Global Time There’s an old Canadian joke that goes, “Repent! The world will end at midnight!—or, 12:30 a.m. in Newfoundland.” It’s humorous because independent-minded Newfoundlanders use a time zone that is a half hour ahead of the other Canadian maritime provinces. It highlights the fact that one single instant across …

The Geographic Grid  It is impossible to lay a flat sheet of paper over a sphere without creasing, folding, or cutting it—as you know if you have tried to gift-wrap a ball. This simple fact has caused mapmakers problems for centuries. Because the Earth’s surface is curved, we cannot divide …

The Shape of the Earth  As we all learn early in school, the Earth’s shape is very close to a sphere. Pictures taken from space by astronauts and by orbiting satellites also show us that the Earth is a ball rotating in space.   Today it seems almost nonsensical that …