Hawking isn't sure reaching out to alien worlds is such a good idea.
We shouldn't announce to aliens that we are here on Planet Earth. Especially if people on other planets are more technologically advanced than us, warns cosmologist Stephen Hawking.
In his half-hour program, "Stephen Hawking's Favorite Places", based on science-themed subscription service Curiosity Stream, the theoretical physicist flies by the potentially habitable exoplanet Gliese 832c in a CGI spaceship. This is another hypothetical dream tour.
With the super-Earth Gliese 832c being a mere 16 light-years away, his Breakthrough: Listen initiative is hoping to search for alien signals, with the help of "sensitive" radio telescopes.
"If intelligent life has evolved (on Gliese 832c), we should be able to hear it," he says, while hovering over the exoplanet in the animated "U.S.S. Hawking." "One day we might receive a signal from a planet like this, but we should be wary of answering back. Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well."
That is an analogy he has used often---even in other programs.
Hence, it is a lot of excitement about foraying into other civilisations, and also worrying about its effects. Apart from Breakthrough: Listen, he is also concerned about Breakthrough: Starshot, which aims to send "tiny nanocraft" to close star-systems to search for earth-like planets harbouring life.
Earlier, in a 2010 Discovery Channel documentary, he had explained: "I imagine they might exist in massive ships, having used up all the resources from their home planet," said Hawkings. "Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach. If so, it makes sense for them to exploit each new planet for material to build more spaceships so they could move on. Who knows what the limits would be?"
Contrary to what he said, Doug Vakoch, president of METI International, which is dedicated to "researching, composing and sending messages from Earth" to other civilizations, said in a recent CraveCast that we have been beaming out signals to various potential civilisations, so we are already trying to achieve some contact with other civilisations.
Many believe, though, that aliens have been visiting us over the centuries, so the whole "should we-shoudn't we" argument goes for a toss.
