# How does this theory for dark matter stack up: gravitationally polarized virtual dipoles
**URL:** https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770
**Category:** Factual Questions
**Created:** [February 9, 2013, 5:40am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770 "2013-02-09T05:40:20Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 9, 2013, 5:40am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/1 "2013-02-09T05:40:20Z")
Actually it’s an alternative to dark matter much as the modified Newtonian dynamics theories are.
Here’s the article on [Phys.org](http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html) and one from [New Scientist](http://www.newscientist.com/article/mg21729014.500-dwarf-planet-eris-may-reveal-quantum-gravity.html).
The idea starts with the zero point field or quantum vacuum and the fact that every point in space is constantly giving rise to pairs of particles. One is made of matter, one anti-matter. As soon as they come into existence though, they meet and annihilate one another.
The assumption that has to be made for this to work is that gravity is dipolar such that anti-particles have a repulsive gravitational field.
> [@](#):
>
> If matter and antimatter are gravitationally repulsive, then it would mean that the virtual particle-antiparticle pairs that exist for a limited time in the quantum vacuum are “gravitational dipoles.” That is, each pair forms a system in which the virtual particle has a positive gravitational charge, while the virtual antiparticle has a negative gravitational charge. In this scenario, the quantum vacuum contains many virtual gravitational dipoles, taking the form of a dipolar fluid.
>
> “We can consider our universe as a union of two mutually interacting entities,” Hajdukovic said. “The first entity is our ‘normal’ matter (hence we do not assume the existence of dark matter and dark energy), immersed in the second entity, the quantum vacuum, considered as a sea of different kinds of virtual dipoles, including gravitational dipoles.”
>
> He goes on to explain that the virtual gravitational dipoles in the quantum vacuum can be gravitationally polarized by the baryonic matter in nearby massive stars and galaxies. When the virtual dipoles align, they produce an additional [gravitational field](http://phys.org/tags/gravitational+field/) that can combine with the gravitational field produced by stars and galaxies. As such, the gravitationally polarized quantum vacuum could produce the same “speeding up” effect on the rotational curves of galaxies as either hypothetical dark matter or a modified law of gravity.
In support of this idea
> [@](#):
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> In his paper, Hajdukovic also presents equations in support of this scenario, one of which allows calculating the effects of the gravitational polarization at different distances from the center of a galaxy, which are in good agreement with observations. He also derives the famous Tully-Fisher relation as a consequence of the gravitational repulsion between matter and antimatter. This relation is an empirical law based on numerical data collected by numerous observations of galaxies and clusters of galaxies, and is still unexplained in the framework of dark matter hypotheses.
Not sure what most of that means but I figured I put it out there for anyone who didn’t fee like looking at the article.
[URL=“[Dark matter may be an illusion caused by the quantum vacuum](http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html#jCp)”]
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 9, 2013, 10:16pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/2 "2013-02-09T22:16:40Z")
It’s already been experimentally shown that antimatter is affected by the Earth’s gravitational field in the same way as normal matter (or at least, in the same direction). For antimatter to produce a different field than matter, then, would require a violation of Newton’s Third Law, which so far as we can tell has no exceptions whatsoever for any phenomenon in the Universe.
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 9, 2013, 10:29pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/3 "2013-02-09T22:29:33Z")
Do you have a cite for that? According to the article which is dated Aug 2011: “Currently, it is not known whether matter and antimatter are gravitationally repulsive, although a few experiments (most notably, the AEGIS experiment at CERN) are testing related concepts.”[URL=“[Dark matter may be an illusion caused by the quantum vacuum](http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html#jCp)”]
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### Author:  [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)
#### Post date: [February 10, 2013, 1:22am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/4 "2013-02-10T01:22:34Z")
When I read the paper on which the article is based the first thing that strikes me is that he doesn’t prove that the assumption of antimatter having negative active gravitational mass leads to a vacuum polarization that leads to a field described by Blanchet (who has claimed to have shown that a cosmic fluid of dipole moments has a field that can re-create the predictions of MOND and on whose work his paper is based). I might be missing something, but it seems his whole argument rests on proving this, but Instead he starts off with hand-waving arguments about virtual particles.
That is of course ignoring the fact that antimatter having negative active gravitational mass causes all sorts of theoretical problems (though as of yet it’s yet to be proven one way or the other experimentally).
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 10, 2013, 1:29am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/5 "2013-02-10T01:29:41Z")
My understanding was that the polarization only happens in the neighborhood of massive objects like stars. Then you get the attractive side of the fluid being pulled toward the star and that causes the polarization.
I don’t think you get any polarization in areas where there isn’t already some significant amount of normal matter.
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### Author:  [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)
#### Post date: [February 10, 2013, 10:07am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/6 "2013-02-10T10:07:12Z")
A test of the equivalence in reaction to the gravitational field of matter and antimatter is provided by the observation of both neutrinos and antineutrinos [produced by the 1987 supernova](http://prd.aps.org/abstract/PRD/v38/i10/p3313_1).
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 10, 2013, 2:02pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/7 "2013-02-10T14:02:36Z")
> [@Half\_Man\_Half\_Wit](#):
>
> A test of the equivalence in reaction to the gravitational field of matter and antimatter is provided by the observation of both neutrinos and antineutrinos [produced by the 1987 supernova](http://prd.aps.org/abstract/PRD/v38/i10/p3313_1).
Yes but in 1987 it was not understood that neutrinos might be [majorana fermions](http://en.wikipedia.org/wiki/Sterile_neutrino#Majorana_or_Dirac.3F) so your information is a bit “dated” shall we say.
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### Author:  [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)
#### Post date: [February 10, 2013, 2:21pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/8 "2013-02-10T14:21:03Z")
> [@deltasigma](#):
>
> Yes but in 1987 it was not understood that neutrinos might be [majorana fermions](http://en.wikipedia.org/wiki/Sterile_neutrino#Majorana_or_Dirac.3F) so your information is a bit “dated” shall we say.
True enough, but if the neutrino were its own antiparticle, then antiparticles couldn’t very well have opposite mass with respect to their normal matter partners.
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 10, 2013, 2:25pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/9 "2013-02-10T14:25:59Z")
> [@Half\_Man\_Half\_Wit](#):
>
> True enough, but if the neutrino were its own antiparticle, then antiparticles couldn’t very well have opposite mass with respect to their normal matter partners.
And if they don’t have opposite mass, what does that imply?
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### Author:  [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)
#### Post date: [February 10, 2013, 2:41pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/10 "2013-02-10T14:41:10Z")
> [@deltasigma](#):
>
> And if they don’t have opposite mass, what does that imply?
That there are no gravitational dipoles, and hence, that this particular idea for resolving the dark matter mystery doesn’t work.
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 10, 2013, 2:43pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/11 "2013-02-10T14:43:36Z")
Physics comedy. Nice.
It means that both neutrinos and anti-neutrinos would be attracted to a gravitational source at the same rate.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 10, 2013, 6:53pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/12 "2013-02-10T18:53:11Z")
Hm, I could have sworn that I had seen an experiment where neutrons and antineutrons were put through an interferometer with one path higher than the other, so the difference in potential energy of the paths would change the interference pattern. I’m not finding it now, though.
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### Author:  [@deltasigma](https://boards.straightdope.com/u/deltasigma)
#### Post date: [February 10, 2013, 7:10pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/13 "2013-02-10T19:10:54Z")
I think that’s one of the motives they have at CERN for trying to make anti-hydrogen, so they have a stable source of anti-matter to use for such tests.
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### Author:  [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)
#### Post date: [February 11, 2013, 2:46pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/14 "2013-02-11T14:46:16Z")
> [@Chronos](#):
>
> It’s already been experimentally shown that antimatter is affected by the Earth’s gravitational field in the same way as normal matter (or at least, in the same direction). For antimatter to produce a different field than matter, then, would require a violation of Newton’s Third Law, which so far as we can tell has no exceptions whatsoever for any phenomenon in the Universe.
Actually, reactionless drive is allowed by general relativity. This paragraph is taken from the Wiki article on reactionless drives.
> [@](#):
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> General relativity allows a hypothetical astronaut to “swim” in curved space without using reaction mass. In other words, if spacetime is flat, then an astronaut can change his or her orientation in space through certain body movements (in the same manner as a falling cat can orient itself so that it hits the ground feet first), but no amount of this sort of exertion will change the position of his center of mass. However, if local spacetime is curved, a similar trick can be used to take advantage of this curvature - mass held in the astronaut’s outstretched hands moves in a slightly different path through curved spacetime than does mass at the astronaut’s feet, and the resulting “force” on the astronaut can change his position. While this concept is allowed by the currently accepted laws of physics, it is not clear how (or if) this effect could provide a useful means of accelerating an actual space vehicle.
Of course, this is different from antigravity, which would, I believe, be utterly incompatible with general relativity.
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### Author:  [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)
#### Post date: [February 12, 2013, 4:43am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/15 "2013-02-12T04:43:00Z")
‘Antigravity’ per se isn’t necessarily incompatible with general relativity. General relativity is so general, admitting an extremely wide variety of solutions and if you ignore energy conditions (which wouldn’t have validity anyway if you accept the existence of negative mass) then you can obtain solutions where gravity is primarily a repulsive force I believe.
However there is direct observational evidence that antiparticles have positive inertial mass and I believe direct observational evidence that they have positive energy which presents probably insurmountable theoretical problems as viewing them as having negative active gravitational mass in a GR framework. Hajdukovic in particular postulates that they have positive inertial mass/passive gravitational mass, but negative active gravitational mass; I don’t believe this would be compatible with general relativity.
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### Author:  [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [February 13, 2013, 5:39pm UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/16 "2013-02-13T17:39:50Z")
Perhaps the “Many Worlds” Theorem can be applied to gravity here.
EM radiates in 3 dimensions…does gravity radiate in 4D?
If gravity radiates _sideways_ from parallel realities, could Dark Energy simply be the gravity of mass we do not directly have contact with?
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 14, 2013, 1:42am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/17 "2013-02-14T01:42:14Z")
> [@](#):
>
> Perhaps the “Many Worlds” Theorem can be applied to gravity here.
>
> EM radiates in 3 dimensions…does gravity radiate in 4D?
I don’t know what “many worlds theorem” you’re referring to, but gravity diminishes as the inverse square of distance, just like electromagnetism, and just like you would expect for something that radiates out in three dimensions. There _are_ models, including some very well-regarded ones, that have gravity propagating through extra dimensions, but they all need to jump through various hoops to recover the inverse-square law.
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### Author:  [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [February 14, 2013, 3:53am UTC](https://boards.straightdope.com/t/how-does-this-theory-for-dark-matter-stack-up-gravitationally-polarized-virtual-dipoles/649770/18 "2013-02-14T03:53:59Z")
Yeah…I could make myself a little clearer there.
If the many worlds theorem is true…whenever a decision is made, each choice creates it’s own parallel universe…we could be feeling the effects of gravity from these alternate realities.
I can comprehend how an inverse square law applies to a 3d sphere…the shape of uniformly radiated energy…but what about a 4d hypersphere?