I don't want people to say, 'Something is true because Tyson says it is true.' That's not critical thinking.

My only hope is that every other alien civilization isn't doing exactly what we are doing because then everybody would be listening, nobody would be receiving, and we would collectively conclude that there is no other intelligent life in the universe.

UV is bad for molecules because its high energy breaks the bonds between a molecule's constituent atoms. That's why UV is bad for you, too: it's always best to avoid things that decompose the molecules of your flesh.

If a scientist is not befuddled by what they're looking at, then they're not a research scientist.

I want upon death to be buried, just like in the old days, where I decompose by the action of microorganisms, and I am dined upon by any form of creeping animal or root system that sees fit to do so.... I will have recycled back to the universe at least some of the energy that I have taken from it. And in so doing, at the conclusion of my scientific adventures, I will have come closer to the heavens than to Earth.

We can trace the elements. They were forged in the centers of high-mass stars that went unstable at the ends of their lives, they exploded, scattered their enriched contents across the galaxy, sprinkled into gas clouds that then collapsed and formed stars and planets and life.

They all knew the mothership was coming, they all knew it was a flying saucer, they all knew it came from another planet through the vacuum of space. And so what do they do, to the left of that monument? They set up runway lights. And I'm thinking, if you could travel through the vacuum of space, you don't need runway lights. Runway lights are if you're using air for lift. Aliens would not need air for lift.