The Universe of the Quantum Theory of the Light // Max Planck

Greetings partners of Steemit, reading friends lover of the science and the knowledge, About 1900, existed difficulties for the interpretation of certain phenomena, in which they were intervening the electromagnetic radiation, especially when it was considered to be his interaction with the matter, Max Planck proposed that the atoms and the molecules were behaving as elementary oscillators and that the energy, which was capable of expressing or of absorbing had to be proportional to the frequency of vibration.

Max Planck _ (1858-1947), source of image of mastery of Wikimedia Commons, Author: Unknowncredited to Transocean Berlin (see imprint in the lower right corner)

In a closed cavity, atoms of the walls, which are existed to certain temperature, express electromagnetic radiation simultaneously, that absorb the expressed one by other atoms of the same wall. When the electromagnetic radiation inside the enclosure is in balance with the walls, the electromagnetic field has a constant thickness and the radiation has a distribution of definite well energy, which depends only on the temperature of the walls.

If a hole is opened in them, it is possible to analyze the radiations that it escapes from the enclosure, to temperature raised the hole goes down turns out to be black completely, since the radiation corresponding to the visible spectrum in this one conditions is invaluable, the radiation that leaves of the cavity is named a radiation of the black body, the energy expressed by unit of area and unit of time is proportional to the fourth potency of the absolute temperature, which meets him as the law of Stefan-Boltzmann.

, on having compared the molecules and the atoms with elementary oscillators, The interpretation of Planck was doing that the energy was not absorbed or expressed in form it continues but in bundles or quantos of value E=hv, where h is the constant of Plack and v is the frequency of vibrations of the atoms. On having exchanged energy in discreet form, the energy of the atomic oscillators must be cuantizada, which it implies, that only can have certain values as: 0, hv, 2hv, 3hv.

A diagram of the atomic model of Bohr, source of image of mastery of Wikimedia Commons

In reference of the photoelectric effect and effect campton, in case of the first one of the photoelectric one it was discovered in 1887 by Heinrich Hertz, it consists of the emission of electrons for a metallic surface on having been illuminated, according to undulatory classic theory of the radiations, the emission would have to take place in all the cases, for values superior to a certain intensity, sufficiently like to start the electrons of the metal. On the other hand experimentally it was observed that this emission only was taking place, for frequencies bigger than a frequency threshold, this way for a built electrode of a certain alone metal step of current is detected if the light is equal or superior to this frequency.

Scheme of the electrical field created in a photovoltaic cell by means of the union pn between two layers of dopados semiconductors, source of image of mastery of Wikimedia Commons, Author en:User:TheNoise

In the moment of the creation of the union pn, the free electrons of the layer n enter instantaneously the layer p and re-get together with the hollows in the region p. It will exist this way during the whole life of the union, a positive load in the region n along the union (because electrons are absent) and a negative load in the region in p along the union (because the hollows have disappeared); the set forms the « Zone of Load of Space » (ZCE) or ' barrier zone ' and an electrical field exists between two o'clock, of n towards p. This electrical field does of the ZCE a diode, which only allows the flow of carriers in a direction: in absence of a source of exterior current and under the alone influence of the field generated in the ZCE the electrons only can move of the region p to n, but not in the opposite direction and on the contrary the hollows do not happen any more than of n towards p.

This tells that for certain metals, the effect should not take place with an intense red light and if on the other hand, with a weak blue light, Albert Einstein, using the concept of quantum, which had introduced Plack, I explain these experimental results in 1905, by which the Nobel Prize was granted to him in 1921, according to the theory of Einstein, the light is formed by individual photons to each of which corresponds to an energy, which depends on his frequency. A photon of bundle of incidental light collides with an electron of an atom of the surface of the electrode and only if his energy is sufficient, manages to start it, that is to say if his frequency is high enough. For frequency it is it lower than the frequency a threshold the photon will bounce and although many are accumulated they will manage neither to start electrons nor to do that I circulated current.

The instantaneous absorption of the photon indicates, that his location in the space is so precise as that of the electron, for Einstein, I it consider that a corpuscle of light, started electron will possess a kinetic equal energy to the difference between the energy threshold, named the last one I work of extraction, it is necessary to think the following thing in effect Compton discovered in 1923 by Arthur Compton, consists of the dispersion of a photon for the electrons of an atom. In the interaction the photon behaves as a particle that exchanges energy and quantity of movement with the electron as if about two balls it was talking each other, the exchange of energy is translated in a change in the frequency of the photon.

The duality wave - corpuscle, certain phenomena in which there intervenes the light, like the spread the interferences the diffraction and the polarization comes explained to the perfection for the undulatory theory, nevertheless some phenomena, especially regarding the interaction with the matter, he awards to the light an indisputable nature corpuscular, these facts make to admit that the light possesses a double nature, corpuscular and undulatory, whose aspects complement each other also, they constitute two ways of perceiving and of observing the only reality. The reasoning as the theory, where the wave associated with a material body, which moves at a certain speed has an associate wavelength, the observation of the only reality from two different, but essentially complementary points of view, demonstrates the inability to use clear images in excess and acquaintances to represent the reality of the matter in his atomic and subatomic appearance.

Secondhand Bibliography

Introduction to the concepts and theories of the physical sciences for Gerald James Holton, ‎Stephen G. Brush - 1996.

quantum Theory relativista - Part 2 for E. M. Lifshitz, ‎Vladimir Borisovich Berestetskii, ‎L. P. Pitaevskii - 1981.

Essentials of quantum mechanics - Page 172 for Sidney Borowitz - 1973.