One of the mysteries of the English language finally explained.
1The distance which a molecule or other particle traverses without encountering another particle and without colliding with the walls of the containing vessel; compare "mean free path".
2The distance a sound wave travels between successive reflections from the walls of an enclosure.
Late 19th century; earliest use found in Proceedings of the Royal Society of London.
In this article we explore how to impress employers with a spot-on CV.