points on a d-dimensional sphere in such a way that every open hemisphere contains at least k points. This lemma, in turn, can be used to calculate the chromatic number of the Kneser graphs, a problem first solved in a different way by László Lovász. The moment curve has also been used in graph drawing, to show that all n-vertex graphs may be drawn with their vertices in a three-dimensional integer grid of side length O(n) and with no two edges crossing. The main idea is to choose a prime number p larger than n and to place vertex i of the graph at coordinates (i, i 2 mod p, i 3 mod p). Then a plane can only cross the curve at three positions. Since two crossing edges must have four vertices in the same plane, this can never happen. A similar construction using the moment curve modulo a prime number, but in two dimensions rather than three, provides a linear bound for the no-three-in-line problem. Notes References . . . . . . . . Algebraic curves