I love the smell of the universe in the morning.

Physics is the only profession in which prophecy is not only accurate but routine.

Curiosity is a self-driven motivation to explore and to learn. Learning is like... you know, you have to take your medicine. And that is what it has become. And that's unfortunate.

Pop culture is the scaffold we all carry around with us.

Dark matter and dark energy are two things we measure in the universe that are making things happen, and we have no idea what the cause is.

I have a personal philosophy in life: If somebody else can do something that I'm doing, they should do it. And what I want to do is find things that would represent a unique contribution to the world-the contribution that only I, and my portfolio of talents, can make happen. Those are my priorities in life.

With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.