While driving through Normandy, I was struck by the wackiness of a lot of the local place names. This is amplified by the large linguistic flow through the area, and local dialects that I’m not familiar with, but still felt very silly. For example: Looking at names like these, I figured that I could make […]

# Category: map

## Equal Area Map Projections

I’m most interested in making equal-area projections of spheres onto different shapes. For example, turning a spherical map of Earth into regular polyhedra. I’ll talk about the math I’ve used for these, and show some of the results. And exellent reference for map projections is Map Projections: A Working Manual. I’ll be using this equirectangular […]

## Cylindrical Earth

Circles are too flat. What if we want to make a cylindrical Earth? We can take the same sort of approach, but we need a couple more parameters. Let’s say we have a cap radius and height , then we can make this: With the sphere radius , by matching the surface areas, the possible […]

## Variable-Radius Flat Earth

No, not the conspiracy theory. For example, here is an Earth-splat: And here is an Earth-square: And both are equal-area projections! How did I do this? Math. Math math math. We’ll use spherical coordinates, with polar angle and azimuthal angle . This means that latitude is, in radians, , and longitude is . We’ll say […]

## Earth as a Disc

I wanted an equal-area projection of the earth onto a disk. This is a simple one. We’ll use spherical coordinates, with polar angle and azimuthal angle . This means that latitude is, in radians, , and longitude is . We’ll say that the sphere has a radius of . We’ll have the North pole at […]