New Delhi: The Google logo takes the form of electromagnetic waves (in Google colours - blue, red, yellow and green) to pay tribute to German physicist Heinrich Rudolf Hertz on his 155th birth anniversary. Hertz was born at Hamburg on February 22, 1857.
Hertz was the first to broadcast and receive radio waves. His pioneering work laid the way for the development of radio, television and radar.
The unit of frequency of a radio wave - one cycle per second - is named the hertz, in honour of Heinrich Hertz.
Hertz proved the existence of radio waves in the late 1880s. He used two rods to serve as a receiver and a spark gap as the receiving antennae. Where the waves were picked up, a spark would jump. Hertz showed in his experiments that these signals possessed all of the properties of electromagnetic waves.
With this oscillator, Hertz solved two problems. First, timing English scientis James Clerk Maxwell's waves. He had demonstrated, in the concrete, what Maxwell had only theorised - that the velocity of radio waves was equal to the velocity of light. (This proved that radio waves were a form of light).
Second, Hertz found out how to make the electric and magnetic fields detach themselves from wires and go free as Maxwell's waves.
Hertz died at the young age of 36 on New Year's Day 1894. There is a lunar crater on the dark side of the Moon named after him.
Google has, till the Hertz doodle, posted 1308 doodles on its home page since the first ever Google doodle back on August 30, 1998.