Tuesday, March 16, 2010

Particles, fields, classic and quantum theory

The quantum theory was not anything that the theoretical ones were wishing. Most of them were led, to his sorrow, to this strange vision of the world because the classic theory, despite his haughty nobility, has some deep difficulties.
The principal cause is the fact that two types of physical objects must coexist: the particles, each of them described by means of a finite number of parameters, three positions and three moments; and the fields that need an infinite number of parameters. This dichotomy is not physically consistent. So that a system with particles and fields they are in balance all the energy of the particles must be transferred to the fields. This is a consequence of the called phenomenon "equipartición of the energy": in the balance the energy is distributed equally between all the grades of freedom of the system. Since the fields have infinite freedom grades to the particles they cannot have left at all by no means.
The classic atoms would not be stable since the whole movement of the particles would be transferred to the undulatory ways of the fields. When an orbital electron moves alededor of the nucleus it should express electromagnetic waves of an increasing intensity up to infinite in a small second fraction. At the same time it would describe a spiral that would close and would sink in the nucleus. Nevertheless nothing of that is observed. What is observed is quite inexplicable on the base of the classic theory. The atoms can express electromagnetic waves (light) but only in twinkles of specific discreet frequencies: the sharp spectral lines observed and typical of every type of element. Also, these frequencies satisfy rules that have not anything in common with the classic theory.
Another declaration of the instability of the field coexistence and particles is the phenomenon known as “radiation of the black body”. In 1900 Rayleigh and Jeans had calculated that all the energy would be absorbed by the field, without limit, in what it has been called “an ultraviolet catastrophe”. The energy would keep on flowing incessantly towards the field with every time major frequencies.
Max Planck, in the same year, proposed a revolutionary idea to eliminate the ways of high frequency of the “black body”: that the electromagnetic oscillations only happen in “all that“ whose energy E supports a relation defined with the frequency f, given for: And = h f, being h a new fundamental constant of the Nature, now known as constant of Planck. With this extravagant ingredient, Planck could obtain a surprising theoretical agreement with the dependency experimentally observed of the intensity with the frequency, now called law of radiation of Planck.
In the end the electromagnetic radiations could only present in discreet bundles called photons to themselves. The light, after everything, as he had insisted Newton two centuries earlier must be formed of "particles", although at the beginning of the XIXth century Thomas Young demonstrated that it was consisting of waves. Waves or particles?. In 1923 the French physicist Louis de Broglie proposed that the proper matter particles were behaving sometimes like waves. The frequency of the wave of Broglie f, of a particle of mass m, satisfies the relation of Planck, combined with the relation Einstein's mass / energy.

The dichotomy between particles / waves or oscillations of the field, which had been a characteristic of the classic theory, is not respected in the Nature. The Nature manages to construct a world consisting of that the particles and the oscillations of the field are the same thing.
To know more:
- "The new mind of the emperor". Roger Penrose.
- "The light, something on his history". LBT.
- "The quantum physics is easy". LBT.

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