Traveling Back in Time? | StarTalk

If I had a time machine, I think I'd go back to when a Mars-sized protoplanet sideswiped Earth in the early solar system, sideswiping our crust, casting billions of tons of rock into orbit around the Earth, which then coalesced to form our Moon. I want, I want to be around when that happened. And by the way, back then the Moon would have formed much, much closer to the Earth, so the Moon would have been huge in the sky, raising really high tides. Just that whole episode, I want to bear witness to it.

Who doesn't love a good collision, especially if a collision and an explosion create something? Explosions and collisions that are portrayed in media today, they… something is always destroyed. But this is one thing that actually created something beautiful: our Moon. Now, if I were to go back in time to when humans still existed, I would go back, I… I chill with Isaac Newton. Yeah, just to tell him how significant his discoveries were in establishing what we now take for granted as modern civilization—the Industrial Revolution.

He was the first person to really put on the page the fact that the universe is knowable. Oh my gosh, the universe is knowable! That means we can figure it out, manipulate it, adjust it, do things with the universe that are in the service of our curiosities. We used Isaac Newton's laws to get to the Moon: his laws of motion and his laws of gravity. I would tell him this; I think he'd want to know that.