The steepest grade on U.S. main-line track is at the small town of Saluda, on a Norfolk Southern route between Spartanburg, South Carolina, and Asheville, North Carolina. The grade goes on for three miles at a slope of 4 or 5 percent. Trains have not been running on the line since 2001, but the tracks are still maintained.
For those who've never experienced a sunrise in the rural Midwest, it's roughly as soft and romantic as someone's abruptly hitting the lights in a dark room. This is because the land is so flat that there is nothing to impede or gradualize the sun's appearance. It's just all of a sudden there.
If all evidence of civilization on Earth was destroyed, and humans had to re-build society from the ground up, what would be different? Feynman reckons that pivotal scientific moments, like the discovery of the atom, will still happen in the same way. Perhaps mathematics will be similarly rediscovered.
Someone told me once in response to this question, no artwork would ever be recreated. The art we create – music, stories, dance, film – isn’t a fundamental element of the universe, or even of humanity. It’s unique to each artist. If you choose to create art, you leave something in the world that has never had a chance to exist before, and will never again have a chance to exist. There will never be another Beatles or Studio Ghibli or Picasso. Art, in its infinite variations of originality, is cosmically unique in a way the sciences will never be. Art immortalizes human experiences that would otherwise vanish in time.