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I remember many years ago, I think at 8th grade, seeing the teacher show us a Crookes radiometer. I remember it being very fascinating. Today I read the wiki article on it, after looking up what it was called, but the article wasn't very clear in my opinion. Essentially the molecules that hit the dark sides have more energy and thus exert pressure which causes the device to rotate. And something about Einstein...

Among the lacks in the article is that it didn't clarify how effective this device is. It seems to me that relatively little energy input results a rather striking output (at least subjectively). So if I heat such a device with, say, $100 \ W$, how many watts would the output be in comparison?

Could such a device be built in large scale and thus used to convert solar energy to movement?

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