Formulation of quantum mechanics
- Date
- 1925–1927
- Category
- Science, technology & invention
- Region
- Europe (Germany, Austria, Denmark)
- Era
- Modern
- Significance
Between 1925 and 1927 physicists developed a complete and self-consistent quantum mechanics, replacing the ad hoc 'old quantum theory' of Planck and Bohr.
In July 1925 Werner Heisenberg published a reinterpretation of atomic mechanics in terms of observable quantities, which Max Born and Pascual Jordan formalised as matrix mechanics. In 1926 Erwin Schrödinger, building on Louis de Broglie's wave–particle duality, published wave mechanics and the Schrödinger equation, an alternative formulation soon shown to be mathematically equivalent. Born then supplied the probabilistic interpretation of the wave function, and in 1927 Heisenberg articulated the uncertainty principle, with Bohr's complementarity completing what became the Copenhagen interpretation. Quantum mechanics provided the theoretical foundation for understanding atoms, chemical bonding, solid-state physics and particle behaviour. It underpinned later technologies including the transistor, the laser, semiconductors and nuclear energy, making it one of the most consequential scientific frameworks of the century. Its probabilistic, non-deterministic character also provoked enduring philosophical debate, including Einstein's objections.
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Empires active in 1925–1927
- Empire of Japan1868 CE – 1947 CE
- French Colonial Empire (Second)1830 CE – 1962 CE
- Soviet Union1922 CE – 1991 CE
- British Empire1583 CE – 1997 CE
- Spanish Empire1492 CE – 1976 CE
- Portuguese Empire1415 CE – 1999 CE
Related science, technology & invention events
- Penicillin and the dawn of the antibiotic era1928 (developed for clinical use 1940–1945)
- Haber-Bosch Process Industrialises Synthetic Nitrogen FertiliserSeptember 1913
- Discovery of nuclear fissionDecember 1938 (explained January–February 1939)
- The Wright Brothers' Powered Flight17 December 1903
- Discovery of X-rays and radioactivity1895–1898
- Germ Theory of Disease Established by Pasteur and Koch1882 (Koch's tuberculosis bacillus, 24 March)
Further reading
The wider story
A Little History of Science
Warm, jargon-free tour of discovery from Babylonian stargazers to the genome.
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