In mathematics, a Cassini oval is a set (or locus) of points in the plane such that each point p on the oval bears a special relation to two other, fixed points q1 and q2: the product of the distance from p to q1 and the distance from p to q2 is constant. http://en.wikipedia.org/wiki/Cassini_oval (Jean-Dominique Cassini (1625-1712) French astronome). Thanks Paddle2See for the idea/
