Quantum mechanics Copenhagen interpretation

Werner Heisenberg (1901-1976 Nobel Prize for physics 1932) developed quantum mechanics, which allowed an accurate description of the atom. Together with his teacher and friend Niels Bohr, he elaborated the consequences in the "Copenhagen Interpretation" — a new world view. He found that the classical laws of physics are not valid at the atomic level. Coincidence and probability replaced cause and effect. According to the Heisenberg Uncertainty Principle, the location and momentum of atomic particles cannot be determined simultaneously. If the value of one is measured, the other is necessarily changed. 

The orthodox or Copenhagen interpretation of quantum theory originated with three seminal papers published in 1925-26 by Heisenberg, Born and Jordan and an independent paper by Dirac (1926) all of these are available in English (translation) in a single volume [13]. A detailed summary was published by Heisenberg [9]. The primary aim of these studies was to formulate a mathematical system for the mechanics of atomic and electronic motion, based entirely on relations between experimentally observable quantities. An immediate consequence of this stipulation was that the motion of electrons could no longer be described in terms of the familiar concepts of space and time, but rather in terms of state functions constructed from matrix elements that relate to the Fourier sums over observed spectroscopic frequencies. The procedure became known as matrix mechanics. 

A worse dilemma was created by the user-friendly nature of wave mechanics, arising from the relative ease of manipulating differential equations, compared to the diagonalization of matrices. Most physicists who had eagerly anticipated the appearance of a generally applicable quantum theory immediately turned to wave mechanics. The Copenhagen school must have perceived this as a dangerous development that could potentially pollute the purity of quantum mechanics and they started to develop an interpretational structure that would eliminate deviant perceptions created by wave mechanics. 

The interminable discussions on the interpretation of quantum theory that followed the pioneering events are now considered to be of interest only to philosophers and historians, but not to physicists. In their view, finality had been reached on acceptance of the Copenhagen interpretation and the mathematical demonstration by John von Neumann of the impossibility of any alternative interpretation. The fact that theoretical chemists still have not managed to realize the initial promise of solving all chemical problems by quantum mechanics probably only means some lack of insight on the their part. 

It is interesting to note that the Gottingen school, who later developed matrix mechanics, followed the mathematical route, while Schrodinger linked his wave mechanics to a physical picture. Despite their mathematical equivalence as Sturm-Liouville problems, the two approaches have never been reconciled. It will be argued that Schrodinger s physical model had no room for classical particles, as later assumed in the Copenhagen interpretation of quantum mechanics. Rather than contemplate the wave alternative the Copenhagen orthodoxy preferred to disperse their point particles in a probability density and to dress up their interpretation with the uncertainty principle and a quantum measurement problem to avoid any wave structure. 

In 1935 Erwin SchrOdinger published an essay questioning whether strict adherence to the Copenhagen interpretation can cause the weirdness of the quantum world to creep into everyday reality. He speculated on how the principle of superposition, which is so fundamental for the quantum-mechanical behavior of microscopic systems, might possibly affect the behavior of a large-scale object. 

Copenhagen interpretation, quantum mechanics, 266 Coulomb s law, 94 Crystal field theory, transition metal complexes, 149-152 Curvilinear coordinates, overview, 80, 86-88... 

What we perceive to be physical reality is actually our cognitive construction of it. This cognitive construction may appear to be substantive, but the Copenhagen Interpretation of Quantum Mechanics leads directly to the conclusion that the physical world itself is not.9... 

The conventional conceptual content of quantum mechanics was initiated by the Copenhagen School when it was recognized that one could express the linear Schrodinger wave mechanics [28] in terms of a probability calculus, whose solutions are represented with a Hilbert function space. Max Bom then interpreted the wave nature of matter in terms of a spatially distributed probability amplitude—a wave represented by a complex function—to accompany the material particle as it moves from one place to another. The Copenhagen view was then to define the basic nature of matter in terms of the measurement process, with an underlying probability calculus, wherein the probability densities (for locating the particles of matter/volume) are the real-number-valued moduli of the matter wave amplitudes. 

The linear superposition principle plays a central role in the theory presented here. It should be noted, however, that the standard Copenhagen interpretation of quantum mechanics is not well adapted to discuss the notion of state amplitudes and measurements in the context required by the GED scheme. A more appropriate theoretical framework for quantum measurement is found in the ideas proposed by Fidder and Tapia [16]. 

However, the problem of A in particle physics remains. It can be traced back to the concept of massive indivisible point particles with infinite self-energy and self-field - the basic premise of field theories based on the Copenhagen interpretation of quantum mechanics. As recollected by one pioneer... 

The months which followed [... ] were a time of the most intensive work in Copenhagen, from which there finally emerged what is called the "Copenhagen interpretation of quantum theory," [... ] BOHR intended to work the new simple pictures, obtained by wave mechanics, into the interpretation of the theory, while I for my part attempted to extend the physical significance. ... 

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