168 years ago today, February 22, 1857 (January 28, 1857 in the lunar calendar), the German physicist Hertz was born. Heinrich Rudolf Hertz was born on February 22, 1857. He was a German physicist who was the first to broadcast and receive radio waves. In 1880, he obtained a doctorate in philosophy from the University of Berlin with distinction under the guidance of Helmholtz. In 1883, he began to study J.C. Maxwell's theory of electromagnetism. 1885-1889 When he was a professor of physics at the Karlsruhe Institute of Technology in 1989, radio waves were generated in the laboratory and the wavelength and speed were measured. He pointed out that the vibration and reflection and refraction characteristics of radio waves are the same as light and thermal waves. As a result, he was absolutely certain that light and heat are both electromagnetic radiation. In 1889, he was appointed professor of physics at the University of Bonn, where he continued to study discharges in rare gases. He died of illness on January 1, 1894.