Hunting for dark matter — inside the Earth

[Admin]

Detectors scattered around the world have been operating for decades, trying to catch the faint trace of a passing dark matter particle, but to no avail. A new paper offers an alternative approach: dig deep.

Hunting for dark matter — inside the Earth : Read more

 

[dfjchem721]

Here is one for all the dark matter freaks out there:

Sorry, off direct topic of article---

According to Wikipedia, Dragonfly 44 is a galaxy which appears to be made up almost entirely of dark matter, with a mass approximating that of the Milky Way, or so the story goes. It is an extreme outlier as it appears, so far at least, to be the only one of its kind. A massive dark matter galaxy. If dark matter is so prevalent, shouldn't we see more galaxies like this, instead of just one? We have been looking in a lot of places. Not a cosmologist, so take it easy on me........

I am dying for an answer on this one! Maybe Dragonfly 44 is not a galaxy of dark matter, but simply some odd-ball. Stranger things have been known, maybe. Or not.

 

[Bigrob215275]

I find the current state of theories absurd. After looking intensely for decades AND FINDING NOTHING Physicists act like spoiled little children screaming and acting out that they are right and it doesn't matter what anyone says they are right because they say it. Instead, they should admit the shortcomings of the theories and keep looking and keep thinking up new theories that may explain the Universe. They have explained only 4-6% of the Universe and they should be humble in their approaches and presentation of ideas. I am a Christian and I believe in GOD because JESUS came to Earth for my sins. There is far more PROOF for my position than there is for DARK ENERGY, DARK MATTER, or DARK FLOW none of which are explained or discovered in any real sense of observations.

 

[dfjchem721]

Physicists get a lot of things right. Hiroshima and Nagasaki are dramatic proof of this. But those bombs were made less than ten years after all the high brows in physics claimed that fission of heavy nuclei was impossible - meaning such bombs were impossible. It took a lowly radio-chemist (Otto Hahn) to prove they were wrong. They were very certain about this before Otto set them straight. Apparently he had not heard that fission was impossible!

Einstein did not believe black holes (BHs) were possible, but he was wrong about that one. Neither did Hawking at first, but his is one of the biggest names in BHs. But I will agree that these people seem to take a lot for granted, and that their big brains are always right. They have big egos that need feeding, just like a black hole. And being wrong in science is the worst fate. We are only human, after all. Cosmological observations strongly suggest dark matter and dark energy, but it remains possible that some of this stuff is simply beyond our comprehension.

 

[rod]

Dark matter apparently does not show up in spectroscopy studies of starlight. From what I understand about stellar spectrums, neither do 11 dimensions that the light traveled through using string theory or a QFT using inflation cosmology. Dark matter is an interpretation of various motions, initially in spiral galaxies and rotation curves like Zwicky in the 1930s and others later. So far, reporting DM on the Periodic Table remains elusive

 

[dfjchem721]

One comment on theories. When one uses theories to support other theories, they sometimes get so far out in left field they are no longer in the ball park.

Dark matter appears to have some support in the Standard Model however. I was reading about how quarks and gluons can form in the Big Bang and not become neutrons and protons, but some unique form of matter. The only place on the Periodic Table I have found reference to dark matter relates to molecular hydrogen, which is very difficult to detect and some believe its quantity is vastly underestimated in the universe, particularly as it relates to "halo objects". But I don't recall anyone ever suggesting that the Periodic Table offers the all-inclusive character of atoms and their properties. So much is unknown.

They could be wrong about H2, or another Otto Hahn. Time will tell, or not............

 

[rod]

Testing for dark matter (DM) remains elusive and not confirmed as to what DM is (assuming DM is real). The solar system does not show DM like observing the Galilean moons and events at Jupiter or Mars moving through Sagittarius this morning when I viewed with the telescope, passing Jupiter's position in Sagittarius. New Horizons is another example, DM is not used to explain New Horizons motion or predict when it flew by Pluto. Astronomy is chasing DM since the 1930s and still looking. If DM is not real, the cosmology department falls apart, no structure can form after the Big Bang

 

[dfjchem721]

Since the Big Bang theory has (at least) one major flaw (baryon asymmetry), it is imprudent to assume the rest of it is absolute. If you have one proven flaw in a theory, you have empirical evidence that other flaws could exist. Many structures made up of quarks and gluons could have formed during the BB, along with protons, neutrons, etc. and all the other things we do not know about.

Again, much is unknown. Almost certainly much more than is known.

 

[Torbjorn Larsson]

Detectors scattered around the world have been operating for decades, trying to catch the faint trace of a passing dark matter particle, but to no avail. A new paper offers an alternative approach: dig deep.

Hunting for dark matter — inside the Earth : Read more

After several experiments failed to find WIMPs at the natural scale - a bit higher in mass that baryon matter - at the same time inflation did find consensus evidence, I lost confidence in supersymmetry and so string theory. Same as now is happening to axions/axion -like particles that are natural to string extensions to the baryon matter sector. There is now no compelling reason to think dark matter or axions are anything as complicated as and/or tied to baryon matter.

But these things will test some of the remainder parameter space, so we'll see.

 

[Torbjorn Larsson]

Here is one for all the dark matter freaks out there:

According to Wikipedia, Dragonfly 44 is a galaxy which appears to be made up almost entirely of dark matter, with a mass approximating that of the Milky Way, or so the story goes. It is an extreme outlier as it appears, so far at least, to be the only one of its kind. A massive dark matter galaxy. If dark matter is so prevalent, shouldn't we see more galaxies like this, instead of just one? We have been looking in a lot of places. Not a cosmologist, so take it easy on me........



I am dying for an answer on this one! Maybe Dragonfly 44 is not a galaxy of dark matter, but simply some odd-ball. Stranger things have been known, maybe. Or not.

Dark matter is part of current Lambda-Cold Dark Matter [LCDM] cosmology, it says so in the name. Dark matter is crucial to star and galaxy formation, else we wouldn't see much of it, since non-dark matter wouldn't suffice to clump itself. So the generic, average result is that those two are seen together in galaxies as a whole.

There are differences between the two types of matter obviously, and one famous consequence is that galaxy collisions may separate the two (since non-dark matter likes to interact and will tend to lump easier).


[ https://en.wikipedia.org/wiki/Bullet_Cluster ]

"Because we've never directly detected whatever particle might be responsible for it, many people — experts and laypersons alike — remain skeptical of its existence. But if our Universe didn't have any dark matter, it would be a very different place. Here's how."

[Specifically on galaxies:]

"On larger cosmic scales, there would be dramatically less structure overall. In a Universe without dark matter, there is no unseen "skeleton" to the cosmic web; instead, structure forms based on the strength of normal matter alone. This means that instead of a cosmic web, where you wind up with galaxies dotting the filaments that connect the great clusters of the Universe together, you'd just wind up with isolated islands of mid-sized galaxies, with not much else.

Sure, some galaxies would still group and cluster together, but there would be far less of them that do so in a Universe without dark matter."

[ https://www.forbes.com/sites/starts...y-different-without-dark-matter/#17f6b10237ea ]

"We can tell that dark matter exists and even infer some of its properties by observing how it affects the matter and light we can observe, particularly in large-scale astrophysical environments. But the fact that dark matter has eluded direct, laboratory detection thus far means that a number of its properties remain open questions. Here are five things we know about dark matter, along with five that we don't, as we probe the limits of our scientific frontiers."

"4.) Dark matter's effects are most dominant, on average, in the smallest galaxies of all.

This one's a little bit counterintuitive, but has been observationally validated practically everywhere we look. Under the laws of gravitation, all forms of matter are treated equally. But the other forces, like nuclear and electromagnetic forces, only affect normal matter. When a large burst of star formation takes place in a galaxy, all of that radiation simply passes through the dark matter, but it can collide with and be absorbed by the normal matter.

This means that if your galaxy is low enough in mass overall, that normal matter can be expelled by intense episodes of star formation. The smaller and lower-in-mass your galaxy is, the greater the amount of normal matter that will be expelled, while all the dark matter will remain. In the most striking examples of all, dwarf galaxies Segue 1 and Segue 3, both satellites of the Milky Way, contain only a few hundred stars, but some 600,000 solar masses of material overall. The dark matter-to-normal matter ratio is approximately 1000-to-1, as opposed to 5-to-1 in most large-scale structures."

[ https://www.forbes.com/sites/starts...about-dark-matter-and-5-we-dont/#784841a736f8 ]

 

[Torbjorn Larsson]

<<Removed by moderator>>

I find the current state of trolls absurd. After not looking at all for decades AND FINDING NOTHING Trolls act like spoiled little children screaming and acting out that they are right and it doesn't matter what anyone says they are right because they say it.

 

[Torbjorn Larsson]

But I will agree that these people seem to take a lot for granted

They take earlier science for granted, naturally. What else? Both Hahn, that was considered the best radio chemist in Germany at the time,*and Einstein did ground breaking research. Of course they got a lot of things wrong too - it's science, ever improving.

*) "After the physicist Harriet Brooks had observed a radioactive recoil in 1904, but interpreted it wrongly, Otto Hahn succeeded, in late 1908 and early 1909, in demonstrating the radioactive recoil incident to alpha particle emission and interpreting it correctly. The physicist Walther Gerlach described this as "a profoundly significant discovery in physics with far-reaching consequences".[18] Rutherford in Manchester wrote in a letter to his mother: "He is doing the best work in Germany at present."[19]

[ https://en.wikipedia.org/wiki/Otto_Hahn ]

 

[Torbjorn Larsson]

Dark matter apparently does not show up in spectroscopy studies of starlight. From what I understand about stellar spectrums, neither do 11 dimensions that the light traveled through using string theory or a QFT using inflation cosmology. Dark matter is an interpretation of various motions, initially in spiral galaxies and rotation curves like Zwicky in the 1930s and others later. So far, reporting DM on the Periodic Table remains elusive

Just some nitpicks:

I already linked to articles that show dark matter is observed in many different and independent ways, it is a robust feature of nature, like gravity.

Inflation is observed to be a Higgs like scalar field in the Planck team 2018 cosmological parameters summary paper [Planck Legacy Archive - look it up].

 

[Torbjorn Larsson]

The only place on the Periodic Table

It's a joke. Dark matter is definitely not part of the element table, since it isn't atoms.

 

[Torbjorn Larsson]

The solar system does not show DM

As expected. If you take the average dark matter density and have Sun gravity scope it up during 4 billion years, the integrated mass differences - which is what affects objects in the system - comes out very small:

"If there’s a sea of dark matter that permeates space where we are — all through the Solar System — the outer planets should see a slightly different (greater) mass than the inner planets. And if there’s enough dark matter, it should be detectable. Because we know the mass of the Milky Way, the relative densities of normal and dark matter, and we have simulations that tell us how the dark matter density ought to behave, we can come up with some very good estimates. When you do these calculations, you find that about 10^13 kg of dark matter ought to be felt by Earth’s orbit, while around 10^17 kg would be felt by a planet like Neptune.

But these values are tiny compared to the other masses of consequence! The Sun has a mass of 2 × 10^30 kg, while Earth is more like 6 × 10^24 kg."

[ https://www.forbes.com/sites/starts...detected-it-in-our-solar-system/#bd194ec352fc ].

 

[Torbjorn Larsson]

Since the Big Bang theory has (at least) one major flaw (baryon asymmetry), it is imprudent to assume the rest of it is absolute. If you have one proven flaw in a theory, you have empirical evidence that other flaws could exist. Many structures made up of quarks and gluons could have formed during the BB, along with protons, neutrons, etc. and all the other things we do not know about.

Again, much is unknown. Almost certainly much more than is known.

Baryon asymmetry isn't a flaw, it is a (necessary) feature. Today it looks like the neutrino sector may explain the symmetry breaking, the chirality is on point (maximal CP break) but the data is still not enough. People seem to think it will take the neutrino experiments a decade at most to accept or reject. The main contender axions . which is more like a string theory natural (axion like particles when you try to extend quantum field theory) - has taken some heavy hits lately.

[No axions where you expect them, string theory also do not see natural WIMPs for dark matter. I think the idea that string theory, WIMPs and axions are physics is pinin' for the fjords, and if physicists wouldn't continue to nail string theory to the perch it would fall off the horizon.]

The observed matter is now - when people have been able to estimate hot and cold gas in and between cosmic filaments - exactly as the cosmic background spectra tell us. That is not a gap to hide dark matter in - especially since the spectra and baryonic acoustic oscillations both - and independently - tell us it does not consist of quarks and gluons.

“Science knows it doesn't know everything; otherwise, it'd stop. But just because science doesn't know everything doesn't mean you can fill in the gaps with whatever fairy tale most appeals to you.”

― Dara O'Briain

Science does not know everything, but it does know everything on cosmological scales: 100 % of the universe content is accounted for, beyond reasonable doubt. And that includes dark matter.

 

[dfjchem721]

I did not notice a reference to the "dark matter" galaxy Dragonfly 44 in all of this commentary. It was otherwise very interesting.

Is Dragonfly 44 not made of dark matter, or if it is, why do we find only one? It appears to be a unique aggregation of matter unlike any other galaxy we have ever studied.

This blasted galaxy is the only reason I posted to this thread. It is really wild!

Dragonfly 44 - Wikipedia

en.wikipedia.org

 

[dfjchem721]

Whoever wrote the article for Wiki on "Baryon Asymmetry" (for what that is worth) would certainly disagree that it is merely a feature. Of course it is required or we wouldn't be debating it!

That Wiki article quotes a statement from an article which is very compelling:

"The origin of matter remains one of the great mysteries in physics."

(Canetti, L.; Drewes, M.; Shaposhnikov, M. (2012). "Matter and Antimatter in the Universe". New J. Phys. 14 (9): 095012. )

This is because the Big Bang "should have produced equal amounts of matter and antimatter." Annihilation would then create a universe of radiation, which is clearly not the case. You call it a "feature". I call it a flaw in the theory. So do a lot others. I have read the issue of baryon asymmetry being this great riddle of all of physics many times. Doesn't sound like a feature - more like a controversy. Riddles, puzzles, enigmas are not features. They are question marks.

Here is one from yesterday on this very web site about people trying to figure out your "feature":

How a 'muon accelerator' could unravel some of the universe's greatest mysteries

The fact that we are here at all is one of the greatest puzzles of physics.

www.space.com

 

[rod]

As expected. If you take the average dark matter density and have Sun gravity scope it up during 4 billion years, the integrated mass differences - which is what affects objects in the system - comes out very small:

"If there’s a sea of dark matter that permeates space where we are — all through the Solar System — the outer planets should see a slightly different (greater) mass than the inner planets. And if there’s enough dark matter, it should be detectable. Because we know the mass of the Milky Way, the relative densities of normal and dark matter, and we have simulations that tell us how the dark matter density ought to behave, we can come up with some very good estimates. When you do these calculations, you find that about 10^13 kg of dark matter ought to be felt by Earth’s orbit, while around 10^17 kg would be felt by a planet like Neptune.

But these values are tiny compared to the other masses of consequence! The Sun has a mass of 2 × 10^30 kg, while Earth is more like 6 × 10^24 kg."

[ https://www.forbes.com/sites/starts...detected-it-in-our-solar-system/#bd194ec352fc ].

If as some claim, QFT and inflatons are real, this can be measured too but apparently not DM in the solar system. I observed the close conjunction of Mars with Jupiter this morning and the moons Europa, Ganymede, and Callisto. No tiny or large amount of DM is observed Occam's razor answer is that DM is not there, at least no in the solar system.

 

[rod]

Also we have dark stars in cosmology too, something not commonly reported on. 'Shedding Light on Dark Stars, Sky & Telescope 119(3):26-29, 2010, March 2010 issue. New computer code allows the formation of the first stars as dark matter stars made of H and He but with a little dark matter. These dark stars could have accelerated the reionization epoch when the cosmos was in the dark ages. There is also Dark stars: a review

Keep searching. DM searches started around 1933 and continue in 2020. The cosmology department will collapse without DM.

 

[rod]

Whoever wrote the article for Wiki on "Baryon Asymmetry" (for what that is worth) would certainly disagree that it is merely a feature. Of course it is required or we wouldn't be debating it!

That Wiki article quotes a statement from an article which is very compelling:

"The origin of matter remains one of the great mysteries in physics."

(Canetti, L.; Drewes, M.; Shaposhnikov, M. (2012). "Matter and Antimatter in the Universe". New J. Phys. 14 (9): 095012. )

This is because the Big Bang "should have produced equal amounts of matter and antimatter." Annihilation would then create a universe of radiation, which is clearly not the case. You call it a "feature". I call it a flaw in the theory. So do a lot others. I have read the issue of baryon asymmetry being this great riddle of all of physics many times. Doesn't sound like a feature - more like a controversy. Riddles, puzzles, enigmas are not features. They are question marks.

Here is one from yesterday on this very web site about people trying to figure out your "feature":

How a 'muon accelerator' could unravel some of the universe's greatest mysteries

The fact that we are here at all is one of the greatest puzzles of physics.

www.space.com

I concur, you are accurate in calling the baryon asymmetry problem in BB a flaw concerning the origin of matter in the universe. The cosmology department does not like to acknowledge flaws it seems. Inflation was invented to solve the horizon problem, a light-travel-time conflict in the expanding universe and evolution of the BB cosmic fireball temperature as the universe expands vs. what is actually observed. I will stop here.