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

The Big Bang banged, and for some reason we’re here. And that’s astonishing. And that we can understand that, that’s the most astonishing.

Researchers have proven that scientifically, that all humans are one people

Our goal in science is to discover universal laws of nature. That pursuit fills me with wonder.

There are two ways to be rich: to have more or need less. It's estimated that we squander about 30 percent of our energy leaving the lights on, the refrigerator door open, and so on. Then there is the enormous amount of food that we expend huge amounts of energy to raise and then throw away.

Climate change is happening, humans are causing it, and I think this is perhaps the most serious environmental issue facing us.

When we explore the cosmos, we come to believe and prove that we can solve problems that have never been solved. It brings out the best in us. Space exploration imbues everyone with an optimistic view of the future.