Math is the language of the universe. So the more equations you know, the more you can converse with the cosmos.

Americans live in a free country, which allows you to believe what you want. Because you think that something is true does not require that it is objectively true. The value of science concerning itself with objective truths is that we can make decisions and statements that affect everyone, which is why legislation really should be based on objective truths, not what is going on in your head.

These are two different exercises. One of them is, "You don't know and I know, so just shut up and listen," and the other one is, you're curious and you're learning, and I have a way where you can learn this so you'll know it as well. And when you know it, and know why you know it, then you don't have to reference me ever again because you take ownership of the knowledge, and you can then share it with someone else.

In the animal kingdom, one of the keys to survival is to outwit your enemies. And when you're surrounded by carnivores, one of the best strategies is to fade into the background and disappear.

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.)

To believe in a universe as young as 6 or 7,000 years old is to extinguish the light from most of the galaxy.

Something bad happened on both Mars with its dried-up watercourses and Venus with its runaway greenhouse effect. Could something bad happen on Earth too? Our species currently turns row upon row of environmental knobs, without much regard to long-term consequences.