Can the value of the potential energy, which is responsible for driving the system, diminish in time, while the system itself is stationary during that time? Can there be dissipation in a system, while no physical degrees of freedom (at all levels) are changing?
Maybe this should be formulated as "Can I write down a time dependend energy, whos total value reduces in time, while this change has no impact on the equations of motion."
Maybe this is just equivalent to a time dependend exteriour force in every case - then I guess the answer is no, in the sense that the exteriour force is also a physical degree of freedom.
(The question is probably motivated by me wondering if one can replace all (spatial?) boundary condition in a system by other forces: A chemical potential equilibration holds particles back from moving in one direction and so replaces a wall, which would be a coordinate restriction in a more mechanical pov. Can one similarly get rid of all spatial aspects of a classical theory? Maybe d'Alamberts principle goes in this direction. Mathematical phase space reduction kind of obscures physical system, I don't know what's real anymore.)