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Dark Matter is Real. “Dark Matter” is a Terrible Name for It
Discover Magazine ^ | 4/1/19 | Corey S. Powell

Posted on 04/03/2019 3:25:28 PM PDT by LibWhacker

Astronomers have been grappling with the mystery of dark matter for a long time, and I mean a looong time. The history of dark-matter investigations goes back at least to 1906, when physicist Henri Poincaré’s 1906 speculated about the amount of “matière obscure” in the Milky Way. Or really, it goes to back to 1846 and the first successful detection of dark matter: the discovery of the planet Neptune, whose existence had been inferred by its gravitational pull well before it was actually observed.

Since then, scientists have identified many different dark components in space: collapsed stars, interstellar dust, hot gas, planets, black holes. Unfortunately, none of those can account for the genuinely invisible dark matter that seems to make up 26 percent of the mass of the universe, outweighing all ordinary matter more than five to one. Failure to identify dark matter has gone on so long that some people have started to wonder if the whole concept is amiss. The recent discovery of two galaxies that seem to contain no dark matter at all hasn’t helped. As often happens these days, some wags on Twitter immediately started joking that dark matter sounds like the fictitious “aether” that physicists sought in the 19th century.

But those jokes miss the exciting truth–in fact, they get it exactly backwards. Dark matter is real. It just may be even stranger and more complicated than we thought.

To show you what I mean, I’ll start by addressing the aether jokes. This is a reference to the discarded belief that empty space can’t be truly empty, because light waves and other forms of radiation are able to pass through it. Sound waves are possible because air vibrates. Ocean waves are possible because water ripples. What then, physicists wondered, is “waving” when a light wave passes through a vacuum? One idea, originally advanced by Isaac Newton and widely discussed during the 19th century, was that the vacuum is filled with an invisible substance called aether.

If the aether were real, it should be possible to detect. The Michelson-Morley experiment of 1887 looked for the effects of an aether wind that would blow past the Earth as it moves in its orbit around the Sun. Light should appear to move more quickly when the aether is blowing toward us, and more slowly when blowing away. Michelson and Morley found no such effect.

One proposed explanation for the null result was that the aether wind causes objects to compress. If objects (including all measuring devices) get smaller in exact proportion to the intensity of the aether wind, then the speed of light would always appear the same: When the wind is blowing toward you, your ruler would shrink, and when the wind is blowing away from you it would appear to expand. This idea was called Lorentz-Fitzgerald contraction, after the two physicists who came up with the concept.

Wait a second. The speed of light is the same for all observers, objects appear to contract when moving at high velocities…those are some of the basic elements of Einstein’s special theory of relativity! Sure enough, Einstein appropriated some of the concepts and even some of the math from Lorentz and Fitzgerald, but showed that the effects attributed to the aether were actually intrinsic properties of the laws of physics–no aether requried. (Quantum physics, in turn, explained why the aether was unnecessary for the propagation of light, either.)

The Michelson-Morley experiment did not, by itself, lead to special relativity, but it was an important part of figuring out how the universe really works.

Be Kind to Your Dark Matter

Now we can take a more enlightened and generous look at the puzzle of dark matter. In the 19th century, the simplistic idea was that space must contain some substance that could transmit waves, because the familiar types of waves all worked that way. In the 20th century, the simplistic idea was that gravity from visible matter is the only long-range force acting on the universe, because that was the only familiar force and the only familiar type of matter. The equivalent of the aether model, then, is a model with no dark matter.

Then in the 1930s, astronomer Jan Oort and physicist Fritz Zwicky deduced additional gravitational effects that seemed to indicate the presence of additional, unseen matter. Oort measured it within our galaxy and called it “nebulous matter”; Zwicky measured it within clusters of distant galaxies and called it “dunkle Materie,” or dark matter. (Gianfranco Bertone and Dan Hooper have published a deeply researched paper on the forgotten history of dark matter, available here.)

The name is not important. What is significant here is that they obtained a result that deviated from the naive assumptions of simple gravity and visible matter only. The discovery of dark matter, then, was the equivalent of the Michelson-Morley experiment. Dark matter is not a cover-up to hide a problem in physics. It is not a new aether. It is the provocative, empirical evidence that our physics is incomplete.

I know just said that the name is not important, but I’m going to take that back. The name is quite important, actually, in the sense that saying “dark matter” creates specific and misleading assumptions about what we are looking for. The word “dark” evokes black, meaning something that absorbs light, but that’s not right. What we are seeking is something that does not interact at all with light. Physicist Lisa Randall therefore prefers the term transparent matter.

Even that is still not right, though, because strictly speaking we are not certain that we are looking for matter at all. What we are really seeking is something invisible that generates an anomalous gravitational pull. I’m under no illusions that I am going to displace “dark matter” as the go-to term, but “hidden gravity” is a far superior description.

The overwhelmingly predominant scientific view right now is that dark matter consists of a fundamental particle or combination of particles. There are a lot of reasons for favoring this explanation. Physicists have detected 18 different types of elementary particles along with a dizzying 200-or-so composites particles, and it’s clear that the current Standard Model of particle physics is not complete.

It is highly likely that there are undiscovered particles out there, and it is entirely reasonable that some of them might not interact with light or other forms of radiation. We already know of one family of particles that behaves as dark matter: the neutrinos. They do not engage with light or with the strong nuclear force, but do contribute a gravitational effect. They just don’t contribute nearly enough to account for the observed evidence.

The Case for “Hidden Gravity”

And mind you, there is a lot of evidence! We see signs of dark matter all across the universe, at a wide variety of scales. It seems to have shaped the initial reverberations of the Big Bang, influenced the production of primordial deuterium and helium, and seeded the formation of galaxies. It appears to provide the crucial gravitational pull that holds those galaxies together, and that binds larger clusters of galaxies together. We can trace it by the way it bends the light in and around those galaxy clusters.

Studies show that dark matter somewhat follows the distribution of visible matter, but not exactly and not always. Those discrepancies offer clues about its nature. The discovery of first one, now two small galaxies that appear to have no dark matter supports the notion of dark matter as a particle. Here’s why:

If unseen gravity (excuse me, dark matter) were some previously unknown property of physics, we would expect to see it everywhere that normal matter appears. Finding normal matter separated from unseen gravity, and unseen gravity separated from normal matter, suggests that the thing creating that gravity is an entity in itself—a dark particle of some sort.

Still, nobody has been able to find that particle despite decades of searches. Claims of annual flux of dark matter passing through a detector in Italy look dubious. Every other direct-detection dark matter experiment has produced null results. Speculation that gamma rays from the center of the Milky Way were caused by decaying dark-matter particles proved unfounded. The results keep coming: nothing, nothing, more nothing.

Repeated failures to find a dark matter particle has left the door open a crack for other explanations, most notably alternate theories of gravity that are often lumped together under the rubric of MOND (modified Newtonian dynamics). In this view, the “unseen gravity” component is a previously unrecognized feature of gravity itself, which operates slightly differently under extreme cosmological conditions (long distance, very low density) than it does on Earth or around the solar system.

There are even more exotic possibilities. Dark matter might be an entirely new fundamental field, not just an additional component of gravity. It might be a kind of cosmic superfluid. Hell, it might possibly be a manifestation of matter in another universe, which creates an otherworldly gravitational pull that is able to cross higher dimensions.

What matters about dark matter is that the phenomena describing it are real, just as the results from the Michelson-Morley experiment were real. The failure of many brilliant scientists to isolate the cause of the phenomena is a strong indication that the answer, whatever it is, will be truly new—which is to say, surprising—which is to say, revelatory.

To paraphrase a famous fake quote by Carl Sagan: Somewhere out there, something astonishing is waiting to be known.


TOPICS: Astronomy; Science
KEYWORDS: aether; astronomy; cosmology; dark; darkenergy; darkforce; darkmatter; einstein; empty; gravity; matter; science; space; speedofdark; stringtheory
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1 posted on 04/03/2019 3:25:28 PM PDT by LibWhacker
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To: LibWhacker

Dark matter matters?


2 posted on 04/03/2019 3:26:06 PM PDT by DannyTN
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To: LibWhacker

Dark matter was actually discovered by Fritz Zwicky in the 1930’s. Neptune doesn’t qualify since it’s not dark and we know what it is.


3 posted on 04/03/2019 3:28:47 PM PDT by Telepathic Intruder
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To: LibWhacker

Pretty good article. The other bizarre quality of the aether was that it needed to be a solid because of transverse waves.

And Einstein referred to the the experiment of Fizeau rather than the Michelson-Morley experiment. I don’t know why.


4 posted on 04/03/2019 3:36:40 PM PDT by Moonman62 (Facts are racist.)
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To: LibWhacker

Studies show that dark matter somewhat follows the distribution of visible matter, but not exactly and not always. Those discrepancies offer clues about its nature. The discovery of first one, now two small galaxies that appear to have no dark matter supports the notion of dark matter as a particle. Here’s why:

If unseen gravity (excuse me, dark matter) were some previously unknown property of physics, we would expect to see it everywhere that normal matter appears. Finding normal matter separated from unseen gravity, and unseen gravity separated from normal matter, suggests that the thing creating that gravity is an entity in itself—a dark particle of some sort.

...

That’s a really good point.


5 posted on 04/03/2019 3:37:55 PM PDT by Moonman62 (Facts are racist.)
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To: LibWhacker
Maybe the inhabitants of the galaxies without dark matter learned to harvest it and used it all up.

6 posted on 04/03/2019 3:44:39 PM PDT by BitWielder1 (I'd rather have Unequal Wealth than Equal Poverty.)
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To: LibWhacker

7 posted on 04/03/2019 3:48:57 PM PDT by GrandJediMasterYoda (As long as Hillary walks free, equal justice under the law will never exist in the USA)
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To: Telepathic Intruder

>> Neptune doesn’t qualify since it’s not dark and we know what it is. <<

Read the article. Dark means “unknown.” We know what it is NOW, but it WAS dark matter. When we discover what more of dark matter is, it will no longer be dark, also.


8 posted on 04/03/2019 3:59:03 PM PDT by dangus
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To: LibWhacker

dark matter is an inferred ‘fudge factor’ to make their equations work. Maybe it exists, or maybe it doesn’t and the equations are missing something.


9 posted on 04/03/2019 3:59:52 PM PDT by Mount Athos
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To: All

Just don’t let Malekith get ahold of the aether.


10 posted on 04/03/2019 4:01:00 PM PDT by BipolarBob (I got dozens of friends and the fun never ends that is, as long as I'm buying)
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To: dangus
Point taken. However, dark matter was never a term until Fritz discovered that there was unaccounted matter in the universe.

The discovery of Neptune was based on the assumption that there was a planet there, which is correct. It was never assumed that it was something entirely unknown at the time. Today, no one still has the answer of what dark matter is. Only hypotheses.
11 posted on 04/03/2019 4:10:27 PM PDT by Telepathic Intruder
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To: LibWhacker

If you really want to twist your noodle, the following link offers a different perspective that isn’t discussed much, though Tesla appeared to have grasped the concept.

https://www.thunderbolts.info/webnews/ghosts_of_dark_matter.htm


12 posted on 04/03/2019 4:10:42 PM PDT by Brown Bag Special (Trust but VERIFY)
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To: Mount Athos

Yes. Names like dark matter, dark energy, event horizon, singularity are names scientists give things when they have no freaking idea what they are.

And yes heavily invested in fudge factors to make things work. The Galaxy would fly apart without Dark Matter. But they haven’t a clue what and where it is. ( the late Vera Rubin discovered that our Galaxy did not operate as a large solar system but spun like a solid disk and should fly apart with the lack of Mass in the visible galaxy...so they assumed there was unseen mass and called it Dark Matter)


13 posted on 04/03/2019 4:22:39 PM PDT by Vaquero (Don't pick a fight with an old guy. If he is too old to fight, he'll just kill you.)
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To: LibWhacker

Definitely a racissss name for it.


14 posted on 04/03/2019 4:23:28 PM PDT by doorgunner69
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To: LibWhacker; 1FreeAmerican; A. Patriot; AndrewC; antonia; aristotleman; Bellflower; Boogieman; ...
No, dark matter doesn’t exist. There is a competing cosmology that actually explains what controls the Universe far better than the gravity driven model and actually predicts the new discoveries that keep surprising, astounding, and shocking the orthodox gravity cosmologists time and time again. This cosmology does not require the invocation of magic fairy dust of dark matter and then later magic dark energy to squish and squeeze their mathematical models to fit reality. They just work and can actually be demonstrated in the laboratory and can be scaled from the microcosm to the macrocosm merely by increasing power. That cosmology is the:
Electric/Plasma Universe Cosmology — PING!


Clear Example of a Birkeland Current
"Z" Pinch with Symmetrical Plasmids
seen in Hubble Telescope View of
The Twin Jet Nebula
ELECTRIC/PLASMA UNIVERSE PING!

If you want on or off the Electric Universe/Plasma Ping List, Freepmail me.

15 posted on 04/03/2019 4:28:41 PM PDT by Swordmaker (My pistol self-identifies as an iPad, so you must accept it in gun-free zones, you hoplaphobe bigot!)
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To: Brown Bag Special; Swordmaker

Excellent article at your link:

The French existentialist writer Albert Camus once wrote, “…there is no more dreadful punishment than futile and hopeless labor.” Though we are not accustomed to thinking of science as hopeless labor, there is a domain of science today for which the description may be perfectly apt. Space Age technology has achieved wonders. But according to critics, many theoretical adventures undertaken to explain astonishing Space Age discoveries have set the theoretical sciences down a dead-end path.

An example of this may be the unyielding belief of a majority of scientists in the existence of “dark matter.” Dark matter entered the lexicon of astronomers and cosmologists as a way of dealing with a serious theoretical problem. In observing the motions of galaxies in clusters, they calculated the mass needed to hold the cluster together. They found there was not nearly enough. So they calculated the amount of mass that could not be seen but MUST be there in order to account for the observed motions.

The line of reasoning seemed unassailable, and it followed directly from a theoretical assumption shared by almost all astronomers. This foundational assumption is that, at the macrocosmic scale, gravity reigns supreme. It is gravity that organizes galaxies and gives birth to their constituent stars. So if there is not enough visible mass to do the surprising things seen in space, then the only option is to add invisible mass to make the astronomers’ equations match observations.

Another “weird” and “invisible” influence that supposedly affects the motions of galaxies is “dark energy.” Discovered (or perhaps “invented”) in 1998 in response to anomalously low brightness of Type 1a supernovae in high-redshift galaxies, dark energy is believed to be a kind of cosmic antigravity. Its proponents say that its repulsive effect causes galaxies to fly apart at an ever-increasing speed – thus accelerating the supposed “expansion” of the Universe. But these claims depend on the astronomers’ interpretation of redshift as a reliable indicator of velocity in an expanding universe and therefore, distance. It also depends on a shaky theoretical understanding of Type 1a supernovae. (See Supernova 1987A Decoded) Today, that interpretation is challenged by a rapidly growing number of contradicting observations, causing scientists to look for alternative causes of redshift. (See The Picture That Won’t Go Away and Redshift Rosetta Stone)

Under the pressure of unsolved enigmas, the current position of official astronomy is that only 4% of the universe is “visible” matter. The other 96%, is composed of dark matter and dark energy—all of which, by definition, is invisible. “The universe is made mostly of dark matter and dark energy,” says Saul Perlmutter, leader of the Supernova Cosmology Project headquartered at Berkeley Lab, “and we don’t know what either of them is.”

But these mysterious, ubiquitous, and invisible inventions are only “necessary” because astronomers hold to a belief that is no longer tenable — that electromagnetism plays no appreciable role in the organization of cosmic structure and powering of stars. Plasma cosmologists and proponents of the “Electric Universe” – who study the behavior of electrically powered plasma in the lab and in nature – insist that the astronomers’ belief is incorrect.

One of the great scientific “secrets” in modern times is that many of astronomy’s most fundamental mysteries find their resolution in plasma discharge behavior. On the pages of Thunderbolts.info, this point has been enumerated in countless Pictures of the Day. For example, computer simulations have demonstrated that the motion of the spiral galaxy can be achieved through nothing other than interactions of electric currents in plasma. From the TPOD Plasma Galaxies:

“Plasma experiments show that rotation is a natural function of interacting electric currents in plasma. Currents can pinch matter together to form rotating stars and galaxies. A good example is the ubiquitous spiral galaxy, a predictable configuration of a cosmic-scale discharge. Computer models of two current filaments interacting in a plasma have, in fact, reproduced fine details of spiral galaxies, where the gravitational schools must rely on invisible matter arbitrarily placed wherever it is needed to make their models ‘work’.


16 posted on 04/03/2019 5:01:34 PM PDT by Windflier (Pitchforks and torches ripen on the vine. Left too long, they become black rifles.)
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To: doorgunner69

Okay, that was funny.

In the same genre of thought, years ago, before my time in the Army, I was on a “ride-along” with an officer friend of mine just north of Baltimore, Maryland.

I kid you not, Baltimore County was already so politically correct, the county government dictated to the police, they could not use the terms “African American” or “Black”, to describe blacks and African Americans.

The default and accepted term used by police was “#2(’s)”.

So, throughout the ride-along, I would hear the term “#2”, all throughout the day over the radio, to describe African Americans or blacks.

This was the acceptable term by a county government, which included seats held by “African Americans”.

Using the same logic as the left, every word from every language could only ever be race derived, and therefore racist. So how is it only “white language” is racist?

These people really are nuts, and truly are a bunch of racists at heart!

True racism is not derived from a word or term, but rather hatred in ones heart, (which could be silent and never spoken”


17 posted on 04/03/2019 5:11:07 PM PDT by patriotfury ((May the fleas of a thousand camels occupy mo' ham mads tents!))
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To: Vaquero
Names like dark matter, dark energy, event horizon, singularity are names scientists give things when they have no freaking idea what they are.

Merely a consequence of the limitations of language itself, not of science, its practitioners, or their seeming clumsiness with english.
18 posted on 04/03/2019 5:20:18 PM PDT by SpaceBar
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To: patriotfury

True racism is not derived from a word or term, but rather hatred in ones heart, (which could be silent and never spoken), toward a group of people, just because of an “unchangeable”, such as is found in physiology or color.

Accusing other of racism, as a way to manipulate others of a different “race” to a specific end, is pure racism!


19 posted on 04/03/2019 5:25:15 PM PDT by patriotfury ((May the fleas of a thousand camels occupy mo' ham mads tents!))
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To: Vaquero

No, they are names given to entities that account for experimental results and observations. The properties of these entities are well-defined so that further tests and observations either can confirm or falsify their existence. Dark matter, for example, is defined to be an entity that interacts only via gravitation and not via any of the other three fundamental interactions (electromagnetism, the strong nuclear force or the weak nuclear force). Since it interacts gravitationally, dark matter must have mass. Since it does not interact in any other way, it must not have electrical charge or color charge. It must not be composed of quarks and therefore cannot have strangeness, charm, topness or bottomness (these are very specific quantum properties that have nothing to do with the ordinary meanings of the words).

The fact is that ALL entities in science are defined in this manner, by inferring their properties from experiment. Just as an example, answer this what is an electron? We can define it only in terms of its mass, charge, spin, etc., all of which are inferred from experiment. We’ve never actually seen an electron or measured one directly. The main difference is simply the amount of evidence we have — there are more observations based on electrons than on dark matter. This is unsurprising since electrons are much easier to interact with. Even if you were sitting in a room full of dark matter or standing on a mountain of it, you’d never notice. Gravity is a very weak interaction, producing noticeable results only when dealing with planet-sized or bigger objects. If we had to rely on the gravitation of electrons, we undoubtedly would know almost nothing about them.

Of course, all conclusions in science are provisional. Dark matter might someday be replaced by a different concept that explains results better. So might electrons, although that would be much more surprising. In either case, though it isn’t true that the name is just a placeholder because we don’t know what it is.


20 posted on 04/03/2019 5:27:33 PM PDT by stremba
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