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.

(On the energy radiated by the Sun) It's four hundred million million million million watts. That is a million times the power consumption of the United States every year, radiated in one second, and we worked that out by using some water, a thermometer, a tin, and an umbrella. And that's why I love physics.

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

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

Climate change: Don't undermine the science just because you don't like the economics

Science is different to all other systems of thought because you dont need faith in it, you can check that it works.

The story of the universe finally comes to an end. For the first time in its life, the universe will be permanent and unchanging. Entropy finally stops increasing because the cosmos cannot get any more disordered. Nothing happens, and it keeps not happening, forever. It's what's known as the heat-death of the universe. An era when the cosmos will remain vast and cold and desolate for the rest of time the arrow of time has simply ceased to exist. It's an inescapable fact of the universe written into the fundamental laws of physics, the entire cosmos will die.