Dark Matter and Wave Particle Duality

[chasmanian]

nFA,

is it possible that Dark Matter has wave particle duality?

https://www.symmetrymagazine.org/articl ... 20a%20wave.


and for that matter (hahaha),

could Dark Energy too?

this is from this article:

“This was actually Einstein’s idea,” Upadhye says. “If you put in a substance with a negative pressure into the equations of general relativity you get this accelerating expansion of universe.”

https://www.symmetrymagazine.org/articl ... y-particle

[notFritzArgelander]

Sorry to be slow responding, it almost fell through the cracks. I read the OP on my mobile device so it got marked as "read" and when I was back on my "not so mobile" device I lost track.

First of all there is a question about what is meant by "wave particle duality". In truth, the common usage refers to pedagogic examples like the double slit experiment where photons and electrons propagate like waves but are detected like particles. In truth this version of "wave particle duality" is artificial, IMO. It is created by the inadequacy of ordinary human language to faithfully describe the situation. Within QM itself the photon or electron is described by a state function in a Hilbert space. In the Hilbert space there is no need to choose between the wave or particle nature of quantum objects at all. We only run into troubles when we try to talk about these things in human languages without mathematics. It leads to manifold confusions by folks who insist on taking "wave particle duality" seriously in this sense. See https://en.wikipedia.org/wiki/Wave–part ... ticle_view for a catalogue on how confusing this can be.

I avoid the confusion with a :shrug: and the certain knowledge that in Hilbert space both pictures are well supported and there is no problem as long as you stick close to the math. To clarify there is an interesting article by Carlo Rovelli that recounts the famous anecdote of a conversation between Felix Bloch and Werner Heisenberg.

Felix Bloch reports an enlightening conversation with Heisenberg: ‘We were on a walk and somehow began to talk about space. I had just read Weyl’s book Space, Time and Matter, and under its influence was proud to declare that space was simply the field of linear operations. ‘Nonsense,’ said Heisenberg, ‘space is blue and birds fly through it.’

The point is that the calculation apparatus is not physically real (the wave particle duality supported by Hilbert spaces, for instance, does not matter) but what is important are the relations between physically observable quantities. The conflict in our minds about wave particle duality have the same ontological status as a scary movie. In much of the popular science press this provides an opportunity to hype and mystify.

The full article by Rovelli was an interesting read for me so it can be found here. https://royalsocietypublishing.org/doi/ ... .2017.0312

I think that Rovelli is onto something with his idea of Relational Quantum Mechanics. I think it closest to Heisenberg's original vision. The usual take on "wave particle duality" is a fiction, a language induced problem.

That said, in Quantum Field Theory there is (because of Hilbert space again) a genuine duality between fields and particles. Quantum Field Theory guarantees that for every particle there is a field and for every field there is a particle. So now that I've provided the "spoiler" to some of the questions raised, more later on the two articles from Symmetry.

[AntennaGuy]

If dark matter "particles" exist and have sufficiently small (but finite) rest masses and not overly-high speeds, then their individual momenta will be low. Thus, their associated de Broglie wavelengths (https://en.wikipedia.org/wiki/Matter_wave) will be long. And since the universe is full of them, I bet they would be plentiful, essentially forming a classically-equivalent continuum (so to speak) much like EM waves. And almost anything in physics that behaves like that, with a long enough wavelength, can/should be detected experimentally via something resembling (more or less, ok!) an antenna, which is itself connected to (more or less) something analogous to a radio (that is, typically a tunable receiving system). I feel pretty comfortable about asserting this, because my assertion is self-evidently valid for acoustic waves, ocean waves, and more. [Yes, really, even various ocean wave energy collection devices (most at various stages of R&D) are designed to operate analogously to radios & antennas.] You want a dark matter antenna? I'll be happy to design one for you. Just... tell me what the physics is. You know, something like Maxwell's equations. Or any other wave equation. Along with some kind of practical/usable matter-coupling term, please (like the Lorentz force law!). And... once you describe it, and once I understand it (hey, it could take a while, I'm not as young as I used to be...), I'll whip up a physics-level "dark matter antenna" design for you within a week or two (or three or four...), because that's (well, sort of) what I normally get paid to do. But no charge to you, my good buddies here at TSS! That said, I may want to hold on to the patent rights. Thanks!

[notFritzArgelander]

Along with some kind of practical/usable matter-coupling term, please (like the Lorentz force law!).

Aye, there's the rub. For axionic DM there are many predicted but so far not experimentally verified matter coupling terms. One proposal is that they require a modification of Maxwell:

https://arxiv.org/pdf/1809.01654.pdf

A reformulation of axion modified electrodynamics is presented where the equations maintain a similar form to the unmodified Maxwell’s equations, with all modifications redefined within the constitutive relations between the D, H, B and E fields. This allows the interpretation of the axion induced background bound charge, polarization current and bound current along with the axion induced polarization and magnetization with the former satisfying the charge-current continuity equation. This representation is of similar form to odd-parity Lorentz invariance violating background fields in the photon sector of the Standard Model Extension. Weshow that when a DC B-field is applied an oscillating background polarization is induced at a frequency equivalent to the axion mass. In contrast, when a large DC E-field is applied, an oscillating background magnetization is induced at a frequency equivalent to the axion mass. It is evident that these terms are equivalent to impressed source terms, analogous to the way that voltage and current sources are impressed into Maxwell’s equations in circuit and antenna theory. The impressed source terms represent the conversion of external energy into electromagnetic energy due to the inverse Primakoff effect converting energy from axions into oscillating electromagnetic fields. It is shown that the impressed electrical DC current that drives a DC magnetic field of an electromagnet, induces an impressed effective magnetic current (or voltage source) parallel to the DC electrical current oscillating at the Compton frequency of the axion. The effective magnetic current drives a voltage source through an electric vector potential and also defines the boundary condition of the oscillating axion induced polarization (or impressed axion induced electric field) inside and outside the electromagnet. This impressed electric field, like in any voltage source, represents an extra force per unit charge supplied to the system, which also adds to the Lorentz force.

So, your work is done.

[chasmanian]

wow, thank you nFA.
I am very grateful awesome generous reply.
fascinating, all of it.

and thank you too AntennaGuy.

[pakarinen]

‘Nonsense,’ said Heisenberg, ‘space is blue and birds fly through it.’

Gotta love it!

[AntennaGuy]

...
So, your work is done.

Thank you. I'll read that article. We'll see how long the "understanding" part of the aforementioned process takes me. Just don't start that 1-4 weeks-to-design countdown, yet.

[chasmanian]

‘Nonsense,’ said Heisenberg, ‘space is blue and birds fly through it.’

Gotta love it!

yes, I also love this. thank you for posting this funny story nFA!!

[notFritzArgelander]

nFA,

is it possible that Dark Matter has wave particle duality?

https://www.symmetrymagazine.org/articl ... 20a%20wave.

I remember posting a link to this article back at the "old sod" and having a favorable view of the proposal, but I don't recall the details of it though. It would be amusing to compare for consistency. :sigh: I think I am more skeptical about this effort today though. I think that the most it has going for it is that it is remarkably low cost to do. The physical reasoning might well be.... errr.... emmm.... hem..... haw...
dubious.

The idea is that if the mass is so low that the Compton wavelength is large then an antenna might be a better idea than a particle detector. But consider the normal standard every day photon which is massless and with no defined Compton wavelength. Sometimes an antenna will work, but the requirement for that is that the number of photons in any frequency be huge. If you HAD to use an antenna to detect photons CCD cameras would be useless. Neutrinos are more massive than photons but less than DM. Yet EVERY neutrino detection involves particle detection. Neutrinos do not couple to Maxwell's equations (except through charged intermediate vector bosons) so there's an out there.

The project has been selected for funding by the DoE. Here's the latest with more highly informative graphics about expectations.

https://irwinlab.sites.stanford.edu/dar ... io-dmradio

But the usual way to look for axions is to look for their conversion to photons in strong magnetic fields. CERN's Axion Solar Telescope uses a high magnetic field to look at axions produced in the Sun.

https://en.wikipedia.org/wiki/CERN_Axio ... _Telescope

Another approach is to look for radio photons from conversion of axions to the same in the very strong magnetic fields of neutron stars.

https://phys.org/news/2020-12-dark-neut ... copes.html

[chasmanian]

thank you nFA.

here is a link to Simple English Wikipedia for Wave-particle duality:

https://simple.wikipedia.org/wiki/Wave% ... le_duality

if you are inclined, would you please expound/elaborate a little about what you think about
Wave-particle duality?

and is Rovelli's saying in Relational Quantum Mechanics,
that the explanation of such phenomena is context sensitive?

[AntennaGuy]

nFA, you (and others) appear to be suggesting that the signal available from even a good dark matter antenna, once designed, will be small. This seems unintuitive to me, if dark matter is so ubiquitous, and of such consequence to the behavior of galaxies and the universe in general. Are we not bathing in dark matter right now? How would you compare the energy density (or, if you prefer, power density) of dark matter (or dark matter waves) in, for example, your living room right now, relative to, for example, the cosmic microwave background radiation?

p.s. Once I get my antenna working, I intend to build a dark matter "radio" receiver AND a transmitter. Since it won't work on RF, it will need a new name. I'm thinking of calling this technology "subspace communication." That phrase isn't already taken, is it?

[chasmanian]

nFA, the idea of vocabulary not properly describing things,
reminds me of this quote:

writing or talking about music is like dancing about architecture.

http://home.pacifier.com/~ascott/they/tamildaa.htm

[notFritzArgelander]

thank you nFA.

here is a link to Simple English Wikipedia for Wave-particle duality:

https://simple.wikipedia.org/wiki/Wave% ... le_duality

if you are inclined, would you please expound/elaborate a little about what you think about
Wave-particle duality?

and is Rovelli's saying in Relational Quantum Mechanics,
that the explanation of such phenomena is context sensitive?

It's a fair representation as far as it goes, more later perhaps.

[notFritzArgelander]

nFA, you (and others) appear to be suggesting that the signal available from even a good dark matter antenna, once designed, will be small. This seems unintuitive to me, if dark matter is so ubiquitous, and of such consequence to the behavior of galaxies and the universe in general. Are we not bathing in dark matter right now? How would you compare the energy density (or, if you prefer, power density) of dark matter (or dark matter waves) in, for example, your living room right now, relative to, for example, the cosmic microwave background radiation?

p.s. Once I get my antenna working, I intend to build a dark matter "radio" receiver AND a transmitter. Since it won't work on RF, it will need a new name. I'm thinking of calling this technology "subspace communication." That phrase isn't already taken, is it?

Good luck on your subspace communicator! Just be sure to stabilize the wormholes for the signal.

We can be (and likely are) bathing in dark matter to the count of hundreds to thousands per cubic centimeter. But if the coupling constant is small (see the link post #4 this thread) then the signal will be small. Remember we are also awash in neutrinos to the count of hundreds per cc. There are already experimental indications that the coupling constant is tiny if axions exist. This is maybe a replay of the neutrino detection problem that took decades to engineer.

[AntennaGuy]

...
We can be (and likely are) bathing in dark matter to the count of hundreds to thousands per cubic centimeter. But if the coupling constant is small (see the link post #4 this thread) then the signal will be small. Remember we are also awash in neutrinos to the count of hundreds per cc. There are already experimental indications that the coupling constant is tiny if axions exist. This is maybe a replay of the neutrino detection problem that took decades to engineer.

Yeah, yeah, I know; I gave up working on compact neutrino-based walkie-talkies for the same reason. Sigh. But perhaps dark matter can still be useful for something beyond providing comfort (and/or justification for NSF grants) to astrophysicists/cosmologists. I guess we'll just have to wait and see.

Thanks, and best regards.

[chasmanian]

thank you for your reply nFA.

in trying to understand some stuff, I found these 2 articles.
the first I read entirely. the second, not yet.

but in case they are of interest to anyone, here are links:

https://www.forbes.com/sites/startswith ... 0d2e1a2c2b

http://www.esalq.usp.br/lepse/imgs/cont ... hysics.pdf

[notFritzArgelander]

thank you for your reply nFA.

in trying to understand some stuff, I found these 2 articles.
the first I read entirely. the second, not yet.

but in case they are of interest to anyone, here are links:

https://www.forbes.com/sites/startswith ... 0d2e1a2c2b

http://www.esalq.usp.br/lepse/imgs/cont ... hysics.pdf

The first article is fine. From the "particle" POV you are mostly empty space. From the wave POV you aren't. BTW the simple Wikipedia article on wave particle duality (fine as far as it goes, I said) does not treat seriously the POV that the wave particle duality is a linguistic artifact that doesn't faithfully represent the mathematical model. A. S. Eddington suggested (rightly so) that the language of waves and particles was inadequate and coined the term "wavicle" which hasn't caught on.

The second link gives me heartburn. It oversimplifies to the point of being misleading. Start with the first phrase: "classical physics is causal" and quantum physics is not? I skimmed the rest but I do not think it is sound. Quantum mechanics is also causal in the sense that given initial state function (or wave function if you prefer) its subsequent evolution is completely determined. It is only the measurement process that introduces probabilities.

[turboscrew]

And usually the initial conditions need to be measured...

I think in the "higher level", the wave particle duality is kind of understandable in a probabilistic sense, or as a feature of "stream of entities". I'm not sure I'd say it's totally linguistic artifact, but I agree, the expression is a bit misleading.

[notFritzArgelander]

And usually the initial conditions need to be measured...

I think in the "higher level", the wave particle duality is kind of understandable in a probabilistic sense, or as a feature of "stream of entities". I'm not sure I'd say it's totally linguistic artifact, but I agree, the expression is a bit misleading.

I think that the way it is presented: 'sometimes it's a wave, sometimes it's a particle, how can it be both?' makes the linguistic problem clear. But then I like my Wittgensteins sunny side up with a dash of hot sauce.

[turboscrew]

And usually the initial conditions need to be measured...

I think in the "higher level", the wave particle duality is kind of understandable in a probabilistic sense, or as a feature of "stream of entities". I'm not sure I'd say it's totally linguistic artifact, but I agree, the expression is a bit misleading.

I think that the way it is presented: 'sometimes it's a wave, sometimes it's a particle, how can it be both?' makes the linguistic problem clear. But then I like my Wittgensteins sunny side up with a dash of hot sauce.

I wonder where the heck I've put my tractatus.