Hertz

Heinrich Hertz was born in Hamburg, Germany in 1857. He studied physics under Hermann von Helmholtz in Berlin, one of the era's greatest physicists. In 1885, Hertz became a professor of physics at Karlsruhe. James Clerk Maxwell had theorized in 1865 that electricity and magnetism could ripple through space as waves, but no one had detected them. Maxwell had died in 1879 without experimental proof.

In 1886, Hertz designed an apparatus: a spark gap that generated rapid electrical oscillations, and a loop of copper wire some distance away that received them. When he sparked one, the copper loop sparked back. He had transmitted electromagnetic radiation across empty space without wires. The waves were traveling at the speed of light. Maxwell's equations were correct.

Hertz measured the wavelength of the electromagnetic radiation he had generated. He varied the frequency of oscillation and measured how it affected the distance the signals traveled. He discovered that the phenomena followed the laws Maxwell had predicted. Between 1886 and 1889, Hertz published nine papers documenting these experiments. He had opened a new window on reality: invisible waves carrying energy through space.

Hertz died of blood poisoning in 1894 at only 36 years old. He never knew that his invisible waves would become the foundation of radio, television, and wireless communication. In 1930, the SI unit of frequency was named the hertz—cycles per second. Every radio station, every WiFi network, every cellular tower operates in hertz. A physicist who died before the radio age began is remembered in every transmission.