Triple Pendulum vs equivalence principle

The motion of a triple pendulum is governed by a set of coupled ordinary differential equations. For certain energies its motion is chaotic. This application solves these differential equations using the Runge-Kutta method for the time stepping. You can influence the movement of the pendulum by holding your device in different positions.

This app represents the equivalence principle which states that gravitational and inertial forces are of a similar nature and often indistinguishable. Left rocket is moving up with constant acceleration a, and right rocket is on the some planet where the gravitational acceleration is g. If a is equal to g, the motion of a ball which is dropped in the left rocket is the same as the motion of a ball which is dropped in the right rocket; two balls experience the same constant acceleration motion. This is the simple demonstration of the equivalence principle. This app doesn't simulate the whole motion of a ball. Only falling motion is intended to show the equivalence principle.