LONDON — "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans," said the world's most famous theoretical physicist, Stephen Hawking, late last month.
He warned scientists not to try to communicate with extraterrestrials, because "we only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet."
Hawking's concern is shared by others in the field. They don't object to passive SETI: It can't do any harm to "Search for Extraterrestrial Intelligence" by listening with radio telescopes for the radio emissions of civilizations around other stars. However, they think that active SETI — sending out messages saying "Here we are" — is just asking for trouble.