I grew up in New York City where there is no night sky. Nobody has a relationship with the sky, because, particularly in the day, there was air pollution and light pollution, and you look up, and your sight line terminates on buildings. You know the sun and maybe the moon, and that's about it. So what happens is that I am exposed to the night sky as you would see it from a mountaintop, and I'm just struck by it. Suppose I grew up on a farm where I had that sky every night of my life - then you're not going to be struck by it. It's just the wallpaper of your nighttime dome.

Now imagine a world in which everyone, but especially people with power and influence, holds an expanded view of our place in the cosmos. With that perspective, our problems would shrink-or never arise at all-and we could celebrate our earthly differences while shunning the behavior of our predecessors who slaughtered each other because of them.

Today secular philosophers call that kind of divine invocation God of the gaps-which comes in handy, because there has never been a shortage of gaps in people's knowledge.

A successful day for me is when I teach people something. They become enlightened by an idea and learn how to think about it, so that later on when someone says, "Tell me about x, y, z," they don't have to say, "I know this because Tyson told me." No, they'll say, "Here's why it's true because I know and understand it."

If Earth ever suffers a runaway greenhouse effect (like what has happened on Venus), then our atmosphere would trap excess amounts of solar energy, the air temperature would rise, and the oceans would swiftly evaporate into the atmosphere as they sustained a rolling boil. This would be bad.

Deep down within anyone there's a flame that maybe had gone dormant that can be fanned or ignited in case it had blown out. This is the flame of curiosity, the flame of wonder, of awe, of all the things that make you want to learn something more tomorrow than you knew today.

I've known from long ago that the universe was calling me. If you were one of those annoying adults that said, 'Oh, what are you gonna be when you grow up?' I would say, 'Astrophysicist .' And then they'd walk away real quickly.