Stephenson:Neal:Quicksilver:6:Cartesian number-line (Neal Stephenson)

From the Quicksilver Metaweb.

Descartes pioneered the use of number-lines as a way of measuring positions in space, and also crossed them at various angles to handle two-dimensional space, but the now-universal practice of crossing them at right angles to form an orthogonal coordinate system appears to have originated elsewhere---so "Cartesian coordinates" is a misnomer (see the Descartes entry in Dictionary of Scientific Biography). Julian Barbour credits Leibniz with inventing "Cartesian" coordinates, however the idea is sufficiently obvious that others may have come up with it independently. Other sources have credited Leibniz with first using the term "ordinate" to denote one of the axes, though this word was in use, to mean related but different things, long before Leibniz was born. This is a fascinating topic, but it is murky enough that I have avoided making a big deal out of it in the novel.