Einstein, in the special theory of relativity, proved that different observers, in different states of motion, see different realities.

A lot of my research time is spent daydreaming - telling an imaginary admiring audience of laymen how to understand some difficult scientific idea.

Unforeseen surprises are the rule in science, not the exception. Remember: Stuff happens.

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.

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 not an historian but I'll venture an opinion: Modern cosmology really began with Darwin and Wallace. Unlike anyone before them, they provided explanations of our existence that completely rejected supernatural agents... Darwin and Wallace set a standard not only for the life sciences but for cosmology as well.

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