Does "dark matter" make up large proportions of those galaxies?

Newtonian gravity behaves differently at very large scales of mass and distance, i.e., galaxy scales, in contra-indication to the assumption that massive quantities of invisible, or "dark matter" make up large proportions of those galaxies.

Preston Guynn added a reply

57 minutes ago

Your discussion statement question is:

• "Does 'dark matter' make up large proportions of those galaxies? Newtonian gravity behaves differently at very large scales of mass and distance, i.e., galaxy scales, in contra-indication to the assumption that massive quantities of invisible, or 'dark matter' make up large proportions of those galaxies."

The phrase "Newtonian gravity" refers to a very specific equation relating mass and acceleration, so saying it behaves differently under some condition is not a correct usage of the phrase. Newtonian gravity is Newtonian gravity, and it gives incorrect results at scales greater than the solar system. There is a significant body of research on modified Newtonian gravity, and you can find it by searching on the phrase or "MOND".

Your question"Does dark matter make up large proportion of those galaxies?" is the question that numerous branches of research are investigating either experimentally or theoretically. First of course is the search for any experimental evidence of any matter that couples gravitationally but not via the electromagnetic field. No evidence of any such matter has been found. Second is that there is no such matter expected from current models such as the so called standard model of physics.

Even if there were some type of matter that couples gravitationally but not via electro-magnetic coupling, the number of non-conforming physical observations cannot be solved by such matter. The galaxies not only have a rotation that is unexplained by GR, but the galaxies interacting in clusters, and the clusters of galaxies interacting in superclusters could not simultaneously be described by such matter regardless of its distribution patterns. Additionally, gravitational lensing observed due to galaxies and clusters of galaxies could not be described by GR simply by applying such conjectured matter. The number of non-conforming observations cannot be solved by adding matter or energy, so general relativity should be abandoned as a dead end. Newtonian gravity does not apply, and no known modification of Newtonian gravity describes all the observed interactions. Modern physics will only progress when GR is abandoned and my research based on special relativity is adopted. See

Article The Physical Basis of the Fine Structure Constant in Relativ...

Article Thomas Precession is the Basis for the Structure of Matter and Space

For some insights on dark matter see :

Article Cold Dark Matter and Strong Gravitational Lensing: Concord o...

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Courtney Seligman added a reply

11 hours ago

It is true that recently, people have started to wonder if G, the constant of gravity, is only constant within a given region, and may be different in regions separated by tens or hundreds of thousands of light years. If so, then the strange rotations observed in the outer regions of galaxies, which are the basis for thinking about "normal" dark matter (as opposed to truly weird ideas about dark matter between galaxies that are favored by many cosmologists), may not be a true measure of the actual mass of galaxies, in which case "dark matter" could be done away with entirely. As I see it, the troubles with that idea are (1) that we will never be able to directly test what "G" is anywhere else, so if it CAN vary over very large distances, there will never be any way to prove it, and (2) if "G" can vary, there is no obvious reason why it should vary in the same way in the outer portions of ALL galaxies. At any rate, it may turn out that the unknown mass ascribed to "dark matter" might simply be a lot of perfectly ordinary stuff that is simply too hard to observe when spread out over vast distances, and if "dark matter" is that kind of stuff that it will probably take decades or centuries to tell that it IS (which is not a promising topic for published papers). {For a historical and speculative discussion of Dark Matter In Galaxies (which is the only kind that we can be "sure" exists), see https://cseligman.com/text/galaxies/dark.htm }

Abbas Kashani added a reply

1 minute ago

Dear Courtney Seligman

Bachelor of Arts (Astronomy and Physics), Master of Arts (Astronomy) Professor Emeritus at Long Beach City College

United States of America

Thank you for your scientific answer. Many thanks Abbas