Philosophy Dictionary of ArgumentsHome
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| Conservation laws: Conservation laws in physics are principles that state that certain physical quantities do not change in an isolated system. Some of the most important conservation laws in physics are the conservation of energy, mass, momentum, and angular momentum._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. | |||
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Bernulf Kanitscheider on Conservation Laws - Dictionary of Arguments
I 204 Conservation of energy/RT/Kanitscheider: the abstract mathematical reason for the non-conservation of energy in General Relativity (GR) is geometrical. For all matter fields there is a tensor Tμν describing their energy content and this satisfies a local conservation-like condition Tμν iv= 0. However, in order to pass from the local conservation statement for energy and momentum to a statement about the finite domain, the structure of spacetime must be such that its metric admits the existence of a symmetry vector. Only in case of symmetry an integration of the local spacetime can be performed. Then and only then one can claim that the flux of energy and momentum vanishes over the edge of a closed surface. Spacetime/SR/GR/Kanitscheider: This is certainly the case in the flat spacetime of SR, which admits a 10-parameter group of isometries. (inhomogeneous Lorentz group), but not in an arbitrary spacetime of AR, where the curvature can be of manifold type. >Universe/Kanitscheider, cf. >Cosmological principle, >Energy, >Relativity theory. I 205 Conservation of energy/FRW worlds/Kanitscheider: (8) Analogue to the energy theorem of thermodynamics: (8') d(ρR³) + pdR³ = 0 Due to the pressure term, the energy density ρ changes in every comobile element of the cosmic liquid, it decreases with expansion and increases with contraction. Since ρR³ is also to be called mass, one can also speak of matter annihilation and matter creation! As the stars continue to radiate, the radiation pressure p continues to increase. In the contracting elements of the comobile volume dV the energy density is higher than in those of the expanding phase. Here it is important to realize that the nonconservation of energy is connected with the homogeneity and boundlessness of the universe. Namely, the photons and matter particles exert a pressure on the edge that triggers a redshift and slowing of motion. If the space were a cylinder, one could imagine that this pressure does a work, like the pressure on a piston. I 206 In homogeneous space-time, where each representative volume is followed by another, none of these volumes can be the winner of the energy loss of another. For it too must lose energy as a result of the pressure exerted on its imaginary boundary walls. . In the case of the steam engine, a real inhomogeneity is introduced by the wall. Thus one sees that in the special situation of cosmology even the conservation of energy becomes inapplicable._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition. |
Kanitsch I B. Kanitscheider Kosmologie Stuttgart 1991 Kanitsch II B. Kanitscheider Im Innern der Natur Darmstadt 1996 |
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> Counter arguments against Kanitscheider
> Counter arguments in relation to Conservation Laws
Ed. Martin Schulz, access date 2024-04-27