>>10758176something something conservative forces and state functions
Forces can be conservative (based) or nonconservative. This relates to how energy is conserved in a system involving them. Gravity and electric fields are conservative, for example. F is a conservative field if there is a scalar potential function of space such that . The implication is that conservative fields are path independent; the work performed only depends on the endpoints of the path and not on what happens along the way. In other words,
Equivalently, conservative fields do not perform any work when the object moved through a closed path.
when C is a closed loop.
Things like friction and magnetic fields are not conservative. Imagine friction: obviously if you take a more circuitous path from A to B, there will be more friction and more work done by friction. Not path independent. The curled magnetic field that forms around a wire is also not path independent, it can be "clockwise" or "counterclockwise." When you start talking about heat, you have to realize that "heat" is actually just the transfer of the kinetic energy of 10^23's of tiny little particles. You can't represent heat with a function of state, meaning you cannot exactly related it to other properties like you can with pressure or specific volume or temperature, etc. Unlike these state or "point" functions, heat cannot be expressed with an exact differential.
Maybe this made some sense, though it's probably not a satisfying answer. An actual physicist will know more, but the real answer will always just be "because just the universe just happens to work that way for God knows the reason."
