Wiki: Newton’s law of universal gravitation states that a particle attracts every other power particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.[note 1] This is a general physical law derived from empirical observations by what Isaac Newton called inductive reasoning. It is a part of classical mechanics and was formulated in Newton’s work Philosophiæ Naturalis Principia Mathematica (“the Principia”), first published on 5 July 1687.
The Devil’s Dictionary defines gravitation as: ‘The tendency of all bodies to approach one another with a strength proportioned to the quantity of matter they contain – the quantity of matter they contain being ascertained by the strength of their tendency to approach one another’.5
Such is the seemingly circular logic underlying standard gravity theory. The figures given for the masses and densities of all planets, stars, etc. are purely theoretical; nobody has ever placed one on a balance and weighed it. It should be borne in mind, however, that weight is always a relative measure, since one mass can only be weighed in relation to some other mass. The fact that observed artificial satellite speeds match predictions is usually taken as evidence that the fundamentals of newtonian theory must be correct. (See: Kepler’s laws of planetary motion)
The Devil’s Dictionary: NEWTONIAN, adj. Pertaining to a philosophy of the universe invented by Newton, who discovered that an apple will fall to the ground, but was unable to say why. His successors and disciples have advanced so far as to be able to say when.
See also: The Universal Newton at Malagabay
Thanks to David Pratt
CODATA’s official (2014) value for the gravitational constant (G) is 6.67408 ± 0.00031 x 10-11 m3 kg-1 s-2. While the values of many ‘fundamental constants’ are known to eight decimal places, experimental values for G often disagree after only three, and sometimes they even disagree about the first; this is regarded as an embarrassment in an age of precision.1
Assuming the correctness of Newton’s gravitational equation, G can be determined in Cavendish-type experiments, by measuring the very small angle of deflection of a torsion balance from which large and small metallic spheres are suspended, or the very small change in its period of oscillation. Such experiments are extremely sensitive and difficult to perform. For instance, electrostatic attraction between the metallic spheres can affect the results: in one experiment in which the small mass of platinum was coated with a thin layer of lacquer, consistently lower values of G were obtained.2 Note that variations in the experimental values of G do not necessarily mean that G itself varies; they could mean that the local manifestation of G, or the earth’s surface gravity (g), varies according to ambient conditions. Scientists have occasionally speculated on whether G is truly constant over very long periods of time, but no conclusive evidence of a gradual increase or decrease has been found.3
In 1981 a paper was published showing that measurements of G in deep mines, boreholes and under the sea gave values about 1% higher than that currently accepted.4 Furthermore, the deeper the experiment, the greater the discrepancy. However, no one took much notice of these results until 1986, when E. Fischbach and his colleagues reanalyzed the data from a series of experiments by Eötvös in the 1920s, which were supposed to have shown that gravitational acceleration is independent of the mass or composition of the attracted body. Fischbach et al. found that there was a consistent anomaly hidden in the data that had been dismissed as random error. On the basis of these laboratory results and the observations from mines, they announced that they had found evidence of a short-range, composition-dependent ‘fifth force’. Their paper caused a great deal of controversy and generated a flurry of experimental activity in physics laboratories around the world.5
The majority of the experiments failed to find any evidence of a composition-dependent force; one or two did, but this is generally attributed to experimental error. Several earlier experimenters have detected anomalies incompatible with newtonian theory, but the results have long since been forgotten. For instance, Charles Brush performed very precise experiments showing that metals of very high atomic weight and density tend to fall very slightly faster than elements of lower atomic weight and density, even though the same mass of each metal is used. He also reported that a constant mass or quantity of certain metals may be appreciably changed in weight by changing its physical condition.6 His work was not taken seriously by the scientific community, and the very precise spark photography technique he used in his free-fall experiments has never been used by other investigators. Experiments by Victor Crémieu showed that gravitation measured in water at the earth’s surface appears to be one tenth greater than that computed by newtonian theory.7
Unexpected anomalies continue to turn up. Mikhail Gersteyn has shown that ‘G’ varies by at least 0.054% depending on orientation of the two test masses relative to the fixed stars.8 Gary Vezzoli has found that the strength of gravitational interactions varies by 0.04 to 0.05% as a function of an object’s temperature, shape and phase.9 Donald Kelly has demonstrated that if the absorption capacity of a body is reduced by magnetizing or electrically energizing it, it is attracted to the earth at a rate less than g.10 Physicists normally measure g in a controlled manner which includes not altering the absorption capacity of bodies from their usual state. A team of Japanese scientists has found that a right-spinning gyroscope falls slightly faster than when it is not spinning.11 Bruce DePalma discovered that rotating objects falling in a magnetic field accelerate faster than g.12
As mentioned above, measurements of gravity below the earth’s surface are consistently higher than predicted on the basis of Newton’s theory.13 Sceptics simply assume that hidden rocks of unusually high density must be present. However, measurements in mines where densities are very well known have given the same anomalous results, as have measurements to a depth of 1673 metres in a homogenous ice sheet in Greenland, well above the underlying rock. Harold Aspden points out that in some of these experiments Faraday cage-type enclosures are placed around the two metal spheres for electrical screening purposes. He argues that this could result in electric charge being induced and held on the spheres, which in turn could induce ‘vacuum’ (or rather ether) spin, producing an influx of ether energy that is shed as excess heat, resulting in errors of 1 or 2% in measurements of G.14
All freely falling bodies – individual atoms as well as macroscopic objects – experience a gravitational acceleration (g) of about 9.8 m/s² near the earth’s surface. The value of g varies slightly all over the earth owing to its departure from a perfect sphere (i.e. the equatorial bulge and local topography) and – in the conventional theory – to local variations in the density of the crust and upper mantle. These ‘gravity anomalies’ are believed to be fully explicable in the context of newtonian theory. However, the net gravitational force is not necessarily proportional to inert mass. Section 2 will consider evidence for gravity shielding, gravity cancellation and antigravity.
On the basis of newtonian gravity, it might be expected that gravitational attraction over continents, and especially mountains, would be higher than over oceans. In reality, the gravity on top of large mountains is less than expected on the basis of their visible mass while over ocean surfaces it is unexpectedly high. To explain this, the concept of isostasy was developed: it was postulated that low-density rock exists 30 to 100 km beneath mountains, which buoys them up, while denser rock exists 30 to 100 km beneath the ocean bottom. However, this hypothesis is far from proven. Physicist Maurice Allais commented: ‘There is an excess of gravity over the ocean and a deficiency above the continents. The theory of isostasy provided only a pseudoexplanation of this.’15
The standard, simplistic theory of isostasy is contradicted by the fact that in regions of tectonic activity vertical movements often intensify gravity anomalies rather than acting to restore isostatic equilibrium. For example, the Greater Caucasus shows a positive gravity anomaly (usually interpreted to mean it is overloaded with excess mass), yet it is rising rather than subsiding.
Newtonian gravity theory is challenged by various aspects of planetary behaviour in our solar system. The rings of Saturn, for example, present a major problem.16 There are tens of thousands of rings and ringlets separated by just as many gaps in which matter is either less dense or essentially absent. The complex, dynamic nature of the rings seems beyond the power of newtonian mechanics to explain. The gaps in the asteroid belt present a similar puzzle. Read it all here
References Gravitational anomalies
D. Kestenbaum, ‘The legend of G’, New Scientist, 17 Jan 1998, pp. 39-42; Vincent Kiernan, ‘Gravitational constant is up in the air’, New Scientist, 26 Apr 1995, p. 18.
Spolter, Gravitational Force of the Sun, p. 117; Pari Spolter, ‘Problems with the gravitational constant’, Infinite Energy, 10:59, 2005, p. 39.
Rupert Sheldrake, Seven Experiments that Could Change the World, London: Fourth Estate, 1994, pp. 176-8.
F.D. Stacey and G.J. Tuck, ‘Geophysical evidence for non-newtonian gravity’, Nature, v. 292, 1981, pp. 230-2.
Seven Experiments that Could Change the World, pp. 174-6; Gravitational Force of the Sun, pp. 146-7.
Charles F. Brush, ‘Some new experiments in gravitation’, Proceedings of the American Philosophy Society, v. 63, 1924, pp. 57-61.
Victor Crémieu, ‘Recherches sur la gravitation’, Comptes Rendus de l’académie des Sciences, Dec 1906, pp. 887-9; Victor Crémieu, ‘Le problème de la gravitation’, Rev. Gen. Sc. Pur. et Appl., v. 18, 1907, pp. 7-13.
Mikhail L. Gershteyn, Lev I. Gershteyn, Arkady Gershteyn and Oleg V. Karagioz, ‘Experimental evidence that the gravitational constant varies with orientation’, Infinite Energy, 10:55, 2004, pp. 26-8.
G.C. Vezzoli, ‘Materials properties of water related to electrical and gravitational interactions’, Infinite Energy, 8:44, 2002, pp. 58-63.
Stephen Mooney, ‘From the cause of gravity to the revolution of science’, Apeiron, 6:1-2, 1999, pp. 138-41; Josef Hasslberger, ‘Comments on gravity drop tests performed by Donald A. Kelly’, Nexus, Dec 1994-Jan 1995, pp. 48-9.
H. Hayasaka et al., ‘Possibility for the existence of anti-gravity: evidence from a free-fall experiment using a spinning gyro’, Speculations in Science and Technology, v. 20, 1997, pp. 173-81; keelynet.com/gravity/gyroag.htm.
The Home of Primordial Energy (Bruce DePalma), depalma.pair.com; Jeane Manning, The Coming Energy Revolution: The search for free energy, NY: Avery, 1996, pp. 82-6.
S.C. Holding and G.J. Tuck, ‘A new mine determination of the newtonian gravitational constant’, Nature, v. 307, 1984, pp. 714-16; Mark A. Zumberge et al., ‘Results from the 1987 Greenland G experiment’, Eos, v. 69, 1988, p. 1046; R. Poole, ‘ “Fifth force” update: more tests needed’, Science, v. 242, 1988, p. 1499; Ian Anderson, ‘Icy tests provide firmer evidence for a fifth force’, New Scientist, 11 Aug 1988, p. 29.
Harold Aspden, ‘Gravity and its thermal anomaly’, Infinite Energy, 7:41, 2002, pp. 61-5.
M.F.C. Allais, ‘Should the laws of gravitation be reconsidered?’, part 2, Aero/Space Engineering, v. 18, Oct 1959, p. 52.
W.R. Corliss (comp.), The Moon and the Planets, Glen Arm, MD: Sourcebook Project, 1985, pp. 282-4.