If you're an adult and you choose not to believe in science, fine, but please don't prevent your children from learning about it and letting them draw their own conclusions.

I like to regard myself as someone who's capable of critical thought, that is to say, who can evaluate claims.

NASA is an engine of innovation and inspiration as well as the world's premier space exploration agency, and we are well served by politicians working to keep it that way, instead of turning it into a mere jobs program, or worse, cutting its budget.

Everyone, red state, blue state, everyone supports space exploration.

I have devoted much time and energy to helping medical physics in developing countries.

Economics is not an exact science. It's a combination of an art and elements of science. And that's almost the first and last lesson to be learned about economics: that in my judgment, we are not converging toward exactitude, but we're improving our data bases and our ways of reasoning about them.

I'm not a very big fan of science fiction. I think that I'm a very big fan of living in the physical world.

When I was younger I wanted to be a big movie star who'd get to be funny on talk shows and then I wanted to retire and write science fiction.