If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans. … We only have… - Stephen Hawking

We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet,

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.

I regard it as almost inevitable that either a nuclear confrontation or environmental catastrophe will cripple the Earth at some point in the next 1,000 years which, as geological time goes, is the mere blink of an eye. By then I hope and believe that our ingenious race will have found a way to slip the surly bonds of Earth and will therefore survive the disaster.

There should be no boundary to human endeavor.

So Hamlet was quite right. We could be bounded in a nutshell and count ourselves kings of infinite space.