"I'm not afraid of death. I'm afraid of dying without having lived a full life."

"The good thing about science is that it's true whether or not you believe in it."

"The universe is a dangerous place. It's full of black holes and gamma-ray bursts."

"Knowing what's true is not the same as knowing what's right."

"I'm a big proponent of space exploration, not just for scientific discovery, but for the inspiration it provides."