Coulomb's law describes the electrostatic force between two electric charges at rest. The force is proportional to the product of the two charges and falls off with the square of the distance between them. Like charges repel and opposite charges attract, along the straight line joining them. French physicist Charles-Augustin de Coulomb published this in 1785, after precise torsion-balance experiments. The law is similar to Newton's law of gravity, but electric forces are far stronger and can be attractive or repulsive. It has been tested across an enormous range of scales.

In 1909 D. W. Griffith made a 14-minute film about a speculator who corners the wheat market and doubles the price of bread. A farmer sows his field while a 'Wheat King' gambles in the Chicago wheat pit; bakers raise the loaf from five cents to ten and the poor line up for bread. Griffith cut back and forth between the farm, the feast and the breadline, a technique called parallel editing, so audiences saw both ends of the economy at once. The film drew on Frank Norris's stories and on a real scheme: months earlier Chicago financier James Patten had cornered wheat, sent bread prices up and made about $5 million, roughly $185 million today.