from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The physical principle that a measured quantity of energy is equivalent to a measured quantity of mass. The equivalence is expressed by Einstein's equation, E = mc2, where E represents energy, m the equivalent mass, and c the speed of light.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (physics) the principle that a measured quantity of mass is equivalent (according to relativity theory) to a measured quantity of energy
Sorry, no etymologies found.