You stop planetary exploration, those people who do that extraordinary work are going to have to go do something else.

Burning carbon-based substances like oil, gas, and especially coal, produces billions of tons of extra carbon dioxide each year. Methane gas from cows and pigs and other animals on our large farms ends up in the atmosphere as well, trapping more of the sun's energy as heat.

The most serious problem facing humankind is climate change.

I am so old, I entered engineering school with a slide rule. And I left engineering school with a calculator. I can still use a slide rule but it's not a skill you especially need anymore.

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

I say to the grownups, if you want to deny evolution and live in your world, that's completely inconsistent with the world we observe, that's fine. But don't make your kids do it. Because we need them. We need scientifically literate voters and taxpayers for the future. We need engineers that can build stuff and solve problems.

We are special in the sense that we can know our place in the cosmos. We can know our place in space. We are at least one of the cosmos's ways of knowing itself. That fills me with reverence and joy. Another insight I really want people to consider is this: everyone has gotten this far. Everyone you meet has made it this far. Nobody is superior to anyone else from an evolutionary standpoint.