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Energodynamic system of physical quantities and concepts(ESQC)To not mix with SI, unifying UNITS (explanation). |
On Main | J.Sh.Kogan
are essentially not compared concepts |
ABSTRACT: Detailed analysis of the distinction that must exist between the systems of physical quantities and the systems of units which in modern metrology does not exist. Offered a different definition of the term "system of physical quantities." Advantages and disadvantages of systems of physical quantities and systems of units deriving from this new definition. |
All readers that introduces described on this site Energodynamic system of physical quantities and concepts ESQC, immediately compare it mentally with the International System of Units SI, and their first question is "Why do we need ESQC, if you already have SI?".
The answer to this question is usually not listen to with the conviction that the answer lies in the question itself. But it is not.
In the International vocabulary of metrology JCGM 200:2012 given such a definition of system quantities: "set of quantities together with a set of noncontradictory equations relating those quantities". However, this definition is inaccurate, since a certain set in itself, even if the order does, not constitute a system (see the definition of the system).
In the same vocabulare given such a definition of system of units: "set of base units and derived units, together with their multiples and submultiples, defined in accordance with given rules, for a given system of quantities".
From these definitions it follows that system of units is based on a system of quantities in accordance with given rules for this system of quantities. Consequently, system of units should be a consequence of the accepted system of of quantities. Only in this today are different systems of units of systems of quantities. But the rules are established on the International metrological conferences and when adopting a set of base physical quantities dominated by considerations of practical metrology, when selected such base units that are easy to measure and create measurement standards. And they had already established a set of supposedly independent base quantities. So actually set of base quantities is the result of a set of base units, and not vice versa, as it should be in compliance with the principle of causality.
But there is another approach. It consists in the fact that the above definition of a system of physical quantities must be replaced with a definition: "the set of independent physical quantities, which a set corresponds to laws of nature, with a set of noncontradictory equations relating those quantities". The words "conforms to the laws of nature" radically change the situation. In place of a voluntary and a priory approach, comes strictly scientific approach, based on the latest achievements of physics. And the systems of physical quantities drawn up according to this new definition, no longer correspond to the systems of units based on the current definition.
To date ESQC is the only known system from the systems of physical quantities that tore contradicting to the principle of causality dependence of system of quantities from a priori accepted system of units. All other systems are known to the author are based on the base quantities of SI or CGS. And ESQC its own set of natural base physical quantities (basis of the system).
Therefore compare ESQC is reasonable only with the systems of physical quantities of other authors, and not with existing systems of units. This has been done in the the review devoted to the history of the problems of systematization of physical quantities.
A detailed response to all of the same question "Why do we need ESQC, if you already have SI?" or of a more specific question: "Why should collate the system of units with the systems of quantities?" shown in the table.
.
(below SPQ)
(below SUM)
these systems?
For systematization the physical laws representing the coupling equations between physical quantities.
For unification of units of mesurement an international scale.
from these
systems?
1. Establishment of the generalized laws iand on their basis of individual laws in various scientific directions.
2. Elimination of dissociation of different chapters of physics and various technical disciplines.
3.Simplification of process of teaching of physics and technical disciplines and process of mastering of a teaching material.
1. Maintenance of unity of measurements
2.Elimination of possible obstacles for dialogue of scientists and engineers of various directions.
3. Opportunity of light comparison of results of research experiments.
4. Simplification of trade in products and as consequence creation of conditions for growth of economy.
1. SPQ offers change of separate terms, symbols and indexes in SUM.
2. SPQ specifies desirability of updating of separate units in SUM.
SUM basically cannot influence on SPQ, but for psychological reasons stirs to its introduction in a science and pedagogics.
SPQ does not interfere with development of SUM, at them the different purposes and tasks.
SUM basically should not interfere with development of SPQ, but for the psychological reasons interferes.
Obligatory, dimension is a basis of the analysis of laws.
Usually applied to the dimension analysis.
Not obligatory, unless as a help material.
Obligatory, for their unification SUM also it is created.
Exist in the nature objectively, the task of a science in revealing them. The set of the base physical quantities in SPQ is not obliged to coincide with the set of base units in SUM.
The set of base units is accepted conditionally at the international conferences, meets the requirements of practical expediency and exists only on the Earth.
In SPQ in them there is no necessity.
Cornerstone in any process of measurement, therefore, in any SUM.
Strictly defined constructed on the basis of the principle of causality in the sequence, which follows from this principle.
Aprioristic, in different chapters of physics and in different technical disciplines depends on preferences of the composer of the list of quantities.
Dimension formula are defined only on the defining equation. Verbal formulations for definition of dimension are inadmissible.
Dimension formula are defined usually on the defining equations, but these equations not always submit to a principle of causality. Definition of dimension under verbal formulations is supposed.
1. SPQ can and even are obliged to predict new laws.
2. SPQ can and are obliged to correct the form of record of laws existing in a science.
The opportunity of a prediction of new laws in SUM is absent.
As one of the tasks of SPQ is not considered.
Determines the preference of application of this or that SUM.
Presence of SPQ, corresponding to the laws of nature, greatly facilitates the process of teaching.
As one of the tasks of SUM is not considered.
Presence of SPQ, corresponding to the laws of nature, contributes to successful research in any branch of physics.
Scientists seek to use in research that SUM, which best suits to a specific section of physics.
Historically, in connection with the development of the theory of electromagnetism physicists are introduced in sequence 9 (nine!) systems of units, and all the work of L.Bryansky (2002) of their listed 16 (sixteen!) systems of units, not including natural and non-metric systems. All this is due to the fact that science still does not know for certain that is an electric and gravitational charges and what their dimension. For this use the laws of Coulomb and Newton, in giving them the dimensional factors and wrongfully called these dimensional factors as fundamental constants. Entered them in different ways, hence there was a large number of systems of units.
It is easy to imagine torture of professionals (not to mention the students) who were forced to understand this conglomeration of systems of units to create a system of units SI. But the system SI, too many, and in many ways is not satisfied. Author of a popular textbook on physics D.Sivukhin (1979) points out that SI imposed by physicists from metrologists, that SI unnecessarily complicates the research and teaching of physics.
1.The measurement process is not the task of systematization of physical quantities. In system of units SI there is no sign of systematization of physical quantities.
2. In ESQC and SI different set of basic quantities. In SI there are 7 base units, but 4 of them can be easily reduced to units of base quantities ESQC. In SI as the base quantities taken derived quantities they accepted only on planet Earth (electric current, thermodynamic temperature, amount of substance, luminous intensity). When systematization of physical quantities such a priori unacceptable.
3. A set of basic quantities in ESQC unacceptable for the unification of units because it would create an measurement standard of energy. But by systematization of physical quantities problem of measurement standards does not occur. Moreover, the current trend of redefining of base quantities will lead to the introduction of the fundamental physical constants as the standard of energy (K.Tomilin, 2006).
4. In the tables ESQC all physical quantities are arranged in strict accordance with the principle of consistency. This principle requires that in the lists of of physical quantities derived quantities followed after those physical quantities that define them. And in all systems of units, including SI, this principle is not taken into account. All depends on the order of preference of the originator of the list. This indicates that SI does not meet the definition of "physical system".
5. The dimensions in ESQC set only by defining equations rather than verbal formulations. As wittily remarked R. Feynman (1965, Volume 1), "... from one definition nobody never nothing no deduced...". Governing equations in the ESQC sometimes do not match the verbal formulations or defining equations accepted in modern physics, and, accordingly, to SI.
6. In ESQC a dimension of one physical quantity can match of dimension of other physical quantity of the same kind, if they are similar the defining equations. In SI this principle is not always respected (for example, dimensions of energy and moment of force were the same). In the tables ESQC eliminated, if possible, the violations of the principle of causality in compiling of the defining equations, which take place in SI. In the construction of systems of units, according to N.Studentsov (1997), to "guided by a single principle - the practical expediency". When building a of systems of physical quantities practicality expediency be inferior in their significance to the principle of causality.
7. In ESQC the presence of units is not required. But if you write them down, then they sometimes do not look like in the SI, because the lists of basic physical quantities are different. And not just for that reason. In dimensions of electromagnetic quantities present a dimension of mass, and units should therefore be present unit kilogram. To avoid puzzling questions, physics assigned to units of electromagnetic quantities a named names (Weber, Tesla, Henry, Farad). And condemned to torment students and engineers when they need to move from one unit to another.
8. The majority of engineers and physicists in the dimensional analysis, in practice, do not produce the dimensional analysis, but the analysis of units SI. And this is understandable. For example, a unit of volume energy density in SI is J/m^{3}, and this unit looks natural and understandable. But dimension of the same volumetric energy density in SI is equal to ML^{-1}T^{-2}, which translates into units kg/(m·s^{2}). Although this is the same thing as J/m^{3}. This bifurcation of practitioners nothing but irritation can cause. In ESQC such situations cannot be in principle.
Author is aware of the feelings of those readers who are asked to give up the illusion that SI is the best and almost the only possible system of units. It's really good, but only for the purpose for which created. And nothing more.
1. JCGM 200:2012 International vocabulary of metrology – Basic and general concepts and associated terms (VIM). 3rd ed. 2008 version with minor corrections. URL: http://www.bipm.org/utils/common/documents/jcgm/JCGM_200_2012.pdf,
2.Брянский Л.Н., 2002, Непричесанная метрология. - М.: ПОТОК-ТЕСТ, 160 с. (Bryansky L.N., 2002, Not smooth out metrology. - Moscow: POTOK-TEST, 160 pp.)
3. Сивухин Д.В., 1979, О Международной системе физических величин. – “Успехи физических наук”, 129, вып. 2, с.с. 335-338. (Sivukhin D., 1979, On the International System of physical quantities. - "Advances of Physical Sciences", 129, No. 2, pp. 335-338.)
4. Студенцов Н.В., 1997, Системы единиц и фундаментальные константы. – “Измерительная техника“, 3, с.3 (Studentsov NV, 1997, Systems of units and fundamental constants. - "Measurement Techniques", 3, p.3 )
5. Томилин К.А. Фундаментальные физические постоянные в историческом и методологическом аспектах, – М.: Физматлит. 2006, 368 с. (Tomilin K.A., Fundamental physical constants in the historical and methodological aspects, - M.: Fizmatlit. 2006, 368 p.)
6. Feynman R., Leighton R., Sands M., 1965 - 1977, The Feynman Lectures on Physics, 9 volumes. M: "Mir".
Date of last updating 29.01.2014