TITLE: Static magnetic fields
QUESTION [0 upvotes]: My textbook says:

All static magnetic fields are produced by moving electric charge.

Is this true? What about the magnetic field produced by a bar magnet?

REPLY [1 votes]: Of course Emilio Pisanty is right, but let me add a few things.
Originally the word Magnet comes from Magnesia region of Asia Minor. In those times, people found those first stones that repelled or attracted each other.
Now in that case those stones had as per QM electrons in them, and the electrons' and nuclei's magnetic dipole moment and spin were all directed in the same direction, they were aligned. The reason for that is the Earth's magnetic field, and that it took ages for those stones to gather that quality.
Now you can create permanent magnets with EM fields, and in that case the magnetization takes much less time, and in that case the EM field, that has moving electrons in a certain direction will affect the electrons in the magnet and will cause the same thing, those electrons and nuclei in the magnet will align their magnetic dipole moment and spin in a certain direction.
Together those tiny magnets (electrons) will create a bigger magnetic field, their magnetic field's forces will add up.
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