I believe everyone should have a broad picture of how the universe operates and our place in it. It is a basic human desire. And it also puts our worries in perspective.

Evolution has ensured that our brains just aren't equipped to visualise 11 dimensions directly. However, from a purely mathematical point of view it's just as easy to think in 11 dimensions, as it is to think in three or four.

Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill.

Please join me in applauding the ESA - European Space Agency’s historic efforts with the Rosetta Mission and landing a spacecraft on rotating comet. It may seem like a work of fiction, but it is very real, very impressive, and will help us to further uncover the mysteries surrounding the formation of the solar system. They made a beautiful short film using an imaginary landscape to illustrate today’s historic feat.

I have sold more books on physics than Madonna has on sex.

The Simpsons is the best thing on American television.

If the rate of expansion one second after the Big Bang had been smaller by even one part in a hundred thousand million million, it would have recollapsed before it reached its present size. On the other hand, if it had been greater by a part in a million, the universe would have expanded too rapidly for stars and planets to form.