One answer for the nutcase
Johannes smugly(and ignorantly) asked: "PS
It is a mathematical fact that a derivative of a constant equals zero. Perhaps Robert or Nick can explain how that applies to the formula of E=MC^2.
You failed to respond to this comment, I wonder why."
I assume you mean time derivative? Why don't you tell us why this interests you so much- The mathematical fact applies perfectly to the formula, and if that is in any way significant to you then you really don't understand a thing you are talking about- but then that was a given