J.L. Lagrange

J.L. Lagrange is a mathematician who, in 1772, proved that, in any two-body gravitational system, there will be five points where gravity and observed centrifugal force cancel each other out (thus, any object in these points will appear to remain stationary in relation to the two.

These points are known as Lagrange points.

Background information
For more on J.L. Lagrange, see Wikipedia's article: Joseph-Louis Lagrange