We often say that the earth is a sphere, but to be precise, the term sphere refers only to the surface. The correct mathematical term for the solid earth is a ball.

[Richard Feynman] truly believed that if you couldn't explain something simply, you didn't understand it.

We often say that the earth is a sphere, but to be precise, the term sphere refers only to the surface. The correct mathematical term for the solid earth is a ball.

I'm afraid I am a bit of a technophobe - a nineteenth-century man caught in the twenty-first century. But there is one piece of technology that I would especially welcome: a device to automatically balance restaurant tables on all four legs so that they don't rock back and forth.

I did not come from an academic background. My father was a smart man, but he had a fifth-grade education. He and all his friends were plumbers. They were all born around 1905 in great poverty in New York City and had to go to work when they were 12 or 13 years old.

Science blogs bore me. When everyone is an expert, no one is an expert.

There is a philosophy that says that if something is unobservable -- unobservable in principle -- it is not part of science. If there is no way to falsify or confirm a hypothesis, it belongs to the realm of metaphysical speculation, together with astrology and spiritualism. By that standard, most of the universe has no scientific reality -- it's just a figment of our imaginations.