Odd that you use Hawking, considering he is fairly sympathetic to the possibility of alien visitors. Most cosmologists agree that it is a virtual certainty that life exists elsewhere in the universe. Whether or not they have visited earth is the debate.
"Odd that you use Hawking, considering he is fairly sympathetic to the possibility of alien visitors."OH REALLY? Funny, I recall him saying the exact opposite. Like in his lecture Life In The Universe?
"I discount suggestions that UFO's contain beings from outer space. I think any visits by aliens, would be much more obvious, and probably also, much more unpleasant."Yeah, I see your as accurate as your brother delusionals.
"What is the explanation of why we have not been visited? One possibility is that the argument, about the appearance of life on Earth, is wrong. Maybe the probability of life spontaneously appearing is so low, that Earth is the only planet in the galaxy, or in the observable universe, in which it happened. Another possibility is that there was a reasonable probability of forming self reproducing systems, like cells, but that most of these forms of life did not evolve intelligence."
I am discounting reports of UFOs. Why would they appear only to cranks and weirdos?