When something is made idiot proof, they will just make better idiots.

We explore because we are human and we want to know. I hope that Pluto will help us on that journey.

When I hear of Schrödinger's cat, I reach for my pistol.

Before we understand science, it is natural to believe that God created the universe. But now science offers a more convincing explanation.

We live in the most probable of all possible worlds.

My first popular book, 'A Brief History of Time,' aroused a great deal of interest, but many found it difficult to understand.

Think of our DNA. In the last million years, our DNA hasn't changed at all. It's really much the same as it was in the jungle, a million, two millions years ago. But in the last 200 years, our destructive capacities have increased many, many millions of times over. Why don't we see intelligent signals from outer space? Because in all likelihood, once the civilization reaches the point our civilization has reached, it destroys itself.