Zur Theorie des Gesetzes der Energieverteilung im normalspectrum
Max Karl Ernst Ludwig Planck(1858-1947)
 It was Planck’s quantum theory and Einstein’s theory of relativity that entirely innovated the field of physics and the scientific view of the world itself which had been established by Newton. This paper was the celebrated announcement of Planck’s quantum theory.
 Planck started his career with research in thermodynamics and later took interest in the problem of black-body radiation. The black-body is an ideal body which can totally absorb the all incident radiation and radiates the gamut of light when heated. In this ideal type of radiation, the number of short wave-length waves is far greater than the number of long wave-length waves at a high temperature. This means that almost all of the energy is radiated in the high-frequency wave. Therefore, if the energy were radiated continuously in uniform distribution, it should cause an ultraviolet catastrophe.
 In the actual process of radiation, however, these phenomena do not take place. With the intention of resolving this antinomy, Planck propounded a new formula of energy distribution, which could be applied to the total range of wave-lengths in radiation. By denying the hypothesis of energy continuity, Planck concluded that energy does not flow continuously, but is absorbed and then radiates in a discrete quantity, which he called “quantum,” the smallest quantity of radiant energy which is the product of frequency and an action quantum equal to 6.624 x 10 erg seconds. This constant was called Planck’s constant and became the most fundamental constant in physics. This conclusion was somewhat strange because it proposed that frequency was a property of wave continuity, whereas “quantum” showed discreteness of energy. It suggested, however, that dual properties of energy such as corpuscles and waves existed and therefore also suggested the limitations of classical physics.
 Unaware of the revolutionary importance of this theory at that time, Planck had initiated a new realm of physics, which came to be known as quantum mechanics. It was expanded and confirmed by Einstein is his research on photoelectric effect, and finally was established by Schrodinger, Heisenberg and Dirac. Planck was awarded the 1918 Nobel Prize for this contribution to physics.