If the Universe Is Teeming with Aliens … Where Is Everybody?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial LifeStephen Webb4.1
Cosmic Queries: StarTalk’s Guide to Who We Are, How We Got Here, and Where We’re GoingJames Trefil4.4
Hyperspace: A Scientific Odyssey Through Parallel Universes, Time Warps, and the 10th DimensionMichio Kaku3.3