# Quantum Theory

Quantum theory is a comprehensive set of theoretical disciplines describing the characteristics and behavior of particulate matter and physical fields and their interaction. There is a part of physics apparatus utilizing quantum theory called quantum physics. Word bounty comes from Latin and means "how much", "many", "as"

## Quantum theory is divided into:

**Quantum mechanics:** The physics, which explores and describes events at nanoscopic scales. Traditional problems explained by quantum mechanics is the behavior of microparticles, atoms, molecules and atomic nuclei. Quantum mechanics relates probabilities. It says that it can not predict where the electron will be at a given time, it can only state probabilities for the various positions. In a sense, even the electron does not exist, if not observed, and it should be as long talk about it, that is at once everywhere and nowhere (Schrödinger's cat). After decades of studies of quantum mechanics and certificates. There is also a number of completely absurd predictions come to the fore bizarre consequence of the mathematical foundations of speaking, that every phenomenon which assigns zero probability theory, not only could happen, but in any event actually takes place. In one of the many alternative realities, each one represents actually a parallel universe. Quantum mechanics is based on a deeper level of scientific knowledge than classical physics and also provides general laws. The laws of classical physics appear in terms of quantum mechanics as an approximation of this new theory. The behavior of subatomic particles (electrons, protons, neutrons, photons and others) that make up the matter satisfactorily describes as quantum mechanics. Quantum mechanics significantly affected string theory, which is a candidate for a theory of everything.

**Quantum theory of fields and elementary particles:** The application of quantum mechanics to the behavior of the fields. There is the basis of the examination of elementary particles and their interactions and in the modern theory of solids. The reason for seeking a new theory was that quantum mechanics describes the behavior of those systems where the number of particles remain unchanged (exemplified by the electron in a hydrogen atom). Radiated photon when skipping electron from a higher energy level to a lower but is already beyond the use of quantum mechanics - while skipping is added new particle, the photon. The work on quantum field theory began Dirac late 20-ies of the 20th century. A successful quantum theory of the electromagnetic field, however, has been done up to about 30 years later, with the contribution of several well-known physicists

**Quantum electrodynamics: ** The science of the motion of electric charges (charged bodies) in general variable electromagnetic fields. Classical Electrodynamics studying the electrodynamic interaction between macroscopic bodies, quantum electrodynamics interaction between microobjects (atomic and subatomic dimensions). It's quantum theory of electromagnetic processes. Quantum electrodynamics created the theory of the interaction of electromagnetic fields and fields describing electrons and positrons. The interaction is described in quantum electrodynamics as exchange of photons. It is first carefully prepared by quantum theory forcefield.

**Quantum statistical physics:**: It is one of the fundamental physical theories. It uses statistical methods to describe the behavior of systems with a large number of particles. So it's able to describe a wide range of phenomena, including even those whose nature is strictly coincidental. The use is fusion research, Radiation of objects, the theory of gases, but also in biology, chemistry, neurology and sociology. One of the new areas of research are complex graphs.

**Quantum chromodynamics: ** The gauge theory of color interactions of quarks, antiquarks and gluons. Quantum chromodynamics as a theory of strong interactions was established in the mid-70s. Its validity was confirmed by a considerable number of experiments. Today, however, the prediction restricted to cases interactions over very short distances, where applicable perturbation theory.

**Quantum chemistry:** The Department of Theoretical Chemistry, which uses quantum mechanics and quantum field theory to the solution of chemical problems. One of the major fields of quantum chemistry is a description of the behavior of electrons in atoms and molecules and their impact on reactivity. Quantum chemistry lies at the interface between chemistry and physics. It contributes significantly to both of these fields.