longer at high latitudes than at low latitudes, and why they are so much longer in summer than in winter at high latitudes but almost the same near the equator. It seems hard to come up with a reasonable explanation (and math) that doesn't involve the Earth being a tilted sphere circling the Sun. At least not with some serious mental gymnastics and belief in goofy supernatural stuff.

I was in Alaska last week and thought about this as I watched the sun set at 11:40 pm, and rise again at 4:20 am or whatever. And it never got completely dark, even at 2 am. Then I came back to Orange County where sunset is at 8 pm, and sunrise is at 5:50 am, and it's pitch black by 8:45 pm.