Community-built physics experiments and study materials — run an experiment live and fork it into your own studio, or read a guide someone wrote.
Twenty-four perfectly elastic balls in a sealed box. There is no temperature setting here, because temperature is not a thing you set -- it is the average kinetic energy of these bodies, on the energy chart. Pressure is the balls hitting the walls. Nothing damps them, so the total energy line stays flat, and the speeds shuffle into a spread through collisions alone: thermodynamics as mechanics, with the statistics left to emerge.
A six-kilogram bob is pulled aside and let go. It will swing down, sweep along the floor, and rise on the far side — and it will not, ever, come back higher than where it started. Everything it has at the bottom it bought with height on the way down. The block is placed exactly where the bob still has enough left to reach it. Move the rope length, change the bob's mass, and see which of those two the arrival speed actually cares about.
