A supernova is one of the most powerful explosions in the universe. It's so luminous, it can be seen across billions of light years. It releases as much energy in an instant as our sun will produce over its 10-billion-year lifetime.

I have a very high respect for professional comedians. What they do astonishes me. You have to be really smart and absorb everything, repackage it, bring it back to the person, and make them laugh at themselves. I can make people laugh during my talks because they didn't come to have me make them laugh. It's added value. So my job is way easier than that of a professional comic.

In five billion years, the sun will expand and engulf our orbit as the charred ember that was once Earth vaporizes. Have a nice day

I'm often asked whether I believe in Global Warming. I now just reply with the question: "Do you believe in Gravity?"

One should not be too distracted by definitions. Ideas transcend definitions.

On Venus you could cook a 16-inch pepperoni pizza in seven seconds, just by holding it out to the air. (Yes, I did the math.)

Intelligent design is a philosophy of ignorance.