1857-1894

German physicist who was the first to broadcast and receive radio waves.

Hertz expanded the electromagnetic theory of light developed by the British physicist Maxwell in 1884; Hertz proved that electricity can be transmitted in electromagnetic waves, which travel at the speed of light and which possess many other properties of light. His experiments with these electromagnetic waves led to the development of the wireless telegraph and the radio. The unit of frequency that is measured in cycles per second was renamed the hertz.