A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa.

Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them.

The universe does not care what we want.

The one experience that I hope every student has at some point in their lives is to have some belief you profoundly, deeply hold, proved to be wrong because that is the most eye-opening experience you can have, and as a scientist, to me, is the most exciting experience I can ever have.

The root cause of the looming energy problem - and the key to easing environmental, economic and religious tensions while improving public health - is to address the unending, and unequal, growth of the human population. And the one proven way to reduce fertility rates is to empower young women by educating them.

It really is the most poetic thing I know about physics: you are all stardust.

You shouldn't be afraid of science. Accepting the reality of nature makes life more exciting and even more precious.