On 14 December 1900, the German physicist Max Planck presented to the German Physical Society in Berlin a formula for the radiation emitted by a hot body, which only agreed with experiment if the energy was emitted in discrete packets, or quanta, proportional to frequency. Planck regarded it as a mathematical trick, but it gave rise to quantum theory. Einstein used the idea in 1905 to explain the photoelectric effect, Bohr applied it to the atom in 1913, and in 1925 to 1926 Heisenberg and Schrodinger built quantum mechanics, the basis of modern physics and electronics.
Before and after
- 8 September 1900The Galveston hurricane
- 7 October 1900Birth of Heinrich Himmler
- 8 November 1900Birth of Margaret Mitchell
- 30 November 1900Death of Oscar Wilde
- 14 December 1900Max Planck introduces the quantum
- 20 December 1900Discovery of 21P/Giacobini–Zinner
- from 1901 to 1904Discovery Expedition (1901-1904)
- 1901Discovery of europium
- from 1901 to 1910Edwardian era
More in Science & technology
The era
This moment belongs to the Industrial era (1760 CE to 1914 CE), steam, factories and revolutions. You can also browse everything in the 19th century.