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.

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

Science will win because it works.

Then we shall... be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason - for then we would know the mind of God.

If a superior alien civilization sent us a message saying, 'We'll arrive in a few decades', would we just reply, 'OK, call us when you get here - we'll leave the lights on'? Probably not - but this is more or less what is happening with AI.

Sometimes I wonder if I'm as famous for my wheelchair and disabilities as I am for my discoveries.

A lot of prizes have been awarded for showing the universe is not as simple as we might have thought.