Conservation laws are fundamental physical laws , according to which, under certain conditions, some measurable physical quantities that characterize a closed physical system do not change over time . They are the most general laws in any physical theory. They are of great heuristic value.
| Symmetry in Physics | ||
|---|---|---|
| Conversion | Relevant invariance | Appropriate law conservation |
| ↕ Broadcast time | Uniformity time | ... energy |
| ⊠ C , P , CP, and T symmetries | Isotropy time | ... parity |
| ↔ Broadcast space | Uniformity of space | ... momentum |
| ↺ Space rotation | Isotropy of space | ... of the moment momentum |
| ⇆ Lorentz group (boosts) | Relativity Lorentz covariance | ... movement center of mass |
| ~ Gauge Conversion | Gauge invariance | ... charge |
Content
Description
Some of the conservation laws are always satisfied under all conditions (for example, the laws of conservation of energy , momentum , angular momentum , electric charge ), or, in any case, processes that contradict these laws have never been observed. Other laws are only approximate and valid under certain conditions (for example, the parity conservation law is valid for strong and electromagnetic interactions , but is violated in weak interactions ).
- Law of energy conservation
- The law of conservation of momentum
- The law of conservation of angular momentum
- Mass conservation law
- The law of conservation of electric charge
- The law of conservation of lepton number
- The law of conservation of baryon number
- The law of conservation of parity
Conservation laws are related to the symmetries of physical systems ( Noether's theorem ). So, the laws of conservation of energy, momentum and angular momentum are consequences of spatio-temporal symmetries (respectively: time homogeneity , space homogeneity and isotropy ). Moreover, the listed properties of space and time in analytical mechanics are commonly understood as the invariance of the Lagrangian with respect to a change in the origin of the time, the transfer of the origin of the coordinate system, and the rotation of its coordinate axes.
Discovery of Laws
The philosophical prerequisites for the discovery of the law were laid down by ancient philosophers , in particular Parmenides [1] .
In particular, in a letter to Euler, Lomonosov formulates his “universal natural law” (July 5, 1748), repeating it in his dissertation “Reasoning on the hardness and liquid of bodies” (1760) [2] [3] :
| ... All changes occurring in nature are such an essence of a state that how many things will be taken away from one body, it will add up to another, so if a few matter disappears, it will multiply in another place ... This universal natural law extends to rules of movement, for a body moving by its own strength is different, loses the same amount of it from itself as it tells another that it receives movement from it [4]M.V. Lomonosov |
The philosophical significance of conservation laws
From the point of view of dialectical materialism , conservation laws show the indestructibility and indissolubility of moving matter with all its properties in the processes of its transition from one form to another. The motion of matter is eternal and only passes from one form to another [5] [6]
See also
- Continuity equation
Notes
- ↑ Encyclopedia
- ↑ Mikhail Vasilievich Lomonosov. Selected works in 2 volumes. M .: Science. 1986
- ↑ Figurovsky N. A. Essay on the general history of chemistry. From ancient times to the beginning of the XIX century. - M .: Nauka, 1969
- ↑ The Latin text of the letter refers to the preservation of movement - the Russian translation refers to the preservation of strength. In a letter, MV Lomonosov for the first time combines the laws of conservation of matter and motion in one formulation and calls this “universal natural law”.
- ↑ Moshchansky V.N. Formation of students' worldview in the study of physics. - M .: Education, 1976. - Circulation of 80,000 copies. - S.72 - 76
- ↑ Conservation laws. // Philosophical dictionary. - Ed. M. M. Rosenthal and P.F. Yudin . - M .: Politizdat, 1963. - Circulation 400,000 copies. - S. 418 - 419
Literature
- Vizgin V.P. Development of the relationship of the principles of invariance with conservation laws in classical physics. M .: Nauka, 1972.240 s.