Today's soundtrack is Eluveitie: Spirit.
I'm on chapter 12 of The Cartoon Guide to Physics, a comic-book style physics primer. The chapter is entitled "Charge," and is about electricity and magnetism.
According to the book, we know how charge behaves, but classical electricity and magnetism doesn't tell us what it is. We now know that electrons, protons, and neutrons make up charge.
There are two kinds of charges: positive and negative. Like charges repel; opposite (or unlike) charges attract.
Electrical force weakens with distance. Charged electrons can be transferred between objects and can be transmitted through some objects (conductors), but not through others (insulators).
Like gravity, electrical force is decreased by the inverse square of the distance. However, unlike gravity (which can only attract), electrical forces can either attract or repel, and electrical forces are stronger than gravity.
Like energy, charge is conserved. It will always be either positive, negative, or neutral.
