by now?
Or so Fermi argued over his club sandwich (or whatever he was eating) in a half-serious conversation about flying saucers. Of course there are plenty of objections to Fermi’s line of reasoning here, but I’m not going to weigh in on that. Not today. I’m saving my opinion for Monday’s post.