It could be that these other civilizations, if they are far more advanced intellectually than we are, would not even measure our existence as a blip on the intelligence radar. They could be so advanced that we are to them what worms are to us.

If NASA were advancing a space frontier there would be challenges you've never seen before. You have to be creative and you have to patent some new idea. You get to Mars...well, how do we get the water from the soil? I gotta invent a new device that will do that. And the carbon dioxide in the atmosphere, how can we use that? Can we breathe the oxygen from the carbon dioxide?

We should not be ashamed of not having answers to all questions yet... I'm perfectly happy staring somebody in the face saying, 'I don't know yet, and we've got top people working on it.' The moment you feel compelled to provide an answer, then you're doing the same thing that the religious community does: providing answers to every possible question.

Why can't we summon the ingenuity and courage of the generations that came before us? The dinosaurs never saw that asteroid coming. What's our excuse?

Part of me thinks that I've been called by the universe, to get all sort of spiritual about it. Like, I've had no actual say in the matter. The universe found me.

If we want to unlock the secret behind the origin of our sun and its planets, it would be helpful to find some remnants from the birth itself, an event that took place about four-and-a-half-billion years ago.

You have the illusion of free will, but, in fact, that illusion comes about because you don't know the future. Because you are a prisoner of the present, forever locked in transition, between the past and the future.