Perhaps my favorite essay in “Aliens: The World’s Leading Scientists on the Search for Extraterrestrial Life” is by astrobiologist Lewis Dartnell, who patiently explains why aliens would not come here to have sex with us or eat us for supper.
I can only assume that he gets these questions a lot.
Here are the answers, should you find these possibilities concerning: The likelihood that we’d be genetically compatible with aliens is terribly remote, which means that they’d almost certainly be immune to our sexual charms. For similar reasons, having to do with biochemistry, we’d be lousy refreshments for them – they would almost certainly lack the proper enzymes to digest us.
As a bonus, Dartnell goes on to reassure us why aliens wouldn’t be especially interested in raiding our planet for raw materials either (asteroids are a far easier source to mine); and if it were water they were after, they’d be far better off going to Europa, one of Jupiter’s largest moons, which contains more water beneath its icy shell than all the oceans on Earth combined.
If you’re interested in non-Earthly life, don’t look to the movies.
One of the most consistent takeaways from this anthology is just how banal extraterrestrial life might be. Often, when entertaining the possibility of aliens, what we’re really entertaining is the possibility of hardy microbes that can withstand extreme conditions. Read enough of “Aliens,” and you realize that the search for life is just as much about the most mundane aspects of biology as about the trippier questions of cosmology.
The experience of reading almost any anthology is a bit like traveling across the country in a rental car with only an FM radio for company. Sometimes you get Sinatra; other times you get Nickelback.
This collection has its share of Nickelback. One of its most disappointing essays is about aliens in science fiction, which manages, against stupefying odds, to contain just one interesting insight: that authors tend to be more concerned with physics than with biology.
But the best of these essays are far out in more ways than one.
Seth Shostak, a senior astronomer at the SETI institute (short for Search for Extraterrestrial Intelligence), says that if we really want to be attuned to alien life in the cosmos, it’s so likely to be in the form of machine intelligence that we ought to “be alert to apparent violations of physics.”
These forms of life may well be speaking to us even now. It’s just that our radio telescopes, which listen to the skies for signals from alien beings, can’t understand what they’re hearing. “Even if the search succeeded,” Rees writes, “it would still in my view be unlikely that the ‘signal' would be a decodable message.”
It’s a whole new twist on George Berkeley’s question. The tree would fall in the forest. We’d hear it. But it would sound nothing like a tree
“Aliens: The World’s Leading Scientists on the Search for Extraterrestrial Life”
Edited and With an Introduction by Jim Al-Khalili.
Picador, 232 pages