Interactive simulations
Play with the physics from our reels
Each simulation uses the same equations as the video it comes from, and it runs live in your browser. Change the numbers and see what happens.
Pendulum wave
15 pendulums, one release. They make snakes and two lines, then all line up again at exactly 60 s.
Swings · timing · large-angle period
π collisions
Two blocks and a wall. Count the hits: 3, 31, 314, 3,141. Those are the digits of π.
Elastic collisions · exact event solver
Chaos fan
100 double pendulums start 0.000001 rad apart. Watch them move as one, then fly apart.
Chaos · sensitive dependence
How these are made
Everything here is code. The simulations step the real equations of motion (RK4 with a fixed time step, or an exact collision solver) and draw each frame on a canvas. There are no recordings and no AI images. The physics step never depends on your screen's frame rate. If a phone can't keep up, the sim slows down and says so instead of cutting corners.