Mass–energy equivalence
In physics,
mass–energy equivalence is the concept that the mass of an object or system is a measure of its energy content. For instance, adding 25 kilowatt-hours of
any form of energy to any object increases its mass by 1 microgram, increasing its inertia and weight accordingly, even though no matter has been added. A physical system has a property called energy and a corresponding property called mass; the two properties are equivalent in that they are always both present in the same proportion to one another. Mass–energy equivalence arose originally from special relativity, as developed by Albert Einstein, who proposed this equivalence in 1905 in one of his
Annus Mirabilis papers entitled "Does the inertia of an object depend upon its energy content?" The equivalence of energy
E and mass
m is reliant on the speed of light
c and is described by the famous equation: Thus, this mass–energy relation states that the universal proportionality factor between equivalent amounts of energy and mass is equal to the speed of light squared.