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.

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

We do not know whether there are extra dimensions or multiverse. Let's go forward with the possible ideas that come out of the mathematics. It's hard for us to imagine a universe that would have no time at all.

The main challenge that television presents is that I have a tendency to say things with a great deal of precision and accuracy. Often a description of that sort, which will work in a book because people can read it slowly - they can turn the pages back and so on - doesn't really work on TV because it interrupts the flow of the moving image.

Our eyes only see the big dimensions, but beyond those there are others that escape detection because they are so small.

Exploring the unknown requires tolerating uncertainty.

We are living through a remarkably privileged era when certain deep truths about the cosmos are still within reach of the human spirit of exploration.