Does Einsteins E=MC2 break the law of conservation of mass?
There is sometimes confusion surrounding the subject of mass in relativity. This is because there are two separate uses of the term. Sometimes people say “mass” when they mean “relativistic mass”, mr but at other times they say “mass” when they mean “invariant mass”, m0. These two meanings are not the same. The invariant mass of a particle is independent of its speed v, whereas relativistic mass increases with speed and tends to infinity as the speed approaches that of light, c. They can be defined as follows: mr = E/c2 m0 = sqrt(E2/c4 – p2/c2) where E is energy, p is momentum and c is the speed of light in a vacuum.
