Stephen Hawking

With genetic engineering, we will be able to increase the complexity of our DNA, and improve the human race. But it will be a slow process, because one will have to wait about 18 years to see the effect of changes to the genetic code.

There is no physical law precluding particles from being organised in ways that perform even more advanced computations than the arrangements of particles in human brains.

Up until the 1920s, everyone thought the universe was essentially static and unchanging in time.

Time can behave like another direction in space under extreme conditions.

It now appears that the way the universe began can indeed be determined, using imaginary time.

If we do discover a complete theory, it should be in time understandable in broad principle by everyone. Then we shall all, philosophers, scientists, and just ordinary people be able to take part in the discussion of why we and the universe exist.

Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out.

I had not expected 'A Brief History of Time' to be a best seller. It was my first popular book and aroused a great deal of interest. Initially, many people found it difficult to understand. I therefore decided to try to write a new version that would be easier to follow.

My first popular book, 'A Brief History of Time,' aroused a great deal of interest, but many found it difficult to understand.

We lived in a tall, narrow Victorian house, which my parents had bought very cheaply during the war, when everyone thought London was going to be bombed flat. In fact, a V-2 rocket landed a few houses away from ours. I was away with my mother and sister at the time, but my father was in the house.

I had not expected 'A Brief History of Time' to be a best seller.

I was not a good student. I did not spend much time at college; I was too busy enjoying myself.