The light perceived by the human eye is measured in units called lumen-hours. This is about the amount produced by burning a candle for an hour. In 1700 a typical Briton consumed 580 lumen-hours in the course of a year, from candles, wood and oil. Today, burning electric lights, he uses about 46 megalumen-hours—almost 100,000 times as much.
"The beard-second is a unit of length inspired by the light year, but used for extremely short distances such as those in nuclear physics. The beard-second is defined as the length an average beard grows in a second, or about 5 nanometers[1]. One beard-second equals 50 Ångströms (10-10 m)."
— Beard-second - Wikipedia, the free encyclopedia discovered via reddit.com
