Stephen Hawking

Most people don't have time to master the very mathematical details of theoretical physics.

Even if it turns out that time travel is impossible, it is important that we understand why it is impossible.

Imaginary time is a new dimension, at right angles to ordinary, real time.

I have so much that I want to do. I hate wasting time.

People won't have time for you if you are always angry or complaining.

If I had a time machine, I'd visit Marilyn Monroe in her prime or drop in on Galileo as he turned his telescope to the heavens.

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

I think we have a good chance of surviving long enough to colonize the solar system.

Time travel was once considered scientific heresy, and I used to avoid talking about it for fear of being labelled a 'crank.'

I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.

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.

There is no heaven or afterlife for broken-down computers; that is a fairy story for people afraid of the dark.