Outer Billiard
Outer Billiards is a dynamical system based on a convex shape in the plane. Classically, this system is defined for the Euclidean plane but one can also consider the system in the hyperbolic plane or in other spaces that suitably generalize the plane. Outer billiards differs from a usual dynamical billiard in that it deals with a discrete sequence of moves outside the shape rather than inside of it.
Read more about Outer Billiard: History, Existence of Periodic Orbits, Open Questions
Famous quotes containing the word outer:
“No one knows better than children how much they need the authority that protects, that sets the outer limits of behavior with known and prescribed consequences. As one little boy expressed it to his mother, You care what I do.”
—Leontine Young (20th century)