Meaning of free path in English:

free path

noun

Physics
  • 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.

Origin

Late 19th century; earliest use found in James Clerk Maxwell (1831–1879), physicist.