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Astro*Dictionary by Michael Erlewine





1 article for "Plank, Max Karl Ernst Ludwig"

Plank, Max Karl Ernst Ludwig [Astro*Index]

(1858-1947) German physicist.

In 1900, he derived a relatively simple equation that described the distribution of radiation over the entire range of frequencies of a Black Body. His equation rests upon a fundamental assumption: that energy is not infinitely subdivisible and, like matter, exists in `particles' which he called quanta. He also proposed that the size of the quantum for any particular form of electromagnetic radiation was in direct proportion to its frequency. These concepts led to the determination of small constant (symbolized as h) which is the ratio of the frequency of the radiation and the size of the quantum. This constant is called Plank's Constant, and is recognized as one of the fundamental constants of the universe. So revolutionary were his ideas of Quantum Physics, that physics before 1900 is now known as classical physics, and afterwards as modern physics. His contributions earned him the Nobel Prize in Physics, in 1918; he was followed a few years later by Einstein and Bohr for the use they made of his contributions.

See also:
♦ Einstein, Albert


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