Extraterrestrial: The First Sign of Intelligent Life Beyond Earth

Intelligent life is out there—or at least its cast-off equipment is­—and it’s time earthlings dealt with it, argues Harvard physicist Loeb (The First Galaxies in the Universe) in this contentious manifesto. The author’s concerns are twofold: first, he believes there is evidence for extraterrestrial life. Second, he posits that humans aren’t prepared to accept that fact. This survey, then, is a brief on alien life and its implications for humanity. Loeb bases his case on ‘Oumuamua, an interstellar object that baffled scientists when it appeared in 2017. Based on its shape, brightness, and trajectory, Loeb proposes it could be a reflective light sail made by extraterrestrial life. While his advice on how to find inhabited exoplanets is often ingenious (“one can distinguish an artificial source of light by the way it dims as it recedes from us”), less cogent is his attack on astronomical orthodoxy, which he considers too dismissive of research into extraterrestrial intelligence. He suggests that finding extraterrestrial life will help cure human arrogance and self-destructiveness: aliens, he contends, are likely to be “superior being[s]” who can reveal “the meaning of life,” though he also speculates they could turn out to be existentialists who believe that “life is absurd.” Loeb’s thought-provoking work of popular science will entertain those who wonder if humans are alone in the universe. Photos. (Jan.)