Crookes Radiometer
Published on March 17, 2017
This item can be bought from the Grand Illusions Toy Shop – see
Invented by the British scientist Sir William Crookes in 1873, the Crookes Radiometer or Light Mill is a fascinating scientific device. Inside the airtight glass bulb is a set of vanes, mounted on a spindle. When light shines on the vanes, they spin round!
Sometimes used to show ‘radiation pressure’ , this is in fact not the correct explanation. Instead the radiometer is a form of heat engine.
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