quantum theory

American  

[kwon-tuhm thee-uh-ree, theer-ee] / ˈkwɒn təm ˌθi ə ri, ˌθɪər i /

noun

Physics.

1. any theory predating quantum mechanics that encompassed Planck's radiation law and a scheme for obtaining discrete energy states for atoms, such as the Bohr model.

2. any theory that treats certain phenomena by the methods of quantum mechanics.

   a quantum theory of gravitation.

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quantum theory British  

noun

1. a theory concerning the behaviour of physical systems based on Planck's idea that they can only possess certain properties, such as energy and angular momentum, in discrete amounts (quanta). The theory later developed in several equivalent mathematical forms based on De Broglie's theory and on the Heisenberg uncertainty principle See wave mechanics

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quantum theory Scientific  

1. See quantum mechanics

2. Any of various theories that makes use of the assumptions, principles, and laws of quantum mechanics.

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Etymology

Origin of quantum theory

First recorded in 1910–15

Example Sentences

See Examples For:

quantum theory

Such an interpretation could provide new ways to investigate the relationships among gravity, quantum theory, dark energy, cosmic evolution, and the emergence of complex structures.

From Science Daily ● Jul. 21, 2026

Schrödinger introduced the idea to highlight how strange quantum theory appeared.

From Science Daily ● Jul. 5, 2026

Macroscopicity allows scientists to evaluate experiments involving systems such as nano-oscillators, atomic interferometers, and nanoacoustic resonators by measuring how effectively they rule out even tiny deviations from standard quantum theory.

From Science Daily ● May 11, 2026

However, quantum theory also offers another equally important framework developed by Werner Heisenberg.

From Science Daily ● Apr. 14, 2026

One is that it should incorporate Feynman’s proposal to formulate quantum theory in terms of a sum over histories.

From "A Brief History of Time: And Other Essays" by Stephen Hawking