Fermi Paradox

alien civilization

Fermi Paradox

Our Galaxy Should Be Teeming With Civilizations, But Where Are They? Is there obvious proof that we could be alone in the Galaxy? Enrico Fermi thought so -- and he was a pretty smart guy. Might he have been right? It's been a hundred years since Fermi, an icon of physics, was born (and nearly a half-century since he died). He's best remembered for building a working atomic reactor in a squash…

Zookeepers, Alien Visitors, or Simple Life

How Can We Explain Our Isolation? We seem to have the Galaxy to ourselves. At least, thats the obvious conclusion from the apparent lack of aliens in the neighborhood. But this conclusion might be a bit too obvious, and possibly wrong. In previous articles, weve considered why extraterrestrial intelligence even if common would have restrained itself from spreading to every half-decent star…

What's Blocking Galactic Civilizations?

Could galactic empires exist? In a previous article, we noted that there has been plenty of time for aliens keen on colonizing the Milky Way to pull it off. However, we see no signs of galactic federation ("Star Trek" aside). Why does the cosmos look so untouched and unconquered? What is keeping advanced extraterrestrials from claiming every star system in sight? This puzzle, known as the Fermi…