>From Feynman's Lecture on Physics http://www.feynmanlectures.caltech.edu/I_14.html
<<We have spent a considerable time discussing conservative forces; what about nonconservative forces? We shall take a deeper view of this than is usual, and state that there are no nonconservative forces! As a matter of fact, all the fundamental forces in nature appear to be conservative. This is not a consequence of Newton’s laws. In fact, so far as Newton himself knew, the forces could be nonconservative, as friction apparently is. When we say friction apparently is, we are taking a modern view, in which it has been discovered that all the deep forces, the forces between the particles at the most fundamental level, are conservative.>> Is he saying that if forces between particles are not fundamentally conservative this will result in a violation of CoE? If so, I don't think this is true. For example with regard to friction, it is still possible to speak confidently about the CoE and say that kinetic-energy is converted into heat-energy without needing to have an underlying theory of heat-energy. Something similar happens with the the relation E = mc^2. We accept that mass and energy are interconvertible and we don't seem to need an underlying model of mass-energy to speak confidently about CoE. Therefore, it seems to me more a matter of aesthetics than of logic that all forces should be modeled as conservative forces at the most fundamental level. Harry
