Magnets and Spin

Every chemist learns about the electron spin and magnetism. The so called magnetic field is just the propensity for electrons to 'curl' to borrow a term from vector calculus. So from the North pole of a magnet to the South pole of another magnet the curl will tend to align. The curl will also tend to make a round trip. The electrons curl on the way into one pole of a magnet and they curl on the way out of the other end of a magnet.

So what of electric generators and motors? We set up a field of curling electrons and we expose a coil to the field.The tight curl of electrons begs for the coil to conserve angular momentum. There are tight swirls due to the magnet and an induced larger swirl that constitutes the current that makes up the voltage presented in a generator.

As a generator turns it exposes itself to more and more of the curled field of electrons. Then as the generator coil moves past pi radians the process reverses itself. This can be characterized by Maxwell-Faraday's law but also invokes Lenz's law. These two laws or relationships can be explained as one idea but I will reserve this explanation for another post.

The reason magnets attract different poles is due to a mess of electrons rotating in opposite directions. At the boundary between electrons moving one way and another (magnetic field lines in opposing directions) there are many collisions. These collisions will at as a relative low pressure zone pulling the magnets towards each other. The sheer pressure of the electrons puts a mechanical force on the rotor of the generator.

Conversely, when two like poles are put next to each other the spin of their electrons does a tight loop to its opposing pole. This looping of electrons draws in matter and causes the two like poles to push away from each other. The same phenomenon is at play in Ampere's laws of attraction.