Michael Banashak has written that the mass-energy relationship does not exist. I think that saying about “equivalence of mass energy” is even more misleading.

Energy, as a conserved quantity, is connected to the symmetry of a system, with respect to time translations (it follows from Noether Theorem).

The square of mass is equal to (with the sign “minus”) the eigenvalue of the Casimir operator, which here is square of four-momentum

P^{\mu}P_{\mu} (the representation of the Poincare algebra – the massive case).

Best wishes,

Lukasz T. Stepien

There is no such thing as a mass- energy relationship. What there is, is a mass-energy-momentum relationship. Einstein rejected the idea of relativistic mass in his later years, strongly warning against it. An objects energy can change with speed (velocity) but its mass NEVER changes.

Einstein’s great discovery was the “rest-energy.” The only energy being put equal to mass is the ” rest -energy.” Mass is invariant.

Eistein real equation for an object at rest was Eo=moc2 , also written Eo=mc2. “E=mc2” was a result of his careless writing that the medi latched on to. For further information, look inot the great Russian physicists Lev Okun’s articles.

Best wishes,

Mike Banashak

*[Corrected, thanks – T.]*

*[Corrected, thanks – T.]*