Volta

Alessandro Volta was born in Como, Italy in 1745. He taught physics in local schools and became obsessed with electricity—then a mysterious phenomenon that scientists barely understood. In 1775, he invented the electric gun, a machine that used electrical sparks to ignite gases. In 1776, he invented the electrophorus, a device that could generate static electricity through mechanical induction. But he needed a way to create constant, steady electrical current.

In 1800, Volta stacked alternating discs of zinc and copper separated by cardboard soaked in salt water. When connected by a wire, electrons flowed continuously from one end to the other. He had built the first electric battery—the Voltaic pile. He wrote to the Royal Society in London describing his achievement. Suddenly, scientists could experiment with electric current in controlled, repeatable ways.

The Voltaic pile became the foundation of electrochemistry and every battery that followed. Volta received honors across Europe. Napoleon made him a count. The French emperor understood immediately what Volta had done: he had made electricity commodifiable. It could be stored, transported, measured, and used.

Volta died in Como in 1827, having lived to see electric current become practical technology. In 1881, the International Electrical Congress adopted the 'volt' as the unit of electrical potential—the amount of energy a charge carries. Every time you check a battery's voltage or plug something into a wall, you're using a unit named after a man who turned an abstract phenomenon into an object you could hold in your hand.