Stephen Hawking

Using e-mail, I can communicate with scientists all over the world.

The human race may be the only intelligent beings in the galaxy.

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

The thing about smart people is that they seem like crazy people to dumb people.

Now, radical forward thinking is offering hope for the future: Replacement body parts to order. A team of scientists in California believe that if you can design them on a computer, you should be able to print them out.

The Planck satellite may detect the imprint of the gravitational waves predicted by inflation. This would be quantum gravity written across the sky.

Throughout history, people have studied pure science from a desire to understand the universe rather than practical applications for commercial gain. But their discoveries later turned out to have great practical benefits.

I entered the health care debate in response to a statement in the United States press in summer 2009 which claimed the National Health Service in Great Britain would have killed me off, were I a British citizen. I felt compelled to make a statement to explain the error.

I was born on January 8, 1942, exactly three hundred years after the death of Galileo. I estimate, however, that about two hundred thousand other babies were also born that day. I don't know whether any of them was later interested in astronomy.

It's a pity that nobody has found an exploding black hole. If they had, I would have won a Nobel prize.

In the past, there was active discrimination against women in science. That has now gone, and although there are residual effects, these are not enough to account for the small numbers of women, particularly in mathematics and physics.

Keeping an active mind has been vital to my survival, as has been maintaining a sense of humor.

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.

Theoretical physics is one of the few fields in which being disabled is no handicap - it is all in the mind.

Not only does God play dice, but... he sometimes throws them where they cannot be seen.

We are all now connected by the Internet, like neurons in a giant brain.

I think those who have a terminal illness and are in great pain should have the right to choose to end their own life, and those that help them should be free from prosecution.

We are the product of quantum fluctuations in the very early universe.

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.

The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?

Observations indicate that the universe is expanding at an ever increasing rate. It will expand forever, getting emptier and darker.