Super 8.” “Cowboys & Aliens.” “Battle: Los Angeles.” If this year’s crop of movies is any indication, our interest in the possibility of extraterrestrial life remains strong.
But do aliens really exist? And if they do, and they made contact, would they seek peace with us or us in pieces? I think these are questions that fascinate everybody, me included.
The Drake Equation, presented by an astrophysicist in 1961, estimates the number of communicative civilizations in the Milky Way Galaxy. Among other factors, it takes into account the average creation-rate of stars, the fraction of these stars with planets, and the average number of planets that could support life.
Frank Drake, who formulated the equation, estimates there are 10,000 technologically advanced societies in our galaxy alone. The late astronomer Carl Sagan estimated there could be as many as 1 million.
This leads to the Fermi Paradox. Essentially it asks, if outer space is so teeming with life, where is everyone? Scientists have put forward a number of theoretical explanations to the dilemma.
One hypothesis is that the conditions needed to develop life are more rare than believed, and as a result there’s a small number of civilizations. Perhaps there are no others.
Another theory is societies reach a certain level of scientific development before technology leads to self-immolation through warfare, experimentation, or other catastrophic events.
Perhaps the most plausible hypothesis is we simply haven’t encountered evidence of aliens due to technological limitations, constraining physical distances, or other civilization’s lack of interest in engaging with us.
Stephen Hawking, likely the most celebrated living scientist, has described the belief in extraterrestrial life as “perfectly rational,” living as we do in a universe of 100 billion galaxies. But he holds a dismal view of potential alien-human contact.
“If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the American Indians,” Hawking said.