Physics deals with the combination of matter and energy. It also deals with the various systems, about the theories that have been developed that are used by physicists. In general, the theory is tested experimentally several times before being accepted as true as the description of Nature (in the domain of certain validity). For example, classical mechanical theory accurately describes the motion of objects, provided they are much larger than atoms and move much less than the speed of light. These theories continue to be active areas of research: for example, the remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642-1727). This "central theory" is an important tool for research in more specialized topics, and every physicist, regardless of his specialty, is expected to be literate in it.
Video Branches of physics
Mekanika klasik
Classical mechanics is a model of physical physics that works on the body; including sub-fields to describe the behavior of solids, gases, and liquids. This is often referred to as "Newtonian mechanics" after Isaac Newton and his motion laws. It also includes the classical approaches as given by the Hamiltonian and Lagrange methods. It deals with particle motion and the general system of particles.
There are many branches of classical mechanics, such as: statics, dynamics, kinematics, continuum mechanics (which include fluid mechanics), statistical mechanics, etc.
- Mechanics: the branch of physics in which we learn about objects and properties of an object in the form of motion under force action.
Maps Branches of physics
Thermodynamics and statistical mechanics
The first chapter of The Feynman Lectures on Physics is about the existence of atoms, which Feynman regarded as the most concise physics statement, from which science can easily occur even if all other knowledge is lost. By modeling the material as a sphere of hard balls, it is possible to describe the kinetic theory of gases, which form the basis of classical thermodynamics.
Thermodynamics studies the effects of changes in temperature, pressure, and volume on the physical system on a macroscopic scale, and energy transfer as heat. Historically, thermodynamics developed from a desire to improve the efficiency of the initial steam engine.
The starting point for most thermodynamic considerations is the law of thermodynamics, which postulates that energy can be exchanged between physical systems as heat or work. They also postulate the existence of a quantity called entropy, which can be defined for any system. In thermodynamics, the interaction between large ensembles of objects is studied and categorized. The center for this is the concept of the system and its surroundings. A system consists of particles, whose average movements define their properties, which in turn are related to each other through state equations. Property can be combined to express internal energy and thermodynamic potential, which is useful for determining conditions for equilibrium and spontaneous processes.
Electromagnetism and electronics
Relativity
Special relativity theory enjoys relation to electromagnetism and mechanics; ie, the principle of relativity and the principle of silent action in mechanics can be used to derive Maxwell's equations, and otherwise .
The special theory of relativity was proposed in 1905 by Albert Einstein in his article "On the Electrodynamics of Moving Bodies". The title of this article refers to the fact that special relativity solves inconsistencies between Maxwell's equations and classical mechanics. This theory is based on two postulates: (1) that the mathematical forms of the laws of physics are invariant in all inertia systems; and (2) that the speed of light in a vacuum is constant and independent of the source or observer. The reconciliation of two postulates requires the unification of space and time into the concept of time-dependent spacetime.
General relativity is a geometric theory of gravity published by Albert Einstein in 1915/16. It unifies special relativity, Newton's universal law of gravity, and the insight that gravity can be explained by the curvature of space and time. In general relativity, the curvature of spacetime is produced by the energy of matter and of radiation.
Quantum mechanics
Quantum mechanics is a branch of physics that deals with atomic and subatomic systems and their interaction with radiation. It is based on the observation that all forms of energy are released in discrete units or bundles called "quanta". Remarkably, quantum theory usually allows only probable or statistical calculations of the observed features of subatomic particles, understood in terms of wave functions. The Schrödinger equation plays a role in the quantum mechanics that Newtonian law and energy conservation serve in classical mechanics - that is, predicting the future behavior of dynamic systems - and is the wave equation used to solve wave functions.
For example, light, or electromagnetic radiation emitted or absorbed by atoms has only a certain frequency (or wavelength), as can be seen from the line spectrum associated with the chemical element represented by that atom. Quantum theory shows that these frequencies correspond to the definite energies of the light quanta, or photons, and the result of the fact that atomic atoms can only have certain permitted energy values; when an electron changes from one level to another, a quantum of energy is emitted or absorbed by a frequency that is directly proportional to the energy difference between two levels. The photoelectric effect further confirms the quantization of light.
In 1924, Louis de Broglie proposed that not only light waves sometimes exhibit particle-like properties, but particles can also exhibit properties like waves. Two different quantum mechanical formulations are presented following de Broglie's suggestion. Erwin SchrÃÆ'ödinger (1926) wave mechanics involves the use of mathematical entities, wave functions, which are related to the probability of finding particles at a particular point in space. The matrix matrix Werner Heisenberg (1925) does not mention a similar wave or concept function but is mathematically proved to be equivalent to Schrädinger's theory. A very important discovery of quantum theory is the principle of uncertainty, uttered by Heisenberg in 1927, which places an absolute theoretical limit on the accuracy of certain measurements; as a result, the assumption by previous scientists that the physical state of a system can be measured appropriately and used to predict future circumstances should be abandoned. Quantum mechanics is combined with the theory of relativity in the formulation of Paul Dirac. Other developments include quantum statistics, quantum electrodynamics, related to the interaction between charged particles and electromagnetic fields; and its generalization, quantum field theory.
Teori String
Also known as everything theory, this theory combines the theory of general relativity and quantum mechanics to create a single theory. This theory can predict about properties of small and large objects. This theory is currently under development.
Optics, and atomic, molecular, and optical physics
Optics are the study of light, and instruments are made to use or detect (ie telescopes, spectrometers, etc.). Atomic physics, molecular physics, and optical physics of each sub-field of AMO study the physical properties of atoms, molecules, and light.
Condensed matter physics
Study of the physical properties of matter in viscous phase.
High particle energy/physics and nuclear physics
Particle physics studies the nature of particles, while nuclear physics studies the nuclei of atoms.
Cosmology
Cosmology studies how the universe came into being, and its ultimate fate. This is studied by physicists and astrophysicists.
Interdisciplinary Field
Into the interdisciplinary field, which defines some of their own science, including for example
- astrophysics, physics in the universe, including the properties and interactions of celestial bodies in astronomy.
- biophysics, studying the physical interactions of biological processes.
- chemical physics, physical relations in chemistry.
- econophysics, dealing with physical processes and their relationships in economics.
- physics techniques, combined disciplines of physics and engineering.
- geophysics, the science of physical connection on our planet.
- mathematical physics, mathematics related to physical problems.
- medical physics, the application of physics for prevention, diagnosis, and treatment.
- physical chemistry, dealing with physical processes and their relationships in physical chemistry.
- quantum computing, the study of quantum mechanical calculation systems.
Summary
The table below lists the core theories along with the many concepts they use.
References
Source of the article : Wikipedia