One of the world's leading scientists, British theoretical physicist Stephen Hawking says that aliens almost certainly exist but mankind should be doing everything they can to avoid contact。
"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational," he said. "The real challenge is to work out what aliens might actually be like."
His views are expressed in a new documentary made for the Discovery Channel. In it he points out that the universe has more than 100 billion galaxies, each containing hundreds of millions of stars. In such circumstances, Earth is unlikely to be the only planet where life has evolved, Hawking claims。
While many forms of life may be little more than microbes, Hawking says a few life forms could be intelligent and pose a threat to the human race. Aliens might simply raid Earth for its resources and then move on. "I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach," Hawking says。
"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 Native Americans," the scientist says。