For over a century, humans have been searching for alien civilizations somewhere out there in the universe. Though we obviously have found nothing so far, we have become rather good at finding planets, confirming over 5,000 of them in the Milky Way since our first discovery in the 1990s.
Analyzing the spectrum of light from those planets, we’ve even identified some intriguing possible hints of life, including dimethyl sulfide on exoplanet K2-18b, a gas that, on Earth, is produced only by life. But were we to find a planet with life, or advanced civilizations, should we initiate contact?
Not everybody thinks that is a good idea, and among them was physicist Stephen Hawking. In 2015, while launching a project to listen out for alien civilizations, Hawking explained why it’s probably best not to say hello back.
“We don’t know much about aliens, but we know about humans,” Hawking said at the event, per Space.com. “If you look at history, contact between humans and less intelligent organisms have often been disastrous from their point of view, and encounters between civilizations with advanced versus primitive technologies have gone badly for the less advanced. A civilization reading one of our messages could be billions of years ahead of us. If so, they will be vastly more powerful, and may not see us as any more valuable than we see bacteria.”
This is similar to the Dark Forest Theory, outlined in Liu Cixin’s sci-fi novel The Dark Forest. In the book, one character argues that given the uncertainty about the motivations of alien civilizations, it makes sense to stay quiet. If even one civilization is hostile, or hell-bent on destroying all other possible threats to their own civilization, we should take care not to advertise our existence too loudly.
Despite having trepidations about contacting aliens, Hawking was very much in favor of continuing to look.
“We believe that life arose spontaneously on Earth, so in an infinite universe, there must be other occurrences of life,” Hawking added. “Somewhere in the cosmos, perhaps intelligent life might be watching these lights of ours, aware of what they mean. Or do our lights wander a lifeless cosmos, unseen beacons announcing that, here on one rock, the universe discovered its existence? Either way, there is no better question. It’s time to commit to finding the answer, to search for life beyond Earth. The Breakthrough initiatives are making that commitment. We are alive. We are intelligent. We must know.”
Of course, the decision on whether to alert alien civilizations to our presence could be out of our hands. It’s possible that aliens could find us in similar ways to how we are finding them (only they may have had thousands of years to look, not hundreds), or could even pick up on the signals we are leaking from our planet. It may already be too late to lie low and pretend nobody is home.
Source Link: Why Stephen Hawking Warned Against Contacting Alien Civilizations