A Close Shave

Astronomers have the light-year, but nuclear physicists need an analogous unit for measuring tiny distances.

Happily, they have one: The Physics Handbook for Science and Engineering defines the “beard-second” as the length the average physicist’s beard grows in one second, or about 5 nanometers.

Google will even make the conversion for you — type 1 inch in beard-seconds into your search box and see what you get.