This is an old revision of the document!
Magnetic Interaction
New Interaction
N and S poles, likes repel opposites attract - sounds familiar for a reason. Some differences - can't have N without S (demo??), not the same thing as charge (not interchangable)
Magnetic Field
Both mag and direction at every point in space, use letter B for magnetic field, units, magnitude (fridge magnet, earth's field, MRI machine)
Rest of notes will talk about sources of B-field and formalize math