REFLECTIONS

I found this radiometer  GIF on the internet.  I've had a radiometer for decades, fascinated by the way it spins in the light.  It works with sunlight or an incandescent light bulb. I finally decided to order a new one after mine stopped working. Here's a photo from the internet that looks just like mine. Sir William Crroke invented the radiometer. Below are explanations about how it works.  It's not so simple! ==================================== "The  radiometer  is made from a glass bulb from which much of the air has been removed to form a partial  vacuum . Inside the bulb, on a low  friction  spindle, is a rotor with several (usually four) vertical lightweight vanes spaced equally around the axis. The vanes are polished or white on one side and black on the other. When exposed to  sunlight , artificial light, or  infrared  radiation (even the heat of a hand nearby can be enough), the vanes turn with no apparent motive power, the d