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The Question

(Submitted March 26, 1997)

What does E=mc2 mean?

The Answer

E=mc2 is a version of Einstein's famous Relativity equation. Specifically, it means that Energy is equal to Mass times the speed of light squared. In essence, it states that there is an equivalence between mass and energy. This simple statement has many profound implications... such as no object with mass can ever go faster than the speed of light!

Here are some references (some more advanced than others..)

Rosser, W. G. V. (William Geraint Vaughan). - Introductory special relativity. - London : Taylor & Francis, 1991. - 0850668387

My personal favorites are:

Taylor, Edwin F. (Edwin Floriman). - Spacetime physics : introduction to special relativity / Edwin F. Taylor, Jo. - 2nd ed. - New York : W.H. Freeman, 1992. - 0716723263


Feynman, Richard P., Richard Phillips, 1918-1988. - The Feynman lectures on physics. - Vol. 1: [mainly mechanics, radiation and. - Reading (Mass.); London : Addison-Wesley, 1964. - x1574051

Hope this helps,

Laura Whitlock and Tim Kallman
for Ask an Astrophysicist

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