Planck's law of black-body radiation and the quantum of action
Ley de radiación del cuerpo negro y cuanto de acción
- Date
- 1900 · confidence high
- Place
- University of Berlin, Germany
- Credited to
- Max Planck
- People
- 👤 Max Planck1858–1947
- Field
- Cosmos & Earth
What was discovered
To explain the black-body spectrum, Planck assumes that energy is emitted in discrete packets E = hν, introducing the constant h. On 14 December 1900 quantum physics is born, although Planck considered it an 'act of desperation'.
Precision measurements were made at the Physikalisch-Technische Reichsanstalt in Charlottenburg.
What it led to
- Quantum theory (Einstein, Bohr)
- Quantum mechanics
- Planck constant as a basis of the SI (2019)
- Cosmology (cosmic microwave background as a black body)
Built on
- Rayleigh–Jeans law1900-1905
- Kirchhoff's law (1860)
- Rubens and Kurlbaum's measurements at the Berlin PTR
- Boltzmann's combinatorial method
Made possible
- Stimulated emission of radiation1917
- Bose-Einstein statistics1924
- Pyrometry and thermography
- Design of lamps and light sources