why should we believe a retard?

It makes perfect sense.
If aliens can travel here, obviously they've mastered space travel at light speed, or faster, like wormhole.
There's absolutely NO f*cking way we can avoid contact or if we do get into conflict, we can never win them.
If we do contact with aliens at their planet, observing them, assuming they're primitive, they can't do harm to us anyway on their planet, not to earthlings from here.

At most, only to the earth explorers who go there.
So Stephen Hawking makes no sense... He's not that smart.

He lacks common sense.
You people here are idolizing him, without even daring to question his wisdom, or lack of, when it comes to common sense.

Wow, so no one can challenge the logic of Stephen Hawking just because he has way more PHD?

So he's always right because of his awards/phd?
Fantastic. I suppose he can go around shagging anyone's wife as well, because he cannot possibly be wrong and he deserves it because he has PHD and Nobel prizes.
Mor*n!

I have more respect for Michio Kaku than that wheelchair bound overrated crank with huge ego Stephen Hawking.