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Dark Matter Even More Missing Now ...

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Is it Tuesday?  No, it’s Wednesday ... but it’s still time for a new Dark Matter gnome.


DARK FUSION.


https://www.sciencenews.org/article/if-real-dark-fusion-could-help-demystify-physics-puzzle

 

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If real, dark fusion could help demystify this physics puzzle

 

… snip …


For now, if fusion does have an alter ego, scientists remain in the dark.

 


And THAT is the understatement of the century.  B)

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http://www.spacedaily.com/reports/Proof_of_dark_matter_in_dwarf_galaxies_is_refuted_999.html

 

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Proof of dark matter in dwarf galaxies is refuted


Astronomers from Observatoire de Paris/PSL, Laboratory Galaxies, Etoiles, Physique et Instrumentation/GEPI (Observatoire de Paris/PSL/CNRS) have refuted the formerly well-established proof of dark matter in dwarf galaxies. They demonstrate that star motions in dwarf galaxies that were believed to be governed by in-situ dark matter are indeed due to the gravitational forces of the Milky Way. The study will appear in the Astrophysical Journal, June the 14th, 2018.


Since the 70s, astronomers have been convinced that dark matter is the main component of the matter in the universe. The American astronomer Vera Rubin was the first to realize the need for dark -or invisible- matter to explain the high speed rotating gas at the edge of galactic disks.

 

This had been verified by the Dutch astronomer, Albert Bosma, who confirmed the need of dark matter at much further distances from the disk, within the galactic haloes. Later on, in the 80s, the American astronomer Marc Aaronson discovered a similar effect, this time within the tiniest galaxies surrounding the Milky Way.


Since that time, several new dwarf galaxies have been discovered and motions of their stars have been studied. These have confirmed that stellar motions are too fast to be governed by the sole gravitational force due to the stellar or visible mass.


Assuming dwarf galaxies being at equilibrium, cosmologists have explained the fast stellar motions to gravitational forces exerted by dark matter. They calculated that the smallest of them may contain thousand times more dark matter than visible matter. In such a frame, it was also assumed that the gravitational forces from the Milky Way are negligible.


An Insufficiently Explored Alternative: The Milky Way Gravitation

 


The tiniest dwarf galaxies contain only few thousands of stars and are so faint that they cannot be observed elsewhere, farther than the halo of the Milky Way. By analysing their dynamical properties, a French-Chinese team of astronomers from the Paris Observatory/PSL, the National Astronomical Observatory of China (NAOC), and the CNRS, has discovered an exceptionally strong relation between the assumed dark matter content in most dwarf galaxies, and the gravitational force due to the Milky Way.


The relationship is so strong that the probability it is only due to a coincidental chance is smaller than one part over ten billion. This implies that the Milky Way gravitation does control the stellar motions in these dwarf galaxies, and conversely, that the in-situ dark matter does not.

 

 

Oh my …

 

 

 



 

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http://www.bhpioneer.com/local_news/surf-readies-for-bigger-better-dark-matter-detector/article_1bd2f82a-8142-11e8-a6e1-d33c3fb5a820.html

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SURF readies for bigger, better dark matter detector

 

… snip …

 

This set the stage for the new, larger dark matter detector currently under construction at SURF.


LZ will use 10 metric tons of ultra-purified xenon, making it at least 100 times more sensitive than LUX. The increased amount of xenon means an increased likelihood of finding a reaction, which could point to the detection of dark matter. LZ will be housed in the same chamber that Ray Davis’ original dark matter detection experiment occupied starting in 1969, known as the Davis Campus. 


Renovations to the Davis Campus began in January to accommodate the larger LZ experiment.

“Essentially what they did is they took out a clean room to make more space for the large computer basses that they’ll need,” Constance Walter, communications director for the Sanford Lab, said. 


No meager feat, considering the Davis Campus lies at the 4,850 level of the facility and any equipment must be transported to and from the surface via a 15-minute ride in the Yates shaft hoist cage.


The renovation will also include installing a work deck, which will allow researchers easier access to experiment apparatus such as detector cables and electrical wires that connect to systems within the tank; construction of a larger water tank in which the cryostats will be submerged; updating the hoist system used to lower and raise the cryostats into and out of the tank; as well as more storage space for the liquid xenon not being actively used in the experiment.


The cryostats themselves, which will be filled with the liquid xenon, were delivered in May and are currently located in the surface lab clean room being tested and prepped for installation later this year. 


All the renovations to the campus and construction of the experiment are expected to be completed by 2019, and LZ should be able to start its search for dark matter in 2020.

 


That’s right, LF denizens.   


They’re busy spending a lot more of your money.


In a desperate attempt of prove DM exists.


Prediction?   This too shall fail.


Because DM does NOT exist.


It’s a GNOME.

 

And by the way … we’re half way through the year.


Where’s that picture of a black hole they promised us?


They’re not having a problem, are they?

 

:P

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It’s Tuesday … guess the title …


https://www.livescience.com/63201-no-wimps-pandax-dark-matter.html

 

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Another Dark-Matter Search Fails — Shedding Light on the Universe


Once again, dark matter has failed to turn up where researchers hoped they might find it.


PandaX — essentially a tank holding 1,280 lbs. (580 kilograms) of liquid xenon beneath the Jinping Mountains of Sichuan, China — is one of the most sensitive dark-matter detectors on the planet. If dark matter is capable of bumping into the matter we can detect, and if dark matter is made up of big, bulky particles called WIMPs (weakly interacting massive particles) as scientists have long assumed, then sooner or later, some of the dark stuff should knock into xenon particles inside PandaX in a way researchers can detect.


But recently reported data from an 80-day experiment at the facility, which was completed in 2015, tells physicists that hasn't happened. And that null result, the umpteenth null result in the hunt for dark matter, tells us something about dark matter.


… snip …


In a paper published July 12 in the journal Physical Review Letters, a team of researchers interpreted the null data from PandaX to put new limits on what dark matter could possibly be — and the work offers possible alternative explanations for what could really be out there.


The basic process of elimination reported in the paper seems pretty simple: Dark matter is unlikely to be made up of particles that interact meaningfully with ordinary matter and have masses between about 5 million and 10 million times the mass of a proton.


But that's a big deal, as Hai-Bo Yu, a physicist at the University of California, Riverside and co-author of the paper, explained.


It shows, he said, that certain proposed explanations for dark matter — most importantly, WIMPs, which should show up in an experiment on the scale of PandaX — are likely incorrect. Dark-matter particles are likely much smaller than WIMPs would have to be, he said, and may not behave in ways that make them easy to study.


"We have to be prepared for the idea that dark matter might not interact with other matter except through gravity," Yu told Live Science.


Based on the limitations placed on dark matter by PandaX and other experiments, Yu and his colleagues are moving toward the conclusion that the best laboratory for understanding dark matter might be the night sky. Stars and galaxies exhibit subtle behaviors that researchers can use to glean information about dark matter.


And astronomical observations, Yu said, point increasingly toward a model called self-interacting dark matter — particles that interact primarily with one another through unknown means, rather than interacting primarily (or interacting at all) with the ordinary matter we're used to. And the best way to observe dark matter of this sort, he said, is through its effects on what we can see in outer space.

 


Ah yes … A GNOME.   LOL!

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Oh no … say it ain’t so …


https://www.sciencenews.org/article/hopes-dim-gamma-rays-can-reveal-dark-matter

 

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Hopes dim that gamma rays can reveal dark matter


The distribution of stars in the Milky Way points to a more mundane source of the excess light

 

An astronomical calling card, tentatively attributed to mysterious dark matter, seems likely to be due to a more mundane source.


An unexplained glow of high-energy light from the center of the Milky Way, first spotted in 2009, raised scientists’ hopes of better pinning down dark matter (SN: 11/20/10, p. 11). That unidentified substance has been detected so far only via its gravitational tug on other matter.


Physicists thought that this excess of energetic light known as gamma rays might be released by the annihilation of particles of dark matter that mill about the galaxy’s core (SN: 5/17/14, p. 8). But an analysis published August 6 in Nature Astronomy suggests that the light isn’t from dark matter after all. Instead, the gamma rays might be spit out by other galactic denizens, such as spinning dead stars called pulsars that are known to produce the light.


The scientists studied the distribution of the gamma rays to get a handle on the light’s origins. Dark matter is thought to shroud the Milky Way in a featureless, spherical halo. But stars within the galaxy are distributed differently, residing in a thin disk with a bulge at the center of the Milky Way. The regions of the galaxy that the gamma rays are coming from match up better with the distribution of stars than that of dark matter, the researchers found.


Other recent studies have likewise raised doubt that the gamma rays are due to dark matter (SN: 5/27/17, p. 15), casting a shadow on scientists’ bright hopes.

 

 

Oh well ... back to the drawing board.  :rolleyes:

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On 4/22/2012 at 10:33 PM, BeAChooser said:

Inferring that dark matter exists based on the rotational velocity observations was not good science. Never was. Never will be

 

Yep, that's what I used to say too.  I can't remember what changed my mind though.  I was watching a video and something was said that made me resign myself to finally accepting dark matter.

 

 

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1 hour ago, Bluenami said:

 

Yep, that's what I used to say too.  I can't remember what changed my mind though.  I was watching a video and something was said that made me resign myself to finally accepting dark matter.

 

Well that's going to do you a lot of good in this discussion.   ;)

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4 minutes ago, BeAChooser said:

 

Well that's going to do you a lot of good in this discussion.   ;)

 

I can't remember.  Maybe something to do with this

 

cosmic.jpg

 

Why does it have that structure?

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On 9/5/2018 at 10:26 PM, Bluenami said:

 

I can't remember.  Maybe something to do with this

 

cosmic.jpg

 

Why does it have that structure?

 

First of all, that image isn't anything real.  That's the result of a computer model which used unproven properties of the gnome dark matter to explain the observed filamentary nature of the universe.  If you'd bothered to read this thread, you'd already know the alternative answer to your question ... at least from the perspective of plasma cosmologists.    The universe is filled with plasma (99.9999%) and electric currents.   Electric currents (Birkeland currents) naturally organize plasmas into filaments.  And sure enough at all levels in the universe we observe filamentary plasmas.    And current carrying plasma filaments will naturally interact with one another, producing another phenomena that is observed in the universe at all scales ... helical winding.    These and other electromagnetic effects on plasmas (like pinching) cause areas along the filaments to grow in density ... to create nodes like those seen in the mainstream model.    For very large filaments, those nodes develop into galaxies.   For smaller filaments, the pinches develop into stars.     This thread is chock full of discussions about filaments ... one of my favorite subjects ... and how plasmas become filamentary and end up as galaxies and stars ... all without the need for dark matter to make gravity alone do it.   

 

Here is a report on the largest computer model the mainstream had built for the universe up till 2007:  http://www.physorg.com/news116170410.html.  It contains output like that in your image.    And it illustrates the mainstream's underlying problem. While noting that "much of the gaseous mass of the universe is bound up in a tangled web of cosmic filaments that stretch for hundreds of millions of light-years", the report doesn't refer even once to the material in the filaments as being "plasma", nor does it recognize that electromagnetic effects naturally tend to organize plasmas into long filaments. The model doesn't include any of those effects ... only gravity.   It's garbage in and garbage out, Bluenami.

 

By the way, you should know that mainstream scientists once argued that the universe would NOT be filamentary and that electric currents would be rare.   Mainstream astrophyicists/astronomers/cosmologists dismissed the notion that filaments had much of a role in anything out in space. If you posted an image of a filament that was then observed in our solar system, they'd say there are no filaments outside of star systems. If you posted a filament observed in the core of our own galaxy, they dismissed that as a rarity … as totally meaningless. Plasma cosmologists, on the other hand, argued that those two things would be ubiquitous ... from the very beginning.  That was an important prediction that was born out by later observations.    Plasma cosmologists got it right ... the mainstream got it wrong.   And then the mainstream compounded their mistake by dreaming up mathematic and mythical gnomes to explain what they found, rather than reexamine their original assumptions ... rather than listen to what the plasma cosmology (electric universe) community was saying.   

 

New observations forced them to admit that filaments are ubiquitous, not only in this galaxy but in all galaxies and between galaxies. They can't deny that any longer, but their explanations for what those filaments represent and their origin is still nothing more than nonsense. Wind? Shock? Gravity-somehow? Turbulence? And don't forget Dark Matter? Not ONCE have they honestly looked at what plasma scientist have said about filaments for half a century or more. Probably because they no longer even teach that stuff in the universities where mainstream *astrophysicists* get their *advanced* degrees. They can’t explain the helical winding of filaments, which seems to show up everywhere that filaments show up. If you look, you’ll find that time and time again, they simply ignore this phenomena now ... or dream up another magical gnome to explain them.    But plasma universe theorists can explain them easily with physics they can even replicate here on earth. In my thread I’ve posted dozens of examples of helically wound filaments and shown experiments on earth that show how those can come about IF you assume a plasma and current filled universe. No gnomes needs. No fairies needed.  No dark matter needed. No black holes needed.  No Big Bang needed.

 

 

 

 

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LOL!   


I foresee another instance of garbage in,  garbage out …


https://phys.org/news/2017-11-cosmic-web-filaments-star-formation.html

 

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New research looks at how 'cosmic web' of filaments alters star formation in galaxies


November 1, 2017, University of Kansas


Astronomer Gregory Rudnick sees the universe crisscrossed by something like an interstellar superhighway system. Filaments—the strands of aggregated matter that stretch millions of light years across the universe to connect galaxy clusters—are the freeways.


"Galaxies will flow along filaments from less dense parts of the universe to more dense parts of the universe, kind of like cars flowing down a highway to the big city. In this case, they are going toward big clusters, being pulled by the gravity of those large concentrations of matter," he said.


Rudnick, associate professor of physics & astronomy at the University of Kansas, wants to know more about how filaments influence galaxies that are moving through them. Now, the KU researcher has earned a $280,000 grant from the National Science Foundation to lead an international collaboration that is investigating galaxies that extend along this "cosmic web" of filaments.


"I'm interested in how galaxies are affected by the regions in which they live," Rudnick said. "Filaments are the first place where galaxies come into contact with higher density regions of the universe. If a galaxy in a 'rural' part of the universe enters a dense part, I want to know how its properties change—for example, does it change the number of stars it forms, or does its shape get altered? Using the highway analogy, when you drive into Kansas City, as you go there are more and more cars building up next to you, and sometimes there are car accidents—this is something like the real universe because galaxies can collide, too."


Rudnick and colleagues will use multiple telescopes around the world to observe neutral hydrogen and molecular gas in galaxies as they travel along filaments. The team hopes to determine if the amount of gas—the fuel for star formation—is less abundant in filament galaxies than in galaxies from other environments, like those by themselves or those in groups or clusters of galaxies.


"When galaxies enter a filament the pressure of the diffuse gas in the filament may slow down how quickly the galaxy forms stars," Rudnick said. "Every galaxy has gas—and if there's enough, it can collapse into little nuggets and form stars. Galaxies are constantly being fed by gas and blowing it out in a complex system. When a galaxy enters a filament, the gas that usually feeds into a galaxy now just becomes part of the filament. The galaxy might get disconnected from its gas umbilical cord."


In other words, Rudnick said, "Maybe a filament is like a long stretch of highway without a lot of gas stations."


Rudnick's collaborators include Rose Finn and Graziano Vernizzi of Sienna College in Loudonville, New York, as well as researchers around the world and KU students—including one graduate student who will be directly supported by the grant. The team will utilize several telescopes including the Philips Claude Telescope on Mount Laguna Observatory in California, of which KU owns a share. The group will also use the IRAM telescope at Pico Veleta in the Spanish Sierra Nevada, the Nançay Radio Telescope in France and one of NASA's infrared-wavelength astronomical space telescopes, dubbed "WISE" for the Wide-field Infrared Survey Explorer.


The team's observations will study the target galaxies in many different wavelengths of light, revealing diverse pieces of information about them. For example, not only will the investigators observe the stars that are present in the galaxies but also the gas that is the raw material for the formation of new stars.


"Gas has many phases and different forms," Rudnick said. "Neutral hydrogen is single hydrogen atoms with one proton and one electron. But when that gets compressed, the hydrogen atoms can combine to form molecular hydrogen with two atoms—that's what stars form from. Neutral hydrogen is the reservoir of gas, and when it gets funneled on into galaxies it becomes molecular hydrogen and can form stars—and it glows. By observing that glow in light that is invisible to the eye, but visible with radio telescopes, we can measure the fuel supply of galaxies."


Rudnick said that the team would make observations at many different wavelengths to better grasp the cycle of gas within galaxies as it is supplied, heated, used and expelled. For example, to observe the emission of ionized hydrogen, the team will focus on specific wavelengths of light that correspond to those in the red part of the visible spectrum. It is these observations that will be carried out with KU's share in the Philips Claud Telescope on Mount Laguna.


"If you take a hydrogen atom and knock an electron off and if it falls back onto the atom later, it emits light at a specific wavelength," Rudnick said. "The glow of that specific light tells us where stars are forming right now. And 'right now' is within five to 10 million years—in astronomy terms that's a blink of an eye as these galaxies take at least a few hundred million years to noticeably evolve."


Part of the grant work also will support a successful research-based astronomy program in local Kansas schools, expanding it to 20 students of diverse backgrounds.


"I'm now in the fifth year of running an outreach program at Lawrence High School," Rudnick said. "As part of the program, I work with a teacher who earned his BA in astronomy at KU and with a KU graduate, both who help to run the course. In the first semester, students take a class in astronomy similar to what we teach students at KU. In the second semester, they do a research project with data from NASA's Spitzer Space Telescope, which culminates in a mini-symposium at KU attended by faculty and graduate students."

 


Notice the problems?


A study of filaments … that doesn’t use the word “plasma” … just “gas”.


A study that is once again based on *models*.


Models that very likely don’t properly account for electromagnetic effects on plasmas.


Models that very likely don’t simulate phenomena like Birkeland currents or plasmoids.


Models that ASSUME galaxies form outside filaments and fall into them.


A study that assumes filaments are carried along by the “gas”.


A study conducted by 2nd semester graduate students … after they’ve been indoctrinated by Professor Rudnick and the other gnome believers at KU.


Just saying …
 

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http://blogs.discovermagazine.com/crux/2018/09/21/the-dark-matter-crisis/#.W6cf962ZO-o
 

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What is Dark Matter? Even the Best Theories Are Crumbling


Dark matter research is unsettling. Scientists were unnerved when they first noticed that galaxies don’t rotate by the same physics as a spinning plate. The stars at a galaxy’s edge rotate faster than expected. And their motion can only be explained by a lot of invisible matter that we can’t see.


That was exciting more than unsettling when the field was new and ideas were plentiful and had yet to be proven wrong. Researchers consolidated the possibilities into two main camps, complete with clever acronyms: MACHOs (Massive Compact Halo Objects) and WIMPs (Weakly Interacting Massive Particles).


MACHOS Aren’t the Answer


MACHOs are the less exotic possibility. You and I don’t glow or reflect light terribly well, so it’s perfectly reasonable to suggest that space and galaxies contain lots of stuff — planets, stars not quite big enough to turn on and light up, world-gobbling space worms — that we simply can’t see because they are literally dark and we don’t have a big enough flashlight.


Except we can detect some of those objects out there (not the worms) because they’re so massive that they bend light around them. They do exist, and we know they’re there despite their darkness. And yet there’s just not enough of them to make the galaxy-rotation math work. The same problem pops up if we imagine a universe littered with black holes. We would need to see these light-bending gravitational lenses everywhere and we don’t, even when we look very hard.


The search for WIMPs

 

So the astrophysics community mostly moved on to WIMPs. Rather than big objects, maybe the universe is full of little things we can’t see. These would be swarms of objects like atoms that just don’t reflect or absorb light or any other kind of electromagnetic energy, unlike all the matter we can touch and measure and see around us on Earth. This concept is more unsettling, or it should be if you remember that one of the rules of science is that it’s supposed to work the same everywhere in the universe. We do know that neutrinos exist: tiny, mostly mass-less particles that barely interact with the universe around them. The problem there is that they’re mostly mass-less. We can’t figure out how there are enough of them to make up the 84 percent of the universe’s matter that we can’t see.


So maybe dark matter is a different object we haven’t observed at all yet, something called a neutralino. Researchers have come up with a plausible description of such a particle, how the Big Bang as we know it might have created them, and how they would fit into the standard model of particle physics without breaking everything else along the way.


Is Dark Matter the New Ether?


But we’ve been looking for them for a while. We’ve built incredibly sensitive, bizarre instruments to look for them. These include vats of liquid xenon stored miles underground, and telescopes looking for dark matter particles decaying into things we can see and measure, like gamma rays. It includes the Large Hadron Collider, one of the most expensive science experiments ever built. And we haven’t found them. We haven’t found the WIMPs themselves, and we haven’t found convincing evidence that they exist.

Except, of course, for the persistent evidence we can’t ignore that says the universe is heavier than what we can see.


At this point, the unsettling feeling is growing again. Decades ago, scientists were confident about the existence of the “luminiferous aether” as a medium to carry light. Now, that’s looked back on as a clumsy belief that should have been dropped far earlier than it was. Scientists persisted because they were sure that light, like sound, required a medium to move through in spite of the evidence piling up against that concept. Having been fooled once, scientists have to ask: Is dark matter the new ether?


For decades, a few rogue scientists have stood hopefully at the edge of respectability, offering their theory called Modified Newtonian Dynamics, or MOND. Essentially, it says that physics doesn’t work as we know it at the largest scales. It says we’ve been drawing the wrong conclusions, and dark matter isn’t required to explain the universe. No one has managed to develop a theory of MOND that adequately explains the universe around us, but it occasionally gains converts simply because the competing theory of dark matter has a glaring flaw: we can’t find it.


Perhaps we’re wrong about something in the standard model that defines how the tiniest particles in the universe behave and interact, and dark matter exists, but in a very different form than we’re expecting. Or perhaps we are wrong about the laws of gravity.


Or perhaps, maybe even tomorrow, an experiment will turn up a neutralino exactly where researchers say it should be. A particle will strike a tank of supercooled xenon. The LHC team will discover a new particle. Science is hard, and seen against the long story of scientific progress, we only started looking for dark matter yesterday. Until something changes, we’ll have to rest uneasy with the unsettling possibility that physics as we know it might be very wrong.

 

 

Or maybe the problem is that the physics the mainstream now teaches all it's future astrophysicists is only a subset of what they should be teaching them.   Maybe the problem is that belief in Big Bang, Dark Matter, Black Holes etc etc now has more similarity to a RELIGIOUS CULT than SCIENCE.   Just saying ...

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https://cosmosmagazine.com/space/the-dark-universe

 

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Is the search for dark energy a dead end?


After decades of research, dark matter and dark energy remain elusive. Is it time to admit that cosmology is ensnared by dimly understood forces? Michael Brooks investigates.


In 2006, I ventured to the Carnegie Institution in Washington DC. There, I had a long conversation with the astronomer Vera Rubin. Thirty-six years earlier, she was one of the first modern cosmologists to suggest that a huge part of the universe was missing. At the time, she had suggested it might take a decade to find this missing stuff, now best known as “dark matter”.


By 1990, two decades later, when dark matter was still missing, the English Astronomer Royal Martin Rees said it would turn up within a decade. In 1999 dark matter hadn’t made an appearance, but Rees was unbowed: he declared himself “optimistic” that, in five years’ time, he would be able to report what dark matter is.


But by the time Rubin and I met in Washington, astronomers were all still empty-handed. What’s more, things had gotten worse: in 1997 astronomers had discovered “dark energy”, another missing component of the cosmos. Now a full 96% of the universe involved a form of matter and energy unknown to science.


Has there been progress since then? Not really. In 2018, more than 20 years after we had to acknowledge our ignorance of the vast majority of the universe, we still haven’t identified what dark matter or dark energy might be. “I’m certainly ready for the great leap forward,” says Rocky Kolb, an astronomer based at the University of Chicago.

 

And there is not much hope of making such a leap either. In fact, some researchers are proposing that we might be living through our generation’s “ether moment”. For centuries, mainstream science believed that light propagated through a space filled with a mysterious stuff – the ether. But by the turn of the 20th century, the ether’s existence had been refuted. Could both dark matter and dark energy be similarly seductive illusions?


The first hint of a dark side to the universe came in 1933, when the Swiss astronomer Fritz Zwicky noticed that the Coma galaxy cluster was spinning so fast that it should be falling apart due to centripetal forces. Zwicky suggested that they might be holding together because of the gravitational action of embedded massive particles that didn’t betray their presence by reflecting light. He called this hypothetical stuff “Dunkle Materie”: dark matter.


The search didn’t really get off the ground though until the 1970s. It was the heyday of particle physics, so when Rubin noticed an anomaly in the Andromeda galaxy “that suggested the presence of a novel form of matter particle”, physicists were all ears. Rubin had measured the galaxy’s “rotation curve”, a graph of the speed at which its stars are orbiting the galaxy’s centre, plotted against their distance from the centre. The problem Rubin noticed was that, far out from the centre, the graph was flat.


Just as Pluto’s motion through space is slower than Earth’s, the outer stars should have a lower velocity than the inner stars. If their velocity is equally high, what’s to stop them flying off into space? Certainly not the gravitational pull of the galaxy’s visible matter, which is nowhere near strong enough. There must be a gravitational pull from dark matter holding these fast-spinning stars in place, Rubin said.


So what is this stuff? Physicists have come up with various candidates. The basic qualification is that it must have mass but no interaction with electromagnetic radiation: it must, in other words, have a gravitational pull without being detectable in any other way.


Contenders have included mini black holes, neutrinos, hypothesised particles called axions, other things called Massive Compact Halo Objects (MACHOs) – and many more. There have been scores of experiments direct and indirect, looking for such candidates, and none have succeeded.


Two elaborately designed snares for dark matter caused particularly bitter disappointment when they failed to capture anything. One involved smashing dense particles of matter like protons together in the Large Hadron Collider at CERN, the European particle physics lab in Geneva, and looking for dark matter candidates in the debris. None have been found. The other was the Large Underground Xenon or LUX experiment in the former Homestake gold mine in South Dakota, which hoped to detect “Weakly Interacting Massive Particles” or WIMPs, that are believed to gently rain down on our planet.


LUX’s detector, buried deep underground to avoid noise, comprises a cylinder filled with cooled liquid xenon. The idea is that if a WIMP collides with a xenon atom, the atom emits a tiny flash of light that gets picked up by a bank of detectors encircling the tank. However, since we don’t know how often a WIMP would nudge a xenon atom, or how hard, the detector has had to search through a range of possible energy levels. In 2016, after a two-year, $US10 million-dollar search, its operators gave up the hunt, their snares conspicuously empty.


“I thought this would be the decade of the WIMPs,” Kolb says. “But we are 70% through the decade, with experiments and observations that in principle finally have the sensitivity and range to have discovered a WIMP. And we are empty-handed. All of the parameter space hasn’t been closed yet but it’s getting less likely that a WIMP is the answer.”


As a result, physicists are starting to look for new ideas about dark matter particles, or resurrecting ideas that were previously discarded. As Martin Sloth of the University of Southern Denmark has put it: “Everybody is signing up, thinking that they now have a chance”.


But if all comers are now welcome in the new search for dark matter particles, alternative explanations for the anomalous observations in galaxy rotation curves and galaxy cluster spins are not. Take, for example, the work of Stacy McGaugh, a professor at Case Western Reserve University in Ohio and a former colleague of Vera Rubin. McGaugh has gone back to the drawing board. Rather than a problem of insufficient matter, perhaps gravity simply obeys a different rule over the huge, intergalactic distances involved?

 

The idea that gravity might not obey Newtonian (or Einsteinian) laws, so called Modified Newtonian Dynamics (MOND), was first put forward in the 1980s by Israeli physicist Mordehai Milgrom. “There are already observations explained by modified gravity that can’t be explained by dark matter,” McGaugh points out. One, he suggests, is the distribution of mass in dwarf spheroidal galaxies, which are small, dim galaxies dotted around the edges of the Milky Way and Andromeda. Because they contain comparatively little dust, their contents are relatively easy to scrutinise.


But modifying gravity certainly doesn’t solve all the cosmological conundrums that astronomers want to resolve. Even McGaugh admits that for some observations, such as gravitational lensing where light from distant galaxies is bent by the pull of invisible matter, dark matter is a better explanation than modified gravity.


But, rather than point scoring for the different theories, McGaugh says it’s time for a reckoning. If the dark matter search has turned up nothing since the 1930s, who gets to decide how long we keep looking? “Every five years for the past 25 years I’ve heard a talk by some impressive person in which it was confidently asserted that in five years we would know what the dark matter was,” McGaugh says. “It was always an ‘odds on slam dunk’ – and always an overly optimistic assessment.”


The problem is, we can’t ever rule out dark matter’s existence just because we haven’t found it. “If we get tired of looking for WIMPs, maybe it is axions. When we tire of those, we’re free to make something else up, ad infinitum,” McGaugh says. He believes this transgresses the very idea of a scientific endeavour. “Is that science? Popper would say ‘no’.”


The iconic 20th century science philosopher, Karl Popper, held that if there is no piece of evidence that – if found – could show unequivocally that your theory is false, you’re not doing science. The theory of dark matter is unfalsifiable, McGaugh says.


But according to Michela Massimi, a philosopher of science based at the University of Edinburgh, that doesn’t disqualify its merit. Invoking Popper’s falsifiability is inadequate for capturing cosmology’s issues, she says.


Indeed, while most cosmologists today still hope to find evidence for dark matter through Popperian experiments, the evidence actually accrues through a variety of channels: from the cosmic microwave background radiation (an echo of the big bang) to the motion of galaxy clusters, among others. “Until and unless a rival dark-matter-free model can be found that proves as successful at explaining all these phenomena, the hypothesis of cold dark matter is bound to remain live, even in the absence of direct detection evidence,” Massimi says.


Massimi is sympathetic to those trying to work on rival ideas, though. She describes McGaugh’s work as important and regrets that his ideas, and those of others, don’t receive the attention they should. She remains optimistic, however. “I think things are slowly changing,” she says.


Colin Rourke, a mathematician at the University of Warwick, doesn’t share Massimi’s optimism. Like McGaugh he has also developed a mathematical model of galaxies that does away with the need for dark matter. Instead, he suggests that a rotating, superheavy black hole at the centre of galaxies is enough to create the flat rotation curve.


In his mathematical scheme, which builds on the early 20th century ideas of Austrian Ernst Mach (of sound speed fame), the rotating mass creates a distortion in space-time that would alter the apparent velocity of the stars around it. Because of the distortion (an effect known as frame-dragging), they look from the outside like they are being pulled around more quickly, which creates the illusion of dark matter’s existence. “It’s just something in the geometry, something warping in space-time,” he says.

 

Though he has many mathematical admirers and collaborators, Rourke has had no success trying to get his idea taken seriously by cosmologists, or published in any of the mainstream cosmology journals. “It’s been like dropping it down a deep well. I’m still waiting to hear something,” he says.


For Donald Saari, a mathematics professor from the University of California, Irvine, the answer to missing matter lies in the mathematics of many-body problems or how forces interact between multiple objects. He says he has created simulations that show the theoretical rotation curves of galaxies – the root of Rubin’s observation of dark matter – are the wrong shape.


That is because they rely on solving the two-body problem to give the theoretical rotation curve, approximating the motion of any particular star by assuming it is pulled by the galaxy as a whole, rather than each of the other objects at once.


Saari has worked out the effects of having billions of massive objects simultaneously moving and pulling on one another. The result, he claims, gives precisely the rotation curve that’s observed. “I’ve had it reviewed by astronomers, and they have not found any errors in what I’ve done. They just don’t like the conclusion.” He published his analysis in the Astronomical Journal three years ago, after a four-year review process, but it hasn’t changed anything. “It’s had no impact that I’m aware of,” he says.


Saari is relatively sanguine about being ignored. McGaugh is less happy, and expends a significant amount of energy engaging with the cosmology community, offering new tests for modified gravity, exploring where and how astronomers might test whether it, or dark matter, is the more accurate idea.


Despite all the effort, it is unlikely to make any difference. Modified gravity researchers have long battled mainstream cosmologists over the interpretations of observations, drawing conflicting conclusions from the same evidence.


Even if we were to solve the dark matter problem, we’re still left with another huge hole in our picture of the cosmos – though this too might be an illusion induced by a faulty theory. This hole is occupied by dark energy, and it accounts for 70% of the total mass and energy in the universe. That’s almost three times the size of the dark matter hole, which accounts for about 27%.


As with dark matter, dark energy’s existence was initially inferred from astronomical observations – this time from light emanating from exploding stars known as supernovae. Analysing how the wavelengths of the light had stretched as it travelled through space to our telescopes suggested not only that space was expanding, but also that the expansion was speeding up.


This Nobel prize-winning discovery by the teams of Saul Perlmutter at Lawrence Berkeley National Laboratory, Brian P. Schmidt of the Australian National University and Adam Riess of Johns Hopkins University was a complete surprise in 1997. Our understanding was that in the aftermath of the big bang, gravity should have put a brake on the exploding universe.


We assume that there must be an energy source for this acceleration: hence the hypothesis of dark energy. But so far all attempts to work out what it is, and where it comes from, have failed. There are also those who think it might be a mathematically induced illusion.


One possibility is that we may have made some false assumptions: essentially, the universe is more complex than we might have hoped. Carl Gibson of the University of California San Diego, for instance, reckons we can’t do reliable cosmology without taking into account turbulence and other complexities of fluid dynamics that might have arisen in the high-energy environment of the big bang.


It’s not just about turbulence, though. In order to have a manageable theory, we assume that the universe is isotropic – the same in every direction – and homogeneous, with no areas of the cosmos that have special, peculiar characteristics. Those assumptions make the equations easier to solve, but they may be oversimplifying things. Kolb has been suggesting for more than a decade that we need a more complex, nuanced theory that can work without these assumptions. The trouble is: the maths is prohibitively difficult and, according to some, the effort might be a waste of time. Martin Kunz of the University of Geneva, for instance, has published work suggesting the inhomogeneities would have to be unrealistically huge to account for the dark energy. Kolb isn’t convinced. Rumours of the idea’s death are “exaggerated”, he reckons.


Alternatively, might there be problems with our supernova observations? The conclusions about dark energy rely on all supernovae of the same type emitting their light in exactly the same way. That’s why the ones used for the dark energy calculation are known in the community as “standard candles”.


But maybe that’s another dangerous assumption. We’re currently puzzled by a set of observations of supernova iPTF14hls, for example. Instead of dimming continuously after its initial explosion, it has brightened on occasion, maintaining this variable luminosity for years. Though this is not the same type of supernova as used in dark energy measurements, it does raise the question of whether we understand supernovae as well as we think.


But this avenue of inquiry is still a long shot – like all the others, it seems. Take the idea that the solution to dark energy might come with a re-examination of Einstein’s cosmological constant. Einstein introduced the term as a fudge factor: while his equations showed the universe was expanding, he “knew” the universe to be static. He later referred to this as his biggest blunder and removed it from the equations. But physicists have essentially re-inserted it because since the discovery of dark energy, we need a term that will push hard on space and time, causing the accelerating expansion we observe.


Not everyone is convinced, though, that this simple re-insertion is the right way to account for the observations. After all, the cosmological constant term makes the equations work but doesn’t actually give us any clue about the source of the dark energy. Maybe there are better fudges? “To me, looking for flaws in the cosmological constant is the thing to do,” Kolb says.


It’s worth noting that the universe’s rate of expansion is already the subject of controversy. The value obtained by using stellar measurements such as supernova standard candles is different to the value obtained using the record of the universe’s first moments preserved in the cosmic microwave background (CMB). (Here the expansion rate of the universe is inferred from gravitational lensing effects on the photons of the CMB.)


Some of the researchers involved think we might be able to explain the discrepancy with a hitherto unknown particle called a “sterile neutrino” – which could also be the source of dark matter. “That remains one of the stronger possibilities,” says Riess of Johns Hopkins University.


His group’s latest analysis of the tension, which has been accepted into the Astrophysical Journal, suggests the discrepancy between supernovae and CMB data is not going away with better measurements.


So, as things stand, there is no resolution in sight to the dark energy problem. There are myriad further data-gathering plans, such as the Australian Dark Energy Survey (OzDES), led by Chris Lidman of the Australian Astronomical Observatory in North Ryde, New South Wales, which is measuring the output of more than 3,000 new supernovae to give us more information about the universe’s expansion.


But this will all take years, maybe several decades, to give us a firm conclusion. In the meantime, there’s a familiar non-committal refrain floating through the ether. “It’s just a hard problem,” Riess says. “I am optimistic we will learn more about dark energy in the coming decade.”


Likewise for dark matter. It seems we will just to have to wait for something to change. At the edge of what’s known, Kolb points out, science is not a slow steady march of progress: it’s leaps, bounds and occasional missteps. “I’m willing to be patient for a while longer,” he says.

 

 

 

 

So, although those observing the mainstream physics community are beginning to open up to the possibility that dark matter, etc, is "a seductive illusion", the mainstream physics community itself is apparently not ready to abandon their gnome.    And notice that in the above article, the word “plasma” doesn’t appear ONCE.   Even the word “gas” doesn’t appear  Neither does "electromagnetism."     But gravity?   Eight times.   Dark matter?   Dozens of times.   So even those expressing some doubt are still unconsciously (or unknowingly) clinging to gnomes.   Just saying ...

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https://www.skyandtelescope.com/astronomy-news/black-holes/video-the-glow-of-spiraling-black-holes/

 

Quote

 

Pairs of humongous black holes likely circle each other in the hearts of many galaxies, brought together over the eons by galaxy mergers. As they come within a fraction of a light-year of each other, they create ripples in the fabric of spacetime that undulate across the universe.


But they should also create bizarre light effects. Unlike the smaller black holes that scientists have “seen” merge with LIGO and Virgo (which have long eaten up any nearby gas), supermassive black hole binaries will be surrounded by disks of glowing gas heated by magnetic and gravitational forces. Each black hole will have its own disk; a second, bigger one will ring both, like a playpen around two girls in tutus, their hands linked as they spin around each other.


Simulations by Manuela Campanelli (Rochester Institute of Technology) and her colleagues previously showed that these three disks engage in an almost constant trading scheme, with gas sloshing between the two mini disks and filaments peeling off the circumbinary disk, either to latch onto a mini disk or be flung back to slam into the big ring. All these changes should create distinct signals — not in gravitational waves, but in light.


Reporting in the October 1st Astrophysical Journal, Stéphane d’Ascoli (RIT), Campanelli, and colleagues take the first step in understanding what the light emitted from these systems looks like. The researchers used the same simulation data as before, this time to figure out how light would look after traveling through the warped spacetime landscape created by the black holes’ extreme gravity. Unfortunately they had to leave out the sloshing and peeling filaments to make things simpler, but they were able to create the stunning video below.


No technology in the foreseeable future will enable us to see supermassive black hole binaries this way. Instead, astronomers have to search for unique patterns in how the glow looks at different wavelengths, and how that emission changes with time. The new simulations indicate that the circumbinary disk, the accretion streams, and the mini disks all radiate primarily in ultraviolet. Some X-rays will also come from the particle haze around the mini disks when gas pours onto them. In less intense accretion situations, X-rays will come from the streams, too.


These simulations don’t yet tell observers exactly what to look for — it’s too soon for that. But they’re an important (and gorgeous) milestone along the way to that goal. The team will next dive into more details, like how the sloshing, flinging gas affects things. The previous calculations suggested flares that last hours to days might occur.

 

 

Sounds like another study of NO VALUE.

 

And they've been leaving out the filaments?  

 

Naughty, naughty.

 

Oh ... and notice that its "gas" not plasma they're flinging.

 

Naughty, naughty.

 

Say … at the beginning of this year, these quacks were all assuring us that soon they’d have a photograph of a black hole.    

 

But here we are ... nearing the end of the year, and still not a peep.  

 

Problem?  

 

B) 

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