In a special section on the search for extraterrestrials, "Where Are They?" explores how likely alien civilizations are to exist, and "Where They Could Hide" discusses the fact that no SETI program has ever found a verifiable alien radio signal. In "Intergalactically Speaking," the vastness and vagaries of space will force interstellar correspondents into extreme measures, if we are to make a credible search for extraterrestrial life. These articles originally appeared in Scientific American for July 2000.
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