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 muscle spasm is a sudden, spontaneous, uncontrollable and abnormal tightening or contraction of a muscle. The term muscle cramp is also used to describe a muscle spasm anywh â¦ ere in the body, and when a muscle spasm occurs in the lower leg it is often called a charlie horse..