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.
A Charlie horse is the term used to describe a painful muscle spasm that suddenly occurs in the leg or the foot. Ice your leg or foot if you experience a leg cramp. Ice will numb the pain and give. â¢ Gently massage the area to help increase blood flood to [help relax] the muscle. Once the spasm is released, walk around slowly to maximize blood flow to the muscle.