Get 130-2019: State Primary Special Standard of Unit of Length in Region of Measurements of Deviations from Straightness and Flatness

Author(s):  
Yu. R. Shimolin ◽  
L. A. Tribushevskaya ◽  
A. S. Seregina
2021 ◽  
Vol 310 ◽  
pp. 01001
Author(s):  
Irina Novikova ◽  
Denis Sokolov

The article presents the results of an experimental study of coaxial and orthogonal methods for comparing laser measuring interferometric systems using a standard measuring complex of length from the State Primary Special Standard of a Unit of Length in the range from 2 to 60 m. transmission errors of the unit of length up to 0.5 microns.


Metrologia ◽  
1991 ◽  
Vol 28 (1) ◽  
pp. 51-53
Author(s):  
V N Gorobei ◽  
T S Dzagurova ◽  
S M Kesselman ◽  
V N Rusinova ◽  
L A Shildkret

Antiquity ◽  
1966 ◽  
Vol 40 (158) ◽  
pp. 121-128 ◽  
Author(s):  
Alexander Thom

It is becoming apparent that megalithic man possessed and used a considerable knowledge of geometry. As more of his constructions are unravelled, we obtain an increasing appreciation of his attainments. Undoubtedly he also observed the heavenly bodies and used them to tell the time of day or night and to tell the day of the year. To take geometry first, let us look at the various shapes which, in his hands, a ring of stone could take. To understand these rings fully it is necessary to appreciate that he used extensively a very precise unit of length—the megalithic yard (MY). The exact length of this unit has become known to us by an examination of simple circles and flattened circles. When the author produced the first batch of circle diameters there was no universally accepted statistical analysis for the determination of the reliability of a quantum such as the suggested value for the megalithic yard. Then Broadbent produced two papers providing exactly the methods required to find, from a set of measurements, the most probable value of the quantum and the probability level at which it could be accepted [1,2]. This last is very important because Hammersley had shown that almost any random set of (say) diameters will yield an apparent unit of some sort.


1994 ◽  
Vol 60 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Andrew B. Powell

The Newgrange passage tomb is examined for evidence of ‘Neolithic science’. Claims that it incorporated an astronomical alignment, and was constructed using Pythagorean geometry and the megalithic yard are reviewed as are scientific interpretations of its art. A new analysis of the tomb's structure reveals that it was based on a simple geometric shape measurable by a 13.1 m unit of length. The locations of particular motifs and decorated surfaces are shown to conform to the spatial relationships evident in the tomb's form. These are defined in terms of oppositions between left and right, front and back, inside and outside, visible and hidden, as well as making reference to symbols found in the art of the neighbouring passage tomb at Knowth.These features are interpreted, not as evidence of a specificically scientific discourse in the Irish Neolithic, but as the elaboration of elements common to the passage tomb ritual discourse. Competition for political control, in the context of mortuary practices, resulted in the increasing formalization and rigid interpretation of passage tomb symbolizm, and the ritualization of new areas of knowledge.


Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 282-282

The fundamental unit of the metric system is the METER (the unit of length) from which the units of mass (GRAM) and capacity (LITER) are derived; all other units are the decimal subdivisions or multiples thereof. These three units are simply related, so that for all practical purposes the volume of one kilogram of water (one liter) is equal to one cubic decimeter.


Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 409-409

The fundamental unit of the metric system is the METER (the unit of length) from which the units of mass (GRAM) and capacity (LITER) are derived; all other units are the decimal subdivisions or multiples thereof. These three units are simply related, so that for all practical purposes the volume of one kilogram of water (one liter) is equal to one cubic decimeter.


1995 ◽  
Vol 10 ◽  
pp. 201-201
Author(s):  
N. Capitaine ◽  
B. Guinot

In 1991, IAU Resolution A4 introduced General Relativity as the theoretical background for defining celestial space-time reference sytems. It is now essential that units and constants used in dynamical astronomy be defined in the same framework, at least in a manner which is compatible with the minimum degree of approximation of the metrics given in Resolution A4.This resolution states that astronomical constants and quantities should be expressed in SI units, but does not consider the use of astronomical units. We should first evaluate the usefulness of maintaining the system of astronomical units. If this system is kept, it must be defined in the spirit of Resolution A4. According to Huang T.-Y., Han C.-H., Yi Z.-H., Xu B.-X. (What is the astronomical unit of length?, to be published in Asttron. Astrophys.), the astronomical units for time and length are units for proper quantities and are therefore proper quantities. We fully concur with this point of view. Astronomical units are used to establish the system of graduation of coordinates which appear in ephemerides: the graduation units are not, properly speaking astronomical units. Astronomical constants, expressed in SI or astronomical units, are also proper quantities.


1860 ◽  
Vol 10 ◽  
pp. 415-426 ◽  

Scalar Plane Geometry .— With O as a centre describe a circle with a radius equal to the unit of length. Let OA, OB be any two of its unit radii, termed ‘coordinate axes.’ From any point P in the plane AOB draw PM parallel to BO, so as to cut OA, produced either way if necessary, in M. Then there will exist some ‘scalars’ (‘real’ or ‘possible quantities’) u, v such that OM = u . OA, and Mp = v . OB, all lines being considered in respect both to magnitude and direction. Hence OP, which is the ‘appense’ or ‘geometrical sum’ of OM and MP, or = OM + MP, will = u . OA + v . OB. By varying the values of the 'coordinate scalars’ u, v P may be made to assume any position whatever on the plane of AOB. The angle AOB may be taken at pleasure, but greater symmetry is secured by choosing OI and OJ as coordinate axes, where IOJ is a right angle described in the right-handed direction. If any number of lines OP, OQ, OR, &c., be thus represented, the lengths of the lines PQ, QR, &c., and the sines and cosines of the angles IOP, POQ, QOR, &c., can be immediately furnished in terms of the unit of length and the coordinate scalars. If OP = x . OI + y . OJ, and any relation be assigned between the values of x and y , such as y = fx or ϕ ( x, y ) = 0 , then the possible positions of P are limited to those in which for any scalar value of x there exists a corresponding scalar value of y . The ensemble of all such positions of P constitutes the ‘ locus ’ of the two equations, viz. the ‘concrete equation’ OP = x . Ol + y .OJ, and the ‘abstract equation’ y = f. x. The peculiarity of the present theory consists in the recognition of these two equations to a curve, of which the ordinary theory only furnishes the latter, and inefficiently replaces the former by some convention respecting the use of the letters, whereby the coordinates themselves are not made a part of the calculation.


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