50 Hertz Heinrich Rudolf Hertz
February 22, 1857 – January 1, 1894
Heinrich Rudolf Hertz was a German physicist who clarified and
expanded the electromagnetic theory of light that had been put forth
by Maxwell. He was the first to satisfactorily demonstrate the
existence of electromagnetic waves (radio waves).
In more advanced experiments, Hertz measured the velocity of
electromagnetic radiation and found it to be the same as the light’s
velocity. He also showed that the nature of radio waves’ reflection
and refraction was the same as those of light.
Hertz's experiments would soon trigger the invention of the wireless
telegraph, radio, and later television. In recognition of his work,
the unit of frequency - one cycle per second - is named the "Hertz".
The hertz (symbol Hz) is the SI unit of frequency defined as the
number of cycles per second of a periodic phenomenon. One of its
most common uses is the description of the sine wave, particularly
those used in radio and audio applications.
In the UK our mains electricity has a frequency of 50 Hertz ! If you
ever wondered what it meant when you see "50 Hz" marked on something
electrical, now you know.
