Electromagnetism is everywhere, and humans have observed its many guises for thousands of years. Ancient Egyptians were painfully aware of the Nile River’s electric catfish. The Chinese learned to navigate with magnetized lodestone compasses in the first millennium B.C.E. Our early ancestors must have craned their necks in awe when a lightning bolt lit up the night sky.
Despite this long acquaintance with all sorts of electrical and magnetic phenomena, no one suspected until the early 1800s that the two were inextricably linked (let alone that these twin forces create waves of energy). Over the next century, however, a handful of brilliant thinkers and experimenters gradually unraveled the mysteries of electromagnetism.
Electromagnetism involves the interaction between electrically charged particles. It combines electricity and magnetism into a single theory and is responsible for various phenomena, such as the generation of electric currents and magnetic fields.
We use electromagnetism every day with ...
