Ancient gears tracked the planets
Built around 80 BC, the Antikythera mechanism used a differential gear to calculate planetary movements. Its sophistication challenged the belief that this kind of gearing had been invented only in the 16th century.
How the Antikythera mechanism tracked planetary motion
Built around 80 BC, the Antikythera mechanism used a differential gear to calculate planetary movements. Its sophistication challenged the belief that this kind of gearing had been invented only in the 16th century.