If the Universe Is Teeming with Aliens ... Where Is Everybody?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life

Where Are the Extraterrestrials?

During a Los Alamos lunchtime conversation that took place more than 50 years ago, four world-class scientists agreed, given the size and age of the Universe, that advanced extraterrestrial civilizations simply had to exist. The sheer numbers demanded it. But one of the four, the renowned physicist and back-of-the-envelope calculator Enrico Fermi, asked the telling question. If the extraterrestrial life proposition is true, he wondered, "Where <…