If NASA is to reach beyond the Moon and someday reach Mars, it must be relieved of the burden of launching people and cargo to low earth orbit. To do that, we must invest more in commercial spaceflight.

My father was a very good Boy Scout. He was very skilled with knots, and he showed me how to tie a bow tie.

People get a lot out of being religious. They have strong senses of community and mutual support. So, what's not to love [there]?

It is my mission to change the world. I'm not kidding: Make no small plans, dream mighty things. I feel if we get enough people engaged in climate change, we will get enough people to change the world. We will revolutionize the way we produce electricity and provide clean water to people.

Unlike science, creationism cannot predict anything, and it cannot provide satisfactory answers about the past.

In another couple centuries I'm sure that worldview won't even exist. There's no evidence for it.

Television isn't inherently good or bad. You go to a bookstore, there are how many thousands of books, but how many of those do you want? Five? Television's the same way. If you're going to show people stuff, television is the way to go. Words and pictures show things.