Brass Pinball

An engine-probe bench, honestly flawed and honestly instrumented: a warm parlor bagatelle whose every physics behavior is measured live in the console. The SpringJoint plunger charges while you hold space and fires on release (peak ball speed 4.5 m/s on record); the HingeJoint motor flippers sweep their full arc inside a fifth of a second; the brass bumpers kick a constant-impulse bounce measured in and out; and the steel ball runs ContinuousDynamic collision detection with a live tunneling watchdog — which caught exactly one escape, when the spring release squeeze-popped the ball through the field, and put it straight back. The probe found real engine lessons: a table slope sign that reads backward from intuition, felt friction that parks a ball at exactly the tilt you meant to roll it, and why a kinematically-held striker should never be released into contact. Sampled nylon guitar, glockenspiel and timpani throughout.