Non-symmetric gravitational theory (NGT)

In summary: My recent paper on this is gr-qc/9809001.In summary, Cahill and Moffat have both proposed gravitational theories that eliminate the need for dark matter and dark energy. They both suggest that Einstein's theory of gravity may not be correct on a large scale and propose alternative theories that can explain the observed anomalies in the gravitational behavior of galaxies. While their theories differ in the details, they both point to the fine structure constant as a key factor in understanding gravity and suggest that space has a quantum structure. Further research and analysis is needed to confirm these theories and their implications for our understanding of the universe.
  • #1
yanniru
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Last year I indicated on this forum that some work by Reginald Cahill of Flinders University in Australia had found that Newton's theory of gravity, and Einstein's as well since it is tied to Newton's in the low velocity limit, were both limited to occasions of spherical symmetry. He found extra NGT terms. These terms explained why dark matter is not observed in spherical galaxies, but is observed in spiral galaxies using ordinary symmetric Newtonian theory. The bottomline of Cahill's result is that dark matter does not exist. It's just a theoretical fluke.

The responses on this forum could not decide if Cahill was a fluke or the theory was.

Now I have found, again on the Cornell archives, a recent paper by John Moffat of the University of Toronto, who independently claims that NGT eliminates the need for both dark energy and dark matter. Of course that raises the problem of how the universe could be flat, as established by many independent observations. But nevertheless, we now have two physicists arriving at the same conclusions, more or less, without referencing the other, seemingly independent of the other. I do not understand GR math. So I hope someone else could review these papers for us. The abstracts for the archives and links to the papers follow:

Modified Gravitational Theory as an Alternative to Dark Energy and Dark Matter
Authors: J. W. Moffat
Comments: 17 pages, no figures, LaTex file
The problem of explaining the acceleration of the expansion of the universe and the observational and theoretical difficulties associated with dark matter and dark energy are discussed. The possibility that Einstein gravity does not correctly describe the large-scale structure of the universe is considered and an alternative gravity theory is proposed as a possible resolution to the problems.
Full-text: PostScript, PDF, or Other formats
http://arxiv.org/abs/astro-ph/0403266




Gravitation, the 'Dark Matter' Effect and the Fine Structure Constant
Authors: Reginald T. Cahill (Flinders University)
Comments: 11 pages, 3 eps figures
Subj-class: General Physics
Gravitational anomalies such as the mine/borehole g anomaly, the near-flatness of the spiral galaxy rotation-velocity curves, currently interpreted as a `dark matter' effect, the absence of that effect in ordinary elliptical galaxies, and the ongoing problems in accurately determining Newton's gravitational constant G_N are explained by a generalisation of the Newtonian theory of gravity to a fluid-flow formalism with one new dimensionless constant. By analysing the borehole and spiral galaxy data this constant is shown to be the fine structure constant alpha=1/137. This formalism then also explains the cause of the long-standing uncertainties in G_N and leads to the introduction of a fundamental gravitational constant G not = G_N with value G=(6.6526 +/- 0.013)x 10^-11 m^2s^{-2}kg^{-1}. The occurrence of alpha implies that space has a quantum structure, and we have the first evidence of quantum gravity effects.
Full-text: PostScript, PDF, or Other formats
http://arxiv.org/abs/physics/0401047
 
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  • #2
John Moffat has been pushing NGT for about 30 years, at least. The main problem with the theory is that the metric is really not non-symmetric. Otherwise I suppose it's a realistic model...
 
  • #3
Non-symmetric gravitational theory

"John Moffat has been pushing NGT for about 30 years, at least. The main problem with the theory is that the metric is really not non-symmetric. Otherwise I suppose it's a realistic model..."

Nice to know he is ahead of Cahill. Could you explain how John's theory is not non-symmetric? BTW, he was a consultant of mine at MIT when he was at U. of Michigan almost 40 years ago.
 
  • #4


Originally posted by yanniru
"John Moffat has been pushing NGT for about 30 years, at least. The main problem with the theory is that the metric is really not non-symmetric. Otherwise I suppose it's a realistic model..."

Nice to know he is ahead of Cahill. Could you explain how John's theory is not non-symmetric? BTW, he was a consultant of mine at MIT when he was at U. of Michigan almost 40 years ago.

I meant that there is no reason for a spacetime metric to be non-symmetric. Moffat's is, of course. I suppose some confirmation will come if we ever observe dipole gravitational radiation (one of the NGT predictions).

To be blunt: I see no reason for there to be a non-symmetric metric, and in fact there is lots of reason to assume it isn't.

I didn't know John was at Michigan. He's been at Toronto for as long as I can remember (although now he's at the Perimeter Inst. in Waterloo, working on variable speed of light ideas).
 
  • #5
NGT

It seems I do not know what you mean by 'metric'. Now some galaxies are spherically symmetric and some are spirals. Do they have different metrics? That kind of galactic symmetry or lack thereof seems to be what both Moffat and Cahill mean by non-symmetric gravitational theory. But I do not understand Moffat. Cahill is much more understandable.
 
  • #6
The original nonsymmetric theory of gravity was Einstein's unified field theory. There has recently been some progress in this.
 

1. What is Non-symmetric gravitational theory (NGT)?

Non-symmetric gravitational theory (NGT) is a modified version of Einstein's theory of general relativity that aims to explain the behavior of gravity in a way that is consistent with quantum mechanics. It introduces new mathematical principles and equations to describe the gravitational force, which differ from those in general relativity.

2. How does NGT differ from general relativity?

NGT differs from general relativity in several ways. Firstly, it introduces a new field, called the skewon field, which describes the non-symmetric properties of space-time. Secondly, it modifies the equations for the gravitational field, including the field equations and the energy-momentum tensor. Lastly, it allows for the existence of a preferred frame of reference, which is not present in general relativity.

3. What are the main motivations for developing NGT?

One of the main motivations for developing NGT is the desire to reconcile general relativity with quantum mechanics. General relativity breaks down at a quantum level, and NGT aims to provide a more complete and consistent theory of gravity that can be unified with other fundamental forces in nature. Additionally, NGT offers potential solutions to some long-standing problems in general relativity, such as the cosmological constant problem and the singularity at the center of black holes.

4. Has NGT been tested and verified by experiments?

There have been some experimental tests of NGT, but none have provided conclusive evidence for or against the theory. Some proposed experiments involve measuring the skewon field or detecting differences in gravitational effects between different frames of reference. However, due to the complexity of the theory and the difficulty in designing suitable experiments, NGT remains largely untested.

5. Are there any practical applications of NGT?

NGT is still a relatively new and unproven theory, so there are currently no practical applications that have been derived from it. However, if the theory is confirmed and accepted, it could potentially have significant implications for our understanding of gravity and the universe. It may also lead to new technologies and advancements in fields such as space travel and cosmology.

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