Simulates momentum and energy transfer through a chain of touching pendulums: an outer ball is pulled back, released, and its kinetic energy propagates almost losslessly through the middle balls to launch the ball at the far end. Each sphere is an independent pendulum integrated with semi-implicit Euler across several substeps per frame; collisions are resolved by repeatedly sweeping adjacent pairs and swapping tangential velocities (equal-mass elastic collision) so an impulse can hop through the whole chain within one physics step.