Ohhh Wikipedia, how you never cease to entertain:

"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 one second. Kemp Bennet Kolb defines the distance as exactly 100 Ångströms, (i.e. 10 nanometers) while Nordling and Österman's Physics Handbook has it half the size at 5 nanometers. Google Calculator supports the beard-second for unit conversions using the latter conversion factor."

...etc.