Posted: Jul 21, 2010 3:15 pm
except the "m" on the RHS is the rest mass, whereas your LHS "m" would be the relativstic mass. The formula I gave was the usual relation for the squared length of the energy momentum 4 vector. He's suggesting that might change ....
ETA also I'm using "natural units" where c=1. (Might not be a great choice if c varies !)