Intelligence is the ability to take in information from the world and to find patterns in that information that allow you to organize your perceptions and understand the external world.

Physicists have come to realize that mathematics, when used with sufficient care, is a proven pathway to truth.

I’ve spent something like 17 years working on a theory for which there is essentially no direct experimental support.

In quantum mechanics there is A causing B. The equations do not stand outside that usual paradigm of physics. The real issue is that the kinds of things you predict in quantum mechanics are different from the kinds of things you predict using general relativity. Quantum mechanics, that big, new, spectacular remarkable idea is that you only predict probabilities, the likelihood of one outcome or another. That's the new idea.

Experimental evidence is the final arbiter of right and wrong.

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

Relativity challenges your basic intuitions that you've built up from everyday experience. It says your experience of time is not what you think it is, that time is malleable. Your experience of space is not what you think it is; it can stretch and shrink.