The Longest Way 1.0 - one year walk/beard grow time lapse from Christoph Rehage on Vimeo.

It's actually a scientific unit:

It's the physics tiny measurement partner of the light year. Wikipedia defines it as "the length an average physicist's beard grows in a second", equivalent to either 5 or 10 nanometers. I assume the namer intended some humor and, as far as physics jokes go, it's a damn good one. You can convert measurements to beard-seconds using the Google search bar.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.