出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/05/11 10:38 UTC 版)
The Crookes radiometer, also known as the light mill, consists of an airtight glass bulb, containing a partial vacuum. Inside are a set of vanes which are mounted on a spindle. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity. The reason for the rotation has historically been a cause of much scientific debate.