Observations indicate that the universe is expanding at an ever-increasing rate. It will expand forever, getting emptier and darker. Although the universe doesn’t have an end, it had a beginning in the Big Bang. One might ask what is before that but the answer is that there is nowhere before the Big Bang just as there is nowhere south of the South Pole.

All that my work has shown is that you don't have to say that the way the universe began was the personal whim of God.

Time travel may be possible, but it is not practical.

The intelligent beings in these regions should therefore not be surprised if they observe that their locality in the universe satisfies the conditions that are necessary for their existence. It is a bit like a rich person living in a wealthy neighborhood not seeing any poverty.

Thirty years ago I was diagnosed with motor neurone disease, and given two and a half years to live. I have always wondered how they could be so precise about the half.

If I have questions about the universe on my mind when I go to bed, I can't turn off. I dream equations all night.

I think the next century will be the century of complexity.