Tom Stanton has achieved a remarkable milestone in engineering, becoming the first person to break the sound barrier using a purely gravity-powered trebuchet. On a field in the UK, a 40-kilogram mass dropped a short distance, spinning a carbon-fiber arm past 2,300 revolutions per minute, launching a 4-gram projectile at 776 miles per hour—nine mph past the speed of sound.

Medieval trebuchets used large weights and levers to fling projectiles, but physics limits their speed. A falling weight accelerates at only 9.81 meters per second squared, capping achievable velocities. Stanton solved this with a pulley system featuring a 3:1 ratio, using varying diameters to maximize both force and rotational speed. The counterweight could be lifted up to 1.9 meters, storing more energy than previous designs.

The arm, carved from carbon fiber using a homemade CNC mill, weighed just 116 grams. After multiple failed prototypes and stress tests, Stanton refined the design with asymmetric bracing and aluminum hubs for balance. The mechanically released system used a spring-loaded catch with a release window of mere milliseconds.

Testing progressed from 10 kg to 40 kg, with the final run reaching 2,342 rpm and 776 mph. High-speed footage confirmed the projectile traveled 1.94 meters in 5.6 milliseconds. A sonic boom was heard, validating the supersonic achievement.