We all know from Thermodynamics that energy cannot be created. So where does magnetic energy come from? It doesn’t seem to deplete (at least in rare-earth magnets), and it seems like there’s a rather significant amount of it that is available at all times.
fields such as gravitation, magnetic and electric do not contain energy as such. However to move an interacting body through them may release or need energy.
As to why moving a charge through an electric field or a magnet through a magnetic field or a mass through a gravitation field involves changes of energy - well on one level that is just the definition of a field, on a different level that is one of the fundamental mysteries of the universe
Magnetism is not energy: it’s a force, like gravity. If you gain energy from the use of a magnet, it’s because you supplied energy to the system. For example, if you move a conductor past a magnet, you generate an ekectric current in the cionductor, which is a form of energy. However, you had to supply energy to the system to move the conductor.
If you’re sitting in a chair, you don’t think of the chair as having energy, just because it’s holding you up. Barring termites or rot, your chair could hold you forever, because just exerting a force does not cost any energy. A magnet is doing basically the same thing as the chair is, it’s just doing it at a distance.
Check out this almost exactly same-named thread from almost a year ago here.
In short, magnetism on the tiny scale comes from the electrons whizzing around in atoms. Magnetism on the scale that it matters to your average refrigerator magnet or car ribbon emblem comes from each of those individual atoms lining up in the correct way.
Be warned that the thread Garfield226 linked has an extremely low signal-to-noise ratio. While magnets can in fact lose their magnetism for a variety of reasons, it does not happen because they’re using it up. It’s not just slow, magnetism is not used up at all, not if you waited the lifespan of the Universe, not if you waited an infinite time.
From the spin of electons in the atoms.
rwj