← All simulators

Games

Physics in 3D

Four experiments with things that spin, roll and twist, each worked from the physics, drawn in 3D and held to the physics by tests. The top is Lagrange's heavy top, its tip held at one point: the tests keep its energy and its spin about the vertical and its own axis fixed, hold its steady swing and its nodding to the rates the equations give, and see it stand upright above Maxwell's limit and fall below it. The ball rolls without slipping on a record turning at a steady rate: the tests see a marble come back to its start in 7/2 turns of the record and a ping-pong ball in 5/2, never slipping, and a ball put down still stay still. The Wilberforce pendulum is two oscillators with a weak coupling, the model Berg and Marshall used for it in 1991: tuned, the tests see its bounce fall below 0.2% of its energy and come back, at the beat its two modes give. The T-handle, and the wing nut Vladimir Dzhanibekov saw flip in orbit in 1985, turn by Euler's equations with nothing touching them, their energy and angular momentum kept to a billionth, steady about their axes of most and least inertia and flipping about the middle one (for the wing nut, the bolt's). Ours: every size, mass and spring, no friction or rolling resistance anywhere, and the drawing.