Inverse Marble Run

Remove one marble… and watch the hole travel all the way to the top.

The Inverse Marble Run turns the familiar marble run concept upside down. Instead of adding marbles and watching them roll down, the track starts completely filled. Remove a single marble from the bottom, and an empty space slowly climbs upward as each marble rolls down exactly one position. The result is a mesmerizing chain reaction that's surprisingly satisfying to watch.

Designing this puzzle was a major engineering challenge. Every slope had to be carefully tuned—too steep, and marbles would push each other out of the track; too shallow, and they wouldn't move at all. After more than a dozen prototypes, every angle, wall height, and spacing was refined to create a perfectly functioning mechanism.

The track follows the famous Hilbert Curve, a mathematical space-filling curve that packs an impressively long path into a compact footprint. Whether displayed on your desk or demonstrated to friends, the Inverse Marble Run is both a fascinating kinetic sculpture and a celebration of clever engineering.

Designer: Oskar van Deventer