We live at a very special time . . . the only time when we can observationally verify that we live at a very special time!

There are a lot of legislators who are afraid that kids will learn science and lose their faith.

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 real thing that physics tell us about the universe is that it's big, rare event happens all the time — including life — and that doesn't mean it's special.

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.

In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection.

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