One of the wonders of science is that it is completely universal. It crosses national boundaries with total ease.

Every moment is as real as every other. Every 'now,' when you say, 'This is the real moment,' is as real as every other 'now' - and therefore all the moments are just out there. Just as every location in space is out there, I think every moment in time is out there, too.

General relativity is in the old Newtonian framework where you predict what will happen, not the probability of what will happen. And putting together the probabilities of quantum mechanics with the certainty of general relativity, that's been the big challenge and that's why we have been excited about string theory, as it's one of the only approaches that can put it together.

So many galaxies, so many planets out there in the universe circling so many stars... it just feels like there's a very good chance that there is another Earth-like planet out there that is able to support some kind of life similar to what we're familiar with.

Falsifiability for a theory is great, but a theory can still be respectable even if it is not falsifiable, as long as it is verifiable.

The number of e-mails and letters that I get from choreographers, from sculptors, from composers who are being inspired by science is huge.

Most scientists like to operate in the context of economy. If you don't need an explanatory principle, don't invoke it.