No matter how hard you try to teach your cat general relativity, you're going to fail.

The absolute worst thing that you ever can do, in my opinion, in bringing science to the general public, is be condescending or judgmental. It is so opposite to the way science needs to be brought forth.

In the far, far future, essentially all matter will have returned to energy. But because of the enormous expansion of space, this energy will be spread so thinly that it will hardly ever convert back to even the lightest particles of matter. Instead, a faint mist of light will fall for eternity through an ever colder and quieter cosmos.

Einstein comes along and says, space and time can warp and curve, that's what gravity is. Now string theory comes along and says, yes, gravity, quantum mechanics, electromagnetism - all together in one package, but only if the universe has more dimensions than the ones that we see.

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.

We might be the holographic image of a two-dimensional structure.

Art makes us human, music makes us human, and I deeply feel that science makes us human.