The theory of relativity is a physical theory of space-time , that is, a theory that describes the universal space-time properties of physical processes [1] . The term was introduced in 1906 by Max Planck to emphasize the role of the principle of relativity in the special theory of relativity (and, later, the general theory of relativity ). Sometimes it is used as an equivalent of the concept of “relativistic physics” [approx. 1] .
In a broad sense, the theory of relativity includes the special and general theory of relativity. Special Theory of Relativity (SRT) refers to the processes in the study of which the fields of neglect can be neglected; general theory of relativity (GTR) - the theory of Newtonian [1] . In the narrow sense, the theory of relativity is called the special theory of relativity.
In the history of physics, the term relativity is sometimes used to distinguish the views of Einstein, Minkowski and their followers, who reject the concept of the luminiferous ether , from the views of some of their predecessors, such as Lorenz and Poincaré [2] .
Differences of STR from Newtonian mechanics
For the first time a new theory has pressed the 200-year-old mechanics of Newton . This radically changed the perception of the world. The classical mechanics of Newton turned out to be true only in terrestrial conditions and close to them: at speeds much lower than the speed of light and sizes far exceeding the size of atoms and molecules and at distances or conditions when the propagation speed of gravity can be considered infinite.
Newtonian notions of motion were radically corrected by means of a new, rather deep application of the principle of motion relativity . Time was no longer absolute (and, starting from GR , even time).
Moreover, Einstein changed the fundamental views on time and space. According to the theory of relativity, time should be perceived as an almost equal component (coordinate) of space-time , which can participate in coordinate transformations when the reference system changes along with ordinary spatial coordinates, just as all three spatial coordinates are transformed when the axes of the usual three-dimensional coordinate system rotate .
Area of Applicability
Service area STO
The special theory of relativity is applicable to the study of the motion of bodies at any speeds (including those close to or equal to the speed of light) provided that there are no very strong gravitational fields.
The scope of the GRT
The general theory of relativity is applicable to the study of the motion of bodies at any speeds in gravitational fields of any intensity, if quantum effects can be neglected.
Application
Application STO
The special theory of relativity has been used in physics and astronomy since the 20th century. The theory of relativity has greatly expanded the understanding of physics as a whole, as well as significantly deepened knowledge in the field of elementary particle physics , giving a powerful impetus and serious new theoretical tools for the development of physics, the significance of which is difficult to overestimate.
UTO application
Using this theory, cosmology and astrophysics have been able to predict such unusual phenomena as neutron stars , black holes, and gravitational waves .
Adoption by the scientific community
Adoption of the STO
Currently, the special theory of relativity is generally accepted in the scientific community and forms the basis of modern physics. [3] Some of the leading physicists immediately adopted a new theory, among them Max Planck , Hendrik Lorenz , Hermann Minkowski , Richard Tolman , Erwin Schrödinger and others. In Russia, edited by Orest Danilovich Khvolson , a famous course in general physics was published, which detailed the special theory of relativity and a description of the experimental foundations of the theory. At the same time, the Nobel laureates Philippe Lenard [4] , J. Stark , and J. J. Thomson expressed a critical attitude towards the theories of the theory of relativity; a discussion with Max Abraham and other scientists turned out to be useful.
Adoption of the UTO
A constructive discussion of the fundamental issues of the general theory of relativity ( Schrödinger , etc.) was particularly productive, in fact this discussion is still ongoing.
The general theory of relativity (GTR) has been experimentally tested to a lesser extent than SRT, contains several fundamental problems , and it is known that while some of the alternative theories of gravity are admissible in principle, most of which, it is true, can be considered in one way or another just a modification GRT. However, unlike many of the alternative theories, in the opinion of the scientific community, in its field of applicability, GR complies with all known experimental facts, including those recently discovered (for example, another possible confirmation was recently found for the existence of gravitational waves [ 5] [6] ). In general, GR in its field of applicability is a “standard theory,” that is, recognized by the scientific community as the main one. [3]
Special Relativity
Special theory of relativity [7] (STR) - the theory of the local structure of space-time . It was first introduced in 1905 by Albert Einstein in his work “On the Electrodynamics of Moving Bodies”. The theory describes the movement, the laws of mechanics , as well as the space-time relations that determine them, at any speeds of movement, including those close to the speed of light . Newton's classical mechanics in the framework of the special theory of relativity is an approximation for low velocities. SRT can be used where you can enter inertial reference systems (at least locally); it is not applicable for cases of strong gravitational fields, essentially non-inertial reference systems, and when describing the global geometry of the Universe (except for the special case of the flat empty stationary Universe).
The special theory of relativity emerged as a resolution of the contradiction between classical electrodynamics (including optics) and the classical Galilean principle of relativity . The latter asserts that all processes in inertial reference systems proceed in the same way, regardless of whether the system is stationary or in a state of uniform and rectilinear motion. This means, in particular, that any mechanical experiments in a closed system will not allow bodies without external observation to determine how it moves, if its motion is uniform and straightforward. However, optical experiments (for example, measuring the speed of light propagation in different directions ) inside the system would in principle have to detect such movement. Einstein extended the principle of relativity to electrodynamic phenomena, which, firstly, made it possible to describe almost the entire range of physical phenomena from a unified position, and secondly, allowed to explain the results of the Michelson-Morley experiment (in which no influence of the earth’s quasi-inertial motion was detected on the speed of light propagation). The principle of relativity was the first postulate of the new theory. However, a consistent description of physical phenomena within the framework of the extended principle of relativity became possible only at the cost of abandoning Newton's absolute Euclidean space and absolute time and combining them into a new geometric construct - pseudo-Euclidean space-time , in which the distances and time intervals between events are transformed in a certain way (by means of Lorentz ) depending on the frame of reference from which they are observed. This required the introduction of an additional principle - the postulate of the invariance of the speed of light . Thus, the special theory of relativity is based on two postulates:
1. All physical processes in inertial reference systems proceed in the same way, regardless of whether the system is stationary or it is in a state of uniform and rectilinear motion.
2. The speed of light in vacuum, measured in any inertial reference frame, is the same and does not depend on the movement of the radiator.
The consequence of the second principle (and the general scientific principle of causality ) is the impossibility of the movement of physical bodies and the transmission of information at a speed exceeding the speed of light in a vacuum.
When moving at speeds that are small compared to the speed of light, the kinematics of the SRT is indistinguishable from Newtonian kinematics, and the Lorentz transformations pass into the classical Galilean transformations . Formally, in the limit of the infinite speed of light, formulas of the special theory of relativity transform into formulas of classical mechanics.
General Relativity
The general theory of relativity is the theory of gravity, published by Einstein in 1915-1916 . It is a further development of the special theory of relativity . In the general theory of relativity, it is postulated that gravitational effects are not caused by the force interaction of bodies and fields , but by the deformation of the space-time itself, in which they are located. This deformation is associated, in particular, with the presence of mass-energy.
The general theory of relativity differs from other metric theories of the use of Einstein's equations to relate the curvature of space-time with the matter present in it.
GRT is currently the most successful theory of gravity, well confirmed by observations.
Notes
- Comments
- ↑ Relativistic physics is a branch of physics that studies phenomena occurring during movements with speeds comparable to the speed of light. Under these conditions, the motion is described according to the theory of relativity.
- Sources
- ↑ 1 2 Relativity Theory // Physical Encyclopedia (in 5 volumes) / Edited by Acad. A. M. Prokhorov . - M .: Soviet Encyclopedia , 1992. - T. 3. - p. 493-494. - ISBN 5-85270-034-7 .
- ↑ Suvorov S. G. Einstein: The Formation of the Theory of Relativity and Some Gnoseological Lessons // Uspekhi Fiz. - M., 1979. - T. 128 (July). - Number 3.
- ↑ 1 2 Clifford M. Will. The Confrontation between General Relativity and Experiment Living Rev. Relativity 9, (2006), 3.
- ↑ Philippe Lenard ABOUT THE PRINCIPLE OF RELATIVITY, AIR, TENDERATION Archival copy of July 18, 2013 on the Wayback Machine
- ↑ Space-Warping White Dwarfs Produce Gravitational Waves
- ↑ Press release on the RosInvest website. (inaccessible link) . The date of circulation is September 16, 2012. Archived September 27, 2007.
- ↑ Sometimes the name private theory of relativity is used .
Links
- What is the theory of relativity. - A short popular science film about the theory of relativity. USSR 1964.