Since the distance between the Zeeman sub-levels is a function of the magnetic field, this effect can be used to measure the magnetic field, e.g. that of the Sun and other stars or in laboratory plasmas.
Charley horse: Slang for a cramp in a muscle in the leg, usually caused by a strain or injury. A charley horse can last anywhere from a few seconds to over a quarter of an hour. It is not uncommon for one to recur before it finally resolves.
Origin. 'Charley horse' (sometimes misspelled 'Charlie horse') is an American phrase and originated in the sport of baseball. The term is very much American and not in use in many other English-speaking countries.Charley horse' (sometimes misspelled 'Charlie horse') is an American phrase and originated in the sport of baseball.