from the something-unobservable-made-of-something-unobserved,-it's-axionmatic dept.
In an article Friday on Universe Today, Paul M. Sutter, an astrophysicist at Ohio State, discusses one tantalizing possibility for explaining dark matter, which is that it may be comprised of particles called axions.
Axions are an exotic hypothetical particle invented to explain a conundrum in high energy physics having to to with [sic] charge-parity symmetry and the strong nuclear force. Like dark matter, we have not actually observed axions.
The conundrum is that by all rights the strong nuclear force should violate [CP-symmetry]. There are terms in the mathematics that very obviously break CP-symmetry, and yet we don't see any signs of symmetry breaking with the strong nuclear force in any of our experiments. So something must be going on to restore this symmetry when it ought to be broken.
The answer – or at least one potential answer – is a new kind of particle called the axion. The axion restores a certain kind of balance in the force (yes I'm aware of the Star wars reference here) so that the CP-symmetry is preserved and everyone can go about their daily lives. Of course experiments to date haven't directly revealed the existence of the axion, and there's a range of possible masses and properties that the axion could have.
Based on the relationship of galactic core objects to galaxy sizes, a team of astronomers was able to place upper bounds on axion particle mass, which will help guide future experiments.
It turns out that some of the range of possible axion properties allow that hypothetical particle to be a candidate for the dark matter.
The Dark Axions
If we let the axion be the dark matter it can generally explain all the usual dark matter observations. It can explain the rotation curves inside of galaxies. It can explain the motions of galaxies within galaxy clusters. It can be manufactured in sufficient abundance in the early Universe to fit observations of the cosmic microwave background. And so on.
Axions acting as dark matter also present a potential alternative for black holes in the center of galaxies
axions in the cores of galaxies can bundle together tightly enough to form a single massive ball that would at first blush look a lot like a supermassive black hole. It would be small, it wouldn't interact with light, and it would be incredibly massive.
He also notes that the recent imaging of Sagittarius A* does not rule out axion cores.
(Score: 3, Insightful) by Anonymous Coward on Sunday May 19 2019, @09:26PM (17 children)
Dark matter is made out of figments from the imaginations of people who refuse to accept GR was falsified over 50 years ago. While the idea started out ok, the only question is whether it is due to incompetence or malice at this point.
(Score: 5, Insightful) by darkfeline on Sunday May 19 2019, @09:47PM (5 children)
While I agree with the sentiment here, any physical model we come up with is made out of the figments of our imagination. All we can ever do is make up models that appear to model reality. Reality could be made up of ethereal yoctoyoctoscopic cornflakes for all we know.
We judge the "correctness" of any model by how closely it models reality and by how simple it is. If I can model a ping pong table with balls bouncing off one another, and you can model the ping pong table with a 1000 page text describing mating rituals between fairies and salamanders, even if your model works, it's quite frankly retarded.
Now then, the problem as I understand it is that we have this theory that models most of reality as we can observe it. However, it doesn't work in some situations unless we assume the existence of "dark matter" that is otherwise not observable except that it balances out our equations for gravity.
If we can integrate dark matter into our model in a simple way, it doesn't matter too much whether or not dark matter is real, so long as we can't come up with a simpler model that models all of reality. The problem is that we have spent many years coming up with complex ways of integrating dark matter into our model, none of which really work out.
Join the SDF Public Access UNIX System today!
(Score: 2) by The Mighty Buzzard on Sunday May 19 2019, @11:01PM
Ed Zackery. If it worked without having to constantly cheat the math, I wouldn't bitch much.
My rights don't end where your fear begins.
(Score: 0) by Anonymous Coward on Monday May 20 2019, @01:00AM
The concept you are missing is Bayes' rule.
(Score: 2) by HiThere on Monday May 20 2019, @04:21AM
Only thing is, axions are also something that hasn't been seen. They've been looked for, but not found. So I don't think that this "new theory" is likely to be a step fprwards.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by edIII on Monday May 20 2019, @07:09PM (1 child)
Says the person that doesn't understand multi-dimensional fairy physics, or how their dimension interacts with our specific place in space-time. If you cared to read it, you would've seen about 30 pages on how it might actually be fairy-fucking that's influencing the physics of the ping-pong balls. Not the other way around. It's also not proven that salamanders are responsible, or even consenting, to the rampant buggering that fairies perform seasonally. Only a light causal relationship has been shown with the frequency and ferocity of the sodomising of salamanders and fairy population levels over time. Regardless of the apparent "retardity" of the model, careful measuring of wrecked salamander anus, nonetheless reliably models the ping-pong balls movement. As controversial as the salamander anus diameter constant is, it works.
I believe you owe the fairy scientists an apology. Do you know hard it is to keep a freshly fucked salamander still while you measure it's prolapse? I thought not.
Food for thought.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 0) by Anonymous Coward on Monday May 20 2019, @09:36PM
Scientists of alternate sexuality, please.
(Score: 3, Insightful) by takyon on Sunday May 19 2019, @09:50PM (2 children)
Dark matter is real, and it's made of Gaaarkaons.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1) by NPC-131072 on Monday May 20 2019, @12:50AM
But only for sufficiently small values of θ.
(Score: 3, Informative) by Gaaark on Monday May 20 2019, @03:52AM
Ah! And since Gaaarkaons don't exist because Gaaark is not real, Dark Matter is fiction!
Est ergo absurdum eunt Romanum....Romani? Romanes...?
Hey Brian...lend us a hand, eh?
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by RamiK on Sunday May 19 2019, @10:50PM
Depending on how https://arxiv.org/pdf/1807.08771.pdf [arxiv.org] turns out, combined with https://arxiv.org/pdf/1712.07962.pdf [arxiv.org] you could realistically explain the lack of dark matter as it being a sub-particle of phonons / some other quasi-particle. It's a few years (but not decades if I'm reading it right) away and no one bothered even putting down some equations... But why not?
compiling...
(Score: 2) by pe1rxq on Sunday May 19 2019, @11:32PM
Falsified??? If you said it was a plot by the illuminati it would make more sense
(Score: 3, Insightful) by khallow on Monday May 20 2019, @02:21AM (4 children)
GR was known to be an incomplete theory from its beginning. It doesn't take into account quantum effects. Past that, no, it hasn't been falsified yet. In particular, we don't actually know the distribution of matter in the supposed cases where it supposedly has been falsified. That's why the whole thing about dark matter being wrong is premature.
Well, we don't have perfect knowledge of the universe, right? So a touch of ignorance is good enough to explain things.
(Score: 2) by fyngyrz on Monday May 20 2019, @02:24PM (3 children)
I agree. However, the whole thing about dark matter being right is also premature.
--
Hyphenated.
Non-hyphenated.
Dashed peculiar, if you ask me.
(Score: 1) by khallow on Monday May 20 2019, @03:33PM (2 children)
Nobody here is disagreeing with that.
(Score: 1, Redundant) by fyngyrz on Monday May 20 2019, @03:49PM (1 child)
Glad you figured that out. A little late, but better late than never.
--
I got mood poisioning. Must have been something I hate.
(Score: 1) by khallow on Monday May 20 2019, @05:38PM
Why accuse me of something I never did?
(Score: 5, Interesting) by maxwell demon on Monday May 20 2019, @06:16AM
Guess what? The Higgs boson also hadn't been seen for quite some time. And it (or rather the corresponding Higgs field) was invented to "explain away" a discrepancy between theory (which says that Z and W particles belong to gauge fields, and that gauge field particles have to be massless) and observation (which says that W and Z particles have a quite substantial mass). You probably would have claimed that we should just accept the defeat of gauge theory, instead of inventing a new field with properties like no other known field to save it.
Also the neutrino was initially unobserved, and it was used to "explain away" the observed violations of energy conservation in beta decays, violating the theoretical predictions that energy is conserved. Indeed, it is a quite relevant example here, as the properties of the neutrino basically match those of dark matter, with the exception that neutrinos have too little mass to explain dark matter. You probably would have claimed that we should just have to accept defeat of energy conservation, instead of inventing such a ghostly particle that at the time wasn't even expected to be ever practically observable.
So all in all, I'd say we've been quite successful with "inventing" unobserved particles to "explain away" failures of the theories to correctly predict observed behaviour.
Of course it could be that dark matter doesn't exist, and the explanation requires a modification of gravity. But as of now, dark matter is the best explanation we have (in particular, modified gravitation theories have a hard time to explain why the apparent distribution of dark matter isn't completely determined by the distribution of observable matter).
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Sunday May 19 2019, @10:14PM (2 children)
... and strings are made of dark matter. As this unifies our understanding of everything, please send me my Nobel Prize.
(Score: 5, Funny) by MostCynical on Sunday May 19 2019, @11:19PM (1 child)
Your award has been put where your theory came from.
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
(Score: 0) by Anonymous Coward on Monday May 20 2019, @03:26AM
How exactly does anyone put anything into the luminiferous aether that isn't massless?
(Score: 2) by Gaaark on Monday May 20 2019, @03:59AM (2 children)
Is dark matter made of fairy dust?
Stay tuned:
Same bat time,
Same bat channel
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by takyon on Monday May 20 2019, @04:31AM (1 child)
Well, it's not made of tiny black holes:
https://www.livescience.com/65300-hawking-black-hole-theory-unlikely.html [livescience.com]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Gaaark on Monday May 20 2019, @04:02PM
I'm surprised: I was starting to believe that dark matter was made of everything and anything and was just about to make me lunch, give me a blow job AND assemble a new computer system for me.
Maybe it IS just fairy dust.
Huh.
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---