Thursday, 4 October 2012

World map on a dodecahedron

Basically, the world is a sphere (the shape of a ball), and a map is a flat surface. It's difficult to take a sphere and attempt to form it into a flat surface, since a sphere is a curved object, and a map is completely flat.

Say for example that you have a globe, and you wanted to wrap it in a sheet of paper. The globe is the Earth, and the sheet of paper is a map of its surface. If you tried it, you would find that it is extremely hard to do this.

Likewise, if you've ever peeled an orange, you've found that you can't lay it on a flat surface without tearing it. This is actually just the opposite problem of gift-wrapping the ball. Here we're trying to take a spherical surface and turn it into something flat.

This is also exactly the problem that the mapmaker faces.
There are a dozen different kinds of maps for the Earth, each one using a different pattern or technique. None of them are the "true" map of the Earth, but some come very close.

You can use a dodecahedron to produce a world map. A dodecahedron is a polyhedron with twelve flat faces.

A world map on a dodecahedron is a projection of a world map onto the surface of a dodecahedron, which can be unfolded and flattened to two dimensions.