Let’s begin with this mind-blower: If you cored an orange, and cored the earth, and the remaining rings were the same height, they would have very different diameters, but the same volume. Say what? https://www.instagram.com/p/BwX6ze0g8Te/ It’s true. The so-called “napkin ring problem” dates back to the 17th century and Japanese mathematician Seki Kowa, who dubbed...