Reference Level
The potential energy is a function of the state a system is in, and is defined relative to that for a particular state. This reference state is not always a real state, it may also be a limit, such as with the distances between all bodies tending to infinity, provided that the energy involved in tending to that limit is finite, such as in the case of inverse-square law forces. Any arbitrary reference state could be used, therefore it can be chosen based on convenience.
Typically the potential energy of a system depends on the relative positions of its components only, so the reference state can also be expressed in terms of relative positions.
Read more about this topic: Potential Energy
Famous quotes containing the words reference and/or level:
“Ultimately Warhol’s private moral reference was to the supreme kitsch of the Catholic church.”
—Allen Ginsberg (b. 1926)
“So long as State constitutions say that all may vote when twenty-one, save idiots, lunatics, convicts and women, you are brought down politically to the level of those others disfranchised.”
—Susan B. Anthony (1820–1906)