Dr. David Bowman, orbiting Jupiter, is preparing to leave his spaceship.
By this point in “2001: A Space Odyssey,” the onboard computer, HAL 9000, has murdered his fellow astronauts with the kind of unsmiling single-mindedness we’ve come to expect of artificial intelligence. Bowman slips his sweating forehead into the dome of a helmet and switches the wretched computer off, then opens the ship’s bay door to meet an entirely different category of intelligence on the other side. Contentedly orbiting Jupiter is the alien Monolith, with its perfectly straight surfaces, its inert intelligence boiling under glassy black panels.
No, this is not the kind of extraterrestrial life our imaginations yearn for. Where are the little green men, we ask, with their tentacles and their eyes, with their flying saucers and their warp drives? But according to a new collection of essays written by some of the world’s preeminent cosmologists, astrophysicists and geneticists, assembled and edited by Jim Al-Khalili, Clarke and Kubrick’s 1968 science-fiction film might be more correct than any of our popular imaginings; the gleaming monolith, a foreign and nonbiological intelligence, might be the best we can hope for. The authors of “Aliens: The World’s Leading Scientists on the Search for Extraterrestrial Life” ask the question “Where is everybody?” and come back with predictably scattershot answers.
It’s a question humanity has tried answering before. In 1870, the British astronomer Richard Proctor looked up at Venus, with its thick atmosphere, and nodded. Yes, he said, it’s definitely got life: Probably at the poles. We used to believe there was life on Mars too, huddled around the imaginary canali so confidently etched onto Italian astronomer Giovanni Schiaparelli’s 1877 map of Mars. Well, we know how both of those assumptions turned out.