"We have written the evidence of our existence onto the surface of our planet. Our civilisation has become a beacon, that identifies our planet as home to life."

“Skepticism must go hand in hand with rationality. When theories are shown to be false, the correct thing to do is to move on.”

“What scientists are attached to is journeys into the unknown and discovering things that are completely unexpected and baffling and surprising.”

“As a fraction of the lifespan of the universe as measured from the beginning to the evaporation of the last black hole, life as we know it is only possible for one-thousandth of a billion billion billionth, billion billion billionth, billion billion billionth, of a percent . And that's why, for me, the most astonishing wonder of the universe isn't a star or a planet or a galaxy. It isn't a thing at all. It's an instant in time. And that time is now. Humans have walked the earth for just the shortest fraction of that briefest of moments in deep time. But in our 200,000 years on this planet we've made remarkable progress. It was only 2,500 years ago that we believed that the sun was a god and measured its orbit with stone towers built on the top of a hill. Today the language of curiosity is not sun gods, but science. And we have observatories that are almost infinitely more sophisticated than those towers, that can gaze out deep into the universe. And perhaps even more remarkably through theoretical physics and mathematics we can calculate what the universe will look like in the distant future. And we can even make concrete predictions about its end. And I believe that it's only by continuing our exploration of the cosmos and the laws of nature that govern it that we can truly understand ourselves and our place in this universe of wonders.”

“Science is too important not to be a part of a popular culture.”

“Look at that! If you ever needed convincing that we live in the solar system, that we are on a ball of rock, orbiting around the Sun with other balls of rock, then look at that! That’s the solar system coming down and grabbing you by the throat.”

“Yes, in a sense. I'm comfortable with the unknown, that's the point of science. There are places out there, billions of places out there that we know nothing about. And the fact that we know nothing about them excites me, and I want to go out and find out about them. And that's what science is. So I think if you're not comfortable with the unknown, then it's difficult to be a scientist. So I don't need an answer; I don't need answers to everything. I want to have answers to find.”