There are two different ways of looking at the universe; and it's the same universe with two different windows. The science window gives you a view of the world, and the religion window gives you a totally different view. You can't look at both of them at the same time, but they're both true.

The purpose of thinking about the future is not to predict it but to raise people's hopes.

The question that will decide our destiny is not whether we shall expand into space. It is: shall we be one species or a million? A million species will not exhaust the ecological niches that are awaiting the arrival of intelligence.

It's clear the media, of course, always gives you the bad news. And people who rely on the media, like Mr. Trump, think that everything is a disaster. The media always tries to make everything into a disaster, but it's mostly rubbish. It's a point of fact that we're doing extremely well.

A model is such a fascinating toy that you fall in love with your creation.

Do not imagine that you have to know everything before you can do anything. My own best work was done when I was most ignorant.

Of course, long-distance running has to do with the fact that we're hunters.