quantum theory

[ kwon-tuhm thee-uh-ree, theer-ee ]

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.

quantum theory

noun

1. See wave mechanics
   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

quantum theory

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

Word History and Origins

Origin of quantum theory¹

First recorded in 1910–15

Example Sentences

Then in 1964, John Stewart Bell proved a theorem that would test whether quantum theory was obscuring a full description of reality, as Einstein claimed.

From Quanta Magazine

Nor are the novel one- and two-dimensional materials that display the curiosities of quantum theory.

From Quanta Magazine

It is worth stating specifically why one might have ever imagined something so outlandish as the idea that quantum theory could be used to predict the stock market.

From Nautilus

In quantum theory, a particle has a range of possible locations and speeds.

From Quanta Magazine

The quantum theory presented in standard textbooks involves two distinct rules for the evolution of the state of a physical system.

From Nautilus

For that reason, researchers have developed a framework to describe quantum theory in combination with general relativity.

From The Daily Beast

Quantum theory explains the small stuff, where matter and energy divide into infinitesimal particles.

From The Daily Beast

In that way, it incorporates both classical physics and quantum theory to explain the most general range of phenomena yet.

From The Daily Beast