You can easily make a cylinder out of a sheet of paper by rolling it up. On the other hand, if you want to form a ball out of it, it becomes difficult. And vice versa: the spherical Earth cannot be represented as a two-dimensional map without losses. If you get the angles, the sizes change. If you get the sizes, the angles change.
If we look at a world map, Greenland looks like it is the size of Africa. The Mercator projection, developed in the 16th century, is to blame. There are alternative approaches, but the Mercator projection still shapes our “worldview” today.
Numerous areas of mathematics deal with paths and maps, sizes and distances. How do you find the shortest path between two points? How do you color a map so that neighboring countries have different colors? In the book by the mathematician Paulina Rowińska you can read many stories and learn amazing things. For example, the designation of electoral districts (especially in an electoral system like that of the USA) can determine who wins the election because votes are – intentionally – wasted.
Anyone expecting a lot of illustrations in a book about maps will be disappointed here. You have to put Peter’s equal-area projection on the screen yourself in order to compare it with Mercator’s worldview. But the extensive list of sources invites you to browse and delve deeper. Barbara Messing
Paulina Rowińska
Mapmatics – How maps shape our view of the world
Structure, 448 pages, € 28.–
ISBN 978-3-351-04193-9