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quantum theory

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quantum theory

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 (see wave mechanics) and on the Heisenberg uncertainty principle
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

quantum theory

The theory put forward by the German physicist Max Planck in 1900. Classical physics regarded all changes in the physical properties of a system to be continuous. By departing from this viewpoint and allowing physical quantities such as energy, angular momentum, and action to change only by discrete amounts, quantum theory was born. It grew out of Planck's attempts to explain the form of the curves of intensity against wavelength for a black-body radiator. By assuming that energy could only be emitted and absorbed in discrete amounts, called quanta, he was successful in describing the shape of the curves. Other early applications of quantum theory were Einstein's explanation of the photoelectric effect and Bohr's theory of the atom (see hydrogen spectrum; energy level). The more precise mathematical theory that developed in the 1920s from quantum theory is called quantum mechanics. Relativistic quantum mechanics resulted from the extension of quantum mechanics to include the special theory of relativity.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

quantum theory

[′kwän·təm ‚thē·ə·rē]
(physics)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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References in periodicals archive
Ball also separates fact from fiction, educating readers about the concepts that are not a part of quantum theory, but have become synonymous with it, and are responsible for propagating misunderstandings about the theory.
This result may be just the beginning of many other related discoveries, since it opens up the possibility that other physical features of quantum theory can be reproduced simply by requiring that the theory has a classical limit.
The premise of Penrose is that quantum theory must be limited in its domain.
To now all of a sudden meekly submit to the difficulties we have encountered in interpreting quantum theory, and sweep these essential questions under the rug by escaping into a positivist or instrumentalist position (as certain proponents of the Copenhagen interpretation have done), claiming that science is, and should have been all along, merely about predicting observational patterns; or even worse, to ignore the problem altogether and adopt a shut-up-and-calculate stance, does not satisfy us as natural philosophers.
Besides, it should be noted, however, that the quantum theory of the atom by Bohr received in 1914 and its direct experimental confirmation in the famous experiments of German experimental physicists James Franck (1882-1964) and Gustav Hertz (1887-1975) for the detection of discrete excited states of a number of atoms (e.g., mercury Hg) and determining their ionization energy [2, 4, 6].
The experimental detection of dynamical space required generalisation of Maxwell's EM Theory, Schrodinger's Quantum Theory and a corresponding generalisation of the Dirac Quantum Theory [9], and the determination of a dynamical theory for space.
The researchers have exploited two different areas of physics: Einstein's special relativity - which interprets uniform motion between two objects moving at relative speeds - combined with the power of quantum theory, the new physics of the sub-atomic world that Einstein famously dismissed as 'spooky'.
This culture, in Smolin's telling, eschews the philosophical bent of Einstein and quantum theory's founders, preferring the "shut up and calculate" attitude of later particle physicists.
Evolution, quantum theory and Einstein's theory of relativity play a part.
Nevertheless, Einstein's initial insights, built upon the work of earlier scientists (notably Lorentz and Poincare), are taken as the beginning of modern cosmology, for, eleven years after the publication of his initial papers, his special theory of relativity would lead to the full formulation of his general theory of relativity, and his initial insights into the nature of matter and radiation--built especially upon the work of Max Planck, who asserted in 1900 that energy of radiation is produced in discrete little bundles, in direct proportion to the radiation's frequency (the famous E=hv equation)--would lead Bohr, Heisenberg, Schrodinger, Dirac, and Fynmann to work out the Quantum Theory, which in turn would change our perception of the physical world.
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