Physicists are more like avant-garde composers, willing to bend traditional rules... Mathematicians are more like classical composers.

I can assure you that no string theorist would be interested in working on string theory if it were somehow permanently beyond testability. That would no longer be doing science.

But if you think about a practical implication of enriching your life and giving you a sense of being part of a larger cosmos and possibly being able to use this [gravitational waves] as a tool in the future maybe to listen not just to black holes colliding, but maybe listen to the big bang itself, those kind of applications may happen in the not too distant future.

To tell you the truth, I've never met anybody who can envision more than three dimensions. There are some who claim they can, and maybe they can; it's hard to say.

The boldness of asking deep questions may require unforeseen flexibility if we are to accept the answers.

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.

I have long thought that anyone who does not regularly - or ever - gaze up and see the wonder and glory of a dark night sky filled with countless stars loses a sense of their fundamental connectedness to the universe.