From bookbinding to the laboratory
As an apprentice bookbinder he read the books he was binding. He attended lectures by the chemist Humphry Davy, sent him his notes, and became his assistant at the Royal Institution in London.
Motion makes current
In 1821 he built an experiment in which a current-carrying wire rotated around a magnet — the first seed of the electric motor. In 1831 he discovered the reverse effect: when the magnetic field in a coil changes, a current is produced in it. This is the principle by which generators in power plants produce electricity, and it is how every transformer and wireless charger works.
The Faraday cage
Faraday showed that a metal enclosure shields an electric field. Such a cage protects people in a car during a storm, and the metal mesh in a microwave oven door keeps the microwaves in, even though you can see through it.
The idea of a field
He never mastered advanced mathematics, so he pictured electricity and magnetism as lines of force in space. This idea was later turned into equations by James Clerk Maxwell.