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.

I can't prove that God doesn't exist, but I'd much rather live in a universe without one.

Science has been effective at furthering our understanding of nature because the scientific ethos is based on three key principles: (1) follow the evidence wherever it leads; (2) if one has a theory, one needs to be willing to try to prove it wrong as much as one tries to prove that it is right; (3) the ultimate arbiter of truth is experiment, not the comfort one derives from one's a priori beliefs, nor the beauty or elegance one ascribes to one's theoretical models.

If we wish to draw philosophical conclusions about our own existence, our significance, and the significance of the universe itself, our conclusions should be based on empirical knowledge. A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa, whether or not we like the implications.

The ultimate arbiter of truth is experiment, not the comfort one derives from one's a priori beliefs, nor the beauty or elegance one ascribes to one's theoretical models.

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

We should provide the meaning of the universe in the meaning of our own lives. So I think science doesn't necessarily have to get in the way of kind of spiritual fulfillment.