Gravitational force acts independently.

If there is a stone in a train in motion, then the stone moves at the speed of the moving train. If there is a stone in a train at rest, the stone is at rest in the train. But gravitational force acting on the stone is independent and there is no relation between motion of the stone and its gravitational force.

Appearances (mathematical curves/lines) can definitely vary when observed from different frames. But it is fact that objects in gravitational force of a planet are attracted towards the center of the planet.

Question: "How can the General relativity or Theory of Gravitation be accepted as a scientific fact?"

It is a wonder indeed in the case of General Relativity (GR), since it denies the long proven existence of attraction between masses.

Newton's theory of gravitation does not deny this attraction however.

Actually, it is confirmed in an unexpected way by involving the momentum energy of elementary particles of which all masses are made, from the electromagnetic perspective, as Einstein himself hinted at in a 1910 article.

But not enough was known about electromagnetism at that time in history for this idea to be analyzed further. He then switched to inertial motion of macroscopic masses in the curved spacetime concept of GR.

Dear Preston Guynn

You quote from article

Article Non-Newtonian forces and the invisible mass problem

" Experimental or observational tests of the 1/r-squared gravitational force law are weak or nonexistent at length scales beyond the solar system. This is because at long distances all astrophysical estimates of mass density based on dynamics give larger values than corresponding measurements based on observed luminosity and local mass-to-luminosity ratios. The discrepancy generally increases with increasing distance, from galactic lengths to at least cluster scales near 10 Mpc ..."

Seems to me that such a conclusion that 1/r2 would apply only locally is inconsistent with the fact that hydrogen atoms are known to be the same in deep space and far stars and galaxies from their spectrum, even redshifted due to distance, because the 1/r2 relation is known to be in action between the charged electron and the charged proton in the hydrogen atom.

So 1/r2 would be valid locally everywhere in the universe but not generally?

This makes no logical sense to me at least.

Best Regards, André

Dear Preston Guynn

Thank you for the referred sources.

I know all about the current astronomical theory grounded on the virial theorem related to GR since Fritz Zwicky's quite imaginative conclusion in 1933.

It is grounded on calculations based on this assumption that the data that axiomatically assume the existence of huge amounts of unconfirmable "dark matter" in the universe mandated on the axiomatic assumption that GR is a correct reflection of gravity only at astronomical distances, that far galaxies are made to not conform to 1/r2, as you mention yourself. Previous calculations taking account of luminosity alone did come in agreement with 1/r2.

You wrote: "So 1/r2 is observed to apply at scales of the solar system, but not at larger scales such as galaxies or clusters of galaxies."

Shade of meaning: 1/r2 is observed to apply at scales of the solar system, at the atomic scale and at the astronomical scale according to Newton's theory, but strangely, not at astronomical scale such as galaxies or clusters of galaxies only if unconfirmable and unverifiable arbitrary and axiomatic "dark matter" is conjured up to force the acceptance that GR correctly represent gravity at astronomical scale, which is the only theory which is in disagreement with electromagnetic theory in this regard.

You wrote: "This is because galaxies are massive, and they are rotating"

So is the Solar System, all masses of which are made of the same atoms in which the electronic escorts are known to interact as 1/r2 with their nuclei, and all galaxies whose stars and other bodies are known to be made of the very same atoms in which the electronic escorts are known to also interact as 1/r2 with their nuclei.

Strangely, only GR is in disagreement with all other confirmed kinematic and electromagnetic interaction mechanics in the universe.

Force interaction confirmed valid according to 1/r2 in kinematic mechanics as well as in electromagnetic mechanics across the universe, except for GR, that does not even recognize the existence of any force, and establishes that 1/r2 does not apply in contradiction with all known and confirmed force equations.

Doesn't this flash an attention signal?

Best Regards, André

It all points at a very interesting question: How is the velocity of stars orbiting a Galaxy core measured/determined ?

Dear Preston,

Yes. I asked you "So 1/r2 would be valid locally everywhere in the universe but not generally?"

Simply because you were referring me to material known to attempt disproving 1/r2 at astronomical distances known to stem out of Zwicky's out of the blue axiomatic sudden belief that GR cannot be wrong and that unverifiable "dark matter" had to exist to prove it, which seems to disqualify 1/r2.

For no other reason. All is fine then given that we both agree that GR is wrong, as you mention.

I suppose the original poster also read our exchange, and can pass judgment for himself.

Best Regards, André

Dear Berndt Barkholz

You ask: "How is the velocity of stars orbiting a Galaxy core measured/determined ?"

Estimations have been made grounded on the distance separating our solar system from the center of our galaxy. You will find an analysis of this perspective in Section XIII. Cyclic Solar System Galactic Orbit Variation, in this article:

Article Inside Planets and Stars Masses

All historical formal references are provided, with direct links to those that are directly available on the internet.

Best Regards, André

André Michaud Sorry André, but in that file I couldn't find an answer to my question: "How is the velocity of stars orbiting a Galaxy core measured/determined ?"

Berndt Barkholz

Sorry Berndt, typo on my part. I meant to write Section XVII.

Estimation:

Time for one Solar System orbit, about 250 million years.

Mean radius of the Solar System orbit, (29532 +27700)/2 =28616 light-years.

Length of the mean orbit: 28616 x 2π = 179799.7308 light-years.

So we cover a distance of 179799.7 light-years in 250 million years

250 million years is 60 x 60 x 24 x 365 x 250000000 = 7.884E15 seconds

Distance covered in 1 second

179799.7308 light-years / 7.884E15 seconds = 2.280564825E-11 light-year

Number of meters covered in 1 light-second = 299792458 meters

Number of meters in 1 light-year = 299792458 x 60 x 60 x 24 x 365 = 9.454254955E15 meters

Velocity = distance in meters covered in 2.28E-11 light-year = 9.454254955E15 x 2.28E-11 = 215557.013 meter/second.

Which is approx 215 km/second, if I did not get mixed up in my calculations.

For comparison, this is way below the minimum velocity required for relativistic mass increase to begin to be measurable, which occurs, from the data collected by Kaufmann and the theoretical velocity of the electron on the mean Bohr orbit in the hydrogen atom, starting at about the 2000 km/sec mark, itself way below the 299792.458 km/sec speed of light.

This, of course, if I did not get mixed up in my calculations. From my perspective, just normal Newtonian mechanics.

Best Regards, André

André Michaud

Dear André, thank you for your info, but I was asking: "How is the velocity of stars orbiting a Galaxy core measured/determined ?"... I have no problems calculating that from the data, but I have problems with this:

" Estimation: Time for one Solar System orbit, about 250 million years."

Right, but when I use my thumb and point at our galaxy I could easily estimate a rotation time of 500 million years or 150 million years... the essence of my question is simply: What estimated "facts" is this estimation based on ??

Kind regards, Berndt

General relativity is the application of the escape velocity to the Lorentz transformation, and the analysis is done using four-vectors.

Dear Berndt Barkholz

You ask: "Right, but when I use my thumb and point at our galaxy I could easily estimate a rotation time of 500 million years or 150 million years... the essence of my question is simply: What estimated "facts" is this estimation based on ??"

Of course, you are right. But let's be serious here. Do you really think that estimating distances at distances in the thousands of light-years away can be grounded on anything but best fit "guesses" ?

I did not come up with the figures I used in my 2013 article. They are figures that I located in articles and sources that were established by consensus of real astronomers that were calculated from estimated reasonable figures made from Newton Mechanics according to best fit coherence. What other means is there to do such estimations?

I just reverse calculated the figures that no doubt were made from the estimated mass of the solar system and its estimated distance from the galactic center.

Besides, what does it matter that there is disagreement as to whether the time is 500 million years of 200 million years for events occurring so far away that whatever the figure is will have no impact on our lives.

Whatever real time it may really be will not be impacted by our estimations. We cannot change reality. When we know more about the universe, we will, some time in the future, more precisely estimate it.

There was a time when it was believed that the Sun was orbiting the Earth, then came a time when it was understood that it was the opposite. When we know more, we will be able to make better estimations.

In the mean time, our only tool is make estimations grounded on the only mechanics that makes any coherent sense with respect to all other astronomical observations of motion really verified: Newtonian mechanics.

Best Regards, André

André Michaud

Dear André... OK, thanks that almost answers my question and you are right saying:

"Do you really think that estimating distances at distances in the thousands of light-years away can be grounded on anything but best fit "guesses" ?

...and further:

"Whatever real time it may really be will not be impacted by our estimations. We cannot change reality. When we know more about the universe, we will, some time in the future, more precisely estimate it."

I think about the "dark matter" hype leading astrophysics astray. Measurements seem to point at a wrong velocity curve of the orbiting stars in a galaxy... but are those measurements done in the right way ? It's quite a tough claim that we from hundreds of millions of light-years distance are able to determine those data trustworthy... that is why I ask how is this estimation supported and what measurements are used ?

Regards, Berndt

Berndt Barkholz

Dear Berndt,

You ask: "I think about the "dark matter" hype leading astrophysics astray. Measurementsseem to point at a wrong velocity curve of the orbiting stars in a galaxy... but are those measurements done in the right way ?"

The "dark matter" hypothesis is possibly the worst case of delusion in the astronomical community. I just gave my opinion on this issue in another thread grounded on its historical origin.

The concept of "dark matter", which has never been observed but whose existence is presumed so that the theory of General Relativity is not rejected as invalid, was conceived by Fritz Zwicky in 1933, when he realized that the virial theorem associated with GR could not account for the masses of distant galaxies according to GR combined with the assumed increasing velocity with which they were deemed to move away from us if the red shift of light energy really reflected such increasing velocity, since the calculation of their masses based solely on their luminosity was much lower than what was possible according to the theory of General Relativity according to the red shift interpretation.

Note that Zwicky could not even conceive of the possibility that GR could be wrong, given his level of certainty about it.

This led him to hypothesize a quantity of non-luminous matter that he called "dark matter", which had to be added in an ad hoc manner to arrive at reasonable masses according to GR, in light of the cause of the redshift velocity increase hypothesis.

Like many easy way out of difficult predicaments over the course of the past century, this idea easily caught on in the mindset of all other physicists who were convinced that GR was right and the interpretation of the red shift as being related only to increasing velocity of galaxies away from us the higher the redshift was of light coming to us.

It is paradoxically very easy to understand another much more mundane cause for the increasing redshift of light coming from afar than only increasing velocity, that would be in harmony with the 2nd principle of thermodynamics. Simply that some energy of the incoming photons is expended as work each time their trajectory is deflected on their way in as they pass by intervening galaxies. The farther away they come, the more energy of each photon will have been expended as work in this manner.

Note that Newton's gravitational theory combined with conforming with the 2nd principle of thermo allows calculating quite reasonable masses for distant galaxies from their luminosity alone without any need for any "dark matter" ad hoc assumption.

Best Regards. André

André Michaud

Dear André... I don't think of dark matter and dark energy as worth considering even for a millisecond... right after warped space it's the greatest nonsense ever thought by a human creature... unfortunately very much accepted nonsense and fully supported by the glorious "Elvis of physics" !!

But how do you measure the speed (the red-shift) of an object that moves transverse to the observer ? How is this velocity curve made ? How are the velocities achieved ? If you know about that or have a link... please let me know.

The observed red-shift of stars and galaxies can according to Newtons shell-theorem only be caused by the average density of the universe, there is no Olbers paradox and only a fairy tale of an expanding universe !

Regards, Berndt

Berndt Barkholz

Dear Berndt,

You wrote: "But how do you measure the speed (the red-shift) of an object that moves transverse to the observer ?"

I don't think that the red-shift by itself can give any idea of the velocity away from us of stars and galaxies for the reason already mentioned of the energy loss as work by incoming photons from their trajectories deflections due to the 2nd principle of thermodynamics.

Neither for their motion transverse to us. In the latter case, the only possibility is by comparison with older photographs of the sky that reveal such transverse motion with respect to more recent photographs of the same part of the sky.

You ask: " How is this velocity curve made ? How are the velocities achieved ? If you know about that or have a link... please let me know."

I don't have a link about this. Only common sense, that tells me that comparing such photographs, in relation with the time elapsed between them, the transverse velocities of those stars that have changed position can be reverse calculated. This must have been done by numerous astronomers in the past, but I have no direct knowledge of any of their calculations.

I have no hypothesis about the universe other than what I put in perspective in this article published in 2021:

Article Our Electromagnetic Universe (Expanded republication PI)

Best Regards, André

André Michaud

OK, I agree with you, the red-shift, if used for this estimation, from the center to the outer regions would of course show more or less the same velocity.

If old photographs are used for this estimation, I do not hope that the "Eddington effect" needs to be considered. :o)

Anyway, thank you very much for your information, it was very helpful and confirmed my thoughts about that problem.

kind regards, Berndt

So-Called "evidence" of General Relativity theory is circumstantial, and may have other causality. The metric model is just that...a representation only; a description...a theory only of behaviour and not the phenomenon itself.