See also: mass energy



mass-energy (countable and uncountable, plural mass-energies)

  1. (physics) Mass and energy as a unified concept.
    • Whereas in classical physics mass and energy are distinct concepts, on relativistic scales, they become indistiguishable and are replaced by mass-energy.
    • In higher-energy physics, mass and energy eventually become meaningless as individual concepts; a particle's so-called "mass" is actually mass-energy and is often given equivalently in units of either mass (GeV/c2) or energy (GeV).
    • For equations normalized with Planck units, the quantities of mass and energy become numerically identical, revealing their true nature as mass-energy.
  2. (also spelled mass energy) The energy associated with any given mass according to special relativity, E = mc2.

See alsoEdit


mass-energy (not comparable)

  1. mass-to-energy
    Mass-energy conversion occurs during nuclear fusion and fission.