quantum theory  
—n  
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 
quantum theory n.
The theory that radiant energy is transmitted in the form of discrete units.
quantum theory
