Dark matter may not actually exist – and our alternative theory can be put to the test

Dark matter may not actually exist – and our alternative theory can be put to the test
The bullet cluster. Credit: NASA/CXC/M. Weiss

Scientists have been searching for "dark matter" – an unknown and invisible substance thought to make up the vast majority of matter in the universe – for nearly a century. The reason for this persistence is that dark matter is needed to account for the fact that galaxies don't seem to obey the fundamental laws of physics. However, dark matter searches have remained unsuccessful.

But there are other approaches to make sense of why behave so strangely. Our new study, published in the Journal of Cosmology and Astroparticle Physics, shows that, by tweaking the laws of gravity on the enormous scales of galaxies, we may not actually need dark after all.

The Swiss astronomer Fritz Zwicky discovered in the 1930s that velocities in galaxy clusters were too high to account for how much matter we could see. A similar phenomenon was described by several groups of astronomers, such as Vera Rubin and Kent Ford, when they studied the motion of stars at the far edges of the Andromeda Galaxy.

The velocities of the stars far from its centre were expected to decrease, as they experience less . That's because, according to Newton's second law of motion, the on orbiting matter can be equated to a product of its mass and acceleration (which is related to velocity).

However, the measurements showed that there was no such decrease in velocities with distance. That led scientists to believe there must be some invisible matter there to create a stronger gravitational pull and faster stellar motion. In the past decades, countless other probes of gravitating systems at very large length scales indicated the same problem.

Dark matter may not actually exist – and our alternative theory can be put to the test
Rotation curve of spiral galaxy Messier Triangulum. Credit: Mario De Leo/wikipedia, CC BY-SA
Beyond dark matter

The mystery of what dark matter actually is remains the ultimate challenge of modern fundamental physics. The core question is whether it is indeed a missing mass source, such as a new type of matter, or whether the gravitational law is simply different at gigantic length scales.

While the first option seems very tempting, we haven't actually found any dark matter yet. Also, while gravity laws are well tested within the solar system, one has to be careful extrapolating this to scales which are at least one billion times larger.

One well known attempt to get rid of the need for dark matter is Modified Newtonian Dynamics (MOND), which suggests that Newton's law of gravity becomes irregular when the gravitational pull is very weak – as is the case in the outer regions of the galaxy. But this theory, although successful in many respects, hasn't passed the same stringent tests as our standard model of cosmology, which includes dark matter.

The main problem is that MOND cannot explain the missing mass problem in galaxies and galaxy clusters at the same time. Another very strong argument against MOND is based on the observation of colliding , where the stars of each galaxy pass through each other, but the gas clouds stick together and stay behind. A famous example is the Bullet Cluster, which consists of two such colliding clusters. Observations suggest that dark matter follows the stars in these events, which have a lower total mass than the gas cloud. MOND cannot explain why that is.

Dark matter may not actually exist – and our alternative theory can be put to the test
Gravitational lens around a galaxy. Credit: NASA
Space bubbles

We set out to tweak the laws of gravity in a different way. Our approach assumed that a phenomenon known as Vainshtein screening is at work. This suggests that each sufficiently dense, compact object in space generates an invisible sphere around it which determines how the laws of physics behave with growing distance. This sphere is a theoretical concept to help us understand the difference between small and big scales, rather than an actual physical membrane.

According to our theory, within this bubble the laws of ordinary Newtonian gravity that we see in our solar system hold for objects interacting with the massive body at the centre. Outside the bubble, the theory suggests that the gravitational pull by the central object can be significantly enhanced – even though there is not more mass present.

The bubble size would be proportional to the mass of the central object. If, for example, in a galaxy this sphere has a radius of a few thousand – a typical distance at which signs of dark matter is observed – the corresponding sphere of our sun would have a radius of 50.000 astronomical units (one such unit is the distance between the sun and the Earth). However, the edge of the solar system is only 50 astronomical units away. In other words, there are no objects we could observe that far from the sun to test whether the sun has a different gravitational pull on them than it has on Earth. Only the observation of entire systems very far away allows us to do that.

The surprising effect is that the size of the Newtonian bubble grows with the enclosed mass in a particular way. This means that the law of gravity changes at different length scales in galaxies and clusters of galaxies respectively and therefore it can explain the apparent dark matter in both systems simultaneously. That's not possible with MOND. Furthermore, it is consistent with the observation of the Bullet Cluster. That's because the gas clouds left behind in the collision are not compact enough to generate a sphere around them – meaning that the apparent dark matter is only notable around the more compact stars. MOND doesn't distinguish between stars and gas clouds.

To our big surprise, our theory allowed us to explain the stellar velocities in galaxies a lot better than with Einstein's general relativity, which allows for dark matter to exist. So there may actually be less mysterious out there than we think – and maybe even none at all.

We plan to further investigate this interesting phenomenon. It could also be responsible for the high variability of galactic motion, for which we gather more and more evidence.

Any massive body warps the space and time around it, according to general relativity. As a result, light rays take an apparent turn around the object rather than travelling in a straight line – an effect dubbed gravitational lensing. An extremely interesting test of our finding would be the observation of precise gravitational light deflection by individual galaxies, which is albeit a difficult measurement. Our theory predicts a stronger light deflection for very compact galaxies so, excitingly, it could one day be falsified or confirmed by such a measurement.


Explore further

Dark matter on the move

More information: Moritz Platscher et al. Long range effects in gravity theories with Vainshtein screening, Journal of Cosmology and Astroparticle Physics (2018). DOI: 10.1088/1475-7516/2018/12/009
Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Citation: Dark matter may not actually exist – and our alternative theory can be put to the test (2019, January 31) retrieved 26 June 2019 from https://phys.org/news/2019-01-dark-alternative-theory.html
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Jan 31, 2019
Um, we do have an indirect test of local space circa ~50 kAU, as that is nicely within the Oort Cloud, with its potential comets. Also, such are 'churned' by passing stars. Scholz's Star's pass ~70 kYear ago would be the most recent. A significant modification of Newtonian dynamics in that region may have clear consequences for churned objects' in-fall time...
Any takers ??

Jan 31, 2019
It would be helpful if people started using something like "dark matter effect" rather than "dark matter", which implies a new hadron(s), outside the Standard Model, and which refuses to be found.

The effect - the data - is still there, regardless.

(This is the exact opposite of the "aether" postulated in the 19th c. which theory seemed to demand while data kept refusing to be found).

At this point it makes sense (& saves cents - i.e. $ building/updating & staffing new super-colliders) to look at our possibly flawed understanding of gravity, instead. Good on these folks.

Jan 31, 2019
Just keeping adding epicycles, never ever question whether or not these systems operate via any other mechanism than gravity. Absolutely don't question these assumptions even though they have been solved outside of the gravity only paradigm.
http://www.ptep-o...3-01.PDF
No faerie dust or bubble blowing blather needed.

Jan 31, 2019
The Pop-Cosmology clan living in this chatroom will not be happy reading this. Real quick we'll start getting their lectures about all that inferred "unaccounted for gravity", which in reality only proves gravity really does exist as equally at one side of the Universe as the other.......big surprise.

Jan 31, 2019
Just keeping adding epicycles, never ever question whether or not these systems operate via any other mechanism than gravity. Absolutely don't question these assumptions even though they have been solved outside of the gravity only paradigm.
http://www.ptep-o...3-01.PDF
No faerie dust or bubble blowing blather needed.

So his 'figure 6' is good enough for you? predicting speeds nearly 50% higher than measured is the correct answer? good work.

Jan 31, 2019
though they have been solved outside of the gravity only paradigm.
http://www.ptep-o...3-01.PDF
No faerie dust or bubble blowing blather needed.


Hahahahahahaha. The cretin Scott with a non-peer reviewed piece of erroneous crap in a crank journal! Lol. This is the same idiot that proposed nuclear fusion in the chromosphere to account for neutrinos. Who is too thick to realise we would be fried by gamma if this were the case. He thinks the Sun is powered by an invisible electric current! The guy is a total knob.

Jan 31, 2019
The Pop-Cosmology clan living in this chatroom will not be happy reading this. Real quick we'll start getting their lectures about all that inferred "unaccounted for gravity", which in reality only proves gravity really does exist as equally at one side of the Universe as the other.......big surprise.


What would you know? You understand Jack about physics. As proven.

Jan 31, 2019
So his 'figure 6' is good enough for you? predicting speeds nearly 50% higher than measured is the correct answer? good work.


Not to mention that he screwed up the equations, and the gigantic Birkeland currents (lol) are not seen. Other than that....................it's crap.

Jan 31, 2019
So his 'figure 6' is good enough for you? predicting speeds nearly 50% higher than measured is the correct answer? good work.


Not to mention that he screwed up the equations, and the gigantic Birkeland currents (lol) are not seen. Other than that....................it's crap.
......Mister genius Anthropologist, still wandering around out in the tall grass & weeds picking bones I see.


Jan 31, 2019
So his 'figure 6' is good enough for you? predicting speeds nearly 50% higher than measured is the correct answer? good work.


Not to mention that he screwed up the equations, and the gigantic Birkeland currents (lol) are not seen. Other than that....................it's crap.
......Mister genius Anthropologist, still wandering around out in the tall grass & weeds picking bones I see.



Keep telling you, wanker; I did not do anthropology you lying piece of shit. Now f*** off, you clueless cretin. You know Jack Shit about physics. As proven.

Jan 31, 2019
Dunno what's really going on with cosmology but I do know that whenever the Trolls start arguing the conventional wisdom is usually false.

My hunch is the same as Hubble's: that the red shift may not always indicate velocity, but some other quality of light over distance or time.

The nice thing about such a putative model is that space is Euclidean and the universe is steady state and infinite, leaving no problems with gravity, and no need for all the neo-epicycles.

Folks holding the grant funding purse strings and at the helm of the media don't want to revisit the red shift because it takes away their big bang. It takes away their creation event that keeps everywhere the center of the universe, including the earth.

It's all for the same damn reason as the epicycles were. That's the laugh.

Jan 31, 2019
In search of black holes and dark matter astrophysicists are relying on indirect observations. It would seem that the measurement of the event horizon of a black hole directly would be a direct evidence. However, by the nature of a horizon, any real measurement of the event horizon will be indirect. The Event Horizon Telescope will get picture of the silhouette of the Sgr A* which is due to optical effects of spacetime outside of the event horizon. The result will be determined by the simple quality of the resulting image that does not depend on the properties of the spacetime within the image. So, it will be also indirect and an existence of BH is a hypothesis.
https://www.acade...ilky_Way
https://www.acade...k_Energy

Jan 31, 2019
'Dark Matter' potentially explains a number of conditions where General Relativity predictions deviate from observation but alternative gravity models typically only address the problem of anomalous galactic rotation.

Thus there may be required several alternative explanations, models and/or interpretations to cover all the phenomena for which Dark Matter is used an explanatory bridge.

Jan 31, 2019
Be nice if they could give a little more detail on how this Vainshtein screening works. Maybe something in terms of GRT instead of TUG.

The physicist it's named for seems like a reputable guy, holds a chair at the Kavli instutite, not to mention a couple pretty prestigious prizes in physics, so this isn't some fly-by-night thing or some grad student's work.

If anyone finds a good mid-level explanation (minimal tensors if any, I am not a relativist) I'd sure like to see it. I'm poking around now to see if I can find anything.

Oh, and they got Newtonian gravity wrong; or at least so badly garbled that they've mistaken Newton's Laws of Motion with the Theory of Universal Gravitation.

Jan 31, 2019
OK, a quick scan found a relevant Wikipedia article, which dances around a lot and which I am still digesting. The basic idea is that gravitons have a very small mass, far smaller (20 orders of magnitude or so) less than the neutrino. But it's not clear from the article if the Vainshtein effect shares this, at least not from the article. Still digging, too...

Link: https://en.wikipe...creening

Jan 31, 2019
So his 'figure 6' is good enough for you?

First, the model doesn't deviate until the edges of the disk. The standard model rotation curve shown above deviates almost immediately. Clearly Scott's model is superior.

Second, the Bessel function model is of the Birkeland current only, it makes no attempt to assume how it interacts with its surrounding media. The outer edges of the galaxy may very well experience a drag from intergalactic plasma which could explain the slower than expected speeds at the outer edge of the galaxy.

Third, it's an idealized maths model which given a large enough statistical pool the exact match may be found. Regardless, it is still far closer to a good match than the 'put it exactly where it needs to be' faerie dust guesses.

Lastly, dark matter, the darkists think that invoking faerie dust is legitimate science. There is a sucker born every minute...

Jan 31, 2019
This stuff is really complex; like string physics, it is an outgrowth of GRT and shares its mathematical complexity. We need a real relativist to ask about it. Maybe one will show up if they can ignore the trolls.

Jan 31, 2019
@JaxPavan
...neo-epicycles.

Folks holding the grant funding purse strings and at the helm of the media don't want to revisit the red shift because it takes away their big bang. It takes away their creation event that keeps everywhere the center of the universe, including the earth.

It's all for the same damn reason as the epicycles were. That's the laugh.

This is exactly what I have also found. Whenever I explain to some layperson that the big bang is not something that actually happened, they get all sad. They say they had liked the bbt because it fit so well with what they had read in the bible.

And so, it seems, that the questions of the bbt being real or not is more of a religious topic rather than a problem in physics.

Feb 01, 2019
This stuff is really complex; like string physics, it is an outgrowth of GRT and shares its mathematical complexity. We need a real relativist to ask about it. Maybe one will show up if they can ignore the trolls.

Just tried looking at it - no shit on the complex....

Feb 01, 2019
The concept is genius and beautiful. I too believed gravity did operates differently at different scales but could explain beautifully. The truest thing Einstein could have said are not his formulas, but the statement "Everything is relative". If mass bend space, and space and time are interweaved; Einstein calls this gravity, I call it a Time Field. But do you now see that gravity happens in a Time Field, and thats it's possible that scale separates various Time Fields and that these Time Fields are relative to each other, and that the resulting interaction could logically without ghosts explain all gravity anomalies; ALL. Does it not seem more logical and connected than Dark Matter. Most galaxies are not spirals; that and galaxies clusters are where dark matter is needed most. The dark matter argument is scientifically sound, but it is a piss poor argument because it postulates a "unknown matter" to explain known observations; remove the word matter therein lies the fallacy.

Feb 01, 2019
In other words, the scientific community is unable to accept current formulas of gravity are incorrect, because nobody can prove they are incorrect. The scientific community is correct in this regard, however was incorrect in postulating dark matter even though the theory makes sense. They deny gravity formulas are incorrect because of no evidence, yet postulate dark matter with evidence; now they have observations, however these observation in no way require unknown matter. And for that reason, the scientific community screwed up. The reason: Arrogance.

Feb 01, 2019
Don't pay the theorists, pay those who provide good evidence; data. If Data says something is missing, you cannot say that missing something is matter unless there is no other possibility. Dark Matter had an erroneous birth, and will have an explosive end. Nothing tops critical thinking, especially not the punk that dark matter is.

Feb 01, 2019
Lastly, dark matter, the darkists think that invoking faerie dust is legitimate science. There is a sucker born every minute...
Yes you see its static electricity. Stars stick to galaxies like the socks in your dryer, if your socks were as big as stars. And your dryer were as big as the milky way. And so forth.

Feb 01, 2019
This stuff is really complex; like string physics, it is an outgrowth of GRT and shares its mathematical complexity. We need a real relativist to ask about it. Maybe one will show up if they can ignore the trolls.

Below is a much longer article on Massive Gravity than the wiki one. I read some of it (ha, note 'some') a while back and always meant to go back to it but never did (probably because it was beyond what I was reading [gravitational waves]. It has a lot more detail so I hope you find it useful.
https://link.spri...r-2014-7

Feb 01, 2019
All the hypotheticals about DM Cosmic Fairy Dust has ONLY served to prove just one premise, that gravity is NOT INFERRED, that it really does exist no matter how Pop-Cosmology theorists imagine it came to be.

Feb 01, 2019
Yes you see its static electricity. Stars stick to galaxies like the socks in your dryer

This is not about simple electrostatics as the galaxy behaves as a Faraday disk,MIT is an electrodynamic system.

Feb 01, 2019
MIT= it

Autocorrect is ridiculous sometimes...

Feb 01, 2019
This seems ad hoc. Maybe creative but still more than a little ad hoc. I have no idea whether this would work but generally we view gravitational influence as grading off to zero as distance increases. In a quantum universe can any field value really approach zero as a limit? More likely, the limit is some finite value, and that finite value, at extreme distances, may propagate off to "infinity" or abruptly drop to zero. A gravitational field would have a finite minimum value and maybe a finite maximum extent. I don't know whether that would work but it might not be too hard to see whether that sort of thing would fit observations. It might tie in nicely with quantum gravity.

Feb 01, 2019
galaxy behaves as a Faraday disk.


No, it does not. Rotation curves cannot be explained by any electrical or magnetic interactions. It is a really dumb idea.

Feb 01, 2019
you cannot say that missing something is matter unless there is no other possibility.


Yes, you can. What is causing gravitational lensing if it isn't matter?

Feb 01, 2019
No, it does not. Rotation curves cannot be explained by any electrical or magnetic interactions.

Yet there are the papers and maths which describe just exactly that. All you have to refute is lies, name calling, and willful ignorance. But this is your M.O. though, isn't it?

Feb 01, 2019
No, it does not. Rotation curves cannot be explained by any electrical or magnetic interactions.

Yet there are the papers and maths which describe just exactly that. All you have to refute is lies, name calling, and willful ignorance. But this is your M.O. though, isn't it?


What papers? Not that crap from Scott? Lol. It is a 'paper' where he fuxxed up his equations, and provides no mechanism for shifting around stars at the same velocity as gas. It is a piece of non-peer reviewed garbage in a crank journal. It is nothing to do with science.

Feb 01, 2019
It is a 'paper' where he fuxxed up his equations, and provides no mechanism for shifting around stars

Like I said, lies, name calling, and willful ignorance.

Feb 01, 2019
It is a 'paper' where he fuxxed up his equations, and provides no mechanism for shifting around stars

Like I said, lies, name calling, and willful ignorance.


Nope, erroneous nonsense in a crank journal. No evidence, and he screwed up the equations, as previously discussed. It is junk. Why do you think it is in a crank journal, where it is guaranteed not to be seen by real scientists? How do you think it got published? Do you honestly think that crap would get past peer review in any decent journal? The guy is a fruitloop. Fusion in the chromosphere! Lol. What an eejit.

Feb 01, 2019
Yes you see its static electricity. Stars stick to galaxies like the socks in your dryer

This is not about simple electrostatics as the galaxy behaves as a Faraday disk,MIT is an electrodynamic system.
Yes, quite.

Feb 01, 2019
MIT= it

Autocorrect is ridiculous sometimes...
Maybe its also laughing at you. With you I mean.

Feb 01, 2019
Yes you see its static electricity. Stars stick to galaxies like the socks in your dryer

This is not about simple electrostatics as the galaxy behaves as a Faraday disk,MIT is an electrodynamic system.
Yes, quite.


Unfortunately for cantthink, galactic magnetic fields are very low, and stars are not highly charged. Kind of fails right there. No mechanism. Gets worse when the stars are orbiting at pretty much the same velocity as the local gas. Both neutral and ionised. A scientifically viable mechanism would be useful, but that has never been forthcoming.

Feb 01, 2019
Alternatives to dark matter theory like this should be thoroughly explored because that is just the way good science works.
But, at least for now and until if or when we have good evidence for one of those alternatives, Occam's razor disfavors all these alternatives and dark matter theory still looks like the most credible theory.

Feb 01, 2019
. No evidence, and he screwed up the equations.

Lies
What an eejit.

Name calling
No evidence,

Willful ignorance

It is truly all you have to offer.

Feb 01, 2019
^^^^ Sorry, thicko. Where is the evidence? I showed you where he fuxxed the equations. Schoolboy error. And anybody that suggests fusion in the chromosphere is a cretin. By definition.

Feb 01, 2019
Hint for the scientifically illiterate; fusion produces gamma rays. Very nasty they are. Life would never have started on this planet (certainly not on land) if fusion were occurring in the chromosphere. Only a scientifically illiterate prat would suggest such a thing. He should stick to rewiring houses, or whatever it was he did. He knows Jack about astrophysics or plasma physics. In short, he is a cretin.

Feb 01, 2019
Below is a much longer article on Massive Gravity than the wiki one. I read some of it (ha, note 'some') a while back and always meant to go back to it but never did (probably because it was beyond what I was reading [gravitational waves]. It has a lot more detail so I hope you find it useful.
https://link.spri...r-2014-7

Mimath,
I dived into it for little while until the ADHD took over.
My take is that because gravity has "spin" it can express a "mass effect" (relativistic)
Since gravity only expresses at the speed of light, it means that gravitational expression is expressed in more than 1 direction.
Which kinda makes sense, but what do I know... :-)
I do find it interesting, however... will go back over at I've processed it a little...

Feb 01, 2019
Where is the evidence?

Volumes of evidence is available, however you prefer to hang your hat on the willful ignorance hook.
I showed you where he fuxxed the equations.

No, you showed the completely erroneous claim by one of your buddies which you nor he has a iota of understanding.
And anybody that suggests fusion in the chromosphere is a cretin.

There is that name calling again. In addition to that there is also the fact that radiation trapping by double layers has been observed in the Safire experiment, so a return to willful ignorance for you.

Feb 01, 2019
@Whydening Gyre Apparently in mainstream, the graviton would be a spin 2 & massless while alternative theories give it a tiny mass (< neutrinos I think Ha!). I found the Springer article while searching for a more layman friendly version of Linearized Gravity, which along with with a wave operator forms a simplified basis. Here the metric tensor is separated into two; The Minkowski metric η [ab] + another h[ab] = Lin. Grav. which changes the connection coefficients ([ ] for subscripts). In alternative theories like the current article, h[ab] is multiplied by a factor, gh[ab] which, I think, is the small mass term. My books only give a brief outline of Lin. Grav so searched for a concrete example which I didn't find. Thus I lack a reasonable understanding.

Feb 01, 2019
@@Whydening Gyre An additional note to my last comment I have read that at present there is a debate going on about gravitational waves and a BH 'firewall'. Apparently, some say that there should be and GW echo if a firewall exists. The debate is about an apparent echo has been detected while others say that it is too small and probably 'noise'. Would a graviton of the alternative theories rebound in that way? I don't know but maybe someone else here has a thought on that.

Feb 02, 2019
@cd - I scanned the paper you linked to, and note that:

- it's not published in a peer-reviewed journal, but one that accepts just about anything from the scientific fringe;

- the Fig. 2, p.59, which is used as the basis for the "empirical data" used in the paper, is claimed to be taken from the reference (9), but cannot in fact be found in that reference;

- the "empirical data" has been copied/measured (!) from the above-mentioned graphic, and not taken from a tabulated set of results;

- the Bessel function's profile featured in the Fig. 6 graph has been arbitrarily scaled to provide a "best fit" to the re-graphed "data" measured from Fig. 2;

- it's apparent that, when viewing the rotation curves in the reference (9), that the one for NGC 1620 has been cherry-picked to most closely fit the Bessel function: if Scott had chosen curves for NGC's 3200, 2815, 7083, etc., then the serendipitous "fit" of curves for small R in his Fig. 6 would not have been so good.

Feb 02, 2019
[cont'd] Of course, for larger R, the Bessel function just continues to increase, whereas all galaxy rotation curves flatten out, as @691Boat has alluded to.

Some other points to note:

- the omission of proper scales from Scott's own graphs;

- the introduction of a completely spurious section dealing with the sorting of chemical elements by their ionization potential;

- his complete lack of a hard conclusion
we compare this actual observed |v(r)| data of the example galaxy with our derived velocity profile
(leaving the reader to conclude that they're a) a good fit, or b) that it's bollocks) and
The work being presented here demonstrates that the root cause of the now vast collection of observed "anomalous" galactic stellar rotation profiles is the electrical nature of the Birkeland Currents
which it manifestly fails to do.

Epic fail by a retired electrical engineer to make a meaningful statement on the origin/explanation of galactic rotation curves.

Feb 02, 2019
@DS - thanks for the link to the Wiki's Massive gravity page. Yep, pretty complex but well written I thought. It doesn't seem as though there's much chance yet to be able to distinguish any light-bending effects arising from A massive graviton. However, large-scale cosmological effects might be observable.

Thanks also to @MiMath for your link: attempting to read that right now...

Feb 02, 2019
There is that name calling again. In addition to that there is also the fact that radiation trapping by double layers has been observed in the Safire experiment, so a return to willful ignorance for you.


What the hell has putting a squillion volts through a metallic sphere got to do with the Sun? Lol. And there is no DL that will prevent gamma rays reaching Earth. Otherwise it'd be trapping all the other radiation (including some gammas) that we do detect. Duh! Talk about thick. Like I said; he is a loon who hasn't got a clue about the relevant subject areas. And there is no evidence. Where are these Birkeland currents? Link to proper paper, please. How are they moving stars around at the same velocity as gas? Total nonsense from the lightning bolt cult.


Feb 02, 2019
@SkyLight,

@DS - thanks for the link to the Wiki's Massive gravity page. Yep, pretty complex but well written I thought. It doesn't seem as though there's much chance yet to be able to distinguish any light-bending effects arising from A massive graviton. However, large-scale cosmological effects might be observable.

Thanks also to @MiMath for your link: attempting to read that right now...


Something else you might want to ponder is the total trashing of Scott's equations here;

https://www.chris...8051822/

In particular, post #5. I think we can see why Scott's paper lies ignored in a crank journal!

Feb 02, 2019
@jd - thanks to you for the brilliant link, which I'm now following with glee ;-)

Feb 02, 2019
> Skyhigh, schneibo, jonesy, etc

So entertaining & so much fun watching those of you in the Pop-Cosmology clan living here, as ya'll cloister yourselves into a tiny defensive circle looking for ways to defend the last vestiges & tenets of Cosmic Fairy Dust. This 20th Century dinosaur now all but relegated to the same ashbin that clogged up Pop-Cosmology in the previous 19th century, aether.

As if your cloistered little circle hasn't gone far enough off the rails of fantasy, now you're even taking on the task of spoon feeding the chatroom a concept that gravitational lensing can't occur except in the presence of DM.

Obviously none of you have ever studied the Photon Deflection section of Einstein's General Relativity to know his calculations had nothing to do with the presence of Zwicky's & Vera Rubin's subsequent DM fiasco now under rapid deconstruction.

Keep wandering around in the tall grass & weeds looking for something for which to pat one another on the back.

Feb 02, 2019
So, Benni is up and about, and has just finished his Saturday treat breakfast of a whole bucket of fruit loops. Hi Benni, have you finished winding up your clockwork multimeter yet?

Feb 02, 2019
As if your cloistered little circle hasn't gone far enough off the rails of fantasy, now you're even taking on the task of spoon feeding the chatroom a concept that gravitational lensing can't occur except in the presence of DM.


Nope, there is no way to explain GL without large masses. That's why it's called 'gravitational' lensing. Other effects can happen, but not to the extent needed to explain observations. Otherwise somebody would have proposed them by now. By which I mean an actual scientist, rather than a semi-educated loon.


Feb 02, 2019
The paper @Mimath posted does a handwave at lensing. It does at least mention Vainshtein effect in connection with it but it will be necessary to hunt down secondary papers which may or may not be in the public domain to find out whether there is compelling evidence.

I will say that this hypothesis seems extremely constrained. It will be interesting to see if anyone can make a consistent theory out of it. That should probably be done before anyone gets all excited and stuff.

Feb 02, 2019
For those that haven't noticed, there is an Arxiv preprint of the paper that the article refers to, here;

https://arxiv.org...5318.pdf

Feb 02, 2019
feeding the chatroom a concept that gravitational lensing can't occur except in the presence of DM
You're hearing voices again, Benni - nobody said that. We all understand that GL by galaxies/galactic clusters will be stronger given the presence of galactic DM than if it were absent.

Get that? More mass concentrated in galaxies/galactic clusters => more GL. Now, spit your foot out, Benni.

Feb 02, 2019
Following up on the link @jd provided, it suddenly dawned on me, after getting through about 3/4 of the discussion over 13 pages, that the "Michael" in the discussion - who's punching for the EU team - is none other than Michael Mozina, the author of the Surface of The Sun website, who argues that the sun's surface is made of iron. I remember emailing him a decade ago pointing out that his ideas were ludicrous. Not much has changed since...

Feb 02, 2019
So this is a bigravity theory. I'm extremely suspicious of the fine tuning needed to make it work with all three of rotation curves, cluster dynamics, and observed lensing at various scales such as individual stars, individual galaxies, and galaxy clusters. Sounds like it has a lot more assumptions than dark matter.

Feb 02, 2019
Following up on the link @jd provided, it suddenly dawned on me, after getting through about 3/4 of the discussion over 13 pages, that the "Michael" in the discussion - who's punching for the EU team - is none other than Michael Mozina, the author of the Surface of The Sun website, who argues that the sun's surface is made of iron. I remember emailing him a decade ago pointing out that his ideas were ludicrous. Not much has changed since...


Yes, he's been spouting his nonsense for decades on various fora. There are some particularly lolworthy threads at ISF/ JREF & BAUT/ Cosmoquest. If he is supporting Don Scott, then that is proof positive that Scott is wrong!

KBK
Feb 02, 2019
So.... nothing, in all these comments.... on gravity as a push? Not a pull?

(which ends up being associated with multidimensional theories, as that's the best fit...)

Feb 02, 2019
After perusing the Comments posited by the Pop-Cosmology clan living here, that along with the title of this article casting so much doubt on the existence of DM Cosmic Fairy Dust, a new challenge in the face of the evidence is hereby posited:

INFERRED GRAVITY was once the darling catch phrase of Pop-Cosmology fantasy, that now needs to be changed to INFERRED DARK MATTER. The reasoning being that everywhere we look in the Universe we see evidence for the proofs of the existence of gravity, it thus does exist in a state being INFERRED, but is REAL, like that which is keeping our feet on the surface of planet Earth, therefore there cannot be a force we label gravity that is in a state of INFERRED.

INFERRED should apply only to that which cannot be seen when we see gravitational effects that appear not to conform to the presence mass in the nearby environment, thus the logic for use of the term INFERRED MASS as opposed to INFERRED GRAVITY.

We need a poem......




Feb 02, 2019
Try jumping out a tenth story window and see how inferred it is.

Feb 02, 2019
Oh, and if it's so inferred, how come we only see the data we make the inferences from near obvious bright matter? It's not like we see a gravitational lens out in the middle of nowhere with no mass near it.

Maybe you forgot.

Feb 02, 2019
So.... nothing, in all these comments.... on gravity as a push? Not a pull?

(which ends up being associated with multidimensional theories, as that's the best fit...)

What if it's BOTH....?

Feb 02, 2019
Try jumping out a tenth story window and see how inferred it is.


.....just my point, GRAVITY is NEVER INFERRED is it?


Feb 02, 2019
And that's just exactly my point: it's always near mass. Like I said, it's not like we find gravitational lensing out in the middle of space with no mass to account for it.

Feb 02, 2019
And that's just exactly my point: it's always near mass. Like I said, it's not like we find gravitational lensing out in the middle of space with no mass to account for it.


Yeah, mister embedded Physorg Moderator, just like there's no way to account for your deleted & MISSING POSTS which are just as missing as your precious DM Cosmic Fairy Dust.

Feb 02, 2019
who argues that the sun's surface is made of iron

While unlikely iron, it certainly has a surface of most likely condensed matter which is metallic.
https://youtu.be/Erql613GO_k

Feb 02, 2019
- it's apparent that, when viewing the rotation curves in the reference (9), that the one for NGC 1620 has been cherry-picked to most closely fit the Bessel function

Compare with the rotation curve included in the above article, spot on. As already mentioned, it's an idealized maths model and is viewed as an approximation.
I also already acknowledged the Bessel function is the idealized maths model of the Birkeland current itself and does not account as to how it interacts with its surroundings. There will likely be a flattening of the curve due to the interaction of the Birkeland current and the intergalactic plasma it lies within.

Feb 02, 2019
who argues that the sun's surface is made of iron

While unlikely iron, it certainly has a surface of most likely condensed matter which is metallic.
https://youtu.be/Erql613GO_k


Lol. Helioseismology would say otherwise!

Feb 02, 2019
- it's apparent that, when viewing the rotation curves in the reference (9), that the one for NGC 1620 has been cherry-picked to most closely fit the Bessel function

Compare with the rotation curve included in the above article, spot on. As already mentioned, it's an idealized maths model and is viewed as an approximation.
I also already acknowledged the Bessel function is the idealized maths model of the Birkeland current itself and does not account as to how it interacts with its surroundings. There will likely be a flattening of the curve due to the interaction of the Birkeland current and the intergalactic plasma it lies within.


Except that, as well as having zero evidence for these impossible currents, he screwed up the equations. So, no evidence, no mechanism. Not worth bothering with, is it? Which is why nobody is. Just another crank in a crank journal. These people are ten a penny.

Feb 02, 2019
We need a poem......


Roses are red
Violets are blue
And Benni is a twat.

Nobody said it had to rhyme!

Feb 02, 2019
Following up on the link @jd provided, it suddenly dawned on me, after getting through about 3/4 of the discussion over 13 pages, that the "Michael" in the discussion - who's punching for the EU team - is none other than Michael Mozina, the author of the Surface of The Sun website, who argues that the sun's surface is made of iron. I remember emailing him a decade ago pointing out that his ideas were ludicrous. Not much has changed since...


Here is the thread on Cosmoquest (BAUT, as was);

http://www.forum....mp;pp=30

Feb 02, 2019
Helioseismology would say otherwise!

That helioseismology is possible on the Sun indicates it cannot be gaseous, it must be condensed matter as the measured waves cannot occur in a gas. As stated in the link.

Feb 02, 2019
Notably these types of theories with a varying interaction speed - here from the massive spin-2 field particle - has mostly been excluded by the neutron star merger that multimessenger - gravity and EM - astronomy observed.

Feb 02, 2019
Helioseismology would say otherwise!

That helioseismology is possible on the Sun indicates it cannot be gaseous, it must be condensed matter as the measured waves cannot occur in a gas. As stated in the link.

Are you referring the last you tube link you presented? I recognize that guy - he does "The Science Asylum" on youtube…
You do know that gases can be compressed to very high densities, don't you?

Feb 02, 2019
"A few theories have survived the LIGO blow — and will probably survive the upcoming pulsar data, Zumalacárregui said. There are some Horndeski and beyond-Horndeski theories that do not change the speed of gravitational waves. Then there are so-called massive gravity theories. Ordinarily, physicists assume that the particle associated with the force of gravity — the graviton — has no mass. In these theories, the graviton has a very small but nonzero mass. The neutron-star merger puts tough limits on these theories, Zumalacárregui said, since a massive graviton would travel more slowly than light. But in some theories the mass is assumed to be extremely small, at least 20 orders of magnitude lower than the neutrino's, which means that the graviton would still move at nearly the speed of light."

[ https://www.quant...0180430/ ]

TL;DR: Most physicists think these ideas are dying.

Feb 02, 2019
On the expected and fulfilled train wreck of a thread - though unusually with some sane, interesting comments on the actual subject - is not much to say, Some trolls go into their own world or ironically call cosmology "pop" something or other.

But this merits response:

It would be helpful if people started using something like "dark matter effect" rather than "dark matter",


That would be extremely unhelpful since DM refer to the DM part of our LCDM cosmology, it is not an "effect" unrelated to DM and moreover DM is observed by many independent means. It is the identity of the particles that remains to be more fully constrained, but we know it is particles. (Or you are referring to a vast set of observations that you need to find an alternative physics for.)

Feb 02, 2019
That helioseismology is possible on the Sun indicates it cannot be gaseous


Side show, but realize that the observed modes are *precisely* indicating it is a massive gas sphere. We see p-modes (pressure waves), g-modes (gravity waves) and f-modes (surface waves), the latter described as "analogous to waves on deep water". [ https://en.wikipe...ismology ]

Feb 02, 2019
On the expected and fulfilled train wreck of a thread - though unusually with some sane, interesting comments on the actual subject - is not much to say, Some trolls go into their own world or ironically call cosmology "pop" something or other.


So soon you forgot what the title of the article under discussion, here allow me: "Dark matter may not actually exist – and our alternative theory can be put to the test"

........seems you must be one of the trolls you reference, and any of the other Pop-Cosmology aficionados pushing INFERRED hypotheses of Dark Matter that the author is debunking.

So when the author doesn't agree with your inferred Pop-Cosmology theories the author is a troll, right? And anyone agreeing with the author is a troll because they disagree with mis-educated clowns like yourself. Hey, you ever seen a Differential Equation you could solve you worthless troll?

Feb 02, 2019
...
........seems you must be one of the trolls you reference, and any of the other Pop-Cosmology aficionados pushing INFERRED hypotheses of Dark Matter that the author is debunking.

So when the author doesn't agree with your inferred Pop-Cosmology theories the author is a troll, right? And anyone agreeing with the author is a troll because they disagree with mis-educated clowns like yourself. Hey, you ever seen a Differential Equation you could solve you worthless troll?

And... Benni's on the rag again...
Maybe he should drink a little more... (or maybe, less)

Feb 02, 2019
@Da Schneib
The paper @Mimath posted does a handwave at lensing. It does at least mention Vainshtein effect in connection with it but it will be necessary to hunt down secondary papers which may or may not be in the public domain to find out whether there is compelling evidence.

I will say that this hypothesis seems extremely constrained. It will be interesting to see if anyone can make a consistent theory out of it. That should probably be done before anyone gets all excited and stuff.

Agreed. Since I hadn't read the whole paper I didn't know what it did/did not contain and certainly the GL is an important issue. Hope you find another paper that addresses GL.

Feb 02, 2019
What's the matter, @Benni, all out of arguments?

Feb 02, 2019
What's the matter, @Benni, all out of arguments?


.......another troll out from beneath his bridge, only this troll is one of Physorg's own embedded Moderators, one in the business of creating MISSING COMMENTS of his own & INFERRING others.

So much missing & inferred stuff around here, a helluva way to do SCIENCE, unless of course SCIENCE was never your intent in the first place, right schneibo? Yeah, you know "right", it's all about the "inferred" theories of your favorite fantasy, Pop-Cosmology.

Feb 02, 2019
@torbjorn, we do seem to be running out of parameter space for heavy DM particles. And certainly we can't rule out various tweaks to relativity at this point, not having done the math.

Feb 02, 2019
@Benni, now you're just trolling. Guess the conversation got a little too close to the real for you.

Feb 02, 2019
not having done the math.
.......you should check your history & count the numbers of times you have repeatedly made this statement.

Uh, oh, deletions are about to begin, more MISSING stuff.

Feb 02, 2019
I can't help you with your paranoid psychosis. You should see a professional.

Feb 03, 2019
Helioseismology would say otherwise!

That helioseismology is possible on the Sun indicates it cannot be gaseous, it must be condensed matter as the measured waves cannot occur in a gas. As stated in the link.


Wrong, woo boy. And who is that cretin in the video? Hasn't got a clue!

Helioseismology and the Sun's interior
Thompson, M. J.
https://academic....1/264090

Now where has the cretin in the video written up his woo? Let me guess - vixra? Lol.

Feb 03, 2019
Hey, you ever seen a Differential Equation you could solve you worthless troll?


You certainly haven't. As proven. D-K afflicted loon.

Feb 04, 2019
I originally came here hoping to work on how to express ideas and reactions to theories and discoveries in a sensible way. But here there is only hostility and outrage; everyone has to be on a previously-chosen side, and every word is a potential landmine. What a shame.

Anyway, the problems with LCDM, as I understand them, are:
- what powered the Big Bang, then inflation, then dark energy, to cause increased rates of expansion in each era?
- where did all the antimatter go?
- where is the dark matter, and how can it interact only sometimes and only in the limited ways the theory needs?

On the other hand:
- how else to explain the apparent motion of everything?
- how to get matter and the Big Bang without antimatter that then goes away, somehow?
- what is keeping stars in galaxies, and galaxies in clusters, if not dark matter?
- what about that Bullet Cluster?

Feb 04, 2019
I'll waste a few more minutes, just to clear my head to work on actually important things in my life.

I think the standard theory is ignoring the impact of time in a crucial way. As co-moving masses age, why do they have the same gravity well at 1 second and at 13 billion years? What is pushing back up to keep the well the same depth? If there is nothing pushing back, no rubber sheet in this analogy, shouldn't the well just get deeper over time?

The cosmological constant would then become a cosmological function, relating the depth of the gravity well to the amount of time the masses were co-moving. It's very small, so the theory works great for static snapshots of systems, but it has subtle failures with dynamics between systems over billions of years.

Feb 04, 2019
But how to explain the apparent motion? Well, your gravity well and mine are very similar, but we are not co-moving with that quasar 13 billion light-years away. From our perspective, the quasar is slowly drilling its own gravity well deeper and deeper. From the quasar's perspective, we are doing the same thing. The farther away, the greater the apparent relative motion. But it is only apparent.

But wait, how did it all start, and what am I suggesting we do with all that energy that must have been released?

Okay, what if the Big Bang was actually a Big Pop? What if the universe was always billions of light-years across, and what we are seeing is not the aftermath of an outward explosion and inflation, but instead is simply the decay and condensation of higher-energy states into lower-energy states? Like a soap bubble popping, and surface tension pulls all the matter into strands and voids.

Feb 04, 2019
If I understood it (you can and will tell me I obviously do not), the standard theory needs all that antimatter to produce the normal matter, as they are created in symmetrical pairs that are expected to mutually annihilate. If instead, normal matter is the result of decay and condensation from some higher state, antimatter might not be needed for the origin story, so no need to explain why it all disappeared. Still no clue where everything came from, but no theory addresses the time before time.

This decay story makes sense to me (I know, you disagree because I'm a moron) because all the colliders are built to reach every-higher energy states, to re-create the initial conditions and observe the particles that could only have existed back then. That is, the decay story is integral to the standard theory, but maybe off to the side.

Feb 04, 2019
If gravity wells gradually get deeper for co-moving objects, then older galaxies and clusters will appear to have faster rotational curves than they "should," and dark energy will be stronger for older systems, as well. And the oldest objects do seem to have weaker dark energy and less dark matter as more observational evidence comes in. And those two things co-vary on the same timescales.

Which is what the article above was responding to, so if I'm making it up, pick a fight with those authors first.

What I like about this way of thinking is that entropy does all the work for you; just let your system cool off over enough time and it will condense into lower states. And entropy+time has more explanatory power than the version in the article. The authors posit a different dark energy in different epochs, but they give no reason why that should be so, they just fit their values to the graph.

Feb 04, 2019
Anyway, none of you wanted to hear any of that, and I have spewed enough to be able to get back to stuff that affects me and mine. Cheers!

Feb 04, 2019
....they just fit their values to the graph.


Yep, a bit like most of the MOND theories. An exercise in curve fitting, is how I think I remember it being described by somebody.

Feb 04, 2019
Correction:

My comment

"And the oldest objects do seem to have weaker dark energy and less dark matter as more
observational evidence comes in."

Should have been

"And indeed, the youngest observable/farthest away objects do seem to have weaker dark energy...."

I used opposite readings of the word "oldest" in successive sentences. The first was those objects that are currently old in their own timeframes. The second was those objects whose light is oldest; thus, they emitted the light when they were extremely young in our timeframe.

Feb 04, 2019
What I like about this way of thinking is that entropy does all the work for you; just let your system cool off over enough time and it will condense into lower states. And entropy+time has more explanatory power than the version in the article. The authors posit a different dark energy in different epochs, but they give no reason why that should be so, they just fit their values to the graph.


ENTROPY........."the distribution of energy"

If you ever find a difficult moment of conceptualizing the 2nd Law of Thermodynamics, I just gave it to you.

All energy is transformed mass which is in limited supply in the Universe & thus must be confined to be of use for creating WORK that provides all the MOTION in the Universe.

The hypothesis of Dark Energy is exactly the reverse of Entropy in every sense. DE is best described as perpetual motion, no transformation of mass is required & the energy output is infinite.

Feb 04, 2019
Oh, right: Bullet Cluster.

Time is my answer, again. The objects that are being gravitationally lensed are billions of lights farther away than the Bullet Cluster. There is no place to account for that time difference in LCDM, I think. In my "theory," you would have to account for that when solving the cosmological function.

Why? Because the colliding galaxies in the Bullet Cluster are not co-moving relative to each other, but they are co-moving relative to the distant quasar. Therefore, together they define a gravity well that can lens the light from far behind. In other words, co-moving reduces to "existing in the same frame."

The standard theory gives the same answer at all timescales, so it needs extra mass to explain the "extra" gravity. That extra mass doesn't follow the other mass in the Bullet Cluster, so Dark Matter!

In my "theory," there is no extra gravity to explain. The unexpected lensing is due to the different ages of light and mass.

Feb 04, 2019
What I like about this way of thinking is that entropy does all the work for you; just let your system cool off over enough time and it will condense into lower states. And entropy+time has more explanatory power than the version in the article. The authors posit a different dark energy in different epochs, but they give no reason why that should be so, they just fit their values to the graph.


ENTROPY........."the distribution of energy"

If you ever find a difficult moment of conceptualizing the 2nd Law of Thermodynamics, I just gave it to you.

All energy is transformed mass which is in limited supply in the Universe & thus must be confined to be of use for creating WORK that provides all the MOTION in the Universe.

The hypothesis of Dark Energy is exactly the reverse of Entropy in every sense. DE is best described as perpetual motion, no transformation of mass is required & the energy output is infinite.


What the hell would you know, you clown?

Feb 05, 2019
there is evidence that dark matter should be everywhere, as it gives mass to matter as we know it

Feb 05, 2019
there is evidence that dark matter should be everywhere, as it gives mass to matter as we know it

??????????????

Feb 05, 2019
@Benni, if your theory says one thing and the evidence says another, your theory is wrong.

Science 101.

Feb 06, 2019
there is evidence that dark matter should be everywhere, as it gives mass to matter as we know it

??????????????
Read and watch video
https://www.scrib...savvys84

Feb 17, 2019
The image "Rotation curve of spiral galaxy Messier Triangulum" seems to have rotational speeds increasing without limit. Is there a point where the observed speeds start decreasing?

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