This is a follow-up question to my Physics SE question from yesterday:
The kind responses were very informative, but I still have much to understand about magnetism, as follows:
Imagine a piece of iron laying on an infinitely large flat surface. A magnet is also positioned on the surface, some distance from the iron. The iron is thus attracted to the magnet and slides sideways across the surface. As the iron moves, the magnet is moved in tandem with it such that the iron is never allowed to contact the magnet. Thus, the sliding iron is forever "chasing" the magnet across the surface.
Friction from the iron sliding across the surface results in dissipated heat and sound energy. Since energy can never be created nor destroyed, I presume that the heat and sound energy is derived somehow from the magnet. What then, is the source of that energy, and how is it constantly supplied to the magnet?