Your center of mass is a place you cannot visit but you always carry with you. Like memories, it is part of life's baggage.

What are you doing? Why are you concerning yourself with the meaning of meaning?

Private enterprise can never lead a space frontier. It's not possible because a space frontier is expensive, it has unknown risks and it has unquantified risks.

In whatever you choose to do, do it because it's hard, not because it's easy. Math and physics and astrophysics are hard. For every hard thing you accomplish, fewer other people are out there doing the same thing as you. That's what doing something hard means. And in the limit of this, everyone beats a path to your door because you're the only one around who understands the impossible concept or who solves the unsolvable problem.

Most of what Einstein said and did has no direct impact on what anybody reads in the Bible. Special relativity, his work in quantum mechanics, nobody even knows or cares. Where Einstein really affects the Bible is the fact that general relativity is the organizing principle for the Big Bang.

When we went to the moon and realized that the Soviet Union had no realistic plans of getting to the moon, then we stopped going to the moon.

My popularity does not derive from me pandering to people. People came to me. I don't tell anyone to follow me on Twitter. I don't tell people to like my Facebook page. I don't tell people to fill the venue. I'm offered to people, and then people come.