Exploring the Role of Nucleonic Forces in Understanding Dark Matter

In summary, the experts in the conversation seem to agree that the Large Hadron Collider (LHC) is the most likely solution to the Dark Matter problem, as it may lead to the discovery of the Higgs boson which can solve the Inflation problem. However, they also discuss other possibilities such as the existence of baryonic dark matter and the modification of gravity by the zero point energy of quantum fields. They dismiss other explanations such as neutrinos, more careful general relativity, and errors in data. Ultimately, the conversation suggests that dark matter is a necessary component in understanding the universe, despite not fully understanding its nature.

What do you think will solve the Dark Matter problem?

  • Neutrinos

    Votes: 0 0.0%
  • Error corrections of the data

    Votes: 0 0.0%
  • MACHOS

    Votes: 0 0.0%

  • Total voters
    30
  • #1
EL
Science Advisor
558
0
Which alternative do you think is the most likely to solve the Dark Matter problem?
 
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  • #2
In a word, the LHC. I am confident it will ring out the Higgs boson. [I'm closely guarding my prediction as a trade secret].
 
  • #3
You think the Higgs boson will sove the Dark Matter problem?
 
  • #4
The Higgs boson if it is eventually detected will solve the 'Inflation problem', and turn that postulate from an epicycle, invoked to resolve shortcomings in GR, into a theory verified by laboratory experiment. it will do nothing to resolve the identity of DM.

I voted 'other' as I maintain that DM does exist but that originally it was mainly baryonic in form, that an initial 'IGM' of Omegab ~ 0.22 formed Pop III stars which themselves left IMBHs some gas and dust. This gas and dust then formed the visible matter in the galaxies as we know them, and the IMBH's form the DM.

Note: The Freely Coasting Cosmological model (FCM) produces a Omegab ~ 0.2 from its BBN, and Self Creation Cosmology delivers the strictly linear expansion of FCM. SCC is being tested at this moment as the GPB data is now being processed - results will be known in Summer 2006.

Garth
 
  • #5
Agreed, Garth, but that aside, would you agree some amount of 'dark matter' is necessary?
 
  • #6
Chronos said:
Agreed, Garth, but that aside, would you agree some amount of 'dark matter' is necessary?

I see you don't. Have read some attempts to solve this problem by pure GR, but never really found any convincing arguments. Do you have such?
 
  • #7
:redface:
Garth said:
The Higgs boson ... will do nothing to resolve the identity of DM.
Agree on this.

I voted 'other' as I maintain that DM does exist but that originally it was mainly baryonic in form, that an initial 'IGM' of Omegab ~ 0.22 formed Pop III stars which themselves left IMBHs some gas and dust. This gas and dust then formed the visible matter in the galaxies as we know them, and the IMBH's form the DM.
Ouch, forgott the IMBH alternative in the poll...
 
  • #8
Chronos said:
Agreed, Garth, but that aside, would you agree some amount of 'dark matter' is necessary?
Being made of dark matter myself, I find it indespensible.
 
  • #9
Chronos said:
Agreed, Garth, but that aside, would you agree some amount of 'dark matter' is necessary?
I would not claim that there is nothing left to discover in terms of exotic particles, axions or whatever. I'm just wary of using such to resolve the 'galactic rotation curve', 'cosmological missing mass' and 'large structure formation' problems of GR and thereby conclude that a 96% majority of the universe's mass inventory consists of totally unknown forms of DM and DE.

Already we have about 1% of closure density in the form of neutrinos, who knows what else there is to find?

Garth
 
  • #10
Could the zero point energy of quantum fields be modified by gravity? Might this explain the extra mass around galaxies and clusters, etc? Could this be the dark matter we are looking for?
 
  • #11
Mike2 said:
Could the zero point energy of quantum fields be modified by gravity? Might this explain the extra mass around galaxies and clusters, etc? Could this be the dark matter we are looking for?
How does GR square up with QT and the ZPE, a 10140 mismatch?

Some experiment is required, but what?

For information Self Creation Cosmology suggests that the observed ZPE (i.e. Casimir force) is dependent on curvature and tends to zero as r -> infinity. The theory suggests that the Casimir force rounds off at a plate separation too small to be achieved within the Earth's gravitational field but the rounding off would be detectable in the Sun's gravitational field somewhere between the orbits of Jupiter and Saturn with present experimental sensitivities. An experiment could be miniaturised and placed on the 'Pluto Express' or similar to demonstrate whether "the zero point energy of quantum fields is modified by gravity" or not.

However according to SCC this extra (and moderate) ZPE density would not be sufficient to explain DM. In SCC the DM is originally baryonic and may exist today in the form of IMBHs.

Garth
 
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  • #12
Dark matter is one of those things that sounds dubious to everyone when they first hear it. I can assure you, however that those of us in the field are by and large convinced of it. I can't tell you what it is, but I can say what it most probably isn't:

1) Neutrinos - We have a limit on the mass and can calculate their approximate abundance. They appear to contribute negligibly.
2) More careful GR - Standard GR is very well understood and I find it extremely implausible that we would have just overlooked something in modelling the systems.
3) MOND - Although not completely dead, the theory is on its last legs. It can't seem to reproduce the CMB power spectrum or large scale structure and there is still no real theoretical motivation for the "modification" of gravity.
4) Errors in the Data - Dark matter is a many, many-sigma statistical result at this point. There's absolutely no way to do away with it with more careful observations.
5) MACHOs - The microlensing observations in the Milky Way halo and the low value of [itex]\Omega_b[/itex] pretty much rule this out. Primordial black holes are also a possibility, but are also almost ruled out.
 
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  • #13
Microlensing is the most punishing evidence in favor of DM. I was hardcore against the DM model when it first came out, but, microlensing [and to a certain extent large scale structure studies] convinced me that DM is the only logical explanation.
 
  • #14
Chronos said:
Microlensing is the most punishing evidence in favor of DM. I was hardcore against the DM model when it first came out, but, microlensing [and to a certain extent large scale structure studies] convinced me that DM is the only logical explanation.
Has it been proven that not any kind of distribution of normal, baryoinic matter could account for DM effects because normal matter would scatter light too much, whereas DM WIMPs would not?

Could the ZPE of QFT have enough energy/mass to produce the same effects as DM. Maybe with very large volumes of space there might be enough energy to bend light and change galatic rotation curves.

To this end, is the ZPE background independent? Or does the energy produced depend on the curvature of the spacetime in which it is calculated?

I'm thinking that the tidal forces of a gravitational gradient (from a nearby galaxy or cluster) will increase the probability that virtual pairs will become permanently separated and survive long enough to produce gravitational effects. (Does any ZPE interact with light and cause gravity?) I think this is so for two reasons: one, the particles involved in Hawking radiation near BHs don't locally know they're near an horizon - locally all they feel is the tidal forces. And two, the equivalence principle equates accelerating frames of reference to those in a gravitational field. This being so, then the Unruh temperature effect for accelerating frames should also apply to frames in a gravitational field, right? This would give a particular temperature (and the particles that produce it) to particular gravity gradient, just as near an horizon. Then more ZPE would congregate around more massive objects (on intergalatic scales) and produce the DM effects, right?
 
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  • #15
Mike2 said:
Could the ZPE of QFT have enough energy/mass to produce the same effects as DM. Maybe with very large volumes of space there might be enough energy to bend light and change galatic rotation curves.

To this end, is the ZPE background independent? Or does the energy produced depend on the curvature of the spacetime in which it is calculated?
Einstein was on this track as he continued to develop his theory of General Relativity. By 1920, he was convinced that GR needed a dynamical ether to mediate gravitation and inertia. He also accepted the need for an EM ether to allow for the propagation of light through space, but did not see that the two were united. By 1924, as shown in his paper "On the Ether" he viewed the gravitational and EM ethers as one and the same and was working toward modifying GR to encompass them.

Einstein "On the Ether" said:
The general theory of relativity removes a defect of classical dynamics: in the latter, inertia and weight appear as totally different manifestations, quite independent of one another, in spite of the fact that they are determined by the some body-constant, i.e. the mass. The theory of relativity overcomes this deficiency by determining the dynamical behaviour of the electrically neutral mass-point by means of the geodesic line, in which inertia and weight effects can no longer be distinguished. Thereby it attributes to the ether, varying from point to point, the metric and dynamical properties of the points of matter, which in their turn are determined by physical factors, to wit the distribution of mass or energy respectively. The ether of the general theory of relativity differs from that of classical mechanics or the special theory of relativity respectively, in so far as it is not 'absolute', but is determined in its locally variable properties by ponderable matter. ... The fact that the general theory of relativity has no preferred space-time coordinates which stand in a determinate relation to the metric is more a characteristic of the mathematical form of the theory than of its physical content. ... The metric tensor which determines both gravitational and inertial phenomena on the one hand, and the tensor of the electromagnetic field on the other, still appear as fundamentally different expressions of the state of the ether; but their logical independence is probably more to be attributed to the imperfection of our theoretical edifice than to a complex structure of reality itself.
And on magnetic fields:
Einstein "On the Ether" said:
The Earth and sun have magnetic fields, the orientation and sense of which stand in approximate relationship to the axes of rotation of these heavenly bodies. ... It rather looks as if cyclic movements of neutral masses are producing magnetic fields. The Maxwell theory, neither in its original form, nor as extended by the general theory of relativity, does not allow us to anticipate field generation of this kind. It would appear here that nature is pointing to a fundamental process which is not yet theoretically understood.
Einstein was striving for simplification and unity. A polarizable, self-interacting quantum vacuum field would very neatly serve as his GR ether, with no need for additional entities.

Were the early "null' detections of the ether (via ether drift interferometry) actually null?

http://redshift.vif.com/JournalFiles/Pre2001/V05NO1PDF/V05N1MUN.pdf
 
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  • #16
SpaceTiger said:
Dark matter is one of those things that sounds dubious to everyone when they first hear it. I can assure you, however that those of us in the field are by and large convinced of it. I can't tell you what it is, but I can say what it most probably isn't:

1) Neutrinos - We have a limit on the mass and can calculate their approximate abundance. They appear to contribute negligibly.
2) More careful GR - Standard GR is very well understood and I find it extremely implausible that we would have just overlooked something in modelling the systems.
3) MOND - Although not completely dead, the theory is on its last legs. It can't seem to reproduce the CMB power spectrum or large scale structure and there is still no real theoretical motivation for the "modification" of gravity.
4) Errors in the Data - Dark matter is a many, many-sigma statistical result at this point. There's absolutely no way to do away with it with more careful observations.
5) MACHOs - The microlensing observations in the Milky Way halo and the low value of [itex]\Omega_b[/itex] pretty much rule this out. Primordial black holes are also a possibility, but are also almost ruled out.

I totally agree with you SpaceTiger. I can see you have answered "other". Is this because you have some special other candidate in mind, or that you just don't believe in any of the listed candidates, or simply just because you are being "scientific" and reject to answer a question you don't know the answer to?
 
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  • #17
EL said:
I totally agree with you SpaceTiger. I can see you have answered "other". Is this because you have some special other candidate in mind, or that you just don't believe in any of the listed candidates, or simply just because you are being "scientific" and reject to answer a question you don't know the answer to?

Mostly the latter. My intuition tells me only that the dark matter is probably a particle of some kind. Beyond that, I don't feel qualified to say anything about exactly which particle it's most likely to be.
 
  • #18
SpaceTiger said:
Mostly the latter. My intuition tells me only that the dark matter is probably a particle of some kind. Beyond that, I don't feel qualified to say anything about exactly which particle it's most likely to be.

I suspected that.:smile:

What about if I force you to pick one kind of particle, what would your answer be then?:tongue2:
 
  • #19
The DM particle most likely is very massive Probably on the order of 10 Tev - right around the Higgs mass.
 
  • #20
Chronos said:
The DM particle most likely is very massive Probably on the order of 10 Tev - right around the Higgs mass.
Would that be an interacting or non-interacting DM particle?

Garth
 
  • #21
EL said:
What about if I force you to pick one kind of particle, what would your answer be then?:tongue2:

Neutralinos are popular amongst the experts, so I'll go with that.
 
  • #22
Chronos said:
The DM particle most likely is very massive Probably on the order of 10 Tev - right around the Higgs mass.
Why do you think it should be massive?
 
  • #23
SpaceTiger said:
Neutralinos are popular amongst the experts, so I'll go with that.

Great choice! You should have picked SUSY then...
Actually I'm a little surprised I'm the only one who has chosen it.
 
  • #24
Turbot said:
Einstein was striving for simplification and unity. A polarizable, self-interacting quantum vacuum field would very neatly serve as his GR ether, with no need for additional entities.
I have been considering this for quite a while, and am still of the opinion that this is correct as long as it can be shown that the field is quite equal in all places with no (unexplained) concentrations of the effect.
Turbot said:
Were the early "null' detections of the ether (via ether drift interferometry) actually null?
Probably yes, with the equipment and accuracy available. But, even if it was today, I believe that the "entity" they were trying to detect would leave a null result. Someone posted earlier (above) a mention of the "frame dragging" experiment which was done on a very basic level until the satellite (GRACE) was up, plus some more recent satellite laser-ranging measurements.

So, if there is frame dragging, just try to consider exactly what is being "dragged"..(?) Only the effect of a gravitational field? I think it is more; but that's just food for thought..:confused:
 
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  • #27
I too went with 'other', partly for the same reason as ST, and partly because I'd just love there to be more than one 'solution'!

Perhaps there's some baryonic matter (sure, good observations rule out many alternatives, but aren't there still some small regions of parameter space where it could hide?); perhaps there's a SUSY zoo (gotta keep those HEPs employed, donchaknow?); there are surely at least some errors in the data (there are always errors in the data!); maybe there's a tweak to GR we've all overlooked; ...?

What I'd really like is for the insights Bahcall had about the nature of DM (at least in spirals) - "The most striking feature of rotation curves is that there are no striking features", for example - to be resolved in a delightfully surprising way!
 
  • #28
Nereid said:
I'd just love there to be more than one 'solution'!
Oh, I'd love if there'd be only one (main) solution.
 
  • #29
IMO, vacuum energy (whatever it is) is the only explanation for the apparent missing mass problem. Perhaps the CMBR has something to do with this.
 
  • #30
X-43D said:
IMO, vacuum energy (whatever it is) is the only explanation for the apparent missing mass problem. Perhaps the CMBR has something to do with this.
I agree with you here (And I'd like to change my vote to other). The Unruh effect is a vacuum energy/zero point energy effect that I am presently working on. No conclusions yet. It might be that the virtual particles created by the ZPE/CC/vacuum energy might exist long enough to create a gravitational field of its own. So there might be an average force produced by virtual pair. Anyone ever study this? How long must a particle exist before it produces a gravitational field?

By the way, when a photon loses energy as it climbs out of a gravitational well, what type of particle caries away that energy, gravitons, virtual particles, what?
 
  • #31
Just thinking out loud here, it seems to me that the energies we are involved with are the same energies on the small scales as the large, and we seem not to be taking into account the effect that nucleons repell until they reach a certain distance threshold, at which point they attract fiercely. Also atoms and Molecules seem to attract and repel each other, Not necessarily with only positive/negative interactions, nor with only magnetic, but also with I am supposing these nucleonic forces. I seem to remember the voyager probes encountering something that is changing their trajectory. My thoughts follow along the line that the solar systems as well as molecules and atoms are interacting with these same, albeit magnified and intensified, nucleonic forces. I believe I have not seen a paper addressing these forces, too small perhaps? Well, consider gravity is supposed to be the weakest of energies...
A ton of Aerogel will crush you as handily as a ton of lead... I believe all of the atomic forces accumulate and impinge on the macro world, and subsequently on the galactic.
~Dan
 

1. What is dark matter?

Dark matter is a type of matter that makes up about 85% of the total matter in the universe. It does not emit or absorb light, making it invisible to telescopes and other instruments. Its presence is inferred through its gravitational effects on visible matter.

2. What are nucleonic forces?

Nucleonic forces are the forces that hold together the particles that make up an atom, such as protons and neutrons. These forces are mediated by particles called gluons and are responsible for the stability of atoms and the formation of chemical bonds.

3. How do nucleonic forces relate to dark matter?

Recent research has suggested that dark matter may interact with nucleonic forces, specifically through a weak force known as the weak nuclear force. This interaction could potentially explain some of the observed properties of dark matter.

4. What is the role of nucleonic forces in understanding dark matter?

By studying the potential interaction between dark matter and nucleonic forces, scientists hope to gain a better understanding of the nature of dark matter. This could help explain its origin, composition, and behavior, and ultimately lead to a more complete understanding of the universe.

5. What are some current research efforts focused on exploring the role of nucleonic forces in understanding dark matter?

Scientists are using a variety of methods, such as particle accelerators and astronomical observations, to study the potential interaction between dark matter and nucleonic forces. They are also developing new theoretical models to better understand this relationship and its implications for our understanding of dark matter.

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