See	discussions,	stats,	and	author	profiles	for	this	publication	at:	https://www.researchgate.net/publication/303862772 About	the	Nature	of	Gravitational	Constant	and a	Rational	Metric	System. Working	Paper	*	September	2002 DOI:	10.13140/RG.2.1.1992.9205 1	author: Andrew	Wutke Thales	Group 6	PUBLICATIONS 1	CITATION SEE	PROFILE Available	from:	Andrew	Wutke Retrieved	on:	04	July	2016 DRAF"T About The Nature of G6pffi Constant and Rational Metric SYstem Andrew Wutke SYdneY Australia email andreww @ optus hame. c om. au 15 september,2002 "We are to adtnit no natural things that such and sufficient to appearance*" INewon] mare causes of as are both true explain their Abstract The gravitational constant G has been a sutrject of interest for more than two centuries. Precise measurements indicate #bqual to 6'673(I0)xl0'r m3i1tg s21 with relative standard uncertainty of 1.5x10-3[U. The need fcrr such constant is discussed. Various s)6tem of units of measure have emerged since Newton, and none of them is both piaaical, and usefid in thesetical rqsearch. The relevance ofa metric system that only Las length and time as base units is analysed and such system proposed. As a rssult much highm clarity of physical quantitie.s is achieved. Grmi$d;onstant and electric constant can be eliminated to become nondimensional, that results in elimination of kilogram of mass and Coulomb 9f charge in fuvour of the sarre composite unit for both physical quantities being m3/s2. The system offers a great advantage to General Relativity where only space-time units can be used. Keywords Gravitational Constant, units of measure. 1 lntroduction The gravitational constant G is a proportionality factor in Newton's inverse square law of gravitation for a point mass: lrl=c Y+'r The obvious way to determine this constant is to perform a direct measurement of an attraction force between two tnasses. This has been accomplished by Cavendish [2], resuhing in determination of the rnass of the Earth, Sun and subsequently all celestial bodies in the solar systefiL According to Newton: DRAFT "The qualities of bodies which admit neither intension nor remission of degrees, and which are found to belong to alt bodies within the reach of our experiments, are to be esteemed the universat quatities of all bodies whatsoever"f3l' This then supports the declaration ofthe gravitational constant G as the universal constant a physical propefiy characterising gravitational phenomena. lt is unclear whether G can tre referred as a property of anything. Fundamental physical constants tend to be seen that way. Their nafiES often make it clearTo mention a few we have: a. speed of light in vacuunq b. elementarY charge c. electron rest mass Other constants bear names of famous physicists rather describing their nature such as: Bohr radius, Thomson cross section, Planck length, Compton wave length. ln between there exists Newtonian Constant of GravitationThe constant that Newton himself never found a pafiicular leason to be identified. Earth mass taken aslunit plus astronomical observations are good enough to roughly describe the motion of celestial bodies in our solar system. A typical description of the Newtonian constant found in textbooks, is by reference to its numerical value equal toiforce between two unit rnasses separated by unit distance' This description is hardly revealingForce and inertiaUgravitational rnass are somehow circularly dependent, and force is a complex concept. So G appears to be a property within a system of at least two material bodies under mutual gravitational interactionBy analogy to dielectric constant clearly expressing varying electrical properties of matter on" -uy *uyffioes represent a property of some kind. One can certainly say G makes force equations balance, also its value allows to compare the mass of the Earth with an arbitrary defined unit mass of kilogram. The quest of finding more accurate value of G continuls to thit, date and no widely acclaimed theory derives its value from any other physical coost-$ and the nature of it is often referred to as mysterious. Einstein's General Theory of Relativity (GR) explores gravitation in depttt, but it neither predicts nor in fact eliminates the gravity constant, seemingly present in one of the constants necessary to give real world solutions as in formula: ab. d. DRAFT Nuurerous speculatioas exist as wtpther G is really comtaal A number of researcbs still find differing values of G, which is quite surprising given the increasing precisirrn of measuring equipment and development of more refined experiments. This fact has been reflected try an uausual decisiron of CODATA to degrade the relative uncertainty of the official value of G. On th diagram presented below, researchers from Unirersity of Zurich [4] show a number of rneasurements, tolerances and CODATA standarised values. . I COFATA ?fl0$ r.+ r rnr"ru'ury 1998 . . .qrurer 1998 1 | Richmirn et al. 199fi ' ' ' S*ltrnarr et irll99tl 'r' Luc et al- | 99ll ' '' ' ,Kleinevnrsetall99lliri FitrPerflldet al199fi '+l'itz$erald el al. l99s '' Lutheretal, 1997 * Klragiazct al. 1996 : + ltu'atcsch ct tl. t99-t b{ichaclis ct al, 1995 I' ,*' Fiugcratd rt al, 1995 r Cclrfl$r. rt ill, 199-1 i. iCODATA 1986 6.66 6,6? 6"68 6,69 6,? | 6,7: G lt$'ll *lks'tr'll The gravitatbnal constaat as defired in the retrb system (SI) is not suitable for astronomical applications according to Fitzpatrictslt G is better expressed in astronomical units where: The unit sf mass is that of the Sun deaoted as M=I, The unit of distance is Earth's mean distance to the Sun denoted re, a=7 andl The unit of time is one day and the mean period of Earth rotation about the Sun denoted as P. For such defined units: 8ffiK= ,c 6,? DRAF'T 4n'at 4ts2o =ffi = s6s;a* lau' m,idav-' 1 Thus G is nurnerically equal to the mean angular velocity of the Earth in days, therefore somehow related to inverse square of yearly rotation period: " 4*fito-= T, Needless to say that the accuracy of G is the functircn of accuracy of time measurenrent (provided that the variation of mass of the Sun can be neglected)' The contemporary science seems to have agreed on universality-glg#d more common 's to find new measuring techgiffi# hypotheses of its variable ffiffi.'?hen attempts to find a suitable explanation of itsffiglu n__ :r^_^_ -il. Some researches openly raiST[e issue cf its irelevance. For instance Siepmffi6] says: ,,It is readity apparent thnt the current gravitational constant is not a tangiUi)'pnysicat concept as demonstrated by its units of measure which are cul"rently wandatory for the taw if universal gravitation n yield the correct unitt for force. It is a constnnt thnt grossly works in most instances but yet we have rut understanding of whyThis is because we have had an erroneous understanding of gravity'" This author's claim is based on theory referred as "Laws of Space and Observatiorf' and in particular the "Space Constant Equation". Enough to say, it is an altemative concept of space and time on which I am not in a position to comment' ti the claim of physical irrelevance of G was true, then it is believed one can explain the current value of G within the realrn of classical physics' ln his work [7lt8l Guy Myhre demonstrates how numerical values of universal constants obscwe rather than clarify the laws of physicsIn [8] he writes: ,,It seems to mecut that these const{mts have existed since time bega4 since th'e universe was born tens of bitlions of years ago. Are they fundamental? Are they universal? Are they physical? Are thzy constant? Do they exist in nature? Thz answer to all of these quirion, is NOSo, what are thcse important-sounding things, anyway? Well, they are i;mpty inventi.ons thnt were necessary to make quanrum-based equatinns worlc"when ^riril, units of measure were used (and they always were)[...J As a rule of thumb, if the constant possesses multipte units of mcasure (dimensions), it is not a fundammtal physical constantOne exception is the speed of light"'" Myhre shows in U1, that it is possible to establish a rational system of units that ahllost ,"od"r, all fundamental constant void. He uses a hypothetical particle "masstron" to make his system of units closedMyhre's work whether controversial or not, makes strong points and it was a significant stimulus to conduct investigations described in this workDRAFT Numerous system of units has been proposed since Newton, such as those originated ftom planck or Gauss. And it appears to be a rule that the unit of masslcharge stay as fundamental, irreducible and only scaling is exercisei to gain convenient magnitudes of physical quantities for various reasons. Consistent with the motto presented at the beginning, this work favours the method of simplification of existing concepts rather complicating them relaying on new theories and hypothetical entities. By no means however this statement atteryts to invalidate such theories and approaches. llt #,H 2 The Significance of Metric System Units. The effect of units of measure selection to the values of physical constants is beyond discussion. The foundation of the metric system was a remarkable achievement preceded by centuries long build-up of human knowledge, then an organisational and intellectual effort to put it in action. The group of people involved in this process included famous figures ru"h u" Laplace, Cassini, Talleyrand, to mention a few. Resulting from this effort was the definition of meter, kilogram and second. The serond was arbitrarily defined using period of rotaiion of the Earth on its axis as 1/86400 of a mean solar day. This is an arbitrary interval, the fraction of ll(2*12*60x60), convenient enough to design the face of an ordinary clock. More difEcult issue is how to calibrate a reference device and how to determine the exact moments the Earth starts and completes its cycle. That task was left to astronomers. Following the discovery of Earth ,ot"tion irregularities and new designs of precise clocks, the second had to be re-defined, yet its first concept based original magnitude has been accurately preserved. The current definition of the second is based on Cs133 electron transitions between selected hyperfine energy levels (9, 192,631,7 7 0 cycles). The arbitrary nature of 1 second interval is obvious. There is no known law indicating Earth rotation period to be of universal significance. lt must have treen the result of the state of its composition and surrounding matter at the time of formationNeither earthb mass nor energy content are believed the have some necessary magnitude. The selection of the unit of meter was not that arbitrary' The fust widely known prototype of meter according to Bureau lnternational des Poids et Mesuresis was: .1110 000 000 of the Northem quadrant of the Paris meridian(1 August t793)-" This however was not the first notion of meter's physical magnitude. lt is reported that in 1671, Picard suggested a unit of length based on a pendulum, replicating period of I second. DRAF*T description of motion one can select an interval of any regular cyclic process as a unit and any reference length and should be able to verify basic equations of motion' The idea of the metric systern went beyond simple kinematics as all physics now can be described in the minimum set of units, predominantly length mass and time' As we know, time and length unit closely reliate to the same physical object, that is the Earth. Forgetting the pendulum for the time being, once second is accepted, and the fraction of ihe meridian defined to be the unit of length, one can say without rnaking a big mistake (assuming the Earth is spherical) that it is not necessary to measure such quantities as: a. Earth diameter, circumference, surface and volume, b. Earth tangential rotational speed at the equator and anywhere else, c. Earth angular velocity and angular acceleration 1n 11le idgalistic scenario (spherical Earth) these quantities can be derived ftom geometry, sirnple kinematics and just adopted definition of metric units. It is an important, nontrivial, but a separate problem of how to physically realise such defired reference devices. Until then one can enjoy the metric system by roughly calculating a distance to the Sun in meters by measuring angles to the Sun at noon the same day, from two different latitudes without even knowing how long that meter really is. This task is impossible to accomplish for the unit of foot (well known length) without actually measuring the Earth fnst' Due to the fact that standard meter is nicely correlated with the period of one meter pendulunl that is: the experimentally determined length of the string producing 1 second iralf-period is 'bxactly''equal to the unit length, we may conclude (in the idealistic scenario) that the gruuity acceleration g has been defined as n2 (rather than measured) at certain distance from the Earth centre. From there, it is only one step to approximate G*M from Newton equation: . g=y52 trr/stl defined coincidently with calibration of the pendulum- . R=4*10000000/(2*nxml defined but also correlated with pendulum. . G=?[m3/kg st1 * uokno*no f{=?[kg] unknown' From this we have: , 4000a0cn' GM =Rrg=T.ft2 =4xl|rs from WGS84 sources t10l is GM=-39860009x10's which is inThe best value available error of 0.35L2Vo. DRAFT One thing should be made clear. This is not a suggestion that one can ignore measurements as the ultimate source of usable physical data, but we want to separate concems of experimental techniques used to verify theories from the theories themselvesThe examples above show that abstract concepts can be qualitatively pursued with the minimum of essential approximate measurements. In many cases theories come earlier than their measured confirmation. A theory is rnore convincing if experinrcnts confirm its predictions, than that fitted to akeady known experimental factsSuch remarkable event has occurred for Maxwell equations that Fedicted electromagnetic waves and their propagation speed. 3 The Relevance of G' The short answer to the questicn whether the gravity constant is relevant is yes' More difficult is to define the nature and the domain of relevance. The following analysis will deliberately be performed in accordance with classical physics' Any two measurable properties whether mutually dependent or not, can be related by an observer through the act of observation. Each property if changes in time, can be plotted one versus another and will result as an instance of experimentally established functionThis function may then be represented mathematically. By the fact of existence of functional dependency one cannot derive a conclusion about physical dependency of the two quantities. [f however under some experimental conditions one property can be activeiy changed and it is followed by a correlated response of another, there is a strong evidence of existing dependency. If the two measurable quantities are dependent yet they are of quite different nature, there will be some physical constants involved to make any equation relating them to be dimensionally consistent' Newton's equation simplified in the form: *,*P:-c.*,7:' dt' r{t)' relates two bodies where the left hand side describes the motion of body 1 due to the cause described by the right hand side. Both sides represent equal forces (as we call them)Due to cancellation of mr we will have d2rlt) v m2 at' -n'r|f Or in non differential form: m. c =G-i DRAFT For the first form" G acts as the property in between the field generator, and the moving systern, because of this field. In the second form it is not quite clear. g can still tre seen as the acceleration of the body rnt due to gravity' yet this acceleration will be the same for any body at a distance r. That implies that the field property is conveniently described through the behaviour of an accelerating body' To determine the 'bonrposition" of G we use simple reference one meter pendulum ecuation with other relevant quantities using explicit unit length mass and time symbols: 2 s=2 "Pt where: -82g= r.m Ij fllz = Me*Un r = Re*tn s is a generic placeholder for unit second m is a generic placeholder for unit meter u. is a generic placeholder for unspecified as )et unit of mass Re is the non dimensional number of unit meters in Earth radius Me is a non dimensional number of unit lnasses in the total mass of the Earth. Substituting and rearranging variables we obtain: E'*Ret -(t = -----:-*yaJû t s '1 Me From this elementary if not hivial operation we clearly can see the composition and meaning of G. As a dozen interpretations or rather verbal expressions of G are possible from any derived form of Newton law (such as equations for escape velocity, orbiting angular velocity etc), we will chose one that is exclusively based on the equation above' G teans no more and no less than the defining pararnet€fs present in the above equation namelv: a. b. c. d. eDRAF'T 'G (in the above specified system of units) is a dimensional multiplying the ratio of non-dimensional numbers by the product their respective powers. The ratio is: ,c2*Re2 constant obtained of units of measure Me where a. fie is known/defined ratio of Earth radius to reference one meter of length b,Me|saratioofBarthmasstotheunitmass(yettobedefined) c. I is (approximate) experimentally correlated magnitude of Earth gravitational acceleration in reference lccation" At this stage it can be stated that the physical meaning of gravitational constant is the function of constituting parameters as follows: The physical meaning of G lies in the magnitude of gravitational acceleration approximately represented here as l, experimentally correlated to arbitrary unit of second unO n" unit of length (meter). The process of such correlation can be qualified as the necessary measufement of a physical quantity related to gravity and inertia, thus capturing the essence of these PhenomenaThe value of Re is the result of surveying the Earth and does not reveal any sigfficant physical quantity other than testing Earth geometryIf one select the mass of the Earth as *it * r, the value of G is exactly defined and no more physical contents can be derived from mechanical experiments, nor any mathematical transforrnation of Newton equation can. The question of what makes 'that big" object to accelerate bodies at 'that rate" at 'that distance" must remain unanswered at this stage' If one wants to obtain the value of G in SI, one needs to compare the arbitrary sebcted standard of one kilogram and determine the value of Me. The significance of the first direct force measuement performed by Cavendish is enormous as it was the proof that celestial bodies as weu as small bodies follow Newton's law identically. Recalling the eq uation: E2 * Re2o ='ffxynr3û-ts-2 J we may notice that we have a full freedom in defining the unit of massRitually we think about some object as reference, but this is not the only option. we may chose to define G as a non dimensional number, thus the unit of mass is necessarily: Such definition has no direct reference to any particular object' The bonus is the elimination of G and rough estimate of Me ( ideal earth). More spectacularly one can find the rough average radius of the moon orbit from the rotational period: 2360580s by in | *'1*" =17 ) t0 DRAF'T 'G (in the above specified system of units) is a dimensional multiplying the ratio of non-dimensional numbers by the product their respective powers. The ratio is: ,c2*Re2 constant obtained by of units of measure in Me where a. Re is known/defined ratio of Earth radius to reference one meter of length b,MeisaratioofEarthmasstotheunitmass(yettobedefined) c. I is iapproximate) experimentally correlated magnitude of Earth gravitational acceleration in reference lccation' At this stage it can be stated that the physical meaning of gravitational constant is the function of constituting parameters as follows: The physical meaning of G lies in the magnitude of gravitational acceleration approximately represented here as l, experimentally correlated to arbitrary unit of second *O ttt" unit of length (meter). The process of such correlation can be qualified as the necessary measurement of a physical quantity related to gravity and inertia, thus capturing the essence of these PhenomenaThe value of Re is the result of surveying the Earth and does not reveal any significant physical quantity other than testing Earth geometryIf one select the mass of the Earth as unit mass, the value of G is exactly defired and no more physical contents can be derived from mechanical experiments, nor any mathematical transforrnation of Newton equation can. The question of what makes 'that big" object to accelerate bodies at 'that rate" at 'that distance" must remain unanswered at this stage' If one wants to obtain the value of G in SI, one needs to compare the arbitrary sebcted standard of one kilogram and determine the value of MeThe significance of the first direct force measuement performed by Cavendish is enormous as it was the proof that celestial bodies as well as small bodies follow Newton's law identically. Recalling the eq uation : 6 =ttt ! -R" x1nt3u*ts-2 J Me we may notice that we have a full freedom in defining the unit of massRitually we think about some object as reference, but this is not the only option. We may chose to define G as a non dimensional number, thus the unit of mass is necessarily: Such definition has no direct reference to any particular object' The bonus is the elimination of G and rough estimate of Me ( ideal earth). More spectacularly one can find the rough average radius of the moon orbit from the rotational period: 2360580s | *'1*"=17) 10 DRAFT (Newton) to be 383630004.6 m, that is 0.09 Eo elJor wrt to published average value of 384000000 m.' The measurements of G have the value since they allow us now to determine the mass of smaller objects since the Earth is not a practical standard for mass. The major advantage of this operation is liberating physics from the elementary unit of mass namely from the kilogram. This has a severe impact on other composite units as is discussed in the next chaPter. 4 Kilogram-Free Metric SYstem 4,1 Mechanical Units Firstly it has been found beneficial to alter the usual form of gravitational law: pl=c'!4 for the reason of symmetry with Coulomb Law. Similar attempts have already been undertakenlll]. r j_..1 The consequences of replacing kilogram wfth | ? | are rattrer simpleAny composite Til unit conraining kilogram has to have the kg symbol multiplied by 4*7e:G | =lLkg's" I Where G appears explicitly, it should be replaced by non-dimensional (//4*n). This may appear as a cosmetic change and a nuisance, since G is not very accurately determined while masses in kilograms can be very preciseThe practicality is not an issue here as the current system can be used for measurements anyway, but some interesting consequences for theoretical considerations. For instance Newton's law expressed as; d'zr(t) frtfrz*'-i7- = -7-*n y is conceptually more convenient. One can hy to understand the inverse squafe law as a result of increasing surface of the sphere with the distance rather than distance itself. Also after re-arranging the formula for acceleration: tn=4.fr.12 .g one can attenpt to define rnass m seeing it in the first approximaticn as measured magnitude of gravity acceleration times the surface of the sphere intersecting given point and centered on nr. t Newton (The principia Book ltr prop IV; used Moon data to demonstrate his inverse square law without the concept of G called Newonian constant of gravity' 11 DRAFT Also the question whether G changes over time can be transformed into a question whether material particles change in such a way that they attract other particles at a different rate with respect to tirre determined through other physical (electrical) phenomena. In GR the nuisance constant *=ry becomes K=+ so the theory can now be pursued in pwe space-time geometry domain wiih no explicit reference to gravitational properties as such. For comparison we recall Planck's system of natural units where the gravitational constant is set to one (l), yet it does not really loose its dimension with Planck Mass constituting the unit. The advantage of these natural units is only convenient scaling, but not eliminating redundant reference mass as suchAt the time of writing the author found that such proposal for eliminating the base of unit of mass has already been presented by A. Chuykov [11] at conference in Petersburg in July 2000. This work however takes a different approach to ebctro-magnetic units described in .r the next paragraph. ;_ = {Z [.!_\''L \c j 4,2 Eteetro-magnetic Units. The impact of eliminating the kilogram can be established by examining force equation for two electrons. d'r(t)*" atl = Q"8" l/ ll ), - }t/(t -f1 'll ti' _ u') ll:vrb a-: rrl t4ilLv v: 4 -t .eo .r1t1t The left hand side no longer has the unit of kilogram which is still contained within ar Since the speed of light c=299792458m/s and magnetic constant p,4*n*!0" NIA2 And for the Coulomb: lot . a'l h =0.01055871e022e303' l"-f I When we require the constant & to be non-dimensional and equal one (1), as it was the case in Gauss system, and we find the replacement for Ampere as follows: A = e.731 827077 843336 [5] c = e.731827077843336 t5] ('[ t ,.,, fi,./= r'1 -* aL {/fu I i 2 lt L- : L-!--'' J \(t* ffi gA br{t'unil,, t2 DRAFT Surprisingly the new unit of charge has the same physical dimension as the unit of mass! With no surprise comes that the magnetic constant is: û =L fr1"lc" 29979245f Lm') The elementary charge becomes: e = 1.55e210it&2s0s8s10x1r* l+l LS J In a similar manner every other physical constant can be converted. The mysterious ratio of electric to gravitational force is now: Q, = 4.16635861g454274x1012 fne Which can be seen as the effect of inherent properties of the electron rather then ratio of two forces in the system of two bodies. The conversion table of metric to new system for SI derived units reveals that magnetic freld induction unit is l/s (that is as the unit for frequency or angular velocity) rather then complicated Tesla The elechic field strength is in the units of acceleration rather than'New ton over Coulomb ,. The same units characterize the strength of the gravity field. Most of electro magnetic units are surprisingly simple and overall coherence is apparent. Physical Ouantitv SI unit SI Base Unit Reoresentation Conversion Fomula InASS kg kg kg=8.38566477466*lO m'/s' Current A A A=9.731821071843 m'/s' Force N kg*m/s' N=8.3 856647'7 466" 10 "'4, 4m/s Energy J kg*mta' J= 8.3 85664 7 7 466* lO- "' mlsn Pressure Pa kg(m*s') Pa= 8.385664774f6*IO''),4 m-/s' Potential V kgx6z46*t:; Y=8.61674247558x 1O ttitJ Charge c A*s C=9.73182707784 m'/st t3 DRAFT Physical Ouantitv SI unit SI Base Unit Representation Conversion Formula Capacitance F #*s*/(kg*nt') F= L.1294W066?5*10' m Masnetic flux wb kg*nt'l(A*s') Wb= 8.6 1 67 4247 558* I0''z,In'S lnductance H kgxprTl42x*'; H= 8.8541 8? 811 620* lA'' stlm Resistance o kgxa12714zxt:; Q= 8.854187 817 620* lTlz Vm Magnetic field T kg(A*s') T= 8.61674247558*I0-" 1/s Electric Field N/C kg*n/(st) N/C=8. 6 1 67 4247 558* IO' " mls2 Mass densitv kg/-' kg/*' 8.385664'77466*1,4- !ls2 Charge density C/ m' C/ m' 9.73182701784 1/s2 t4 DRAF'T 5 Conclusions 1. Gravitational constant has no pupose of existence in physical equation being permanently blended into the concept of massboth inertial and gravitatirnal. 2. Electric constant has no purpose of existence being permanently blended together with gravitational constant into the concept of electric charge. 3. Magnetic constant remairls dimensional and equal to inverse light speed squared. 4. Units of mass and charge are identical and suitable for kinematic comparisons. 5. Gravitational field strength and electric field strength have the same units of measure equal to unit of acceleration they, therefore directly comparable6. Magnetic induction has the dimensicn of angular velocity, therefore there exist a simple computational analogy to rotational motion: E=Bxv and a = Qtxv An intelesting relationship can be obtained from the formal proprtbs of the ebctron: If one wishes to express the value of the static electric field strength of the electron at distance r" (being the classical electron radius) by equivalent induced field due to 'lnduction" using equation: E" = B"xc then the value of such'induction"is dimensionally and numerically identical to the orbiting angular velocity at distance r. due to gravitational field of the electron: B"=@ where 0) is obtained from centrifugaugravitational force equation: 6)2.re-- *" 4.fi .re' Note : G is embedded inme aspreviously indicated' In the proposed time-length measurement system' inertial gravitati'onal magnetic and electric properties of the classical electron appear to be logically in harmony' Such view' with a bit of imagination can be propagated to any branch of physics contributing perhaps to the search of grand unification theory'