Gravity - general theory of relativity
The equivalence of acceleration and gravity: the ball in the accelerating inertia racket falls in the same way as the load on the surface of the Earth.
In general relativity (OTR), gravity is explained by the curvature of space-time. This curvature is created by the presence of matter and energy and is manifested, for example, in the fact that the sum of the angles in a triangle does not necessarily have to be 180 °, or in the fact that locally the straightest lines are geodesics are not always "straight". The movement of bodies in the gravitational field occurs according to geodesics, so that their inclination to the time axis indicates the velocity of the body. In popular literature, geodesy is often referred to as the shortest link, but this is not always the case. For weak gravitational fields, OTR makes the same predictions as Newton's theory of gravity.
The idea of a curved space often gives the impression that a curved space is embedded in a multidimensional flat space. However, the mathematical description of OTR does not require such an insertion. The properties of space-time are determined by defining a metric tensor at each of its points and thus defining the so-called metric field. A metric tensor is a set of ten dimensionless geometric quantities that define a metric in a given space, i.e., the way in which generalized distances -intervals - between points in spacetime -events are calculated in a given part of space. Differential geometry deals with the study of metric spaces, which makes it possible to characterize the curvature of a given space using substitutions of the metric tensor.
Based on the assumption of the equality of inert and gravitational mass, Einstein managed to combine the curvature of space-time with the presence of energy (as well as matter) using Einstein's equations (ER). By solving Einstein's equations, metric tensors are obtained at individual points that determine the curvature of space-time.
Some qualitatively new phenomena arise from the REL. One of them is the presence of propagation of changes in the gravitational field - gravitational waves moving at the speed of light . Gravitational waves are emitted, for example, by pairs of bodies orbiting each other. There are at least two devices for detecting them.: American LIGO and Italian VIRGO . Both had already detected the gravitational waves. Manifestations of gravitational wave radiation are also measured in binary star systems. The most famous space laboratory is the double pulsar PSR 1913 + 16, in which a shortening of the orbital period was measured.by 7.6 10.5 seconds per year , which is very closely in line with the OTR forecast.
Another completely new phenomenon is the existence of event horizons, that is, areas that can only be crossed in one direction, and there is no known physical mechanism that would allow information to be received from the other side. This includes the existence of black holes and cosmological event horizons.
The general theory of relativity also predicts the curvature of the trajectories of light rays , leading to the formation of gravitational lenses. This is a well-known phenomenon that manifests itself both on the scale of individual stars and on the scale of clusters and superclusters of galaxies. They are used in many observations, including to detect the presence of dark matter.
For weak gravitational fields, OTR proceeds to predictions consistent with Newton's theory of gravity. One of the most famous corrections to Newton's theory is the twisting of the perihelion of planetary orbits, which was one of the unexplained phenomena, the elucidation of which is one of the main achievements of OTR. The twisting is most evident on planets located closer to the central body, so the twisting of Mercury's orbit is best observed in the Solar System. LiraSpin Casino
In general relativity (OTR), gravity is explained by the curvature of space-time. This curvature is created by the presence of matter and energy and is manifested, for example, in the fact that the sum of the angles in a triangle does not necessarily have to be 180 °, or in the fact that locally the straightest lines are geodesics are not always "straight". The movement of bodies in the gravitational field occurs according to geodesics, so that their inclination to the time axis indicates the velocity of the body. In popular literature, geodesy is often referred to as the shortest link, but this is not always the case. For weak gravitational fields, OTR makes the same predictions as Newton's theory of gravity.
The idea of a curved space often gives the impression that a curved space is embedded in a multidimensional flat space. However, the mathematical description of OTR does not require such an insertion. The properties of space-time are determined by defining a metric tensor at each of its points and thus defining the so-called metric field. A metric tensor is a set of ten dimensionless geometric quantities that define a metric in a given space, i.e., the way in which generalized distances -intervals - between points in spacetime -events are calculated in a given part of space. Differential geometry deals with the study of metric spaces, which makes it possible to characterize the curvature of a given space using substitutions of the metric tensor.
Based on the assumption of the equality of inert and gravitational mass, Einstein managed to combine the curvature of space-time with the presence of energy (as well as matter) using Einstein's equations (ER). By solving Einstein's equations, metric tensors are obtained at individual points that determine the curvature of space-time.
Some qualitatively new phenomena arise from the REL. One of them is the presence of propagation of changes in the gravitational field - gravitational waves moving at the speed of light . Gravitational waves are emitted, for example, by pairs of bodies orbiting each other. There are at least two devices for detecting them.: American LIGO and Italian VIRGO . Both had already detected the gravitational waves. Manifestations of gravitational wave radiation are also measured in binary star systems. The most famous space laboratory is the double pulsar PSR 1913 + 16, in which a shortening of the orbital period was measured.by 7.6 10.5 seconds per year , which is very closely in line with the OTR forecast.
Another completely new phenomenon is the existence of event horizons, that is, areas that can only be crossed in one direction, and there is no known physical mechanism that would allow information to be received from the other side. This includes the existence of black holes and cosmological event horizons.
The general theory of relativity also predicts the curvature of the trajectories of light rays , leading to the formation of gravitational lenses. This is a well-known phenomenon that manifests itself both on the scale of individual stars and on the scale of clusters and superclusters of galaxies. They are used in many observations, including to detect the presence of dark matter.
For weak gravitational fields, OTR proceeds to predictions consistent with Newton's theory of gravity. One of the most famous corrections to Newton's theory is the twisting of the perihelion of planetary orbits, which was one of the unexplained phenomena, the elucidation of which is one of the main achievements of OTR. The twisting is most evident on planets located closer to the central body, so the twisting of Mercury's orbit is best observed in the Solar System. LiraSpin Casino
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