The universe at its largest: the Big Bang, black holes, gravity, light, time and the second law, and what they hint about the whole.
Light from the farthest galaxies has traveled for billions of years to reach your eyes. Relativity says that from the light's side, the trip took no time at all. I couldn't stop asking what that means for the end of everything.
Everything runs from order to mess, so the beginning must have been impossibly neat. But the early universe looks smooth and bland, just like the end. One force flips the whole picture.
Film a glass shattering and play it in reverse. Nearly every equation in physics accepts the reversed film as perfectly legal. You have never seen it happen, and the reason reaches all the way back to the Big Bang.
