Hunt for dark matter is narrowed by new research

November 15, 2017, University of Sussex
Hunt for dark matter is narrowed by new research
Michał Rawlik of ETH Zürich and Nicholas Ayres of Sussex Uni. Credit: University of Sussex

Scientists at the University of Sussex have disproved the existence of a specific type of axion - an important candidate 'dark matter' particle - across a wide range of its possible masses.

The data were collected by an international consortium, the Neutron Electric Dipole Moment (nEDM) Collaboration, whose experiment is based at the Paul Scherrer Institut in Switzerland. Data were taken there and, earlier, at the Institut Laue-Langevin in Grenoble.

Professor Philip Harris, Head of Mathematical and Physical Sciences at the University of Sussex, and head of the nEDM group there, said:

"Experts largely agree that a major portion of the mass in the universe consists of ''. Its nature, however, remains completely obscure. One kind of hypothetical elementary particle that might make up the dark is the so-called axion. If axions with the right properties exist it would be possible to detect their presence through this entirely novel analysis of our data.

"We've analysed the measurements we took in France and Switzerland and they provide evidence that axions – at least the kind that would have been observable in the experiment – do not exist. These results are a thousand times more sensitive than previous ones and they are based on laboratory measurements rather than astronomical observations. This does not fundamentally rule out the existence of axions, but the scope of characteristics that these particles could have is now distinctly limited.

"The results essentially send physicists back to the drawing board in our hunt for dark matter."

It has been believed for decades that axion particles might make up at least some of 'dark matter' – the stuff that we know is in our universe but which cannot be seen. Axions are important because finding them, if they exist, could hold the key to why the universe has lots of matter but relatively little antimatter. Equal amounts of matter and antimatter would have been created when the universe began, and it should all have mutually annihilated, but the Universe clearly now has plenty of matter – but essentially no antimatter – left over; we do not understand why.

This is the first experiment to use laboratory equipment – rather than – to investigate this type of axion. Previously, physicists had been gradually narrowing the range of possible masses of the axion through telescope-based experiments. The research published today wipes out a whole swathe of potential masses. As a result, particle theorists attempting to explain the origins of the Universe and the nature of dark matter will have to go back to the drawing board as they revise, constrain and tune their models. An important benchmark has been set for future experimental searches; and other experiments, working in related topics, will be able to analyse their data in this new way to extend the sensitivity further.

The data were collected for another purpose – to look at why the universe is dominated by matter and not antimatter – when it was realised that the measurements could be used to search for the presence of axions too. The experiment worked by trapping neutrons, then applying a high voltage to their container to see whether it affected the rate at which they spin. A change in this rate would indicate that they have a distorted structure – and changes in that distortion over time (from minutes to years) would indicate that there were axions present. No such distortions were seen, and therefore no axions were detected. The nEDM experiment itself is a "classic" in particle physics, having run in one form or another with ever-increasing sensitivity since 1950, and ruling out many theories along the way. It is one of the most sensitive measurements that it is possible to make, and Sussex-led measurements have provided the world's best sensitivity continously since 1999.

Nicholas Ayres, a graduate student in the School of Mathematical and Physical Sciences at the University of Sussex and co-leader of this particular analysis, said:

"These results open a new front in the hunt for dark matter. They disprove the existence of axions with a wide range of masses and therefore help to limit the variety of particles which could be candidates for dark matter. And it's fantastic to see that these results – which were being collected for another purpose entirely – could be used as a piggyback to search for axions too."

Professor Philip Harris explains how the data could be used to search for axions as well as for its original intended purpose:

"In our original experiment we took a single measurement and repeated it many times to determine the average value over a long time. When we're searching for axions, we watch for whether the measurement fluctuates over time with a constant frequency. If so, it would be proof that there had been some interaction between the neutron and the . We never saw that. "

The experiment does not rule out the existence of axions entirely. Firstly, the axions would need to have interacted strongly enough with the neutrons for any change in its rotation rate to be spotted. Secondly, their mass might either be larger or smaller than expected. It does, however, provide important new constraints, and it points the way forward to future avenues of investigation to help resolve one of cosmology's great outstanding mysteries. These experiments make an important contribution to the search for dark matter.

The paper, "Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields," is published in Physical Review X.

Explore further: Searching for axion dark matter with a new detection device

More information: C. Abel et al. Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields, Physical Review X (2017). DOI: 10.1103/PhysRevX.7.041034

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dirk_bruere
3.5 / 5 (6) Nov 15, 2017
Eventually every model that can be experimentally tested will be ruled out, and the subject will be moved to the theology dept.
fthompson495
1 / 5 (5) Nov 15, 2017
There is evidence of the smoothly distributed, strongly interacting, supersolid dark matter every time a double-slit experiment is performed, as it is the dark matter that waves.
Gigel
5 / 5 (3) Nov 15, 2017
There is evidence of the smoothly distributed, strongly interacting, supersolid dark matter every time a double-slit experiment is performed, as it is the dark matter that waves.


What is the link (if any) between the wave in diffraction and dark matter density?

How can you experimentally check this idea, i.e. draw different conclusions on your idea and current ideas and then build an experiment that confirms one of those conclusions? Without experiment this is only speculation.
antialias_physorg
5 / 5 (9) Nov 15, 2017
Eventually every model that can be experimentally tested will be ruled out

Don't underestimate the inventiveness of scientists and engineers. (in any case scientists can throw out ideas a lot faster than engineers can test them)
fthompson495
1 / 5 (1) Nov 15, 2017
There is evidence of the smoothly distributed, strongly interacting, supersolid dark matter every time a double-slit experiment is performed, as it is the dark matter that waves.


What is the link (if any) between the wave in diffraction and dark matter density?

How can you experimentally check this idea, i.e. draw different conclusions on your idea and current ideas and then build an experiment that confirms one of those conclusions? Without experiment this is only speculation.


https://www.space...ies.html
mackita
5 / 5 (2) Nov 15, 2017
No signal consistent with dark matter is observed for the axion mass range 10E−24≤Ma≤10E−17  eV
Isn't it a bit off to expect interaction of such lightweight particles with atom nuclei? Even common vacuum fluctuations and/or photons of CMB noise have an energy in the range 10E−4 eV. The point is, if the particles are too lightweight (like the neutrinos with rest mass in the range of few eV as mc2 energy), then the vacuum fluctuations permanently excite them, so that their mass also fluctuates (the analogous process occur with quarks inside very dense nuclear matter). The more lightweight particles would remain solely unobservable, because the vacuum fluctuations would spread them across whole energy spectrum.

We can just observe, how physicists gradually converge to realistic physical scales of dark matter by gradually excluding too lightweight or too heavy dark matter particle models. But there isn't too much insight in such a gradualist progress.
Whydening Gyre
5 / 5 (5) Nov 15, 2017
...
We can just observe, how physicists gradually converge to realistic physical scales of dark matter by gradually excluding too lightweight or too heavy dark matter particle models. But there isn't too much insight in such a gradualist progress.

Yet...:-)
fthompson495
1 / 5 (1) Nov 15, 2017
Isn't it a bit off to expect interaction of such lightweight particles with atom nuclei? Even common vacuum fluctuations ...


Dark matter is a smoothly distributed, strongly interacting, supersolid. It's chaotic nature is what causes there to be vacuum fluctuations.

In the following video, the water represents the chaotic nature of the dark matter. It is the chaotic nature of the strongly interacting dark matter which causes the Casimir effect.

https://youtu.be/Dv8IRx43vy0

It is the chaotic nature of the dark matter which leads to the probabilistic results of experiments.
Seeker2
1 / 5 (1) Nov 15, 2017
"Equal amounts of matter and antimatter would have been created when the universe began, and it should all have mutually annihilated,"

Unless one particle of the new particle pair interacts with a particle of similar matter - like a 50-50 chance. Otherwise they annihilate causing inflation and driving the particle zones with similar type matter farther and farther apart - providing more secure safe havens for similar type particles.
Whydening Gyre
5 / 5 (3) Nov 15, 2017
"Equal amounts of matter and antimatter would have been created when the universe began, and it should all have mutually annihilated,"

Unless one particle of the new particle pair interacts with a particle of similar matter - like a 50-50 chance. Otherwise they annihilate causing inflation and driving the particle zones with similar type matter farther and farther apart - providing more secure safe havens for similar type particles.

So... you're thinkin' there is still an equal amount of anti matter out there, somewhere?
Seeker2
1 / 5 (1) Nov 15, 2017
So... you're thinkin' there is still an equal amount of anti matter out there, somewhere?
Yep, Maybe even Andromeda. Oops.
Mimath224
5 / 5 (2) Nov 15, 2017
Well, from my point of view no matter what the tests are and about what 'particle' it's a step in the right direction for a solution...at least theoretically. The more experiments that can be done the better though I would guess (and it is a guess) that such experiments have to wait for funding. I have no idea how academics prioritize but since the argument for & against DM seem to be more publicity these days perhaps that has an influence. I understand that in cosmological realms the Axion has a very low mass 1< to 1 ev (/c^2) and is expected to a very low interaction figure, hence being a DM candidate, but I do admit my understanding of the CP theory in QCD is next to nothing so those more informed than I are better qualified to comment.
howhot3
5 / 5 (4) Nov 15, 2017
Well that is one more experiment that forces us to look at the alternatives. I have all my bets on "Emergent Gravity" as the most realistic solution to the question of 'what is dark-matter'. https://arxiv.org...11.02269

https://arxiv.org...001.0785

The best part is it works well with the standard model with nothing exotic describing dark matter other than a deeper understanding of how space-time curves in the presents of matter.

Gigel
5 / 5 (1) Nov 16, 2017

https://www.space...ies.html


I think this (or a similar) hypothesis was eventually disproved and there was an article on phys.org about this.

Anyway, this still doesn't address the link between dark matter density and the wave character of a particle. The study is about a wavy particle of dark matter, not about any particle behaving as a wave too.
Whydening Gyre
5 / 5 (5) Nov 16, 2017
Well that is one more experiment that forces us to look at the alternatives. I have all my bets on "Emergent Gravity" as the most realistic solution to the question of 'what is dark-matter'. https://arxiv.org...11.02269

The best part is it works well with the standard model with nothing exotic describing dark matter other than a deeper understanding of how space-time curves in the presents of matter.

From the Arxiv summary;
"Gravity is explained as an entropic force caused by changes in the information associated with the positions of material bodies."

Which would change at every moment...
AND which, traveling at the speed of light would produce varying effects at different times...
Interesting thought food...
RogueParticle
4.2 / 5 (5) Nov 16, 2017
I have all my bets on "Emergent Gravity" as the most realistic solution to the question of 'what is dark-matter'
Interesting idea, thanks for the links. The Wiki (https://en.wikipe..._tests), however, lists some criticisms of Verlinde's scheme, so the jury is still out on that one.
fthompson495
1 / 5 (2) Nov 16, 2017
The study is about a wavy particle of dark matter, not about any particle behaving as a wave too.


Wave-particle duality is a moving particle and its associated wave in the dark matter, analogous to a boat and its bow wave. The boat doesn't wave. The boat has an associated wave. Particles don't wave. Particles have associated waves in the dark matter.

https://youtu.be/WIyTZDHuarQ
Seeker2
not rated yet Nov 16, 2017
The boat doesn't wave. The boat has an associated wave. Particles don't wave. Particles have associated waves in the dark matter.
So a stationary particle has no associated wave function. Interesting.
fthompson495
1 / 5 (2) Nov 16, 2017
The boat doesn't wave. The boat has an associated wave. Particles don't wave. Particles have associated waves in the dark matter.
So a stationary particle has no associated wave function. Interesting.


In de Broglie's double solution theory the wave-function is a mathematical construct only. It doesn't physically exist. It is the associated wave in the "subquantic medium" that guides the particle. Today, the "subquantic medium" is referred to as a smoothly distributed, strongly interacting, supersolid dark matter.

A "stationary particle" does not have an associated wave in the dark matter. The particle is never truly "stationary" as it is always getting "knocked around" by the chaotic nature of the dark matter. The particle getting "knocked around" by the chaotic dark matter is the zero-point energy associated with the particle.
Gigel
not rated yet Nov 16, 2017
Dark matter is considered to have nonuniform density in space. How does a normal particle behave as a wave for different dark matter densities?

I think such a connection, if it exists, can be tested. After all, electrons in atoms have states as a function of their wave nature. Atomic emissions may be different in different places if such a connection between dark matter density and the wave nature of a particle were real.
fthompson495
1 / 5 (1) Nov 16, 2017
Dark matter is considered to have nonuniform density in space.


That's what's incorrect about the current notion of dark matter.

'Dark Matter More Ubiquitous Than We Ever Thought'
https://www.inver...-thought

"dark matter is smooth, distributed more evenly throughout space than we thought"

What physicists mistake for lumpy dark matter is actually the state of displacement of the smoothly distributed supersolid dark matter.
fthompson495
1 / 5 (1) Nov 16, 2017
The following are evidence of ordinary matter moving through and displacing the smoothly distributed dark matter.

'The Milky Way's dark matter halo appears to be lopsided'
http://arxiv.org/abs/0903.3802

"he dark matter halo of the Milky Way is dominantly lopsided in nature."

The Milky Way's halo is lopsided due to the ordinary matter in the Milky Way moving through and displacing the strongly interacting dark matter, analogous to a submarine moving through and displacing the water.

"the gravitational potential in clusters is mainly due to a non-baryonic fluid"

The center of the light lensing through the space neighboring the galaxy clusters and the center of the galaxy clusters themselves is offset as the galaxy clusters move through and displace the strongly interacting dark matter, as submarines move through and displace water.
fthompson495
1 / 5 (1) Nov 16, 2017
*edit timeout above*

'Offset between dark matter and ordinary matter: evidence from a sample of 38 lensing clusters of galaxies'
https://arxiv.org...004.1475

"the gravitational potential in clusters is mainly due to a non-baryonic fluid"

The center of the light lensing through the space neighboring the galaxy clusters and the center of the galaxy clusters themselves is offset due to the galaxy clusters moving through and displacing the strongly interacting dark matter, analogous to submarines moving through and displacing the water.
Seeker2
not rated yet Nov 16, 2017
The particle is never truly "stationary" as it is always getting "knocked around" by the chaotic nature of the dark matter. The particle getting "knocked around" by the chaotic dark matter is the zero-point energy associated with the particle.
I would associate the zero-point energy as that of the dark energy
Seeker2
not rated yet Nov 16, 2017
The center of the light lensing through the space neighboring the galaxy clusters and the center of the galaxy clusters themselves is offset due to the galaxy clusters moving through and displacing the strongly interacting dark matter, analogous to submarines moving through and displacing the water.
If the center of mass of the galaxy is moving away from that of the dark matter halo then there must be some driving force. I can believe the chaotic behavior of the halos but not the galaxies, so it would appear the galaxies are only following the halos.
fthompson495
1 / 5 (1) Nov 16, 2017
I would associate the zero-point energy as that of the dark energy


We are in the outflow of a Universal black hole. As ordinary matter falls toward the black hole it evaporates into dark matter. It is the dark matter outflow which pushes the galaxy clusters, causing them to move outward and away from us. The dark matter outflow is dark energy.

The energy described in the following article at the scale of our Universal black hole is dark energy.

'Black holes banish matter into cosmic voids'
http://www.spaced...999.html

"Some of the matter falling towards the [supermassive black] holes is converted into energy. This energy is delivered to the surrounding gas, and leads to large outflows of matter, which stretch for hundreds of thousands of light years from the black holes, reaching far beyond the extent of their host galaxies."
antialias_physorg
5 / 5 (4) Nov 16, 2017
As ordinary matter falls toward the black hole it evaporates into dark matter.

Erm..why should it? (note that we - and you - don't even know what dark matter is at this point)...so talking about an 'evaporation of matter into dark matter' makes no sense...come to think of it: what does 'evaporation' even mean in this context? You're just throwing random words together. Not smart.

The dark matter outflow is dark energy.

You really have no clue what you are posting, do you? Hint: sticking some googled sciency-looking words into a sentence doesn't make you look smart. It actually makes you look really, really dumb.
ShotmanMaslo
5 / 5 (5) Nov 16, 2017
Well that is one more experiment that forces us to look at the alternatives. I have all my bets on "Emergent Gravity" as the most realistic solution to the question of 'what is dark-matter'. https://arxiv.org...11.02269

https://arxiv.org...001.0785


Note that these two papers, while both being by Verlinde and mentioning emergent gravity and entropy, are fundamentally based on different ideas. 2010 paper is where Verlinde proposed his entropic gravity. His 2016 paper is based on ER=EPR correspondence (entanglement-spacetime correspondence), which was proposed by Susskind and Maldacena in 2013. It is not really a followup to his 2010 emergent gravity theory.

https://en.wikipe...ER%3DEPR
fthompson495
1 / 5 (1) Nov 16, 2017
As ordinary matter falls toward the black hole it evaporates into dark matter.

Erm..why should it?


That's what the energy is.

'Black holes banish matter into cosmic voids'
http://www.spaced...999.html

"Some of the matter falling towards the [supermassive black] holes is converted into energy. This energy is delivered to the surrounding gas, and leads to large outflows of matter, which stretch for hundreds of thousands of light years from the black holes, reaching far beyond the extent of their host galaxies."
fthompson495
1 / 5 (1) Nov 16, 2017
If the center of mass of the galaxy is moving away from that of the dark matter halo then there must be some driving force. I can believe the chaotic behavior of the halos but not the galaxies, so it would appear the galaxies are only following the halos.


Dark matter fills 'empty' space. 'Empty' space is a sea of dark matter that ordinary matter moves through and displaces, analogous to submarines moving through and displacing the water. The galaxy is not moving away from the dark matter halo. The galaxy is moving through and displacing the dark matter, analogous to a submarine moving through and displacing the water. The state of displacement of the dark matter is the galaxies halo.
Seeker2
5 / 5 (2) Nov 16, 2017
...analogous to a submarine moving through and displacing the water. The state of displacement of the dark matter is the galaxies halo.
Submarines run on fuel. What fuels the galaxies?
fthompson495
1 / 5 (1) Nov 16, 2017
Submarines run on fuel. What fuels the galaxies?


There is no loss of energy in the interaction of the supersolid dark matter and ordinary matter. if there were, it wouldn't be a supersolid.

Q. Does the galaxy displace the supersolid dark matter or does the supersolid dark matter displace the galaxy?
A. Both occur simultaneously with equal force, and the galaxy moves forever through the supersolid dark matter.
Mimath224
5 / 5 (2) Nov 16, 2017
@antialias_physorg just a small interjection in your above conversation. Something occurred to me that I don't remember reading about; 'movement of DM'? Now I'm not sure if that is even a valid question because, as you point out, we don't know what DM is yet. But I was just thinking if DM does move around would the consequence of that show a movement in some gravitational effect from one place to another? Would it have a type of 'gravity wave' effect on the surrounding space (that is, an equilibrium or balancing effect)? Maybe these points are covered somewhere and I just haven't seen them...or perhaps my thoughts are just plain illogical. What do you think?
Da Schneib
4.2 / 5 (5) Nov 16, 2017
What I find amusing is that #physicscranks who argue against dark matter keep whining as the possibilities for it keep getting reduced.

This is duh ummm.
mackita
5 / 5 (2) Nov 16, 2017
Excess positrons could come from dark matter after all to put it even more simply: the positrons can form a substantial portion of dark matter, together with another antiparticles and highly ionized, i.e. positively charged atom nuclei. Their repulsive forces keeps them at distance against gravity and they prohibit their annihilation. The "missing antimatter" problem will be solved..

It doesn't mean, that all effects of dark matter must be caused by particles - but nothing also indicates, that this artifact is of homogeneous nature (astrophysicists already recognize "cold", "warm" and "hot" dark matter).
Seeker2
5 / 5 (1) Nov 16, 2017
There is no loss of energy in the interaction of the supersolid dark matter and ordinary matter. if there were, it wouldn't be a supersolid.
The only supersolid dark matter I know of would be a black hole. And they release the binding energy of all the ordinary matter that falls into it.
Benni
1 / 5 (4) Nov 16, 2017
What I find amusing is that #physicscranks who argue against dark matter keep whining as the possibilities for it keep getting reduced.


Next, you're gonna make an announcement that you never believed in the existence of DM in he first place, can't wait.
fthompson495
1 / 5 (1) Nov 17, 2017
The only supersolid dark matter I know of would be a black hole. And they release the binding energy of all the ordinary matter that falls into it.


You should know of the supersolid dark matter that fills 'empty' space, as it is the medium that waves in a double slit experiment.
Seeker2
5 / 5 (1) Nov 17, 2017
You should know of the supersolid dark matter that fills 'empty' space, as it is the medium that waves in a double slit experiment.
Maybe it was as my aunt Carrie used to write, having the power to excel but denied the power of thinking well.
fthompson495
1 / 5 (1) Nov 17, 2017
Maybe it was as my aunt Carrie used to write, having the power to excel but denied the power of thinking well.


Or, you can understand in a double slit experiment the particle always travels through a single slit and the associated wave in the dark matter passes through both.
Seeker2
5 / 5 (1) Nov 17, 2017
Or, you can understand in a double slit experiment the particle always travels through a single slit and the associated wave in the dark matter passes through both.
So if the slit isn't big enough the particle bounces back and the wave continues on through?
Seeker2
5 / 5 (1) Nov 17, 2017
Actually if the particle passes thru only one slit then you should be able to tell which slit it was by the pattern of the interference fringes.
fthompson495
1 / 5 (1) Nov 17, 2017
So if the slit isn't big enough the particle bounces back and the wave continues on through?


Yup. And as the particle continues on it then generates another wave which guides it.

https://youtu.be/WIyTZDHuarQ
fthompson495
1 / 5 (1) Nov 17, 2017
Actually if the particle passes thru only one slit then you should be able to tell which slit it was by the pattern of the interference fringes.


No, you wouldn't as the associated wave exiting both slits creates wave interference which then guides the particle.

There is something called weak measurement where you can detect the particle slightly and not completely destroy the interference pattern.

http://physicswor...for-2011

http://www.bbc.co...13626587

http://www.scient...inciple/
Seeker2
5 / 5 (1) Nov 17, 2017
...the associated wave exiting both slits creates wave interference which then guides the particle.
Then you should be able to tell from the inteference pattern between these associated waves which guide the particle exactly which slit the particle passed thru.
fthompson495
1 / 5 (1) Nov 17, 2017
Then you should be able to tell from the inteference pattern between these associated waves which guide the particle exactly which slit the particle passed thru.


If that were knowable then wave-particle duality would have been understood to be a moving particle and its associated wave back in the 1800s.

You have to physically detect (ie. physically interact) with the particle in order to know which slit it exits.
mackita
5 / 5 (2) Nov 17, 2017
Few links which you can ignore: 1,2..3, 4, 5..6,7..8, 9..10, 11
tallenglish
not rated yet Nov 17, 2017
What about Dark Matter = Anti-Matter travelling at -c, so exactly the same stuff as matter and energy we know with opposite spin, etc. Where mass pushes down on the spacetime continuum, DM would push up, i.e. it would corral and trap mass compressing it to form stars (every star, including our own). It would also explain a lot to where all the positrons we see hitting the earth come from and the corona.
Seeker2
5 / 5 (1) Nov 17, 2017
You have to physically detect (ie. physically interact) with the particle in order to know which slit it exits.
So the interference pattern has nothing to do with which slit the particle goes thru. Just checking.
howhot3
5 / 5 (3) Nov 17, 2017
Note that these two papers, while both being by Verlinde and mentioning emergent gravity and entropy, are fundamentally based on different ideas. 2010 paper is where Verlinde proposed his entropic gravity. His 2016 paper is based on ER=EPR correspondence (entanglement-spacetime correspondence), which was proposed by Susskind and Maldacena in 2013. It is not really a followup to his 2010 emergent gravity theory.

Good point. This is why "Quantum" and "Gravity" are like oil and water. The wiki suggest that ER=EPR is dependent on quantum entanglement of blackholes. Is that your reading? I read both Verlinde papers as being on the same Plank scale, and interchangeable. But I'm no expert on quantum gravity.

howhot3
5 / 5 (3) Nov 17, 2017
Just to follow up because the last post is so unclear. Here is what I find objectionable to the ER=EPR conjecture. What is the difference between a spinning black hole compared to a pair of black holes in tight orbit? If the pair are orbiting near singularity, then their quantum wave function would be morphed and look the same as quantum wave of the single spinning blackhole! So ER=EPR. In other words, and QM entangled blackholes are equivalent to spinning blackhole which is always! Thus the two papers by Verlinde are really based on the same thing so I don't see any issue.

The ER=EPR makes sense on big scales and big mass. However, on the scale of micro-blackholes near the Plank scale, does it matter? At that scale everything is entangled anyway!
Seeker2
not rated yet Nov 17, 2017
...]So the interference pattern has nothing to do with which slit the particle goes thru. Just checking.
So how does the particle know which slit to pass thru? Let me guess. The first one it comes to. Also wondering what if the slit is too small? Does the particle just sort of squeeze thru? Or maybe just bounce off? Tricky.
Seeker2
not rated yet Nov 17, 2017
This is why "Quantum" and "Gravity" are like oil and water.
Really. Quantization is the precise reason quantized matter gravitates. That means it doesn't expand like spacetime. So to minimize the interaction between expanding spacetime and non-expanding quantized matter around the surface of the quantized matter, the forces of expansion tend to gather the quantized matter into a spherical distribution according to the principle of least action..
howhot3
5 / 5 (3) Nov 18, 2017
So how does the particle know which slit to pass thru? Let me guess. The first one it comes to. Also wondering what if the slit is too small? Does the particle just sort of squeeze thru? Or maybe just bounce off? Tricky.

Special Relativity (SR) would and does describe well what you are asking. The slit experiment is a puzzle, however, in SR at the speed of light and from the point of view of photons as if you were riding on the photon, 3d space/time collapses to plane perpendicular to your travel. 0 time. From the photon point of view time does not exist and so the slit does not exist. Both slits are the same.

From out point of view, the photon travels through the slit we observe it passing.
mackita
3 / 5 (2) Nov 19, 2017
In pilot wave theory from 1927 every particle is surrounded by wake wave of vacuum like the boat floating at the water surface. The particle can squeeze through slit easily, but its pilot wave not and it interferes with both slits at the same moment, both particle, thus affecting retroactively its path.

The water surface analogy can be extended further, as the water surface usually isn't flat - but covered by myriads of shapeless ripples. Analogously the vacuum can be filled by many pilot waves, which are following vacuum fluctuations: these are forming dark matter without any well distinguished particles in it. What we can observe are only subtle density gradients of these fluctuations observable like the gravitational lensing.
TheGhostofOtto1923
5 / 5 (2) Nov 19, 2017
"Scientists at the University of Sussex have disproved the existence of a specific type of axion"

- But have yet to disprove the existence of the hydrino, which could well be the dark matter constituent.

Or it could be garden fairies, equally elusive. Who knows? Soon maybe?
http://brilliantlightpower.com
The water surface analogy can be extended further, as the water surface usually isn't flat - but covered by myriads of shapeless ripples
Zephyr banned again in 3... 2... 1... poof
fthompson495
not rated yet Nov 19, 2017
In https://phys.org/...pic.html from 1927 ...


The correct interpretation of quantum mechanics is de broglie's double solution theory.

https://en.wikipe...n_Theory
mackita
5 / 5 (1) Nov 19, 2017
@fthompson495: It's better than pilot wave theory, which is better than Copenhagen in certain extent - but in no way perfect. Some phenomena like the entanglement would require even deeper theory outside the realm of wave mechanics.
Seeker2
not rated yet Nov 19, 2017
I understand the wave function for an electron represents the probability of finding the position of the electron at any point and this includes in the whole universe. I presume this holds for any particle. So I should think the double slit experiment really splits the wave function into two parts, one for each slit. As long as the wave function is symmetrical about both slits I don't see any way you could predict which slit the particle would pass thru. Not implying that you could never determine which slit the particle actually passed through for any one event. So you would need several runs to test this theory.
mackita
5 / 5 (1) Nov 19, 2017
you could predict which slit the particle would pass thru
This is not what the pilot wave theory was developed for. But it's very easy to demonstrate it - simply by looking at the target screen. The classical Copenhagen interpretation says, that the particle passes the double slit widespread into its probability wave. So it should stay so - and not to impact the screen like pin-point particle, isn't it true?
Seeker2
not rated yet Nov 19, 2017
The classical Copenhagen interpretation says, that the particle passes the double slit widespread into its probability wave. So it should stay so - and not to impact the screen like pin-point particle, isn't it true?
Sure would be if a single particle produces an interference pattern. Interesting.
fthompson495
not rated yet Nov 20, 2017
@fthompson495: It's better than pilot wave theory, which is better than Copenhagen in certain extent - but in no way perfect. Some phenomena like the entanglement would require even deeper theory outside the realm of wave mechanics.


@mackita https://en.wikipe...nglement
mackita
5 / 5 (1) Nov 20, 2017
@fthompson495 Double solution theory recognizes weak and strong entanglement, because each particle is represented with pair of independent quantum waves (i.e. sets of quantum oscillators within Hilbert space) - but still cannot account to directional aspect of it: the collinear particles get entangled stronger. But in both cases we are talking about aspects, which still wait for its recognition by mainstream physics.

The double solution theory applies in double slit experiment during transition of diffraction from low-energy photons into high energy/frequency ones, when the image of particles at the target screen changes gradually from fuzzy overlapping patterns into pin-point spots typical for fermions: the pilot wave theory cannot account to this transition, not to say about vanilla Copenhagen model, which just deals with wave-like distribution of particle spots, but it has nothing to say about their shape/size.
fthompson495
not rated yet Nov 20, 2017
@fthompson495 Double solution theory recognizes weak and strong entanglement, because each particle is represented with pair of independent quantum waves (i.e. sets of quantum oscillators within Hilbert space)


De Broglie realized configuration space was fictitious and that is why the physical wave exists in the "sub-quantum medium".

https://en.wikipe...n_Theory
Seeker2
not rated yet Nov 20, 2017
So... you're thinkin' there is still an equal amount of anti matter out there, somewhere?
Yep, Maybe even Andromeda. Oops.
Interesting - http://www.syfy.c...up-a-lot
tgmeloche
not rated yet Nov 22, 2017
Spiral galaxies in our universe seem to be achieving an impossible feat. The stars in spiral galaxies are rotating with such speed that the gravity signature generated by the observable matter could not possibly hold them together; they should have torn themselves apart long ago. The same is true of galaxies in clusters, which leads scientists to believe that something we cannot see is at work. They think something we have yet to detect directly is giving these galaxies extra mass, generating the extra gravity they need to stay intact. This strange and unobserved matter was named "dark matter.
Lack of knowledge to how gravity works at the galactic scale is at the root of the problem. The influence of gravity signature within a spiral galaxy is different than that observed by Newton.
21st century solution and innovation to resolve the problem can be found in the google links below.
The principles of atomic gravity are tools used to unify and advance academic research in
mackita
1 / 5 (1) Nov 22, 2017
I can agree, that the dark matter cannot be understood, until we don't understand the mechanism of gravity. Einstein guessed correctly, that the massive bodies curve space-time around them - but how exactly they're doing it is still unknown mystery - despite the most relevant explanation was proposed before 340 years already.

It's worth to note, that people in social groups are also behaving in unison, despite the speed and scope of social interactions remains limited. Such a people follow emergent patterns of the whole crowd. They don't want to differ and remain individualist at the same moment, so that they're filling the memetic holes of the crowd. For example, once the Tamagochi or bell-shaped trousers come into fashion, then every teenager in the class wants to get them first. And the stars aren't very different, once they have an opportunity to fill the space between another stars.
Seeker2
not rated yet Nov 22, 2017
Einstein guessed correctly, that the massive bodies curve space-time around them - but how exactly they're doing it is still unknown mystery -
Sure seemed that way. But I think he's talking about surfaces of spacetime having equal gravitational force. Or equal dark energy densities. Actually equal gradients in the dark energy densities.

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