The Crookes radiometer is a fascinating device invented in 1873 by chemist Sir William Crookes. It consists of a glass bulb with vanes that rotate when exposed to light. The vanes move due to differences in temperature, where the black side becomes hotter than the white side, causing a thermal transpiration effect that leads to motion. There have been multiple theories explaining how it works, including light pressure and outgassing, but the currently accepted theory involves gas flow from the cooler to the hotter side of the vane. Recent advancements have led to the creation of nanoscale and monocolored light mills that operate based on different principles.
https://en.wikipedia.org/wiki/Crookes_radiometer