E0=mc^2 proof

quZz

Hello everyone
Can some one please provide (a link to) the most rigorous proof of [itex]E_0 = mc^2[/itex]?
Actually, I got stuck on this question: why doesn't [itex]E_0 = mc^2 + \rm{const}[/itex]? How to prove that [itex]\rm{const} = 0[/itex]?

DrStupid

I can provide you with the original:

http://www.fourmilab.ch/etexts/einstein/E_mc2/e_mc2.pdf

quZz

Hi, thanks for a quick reply.
In this paper it only proves that if energy of a body at rest is changed by [itex]dE[/itex], its mass also changes by [itex]dm=dE/c^2[/itex]. It doesn't prove, however, a much stronger statement that all its energy equals its mass times c squared...