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I have a simple question. I hope I don't get a stupid answer. Where does the magnetic field of a permanent magnet comes from AND why is it permanent (are we dealing with perpetual motion)?

This is what wiki is saying: "The spin of the electrons in atoms is the main source of ferromagnetism, although there is also a contribution from the orbital angular momentum of the electron about the nucleus. When these tiny magnetic dipoles are aligned in the same direction, their individual magnetic fields add together to create a measurable macroscopic field."

What the wiki is saying is correct, but we have to think further or go one step further... So put your head out of the box:

THIS IS NOT THE ANSWER I WANT TO HEAR. Because then I can ask why is the electron spinning (or what is the origin of spin) and that for an infinit time (CRAZY)? This is of course a physics question......We are missing an important energy source, unless you know where this form of energy is coming from and why it is permanent.

Thank you very much!

Edit:

Wikipedia says: "Truly isolated systems cannot exist in nature..." Just be aware of this, before you are answering. (So before you are answering or commenting ==>THINK!)

user1843090
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You write

Because then I can ask why is the electron spinning and that for an infinit time (CRAZY)?

You have a misunderstanding about the nature of spin. When we say that an electron has spin, we do not mean that it is literally spinning; spin is a quantum mechanical property of the electron.

See another related physics.SE question How do you fit a dipole in an electron?

As a side note (that is frankly not particularly relevant to ferromagnetism), in the context of classical mechanics, if you were to put a rigid, spinning object into space (where it is isolated from interactions with any other body) then the object would continue spinning without any "energy source." This can be justified by noting that angular momentum for a classical mechanical system is conserved in the absence of external torques.

Community
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joshphysics
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The electron is spinning for an infinite time. Yup, it's crazy. Quantum theory does allow for persistent currents, not just electron spin.

In fact you can see this sort of quantum perpetual motion in action at everyday scales with superconductivity and superfluidity. A current flowing in a loop of superconducting wire persists indefinitely without a power source.

This is perpetual motion of what Wikipedia calls the "third kind", elimination of dissipative forces. It cannot be used as an energy source or to reduce entropy (first and second kind). So we are not "missing an important energy source" in that sense.

[Added:] I'll build on amr's comment to a different answer, which makes a relevant observation: you can say the same thing about the electron orbiting the nucleus. Its orbit should decay via electromagnetic radiation and it should spiral into the nucleus. But this is not what happens! Atoms are stable!

This is one of the very facts that lead to quantum theory in the first place. This isn't the place to give an introductory course to quantum theory (and I am not the person to do it), but it was proposed that some things can change only in discrete steps (quanta), not continuously, and the electron's angular momentum is one of them. And this proposal explains many many things that non-quantum explanations don't.

Retarded Potential
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I'm commenting here until someone more knowledgeable comes along. This is my understanding:

Say you have two bars both made of the same exact material, except that one of the bars is a permanent magnet. If you add up the collective "magnetic power" of both materials, you will get the same result. Both materials are equally "magnetic."

The difference is that the permanent magnet has its atoms/molecules aligned in the same direction throughout the material (more accurately, its atoms/molecules are aligned in such a way that its magnetic field lines are aligned throughout the material), and this has a cumulative effect which creates a larger-scale field. On the other hand, in the non-magnet the tiny-scale magnetic fields are all pointing in random directions, so they conflict with each other and you don't get a large field. The same magnetic potential is still there, but they are too random to create a larger-scale effect.

The reason a permanent magnet has its individual magnetic fields aligned probably has to do with the particular manner in which the material cooled as it was released from the Earth. Imagine a molten material made of countless tiny magnets. Remember that magnets want to align with eachother (opposites attract, likes repel), and because the material is molten, the molecules are free to adjust into alignment as the material cools, provided that the atomic structure allows it.

That's probably what that wikipedia article calls "symmetry breaking," and it is not a clean process -- most likely there is cellular-automaton-like warfare between competing orientations before the overall material cools to one orientation. If the material cools too quickly, you won't have a large-scale magnetic field.

As a general note, there is a lot of variation and interesting behavior due to the rate at which various materials cool. For example, the different rates of cooling are partly responsible for why carbon may look like a charred husk in one case and a pristine diamond in another.

If your question is "where does magnetism come from?" then that's a different question. I think the shortest answer is probably "light."

You sound dissapointed that there are no relatable answers. You'll find that a lot of physics is strange and that in the boundaries of our knowledge we necessarily have phenomenological answers, not explicative ones.

amr
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