Today's soundtrack is Mournful Congregation: The Incubus of Karma.
Before I started this blog, I'd been reading through The Cartoon Guide to Physics. I'll be continuing the book this afternoon, reading chapter 13, "Electric Fields."
Electricity and gravity are similar; both have an influence on things separated by space. Things of mass fill their surrounding space with a gravitational field; "similarly, a charge fills space with an electric field" (p. 118). The area further from the charge has a weaker electric field than the area closest to the charged item.
Since we have to use force to push two like charges together, and because "force times distance equals work" (p. 120), and because the work we have done hasn't yet had a release, pushing two like charges together creates potential energy. If we release two like charges that were held close together, they fly apart, and that "potential energy is converted into kinetic energy" (p. 120). To measure how much of electricity we have, we can divide potential energy (the amount of force needed to push two like-charged items together) by the amount of charge. The result of this is the electric potential, which is measured in volts. For each volt, a battery will give one joule of energy per second while current is traveling between the battery's terminals.
