"Although the chance of a disaster to planet Earth in a given year may be quite low, it adds up over time, and becomes a near certainty in the next thousand or 10 thousand years."

"My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all."

"I believe that we are alone in the universe, but I hope we are not."

"Finally, a question about something important. My advice to any heartbroken young girl is to pay close attention to the study of theoretical physics. It would not be beyond the realms of possibility t…"

"I think that the universe is a beautiful and complex place, and I'm very lucky to be able to study it."