the quantum nature of energy.
Planck was as steeped in traditional physics as his colleagues, but he had an open mind. The older way wasn't working. So he changed one basic assumption: energy, instead of being continuous, comes in distinct particles. These were later called "quanta," from the Latin for "how much?" Though it sounded outlandish, applying this idea to the problem of heated bodies revealed a simple relationship that explained previous puzzles. Planck found that the energy radiated from a heated body is exactly proportional to the wavelength of its radiation. So, a black body would not radiate all frequencies equally. As temperature goes up, energy increases and it's more likely that quanta with higher energy will be radiated. So, as an object heats up, the light given off is orange, then yellow, and eventually bluish. The wavelength emitted is a function of the energy times a constant (h), now known as Planck's constant. Though Planck's idea was not immediately believed by most physicists, it is now accepted as one of the fundamental constants in the universe. In fact, Planck himself wasn't sure if it was more than a little mathematics that resolved his own particular problem.
In 1905, Albert Einstein used the theory of quanta to accurately describe the photoelectric effect. In 1913, Niels Bohr incorporated Planck's idea into his revision of model of the atom, resolving inconsistencies that classical physics could not.
Honors and awards
Planck received the Nobel Prize for Physics in 1918.
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Footnotes & References
|1||courtesy ScienCentral Inc and the American Institute of Physics 1999|