. . . . "m" . "\"Mean Free Path\" is the average distance travelled by a moving particle (such as an atom, a molecule, a photon) between successive impacts (collisions) which modify its direction or energy or other particle properties." . . . . . . "http://www.iso.org/iso/catalogue_detail?csnumber=31895"^^ . . . . . "http://www.iso.org/iso/catalogue_detail?csnumber=31894"^^ . . . . . . "\u03BB" . . "http://en.wikipedia.org/wiki/Mean_free_path"^^ . . . . "Mean Free Path"@en . . . . . . . . . . . . . . . . . . .