The Science of Finding We ARE Alone: 209

An Extremely Uncomfortable Investigation into the Great Silence, the Empty Sky, and the Possibility That Humanity Is the Universe's Only Group ChatThere are two great questions that have followed human beings since the first person looked up at the night sky, forgot why they had gone outside, and then pretended they had meant to stand there dramatically. The first is, "What is all that?" The second is, "Is anybody else looking back?"For most of human history, the answer to the second question was supplied by religion, mythology, poetry, speculation, campfire stories, and whichever uncle had recently become very interested in radio frequencies. The heavens were crowded with gods, spirits, ancestors, monsters, angels, devils, hidden kingdoms, and occasionally a fellow named Zorblax who had apparently traveled halfway across the galaxy in order to leave a blurry photograph of a hubcap in somebody's cornfield. The universe was not lonely. It was packed. Possibly too packed. There appeared to be a cosmic population problem.