Pi is used in navigation. When a plane flies over a distance it does not fly in a straight line, it flies in an "arc length". It is also used in statistics with the different types of graphs "bell curves". Also, with the signal transmission, like: Radio waves, designing microwaves, ect. It also helps calculate things in advanced physics, like the universes expansion. "M" theory uses it quite a bit. Is the membrane that is our universe a wave? Possibly and the dark energy might be nothing more than our section of universe approaching an wave arch's max.; thus giving the illusion of expansion at a exponential rate.
