Do dark matter and dark energy exist?

November 22, 2017, University of Geneva
Dark matter map of KiDS survey region (region G12). Credit: KiDS survey

Researchers have hypothesized that the universe contains "dark matter." They have also posited the existence of "dark energy." These two hypotheses account for the movement of stars in galaxies and for the accelerating expansion of the universe. But according to a researcher at UNIGE, these concepts may be no longer valid, as universal phenomena can be demonstrated without them. This research exploits a new theoretical model based on the scale invariance of empty space. This research is reported in The Astrophysical Journal.

In 1933, the Swiss astronomer Fritz Zwicky claimed there is substantially more matter in the than we can actually see. Astronomers called this unknown matter "dark matter," a concept that was to take on yet more importance in the 1970s, when the U.S. astronomer Vera Rubin invoked this enigmatic matter to explain the movements and speed of the stars. Scientists have subsequently devoted considerable resources to identifying dark matter in , on the ground and at CERN, but without success. In 1998, a team of Australian and U.S. astrophysicists discovered the acceleration of the expansion of the universe, earning the Nobel Prize for physics in 2011. However, in spite of enormous science resources, no theory or observation has been able to define this energy that is allegedly stronger than Newton's gravitational attraction. In short, dark matter and are mysteries that have stumped astronomers for decades.

A new model based on the scale invariance of empty space

The way physicists represent the universe and its history are described by Einstein's equations of general relativity, Newton's universal gravitation and quantum mechanics. The consensus at present is that of a Big Bang followed by expansion. "In this model, there is a starting hypothesis that hasn't been taken into account, in my opinion," says André Maeder, honorary professor in the Department of Astronomy in UNIGE's Faculty of Science. "By that, I mean the scale invariance of empty space; in other words, empty space and its properties do not change following a dilatation or contraction."

Empty space plays a primordial role in Einstein's equations as it operates in a quantity known as a "cosmological constant," and the resulting model depends on it. Based on this hypothesis, Maeder is now re-examining the Standard Model of the universe, pointing out that the scale invariance of empty space is also present in the fundamental theory of electromagnetism.

When Maeder carried out cosmological tests on his , he found that it matched observations. He also found that the model predicts the accelerated expansion of the universe without having to factor in dark energy. In short, it appears that dark energy may not actually exist since the acceleration of the expansion is contained in the equations of the physics.

In a second stage, Maeder focused on Newton's law, a specific instance of the equations of . The law is also slightly modified when the model incorporates Maeder's new hypothesis. Indeed, it contains a very small outward acceleration term, which is particularly significant at low densities. This amended law, when applied to clusters of galaxies, leads to masses of clusters in line with that of visible matter (contrary to what Zwicky argued in 1933). This means that no dark is needed to explain the high speeds of the galaxies in the clusters. A second test demonstrated that this law also predicts the high speeds reached by the stars in the outer regions of galaxies (as Rubin had observed), without having to resort to to describe them. Finally, a third test looked at the dispersion of the speeds of the stars oscillating around the plane of the Milky Way. This dispersion, which increases with the age of the relevant stars, can be explained very well using the invariant empty space hypothesis, while there was before no agreement on the origin of this effect.

Maeder's discovery paves the way for a new conception of astronomy that will raise questions and generate controversy. "The announcement of this , which at last solves two of astronomy's greatest mysteries, remains true to the spirit of science: nothing can ever be taken for granted, not in terms of experience, observation or the reasoning of human beings," concluded André Maeder.

Explore further: New insights on dark energy

More information: Andre Maeder. Dynamical Effects of the Scale Invariance of the Empty Space: The Fall of Dark Matter?, The Astrophysical Journal (2017). DOI: 10.3847/1538-4357/aa92cc , iopscience.iop.org/article/10. … 847/1538-4357/aa92cc , On Arxiv: arxiv.org/abs/1710.11425

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44 comments

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zorro6204
5 / 5 (7) Nov 22, 2017
Okay, possibly. But don't you still have to explain the apparent disconnection observed between "normal" matter and the gravitational centers observed in phenomena like the Bullet Cluster? That's not a general condition but a specific observation that doesn't fit with only normal matter existing.
Chris_Reeve
Nov 22, 2017
This comment has been removed by a moderator.
Ojorf
4.3 / 5 (11) Nov 22, 2017
Here is a guy with an idea contrary to the mainstream and he got it published, but that won't shut some people up.

Anyway, this is great, but I'm not holding my breath until some smarter minds have a look at it. It seems it will have a problem with some gravitational lensing observations.
jonesdave
4.1 / 5 (9) Nov 22, 2017
Here is a guy with an idea contrary to the mainstream and he got it published, but that won't shut some people up.

Anyway, this is great, but I'm not holding my breath until some smarter minds have a look at it. It seems it will have a problem with some gravitational lensing observations.


Yep. I downloaded the Arxiv version and did a search for 'lensing' in the paper. It doesn't appear.
KelDude
2.8 / 5 (8) Nov 22, 2017
Dark matter and Dark energy have always been a "bandaid solution" to a problem that didn't exist. I'm glad to see they've been sent to the dust bin.
Solon
1 / 5 (8) Nov 22, 2017
It seems it will have a problem with some gravitational lensing observations.


Replace gravitational lensing with plasma lensing.

http://www.plasma...sing.htm
Nik_2213
5 / 5 (5) Nov 22, 2017
" I'm glad to see they've been sent to the dust bin."

I'd be very, very glad to see both DM & DE subsumed by a simple but obscure correction within basic electromagnetism. But, much too early to say. Lots and lots of phenomena and prior data to consider. If he's right, it's a Nobel for sure, and the DM hunters can hang up their detectors. If he's wrong, it was still *lovely* math...
jonesdave
4.2 / 5 (10) Nov 22, 2017
It seems it will have a problem with some gravitational lensing observations.


Replace gravitational lensing with plasma lensing.

http://www.plasma...sing.htm


Oh dear; more woo!
Da Schneib
3.4 / 5 (5) Nov 22, 2017
Mmmmmm, looks like MOND+(some cobbled-up explanation for DE) to me. But I'll have to look at the papers and see who comments on it.

Problem with it if I'm right is, instead of two hypotheses we're trying to come up with some way to test, instead we get.... wait for it.... two OTHER hypotheses we're trying to come up with some way to test. I'd need to see some evidence other than modeling. That's what I'll go looking for. I'd be more impressed if it wasn't MOND+(somethingorother).

On edit: and @zorro also makes a good point, it's more than just Zwicky and Rubin. The Bullet Cluster evidence is another separate thing there'd need to be yet a THIRD hypothesis for, unless André Maeder can figure out how to shoehorn it into MOND or (somethingorother).
Da Schneib
3.4 / 5 (5) Nov 22, 2017
And to quote my favorite Dilbert of all time:

"You'd be fools to ignore the boolean anti-binary least square approach."
cantdrive85
1.7 / 5 (11) Nov 22, 2017
Do dark matter and dark energy exist?

Only in the fanciful minds of the plasma ignoramuses.
ellbeeyoo
4.5 / 5 (4) Nov 23, 2017
This study appears to me to prove nothing. It also appears that everything was developed in order to come to a specific finding. While Feynman said one should never do an experiment without knowing the results before hand, that does not apply here. The researchers just developed a series of equations that could only lead to their conclusions and nowhere else.
""The announcement of this model, which at last solves two of astronomy's greatest mysteries.." anyone who would say this of their work clearly has ego issues. Nothing was solved and there are dozens of other theories that do exactly the same thing, i.e. String Theory. Trash research.
Nik_2213
5 / 5 (3) Nov 23, 2017
"It also appears that everything was developed in order to come to a specific finding. "
True, but that argument only applies if they're wrong...
Let's wait and see.
usysinc
3 / 5 (1) Nov 23, 2017
Consider the universe is a perfect hypersphere, expanding initially from a singularity mapped entirely upon the surface of the hypersphere of infinite radius. The singularity and hyperspherical surface are mirror images of the same information. During expansion, mass diverges from the singularity to the hyperspherical surface whereby the friction less perfect oscillator sustains a perpetual and irreversible inertial transfer of mass from the singularity towards the hyperspherical surface. Of course as we humans are concerned, this will go on forever. Our problem with understanding this may have to do with our concept once again of time. Once time is placed into the equation then the concept of an infinite radius of the hypersphere leads to an apparent paradox.
humy
5 / 5 (4) Nov 24, 2017
Chris_Reeve
models are only useful to the extent that you can do things with them -- you know, more than just explaining observations.

Why is explaining observations not 'useful'?
I totally disagree. I see no problem calling that "useful".
It is useful to understand what is going on.
Without correct understanding on what is really going on, it is harder to work out what one can do with it.
A model that explains observation and does so correctly is useful.
Whydening Gyre
3.7 / 5 (3) Nov 26, 2017
Dark matter (and dark energy in lesser extent) were accidentally revealed by Oort and Zwicky at the beginning of 30's and confirmed after ignorance of mainstream science some fifty years later.
...
But IMO this failure was partially mistaken too, as https://www.newsc...y-found/ - they just aren't formed by exotic unknown-yet matter. But IMO majority of dark matter has different origin in scalar wave physics, revealed by Tesla and also abandoned for nearly a century. From my perspective physicists did as many mistakes as possible in dark matter subject.

Mack,
Correct me if I'm wrong... but it appears you would have gravitational waves also expressing (additional) gravity...
leetennant
5 / 5 (2) Nov 26, 2017
So I always thought that dark matter and dark energy weren't actually a thing but more like conceptual placeholders for "this thing that is happening that we don't understand yet".
Correct me if I'm wrong but "this thing that is happening that we don't understand yet" is still happening, right?
Da Schneib
2.3 / 5 (3) Nov 26, 2017
@lengould, good question.

DM is apparently collisionless, both with ordinary matter and with itself. However, ordinary matter is not collisionless with itself. Therefore the dynamics of the ordinary matter parts of a pair of colliding galaxy clusters will be different from the dynamics of the DM parts. And that's precisely what we see in the Bullet Cluster, and now that we know to look for it, several other examples.

How can we see both the ordinary and DM parts? First, we can see the stars in the galaxies with ordinary light. Second, we can see the interactions in the intergalactic medium in X-ray. And finally we can map the DM by studying how galaxies beyond the Bullet Cluster are lensed, then subtracting the lensing for the matter we can see.

It's pretty darn good evidence for DM.
Da Schneib
3.4 / 5 (5) Nov 26, 2017
Just to clarify slightly, the stars in galaxies are approximately collisionless, since they're far apart, so what we should see is the galaxies and the DM in about the same place, and the gas and dust in the IGM of the clusters in a different place. And that's just exactly what we see. Pretty good article here: https://astrobite...-matter/

I'm becoming impressed by astrobites. They seem to do a pretty good job of explaining things.
Da Schneib
3.4 / 5 (5) Nov 26, 2017
So I always thought that dark matter and dark energy weren't actually a thing but more like conceptual placeholders for "this thing that is happening that we don't understand yet".
Correct me if I'm wrong but "this thing that is happening that we don't understand yet" is still happening, right?
@lee, yes, pretty much. The thing is, though, that DM has come to mean not just that something's happening but that something's doing it. And the CDM hypothesis has come to mean that there's some sort of material/mass/matter that's doing it. In other words, it isn't just some sort of incompleteness in GRT, but an actual sort of matter that doesn't interact with ordinary matter and that also doesn't interact with itself. We've done a lot of lab searches for such matter, but we haven't found it.

Yet; but I implicitly assume it's out there by saying that. We don't even know that for sure.

[contd]
Da Schneib
3.4 / 5 (5) Nov 26, 2017
[contd]
Another part of it is that most of the theories that involve some incompleteness in GRT are called "MOND." So mostly when you hear someone talk about "DM" they mean some sort of matter, and when you hear someone talk about "MOND" they mean some kind of incompleteness in gravity theory.

The Bullet Cluster evidence rules out the simple MOND hypotheses; that's why it's so important. You pretty much can't see what we see in the Bullet Cluster from MOND; it pretty much has to be DM, in the sense of some sort of matter that exerts gravity, but doesn't collide with itself or with ordinary visible matter.

So that's the state of things right now; the major consensus, based on the various sorts of evidence, seems to tend pretty strongly toward DM. But we haven't found DM in the lab (yet, heh) and we haven't ruled out MOND (but it's not parsimonious; the most parsimony is in DM).
Da Schneib
3.4 / 5 (5) Nov 26, 2017
So, someone could come up with an extension to GRT that explains the effects we observe with parsimony, confirming MOND. Or we could find DM with one of the DM searches. And either of those things could happen tomorrow.

But this here doesn't look like a confirmation of MOND; such a thing would need to require less hypotheses, and this doesn't appear to. Back to the drawing board.
Da Schneib
3 / 5 (4) Nov 26, 2017
I'll take the astrophysics community over one dissident gravity physicist. Bee may be right; but it's more likely she's wrong.

#physicscrankscantcount.
leetennant
5 / 5 (3) Nov 26, 2017
But this here doesn't look like a confirmation of MOND; such a thing would need to require less hypotheses, and this doesn't appear to. Back to the drawing board.


Thanks. I'm no physicist and I'm often confused by pieces like this. Especially when the title is "do dark matter and dark energy exist" when I was pretty sure the answer was "not really" because they're just placeholders for our ongoing investigations.
Da Schneib
4.2 / 5 (5) Nov 26, 2017
Coupla warning signs in Bee's post linked above by #physicscrank @mak:

1.
Dark matter was a convenient invention.
Historically it was the first hypothesis. See Zwicky. Oops.
2.
It heavily relied on computer simulations which were optimized so as to match the observed structures in the universe.
Errr, that's exactly what you're supposed to do: check the models with observations. This is not a defect. What's she suggesting, we should ignore the data? Oops.
3.
But such high collision speeds almost never occurred in the computer simulations based on particle dark matter.
Yep. We've found only a few of them. Ummm, yep, this accords with the evidence. Oops.

Bee is a gravity physicist, not an astrophysicist. I take her astrophysics with a grain of salt and so should you.
Da Schneib
3.4 / 5 (5) Nov 26, 2017
But this here doesn't look like a confirmation of MOND; such a thing would need to require less hypotheses, and this doesn't appear to. Back to the drawing board.


Thanks. I'm no physicist and I'm often confused by pieces like this. Especially when the title is "do dark matter and dark energy exist" when I was pretty sure the answer was "not really" because they're just placeholders for our ongoing investigations.
Well, that's the thing: they might. They might not. Right now the evidence militates toward the conclusion they do. That's why LDCM is the current concordance model, AKA "Standard Model."
Da Schneib
4 / 5 (4) Nov 27, 2017
@mak, there's almost always a contrarian or minority opinion. Evidence determines which one turns out to be correct. Most times it's not going to be the minority opinion, which is exactly what you'd expect. If you're honest about it.
Benni
1 / 5 (4) Nov 27, 2017
.....there's almost always a contrarian or minority opinion. Evidence determines which one turns out to be correct.


"When Maeder carried out cosmological tests on his new model, he found that it matched observations."

Well Schneibo, "observations" is not "contrarian" evidence, and neither is the math contained within the equations of the Physics:

"He also found that the model predicts the accelerated expansion of the universe without having to factor in dark energy. In short, it appears that dark energy may not actually exist since the acceleration of the expansion is contained in the equations of the physics."

Your Perpetual Motion Universe is fast falling apart Schneibo, you're just a bitter clinger to antiquated concepts that prove ENTROPY, the 2nd Law of Thermodynamics, cannot be supplanted by the Perpetual Motion concepts of a free energy source known as DE.

Ojorf
3 / 5 (4) Nov 27, 2017
Where is this perpetual motion you talk about?
Benni
1.8 / 5 (5) Nov 27, 2017
Where is this perpetual motion you talk about?


You see Ojo. dark energy & ENTROPY cannot exist side by side, but I see because you are caught up in an infinitely expanding Universe you will never come to any comprehension why this must be so.

Energy is derived from transformation of matter. To keep the Universe expanding for an infinite period of time there must be an infinite source of matter which must never again transform & revert back to matter or the Universe loses energy within the system if such reversion takes place, it's the simple principle of ENTROPY.

Of course you don't understand that energy also transforms do you? And you probably also don't comprehend in a system undergoing energy transformation that less WORK is being done & the system slows down, 2nd Law of Thermodynamics.

I had Thermodynamics in Engineering school, two semesters worth. We use these principles to design nuclear reactor systems.
Whydening Gyre
5 / 5 (2) Nov 27, 2017
Where is this perpetual motion you talk about?

Energy is derived from transformation of matter.

From what to what?
To keep the Universe expanding for... infinite source of matter which must never again transform & revert back to matter or the Universe loses energy within the system

Not lost. At a lower state,in a much larger volume. Energy is NEVER lost (2nd Law of T)
it's the simple principle of ENTROPY.

In a CLOSED system.
Of course you don't understand that energy also transforms do you?

And you are not aware of the mechanic or what it transforms to.
And you probably also don't comprehend in a system undergoing energy transformation that less WORK is being done & the system slows down, 2nd Law of Thermodynamics.

As a system homogenates, less work is REQUIRED in concentrated form.

I had Thermodynamics in Engineering school, two semesters worth. ...

Perhaps another 2 semesters would help...
Ojorf
4 / 5 (4) Nov 28, 2017
This is interesting, a comment on the article by a real theoretical physicist.

http://backreacti...her.html

Maeder himself shows up in the comments.
Da Schneib
5 / 5 (2) Nov 28, 2017
John Baez showed up too. And called some of the paper "handwaving."

Like I said, MOND+(somethingorother). It's not parsimonious. There might be something wrong with DM+Lambda, but this ain't it.

I don't always agree with Bee, as can be seen from my comments above, but IMHO she got this one right.
Da Schneib
5 / 5 (2) Nov 28, 2017
@Whyde, minor error, 1LOT is conservation of energy. 2LOT is that entropy always increases in any closed system.
Dave_Price
5 / 5 (2) Nov 28, 2017
Good commentary from Da Schneib above, the comments from Maeder at the link above are also interesting. This article is definitely hypey -- the Bullet Cluster would be an excellent test of any such theory and I would be curious what Maeder thinks of it.

I hope this pans out or leads to something that does... I've never liked LCDM, smacks of solving an intransigent astrophysics problem by introducing an equally intransigent particle physics problem, like the old jokes about the Admiral and the General who each have a perfect solution that involves the other's forces doing something impossible.

We may not know for sure in our lifetimes (or ever), but the continuing failure to find any supersymmetry makes me increasingly suspect the ultimate answer to galactic deviations from relativity will look MONDy, and WIMPs will join the phlogiston as something that was useful and predictive in simpler models but ultimately proved to be a less accurate accounting of reality than other model.
Dave_Price
5 / 5 (2) Nov 28, 2017
@Whyde, minor error, 1LOT is conservation of energy. 2LOT is that entropy always increases in any closed system.


I'll just add a trivial quibble -- 2LOT only applies in the vast majority of cases, not always -- if you wait long enough (generally a number with many zeroes and far far longer than the Universe has been around) you will eventually observe entropy to have reversed by some degree in any closed system. I don't know why this qualification always bugs me, but it does.
Da Schneib
not rated yet Nov 28, 2017
@Dave, or if you go small enough and over a short enough time, then you encounter the Fluctuation Theorem and the FT shows that the 2LOT can be violated for a short time over a small distance. This has been shown in the lab.

But over the long run over a macroscopic distance, the 2LOT is a result of the FT. And the result you're talking about decreases in likelihood the smaller the number of particles in the system. It also doesn't work over infinite systems.
Benni
2 / 5 (4) Nov 28, 2017
I had Thermodynamics in Engineering school, two semesters worth.


Perhaps another 2 semesters would help...

I see that the only knowledgeable Commentary on Thermodynamics around here is from those who never took a course in, taken the final exam, & gotten a passing grade?

OK WhyGuy, you explain how ENTROPY & Dark Energy can exist side by side.........you can't so you like Schneibo go on name calling binges when confronted with Real Science.
Whydening Gyre
5 / 5 (1) Nov 28, 2017
I had Thermodynamics in Engineering school, two semesters worth.


Perhaps another 2 semesters would help...


I see that the only knowledgeable Commentary on Thermodynamics around here is from those who never took a course in, taken the final exam, & gotten a passing grade?

Thanks (I think...)
OK WhyGuy, you explain how ENTROPY & Dark Energy can exist side by side...

Would you believe it if I told you they were the same thing, more or less? At the end of the day, Entropy is a descriptor of that Nameless thing we happen to call Dark.
Oh, and it's not "random", it's "chaotic".
One other thing - you need to work on your usage of the "elipsis"...
Whydening Gyre
5 / 5 (1) Nov 28, 2017
@Whyde, minor error, 1LOT is conservation of energy. 2LOT is that entropy always increases in any closed system.

Dang.... that's what I get fer forgetting everything I learned in University. (Thanks, Albert.)
And... I'm with Dave on the disliking of the LCDM thing...
Dave_Price
5 / 5 (1) Nov 29, 2017
Thanks Da Schneib, yes I agree, 2LOT is really a function of the number of possible states... I was actually wondering after I wrote that if the "small numbers of particles" had been observed at the atomic level in the lab. I assumed it probably had been, even though the experiment is sort of a trivial result, but I still love the idea of some poor grad student checking that yes, Box A now has 4 atoms of hydrogen and 1 of helium :)
Da Schneib
not rated yet Nov 29, 2017
@Whyde, I'm not dissing you, I make mistakes all the time myself! I just clear them up for the lurkerz. And you. ;)

@Dave, the big space/long time arguments and the probability theory do support the claim that high entropy must eventually decrease, but on human timespans-- even over the lifetime of human existence which on cosmological timescales is extremely short-- it's still extremely unlikely. Recognizable humans have only existed for one or two million years, and that's many orders of magnitude less than the timescales needed to show macroscopic violation of the 2LOT. And then there's the other evidence, both astrophysical in galaxy and galaxy cluster dynamics, and CMBR measurement. Over trillions of years the argument has substance but this universe is only somewhat over ten billion years old, so we're at least three orders of magnitude from having substantive evidence to support this conjecture.
snoosebaum
not rated yet Nov 30, 2017
What are '' the properties of empty space'' ?
Da Schneib
not rated yet Dec 01, 2017
@mak apparently you didn't notice. I think this paper is BS too.

So what exactly are you arguing about?

#russiantrolls aren't very bright. They argue against people who agree with them.

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