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Dark matter: Agreed terms help sensible discussion

Universe - the definitive visual guide Gen ed Martin Rees Dark matter and dark energy DK 2012
There is far more dark matter in the Universe than that contained in stars and other visible objects. The invisible mass is called "dark matter". Its composition is unknown. Some might take the form of MACHOs (massive compact objects) - dark planet-like bodies - or WIMPs (weakly interacting massive particles) - exotic subatomic entities that scarcely interact with ordinary matter. . . . . . . . . . Cosmologists have proposed the existence of "dark energy", a force that counteracts gravity and causes the Universe to expand faster. The exact nature of dark energy is still speculative."

The Theory of (nearly) Everything BBC Focus Ed Daniel Bennett Searching for dark matter 2016
In terms of mass-energy "the Universe is 68% dark energy, 27% dark matter and 5% baryonic. If we discount the energy part, the numbers revert to - 85% dark matter (and) 15% baryonic matter."
"Has dark matter got anything to do with dark energy?
No. Dark energy is the name given to the mysterious entity thought to be accelerating the overall expansion of the Universe - a sort of anti-gravity. In contrast, dark matter can be thought of as gravitational glue that helps bind galaxies and clusters of galaxies together. We're literally in the dark as to what they are."
"Could dark matter be something else?
So far we've been assuming that dark matter is tangible, something that truly exists. But what if it doesn't . . . - a symptom of the fact that we don't understand gravity properly? That's exactly what proponents of a theory called Modified Newtonian Dynamics (MOND) advocate. . . . dark matter was introduced to account for the fact that stars in the Milky Way don't slow down the further they are from the galactic centre, unlike the planets of our Solar System. . . . . . . . . . The idea was first put forward by . . . Mordehai Milgrom in 1983. He suggested that the strength of gravity could become stronger where acceleration levels are small."

Astronomy Simulations zoom in on dark matter by Mark Zastrow February 2021
"Dark matter is a mysterious material that makes up more than 80% of all matter in the universe, This strange stuff permeates and surrounds every galaxy, and clumps of dark matter, called halos, are where galaxies tend to form. Now, supercomputer simulations have found that these cosmic clumps of dark matter look surprisingly alike, no matter their size - whether they encompass monstrous galaxy clusters or are mini-blobs the size of Earth. . . . . . . . . . While dark matter does not react with normal matter, it should give off a burst of gamma-ray light when it collides with its antimatter equivalent and the particles annihilate each other."

Endless Universe - beyond the big bang by Steinhardt and Turok Doubleday 2007
" . . . . . . dark matter and dark energy, rather unimaginative names for the two most surprising and enigmatic constituents of the Universe. The nomenclature is actually confusing because it suggests that the two are related, whereas the only thing they have in common is that they do not absorb or scatter light. Otherwise, their physical properties are completely different. And their roles in this history of the Universe. Dark matter dominated the past; dark energy will shape the future." . . . . . . . . .
"Most physicists think that dark matter consists of an ocean of elementary particles that are electrically neutral, so that they interact very weakly with ordinary matter, and do not scatter or absorb light. This would explain why the particles are not noticed even though the Earth is constantly moving through a sea of dark matter as it orbits the Sun."

The State of the Universe by Pedro G Ferreira Phoenix 2007
Dark and Exotic Matter
"Two main types of candidate for the missing matter have been proposed . . . . . . very heavy clumps of ordinary matter . . . and an altogether different kind of matter that does not emit or interact with radiation. (The neutrino - a failed candidate for dark matter.) . . . so we have to consider completely new types of particles . . . ." . . . . . . . . .
"The favoured candidate for dark matter drawn from supersymmetry theories is called the neutralino, a heavy, long-lived particle. Such particles would have to be heavy enough that even a small number of them would make an appreciable contribution to the mass density of the Universe. . . . . . . Neutralinos would be very weakly interacting and, if they existed, they would be constantly streaming through normal matter." . . . . . .
" . . . the WIMP (Weakly Interacting Massive Particles) candidate is in fact incredibly light, with a mass of less than one millionth that of the electron. Such a candidate, the axion, was postulated to solve a problem in the theory of strong interactions. . . . . . . . . . As with all other dark matter candidates, the mildness of the axion's interactions makes it incredibly difficult to detect." . . . . . . . . .
"The presence of dark matter is one of the main unsolved problems in cosmology. We are quite convinced that it exists, but we have no real idea of what it is or how to see it."


All About Space Issue 112 Dark Matter by Kulvinder Singh Chadha January 2021
"Dark Matter - where did it come from?
"Fritz Zwicky was a Swiss astronomer . . . . . . averaging the rotations of galaxies in the Coma Cluster . . . Zwicky noticed that their speeds were excessive . . . so much so, that the galaxies should have flown apart. there wasn't enough visible matter to gravitationally bind each galaxy together . . . he concluded that there must be a 'dark matter' component to them. . . . Six years later . . . Horace Babcock showed dark matter present in the Andromeda Galaxy . . . was more concentrated in the periphery of the disc . . . . . . the first indication that galaxies had dark matter haloes. . . . in the late 1970s, Rubin and Ford showed . . . that galaxies contained between 5 and 10 times more dark matter than luminous matter."
"The term 'dark matter' is a slight misnomer. It simply isn't dark; it's completely invisible, no matter which part of the electromagnetic spectrum it's observed in. Its only observed effect is gravitational . . . but this gives dark matter a dramatic character, one predicted by Einstein . . . ".
"No one has yet been successful in detecting dark matter, so how would someone look for dark matter filtered by cosmic bubbles? 'We consider the best prospects for finding evidence for our proposal are collider searches for the new [phi] particle, detection of dark matter annihilation products or detection of background gravitational waves."
"The puzzle of dark matter forces us to think in new ways, and even if these ideas turn out to be unrelated, they could provide the key to understanding some of the deepest mysteries in the Universe."


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Cosmic Dispatches Ed John Noble Wilford Mystery of the Missing Mass Norton 2002
"Dr Tyson's research has concentrated on dark matter in the form of exotic particles . . . . . . . . . if they exist, these subatomic particles must be sluggish and electrically neutral not to be producing detectable radiations; hence their designations as WIMPs, for weakly interacting massive particles."
"Some objects . . . . . . may make up another fraction of the dark matter. . . . . . . these are called MACHOs, for Massive Astrophysical Compact Halo objects. Astronomers estimate that the dark halo around Earth's home galaxy, the Milky Way, could contain ten times more mass than the visible part of the galaxy, and MACHOs could account for about half of that invisible mass."

All About Space Issue 109 November 2020 Dark Stars by Amanda Doyle
"Dark Stars, powered by dark matter, could be responsible for our existence, along with the appearance of today's universe."
"The Universe began with the big bang . . . . . . Matter began to clump together, pulling in ever more material through gravitational attraction. It may have been dark matter - the mysterious substance that has yet to be directly detected - that began to accumulate first. This then drew in the ordinary matter, the stuff we can see, such as hydrogen and helium. Together the dark and ordinary matter created what is known as a 'mini-halo', although the name is somewhat misleading, as minihaloes had masses around a million times that of our Sun.
It was in the minihaloes that the first stars were born 200 million years after the Big Bang." . . . . . . . . .
"The dark matter in the minihalo may have done more than bring elements together - it might also have been present deep within the first stars. These stars are known as 'dark stars', due to the dark matter within them, although they would actually have shone very brightly. . . . . . . . . . Dark matter does not interact with ordinary matter and it does not produce any light. We only know that it must be there as its immense gravitational force tugs on ordinary matter." . . . . . . . . .
"Dark stars could have reached masses up to a million times that of the Sun, with a luminosity a billion times brighter than that. . . . . . . . . . dark stars are so massive that they are fated to become a black hole. "



https://www.forbes.com › startswithabang › 2018/07/26


There's A Debate Raging Over Whether Dark Matter Is Real, But One Side Is Cheating Ethan Siegel, Senior Contributor Jul 26, 2018,10:00am EDT
"You'd wonder if we didn't have something fundamentally wrong. If we hadn't goofed something fundamental, like our theory of gravity. This is the heart of the debate over the existence of dark matter.
"On the scales of groups of galaxies, individual galaxy clusters, colliding galaxy clusters, the cosmic web, and the leftover radiation from the Big Bang, MOND's predictions fail to match reality, whereas dark matter succeeds spectacularly. . . . . . . . . . in the scientific realm, the evidence has already decided the matter, and 5/6ths of it is dark."

NASA Finds Direct Proof of Dark Matter - NASA
https://www.nasa.gov › home › hqnews › aug › HQ_06...
21 Aug 2006 — Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies. The discovery, using ...

Maybe 'dark matter' doesn't exist after all, new research suggests
https://www.nbcnews.com › science › space › maybe-d...
6 Jan 2021 — Now, an international team of scientists says it has found new evidence that perhaps dark matter doesn't really exist after all. In research ...

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Is there any objective proof or attempts to obtain objective proof for the interesting speculations in the above article? Fritz Zwicky identified and Vera Rubin proved the existence of what is now termed Dark Matter. However, dark matter stars, and stars with dark matter and ordinary matter turning into black holes seems a speculative reach.
 

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All About Space Are there other kinds of Dark Energy? by Robert Lea Issue 114 3/2021

"The expansion of the Universe is a phenomenon that can really only be measured by observing galaxies separated by massive gulfs of space. The further apart, the faster they race away from each other. And that effect is speeding up. Dark energy is the name given to the hypothetical force that is causing this acceleration. Think of it as . . . . . . providing a negative pressure that fills the Universe and drives objects apart at an increasingly rapid rate. But dark energy . . . . . . expands the very space between objects. Despite the fact it accounts for roughly 69% of the Universe's total energy, we know very little about this mysterious repulsive energy. . . . . . . However, cosmologists are aware of a number of prime suspects that could account for its effects. The leading candidate is the cosmological constant, lambda, which we associate with the vacuum space's energy. Other possible candidates are quintessence fields, proposed . . . to establish a fifth force responsible for the negative pressure that might cause the accelerated expansion of the Universe." Many flavours arise from this fifth force and "with so many potential candidates for dark energy, its reasonable to ask if dark energy might arise from more than one source (-) a question which cosmologists are really only beginning to consider." In the late 20th century, it was proposed that some form of matter-energy produced a repulsive force and, because of its elusive nature, it was termed dark energy. "This discovery has since been confirmed in a multitude of ways, including observation of the cosmic microwave background (CMB)." To account for the accelerating expansion, and vacuum energy, the cosmological constant was resurrected.
"Unfortunately, it still represents a massive headache for cosmologists, with the observed value delivered by astronomy being hundreds of magnitudes smaller than the value predicted by quantum field theory. . . . . . . The leading explanation for the cosmological constant is the vacuum energy contribution to the expansion of our Universe." It is speculated that it "could possibly be rectified by a multi source approach." . . . . . . . . .
Another approach is "a quantum field that permeates the entirety of space and evolves over time. . . . . . . considering multiple sources for this contribution could solve a multiple of problems presented by such a model."
It appears that more light needs to be shone on these complex issues, and those interested are recommended to consult the original paper.

Sky at Night The Key to unlocking Dark Energy by Colin Stuart September 2020

A short history of Dark Energy
"How do we know that the expansion of the Universe has been getting quicker of late? It's based on a type of exploding star, known as a Type Ia supernova. They detonate when a small, dead star, called a white dwarf, gorges on a nearby star until it becomes unstable. As this always happens at a similar stage, all supernovae of this type should explode with a similar brightness. This makes them great cosmic rulers, as dimmer ones must be further away."
"In 1998, two teams of astronomers were racing to measure the distances to these stellar explosions. They found that type Ia supernovae were consistently further away than they should be, suggesting the Universe had expanded more than we'd previously believed. The search for the culprit behind this accelerated expansion has remained one of cosmology's hot topics."
"Three of the astronomers behind the discovery shared the Nobel Prize in Physics in 2011, but others have called the results into question, pointing out that Type Ia supernovae aren't quite the reliable yardsticks we'd thought they were."

Dark Energy, what could it be?
"The most widely held answer is something called the cosmological constant (known by the Greek letter lambda). It originally appeared in Einstein's general theory of relativity as a way to counteract gravity and keep his notion of a static Universe that isn't expanding. Once Edwin Hubble showed the Universe was expanding in 1929, Einstein labelled his cosmological constant 'the greatest blunder of my life', Yet the idea gained renewed traction after the discoveries of 1998 hinted at the presence of dark energy. At its heart is the idea that even empty space contains energy, and the more that space expands, the more this energy dominates."
"It has had the same value everywhere in space throughout the Universe's history. Quintessence is the other leading dark energy contender. It says that dark energy is, in fact, a substance that pervades space, rather than a property of space itself. Its name means 'fifth essence' as it would be the fifth different component in the Universe after ordinary matter, light, particles like neutrinos and dark matter. Unlike the cosmological constant, the outward pressure exerted can evolve over time, which explains why the Universe's expansion has only started to accelerate relatively recently."






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Universe - the definitive visual guide Gen ed Martin Rees Dark matter and dark energy DK 2012
There is far more dark matter in the Universe than that contained in stars and other visible objects. The invisible mass is called "dark matter". Its composition is unknown. Some might take the form of MACHOs (massive compact objects) - dark planet-like bodies - or WIMPs (weakly interacting massive particles) - exotic subatomic entities that scarcely interact with ordinary matter. . . . . . . . . . Cosmologists have proposed the existence of "dark energy", a force that counteracts gravity and causes the Universe to expand faster. The exact nature of dark energy is still speculative."

The Theory of (nearly) Everything BBC Focus Ed Daniel Bennett Searching for dark matter 2016
In terms of mass-energy "the Universe is 68% dark energy, 27% dark matter and 5% baryonic. If we discount the energy part, the numbers revert to - 85% dark matter (and) 15% baryonic matter."
"Has dark matter got anything to do with dark energy?
No. Dark energy is the name given to the mysterious entity thought to be accelerating the overall expansion of the Universe - a sort of anti-gravity. In contrast, dark matter can be thought of as gravitational glue that helps bind galaxies and clusters of galaxies together. We're literally in the dark as to what they are."
"Could dark matter be something else?
So far we've been assuming that dark matter is tangible, something that truly exists. But what if it doesn't . . . - a symptom of the fact that we don't understand gravity properly? That's exactly what proponents of a theory called Modified Newtonian Dynamics (MOND) advocate. . . . dark matter was introduced to account for the fact that stars in the Milky Way don't slow down the further they are from the galactic centre, unlike the planets of our Solar System. . . . . . . . . . The idea was first put forward by . . . Mordehai Milgrom in 1983. He suggested that the strength of gravity could become stronger where acceleration levels are small."

Astronomy Simulations zoom in on dark matter by Mark Zastrow February 2021
"Dark matter is a mysterious material that makes up more than 80% of all matter in the universe, This strange stuff permeates and surrounds every galaxy, and clumps of dark matter, called halos, are where galaxies tend to form. Now, supercomputer simulations have found that these cosmic clumps of dark matter look surprisingly alike, no matter their size - whether they encompass monstrous galaxy clusters or are mini-blobs the size of Earth. . . . . . . . . . While dark matter does not react with normal matter, it should give off a burst of gamma-ray light when it collides with its antimatter equivalent and the particles annihilate each other."

Endless Universe - beyond the big bang by Steinhardt and Turok Doubleday 2007
" . . . . . . dark matter and dark energy, rather unimaginative names for the two most surprising and enigmatic constituents of the Universe. The nomenclature is actually confusing because it suggests that the two are related, whereas the only thing they have in common is that they do not absorb or scatter light. Otherwise, their physical properties are completely different. And their roles in this history of the Universe. Dark matter dominated the past; dark energy will shape the future." . . . . . . . . .
"Most physicists think that dark matter consists of an ocean of elementary particles that are electrically neutral, so that they interact very weakly with ordinary matter, and do not scatter or absorb light. This would explain why the particles are not noticed even though the Earth is constantly moving through a sea of dark matter as it orbits the Sun."

The State of the Universe by Pedro G Ferreira Phoenix 2007
Dark and Exotic Matter
"Two main types of candidate for the missing matter have been proposed . . . . . . very heavy clumps of ordinary matter . . . and an altogether different kind of matter that does not emit or interact with radiation. (The neutrino - a failed candidate for dark matter.) . . . so we have to consider completely new types of particles . . . ." . . . . . . . . .
"The favoured candidate for dark matter drawn from supersymmetry theories is called the neutralino, a heavy, long-lived particle. Such particles would have to be heavy enough that even a small number of them would make an appreciable contribution to the mass density of the Universe. . . . . . . Neutralinos would be very weakly interacting and, if they existed, they would be constantly streaming through normal matter." . . . . . .
" . . . the WIMP (Weakly Interacting Massive Particles) candidate is in fact incredibly light, with a mass of less than one millionth that of the electron. Such a candidate, the axion, was postulated to solve a problem in the theory of strong interactions. . . . . . . . . . As with all other dark matter candidates, the mildness of the axion's interactions makes it incredibly difficult to detect." . . . . . . . . .
"The presence of dark matter is one of the main unsolved problems in cosmology. We are quite convinced that it exists, but we have no real idea of what it is or how to see it."


All About Space Issue 112 Dark Matter by Kulvinder Singh Chadha January 2021
"Dark Matter - where did it come from?
"Fritz Zwicky was a Swiss astronomer . . . . . . averaging the rotations of galaxies in the Coma Cluster . . . Zwicky noticed that their speeds were excessive . . . so much so, that the galaxies should have flown apart. there wasn't enough visible matter to gravitationally bind each galaxy together . . . he concluded that there must be a 'dark matter' component to them. . . . Six years later . . . Horace Babcock showed dark matter present in the Andromeda Galaxy . . . was more concentrated in the periphery of the disc . . . . . . the first indication that galaxies had dark matter haloes. . . . in the late 1970s, Rubin and Ford showed . . . that galaxies contained between 5 and 10 times more dark matter than luminous matter."
"The term 'dark matter' is a slight misnomer. It simply isn't dark; it's completely invisible, no matter which part of the electromagnetic spectrum it's observed in. Its only observed effect is gravitational . . . but this gives dark matter a dramatic character, one predicted by Einstein . . . ".
"No one has yet been successful in detecting dark matter, so how would someone look for dark matter filtered by cosmic bubbles? 'We consider the best prospects for finding evidence for our proposal are collider searches for the new [phi] particle, detection of dark matter annihilation products or detection of background gravitational waves."
"The puzzle of dark matter forces us to think in new ways, and even if these ideas turn out to be unrelated, they could provide the key to understanding some of the deepest mysteries in the Universe."


Work in progress. Last edit 14.00 BST June 14th 2021.
I believe the Universe is a bubble-like object. The Universe is a vacuum,so how can it be growing? It is not growing it is turning in on its self. Dark matter is heavier and quite dense. The galaxies form through immense explosions which forces the dark matter to yield to the galaxies. Dark matter makes up 85% of the UniverseThink of dark matter as a thick type of gel that galaxies float within. I know it sounds silly but, it is my belief
 

Catastrophe

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You are entitled to believe what you wish. The Universe, however, is not a vacuum. Apart from stars and galaxies, even interstellar space is not a vacuum. You may think the saying that "Nature abhors a vacuum" is a bit antiquated, but, in fact, the hydrogen, helium, et cetera, just spread themselves out a little more thinly. There is no more vacuum than there is infinite density. Higher densities imply greater tendency to expand - but Nature does not compress itself out of nothing. Like you cannot have a thick gel in a vacuum.

Cat :)
 
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Catastrophe

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"Interstellar Gas:
The interstellar gas consists partly of neutral atoms and molecules, as well as charged particles, such as ions and electrons. This gas is extremely dilute, with an average density of about 1 atom per cubic centimeter." Google.
This is not empty space, but it is not a gel either.

Cat :)
 
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You are entitled to believe what you wish. The Universe, however, is not a vacuum. Apart from stars and galaxies, even interstellar space is not a vacuum. You may think the saying that "Nature abhors a vacuum" is a bit antiquated, but, in fact, the hydrogen, helium, et cetera, just spread themselves out a little more thinly. There is no more vacuum than there is infinite density. Higher densities imply greater tendency to expand - but Nature does not compress itself out of nothing. Like you cannot have a thick gel in a vacuum.

Cat :)
The thick gel makes up 85% of the unknown matter and the violent explosions push the matter away from the explosion which forms gases and material to form galaxies. The matter holds the new forming galaxies together due to the pressure of the dark matter in equilibrium with the expansion of the material which is in complete harmony with the gravity equilibrium of the expanding stars and material which is held together by the force of the dark matters compression back onto the expanding material. what do you mean by"Nature does not compress itself out of nothing? "A vacuum is not compression, it is a self-contained unit with the same amount of pressure on every point and on all material that makes up the universe.
 

Catastrophe

The devil is in the detail
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You posted ""Nature does not compress itself out of nothing? "A vacuum is not compression, it is a self-contained unit with the same amount of pressure on every point and on all material that makes up the universe."

Previously you posted " I know it sounds silly but, it is my belief".

I posted "What are your sources for these assertions?"

That is straightforward English. It means 'where did you get such ideas'?

Cat :)
 
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You posted ""Nature does not compress itself out of nothing? "A vacuum is not compression, it is a self-contained unit with the same amount of pressure on every point and on all material that makes up the universe."

Previously you posted " I know it sounds silly but, it is my belief".

I posted "What are your sources for these assertions?"

That is straightforward English. It means 'where did you get such ideas'?

Cat :)
Where did you get yours, Sir? Nature is not anything, the compression of space is caused by space, a vacuum is a bubble, with the same amount of force from all directions. In this bubble, nuclear reactions cause the Bubble to expand. Yet the force does not change. And it will not change. If our universe is expanding then our solar system is expanding. If our solar system is expanding then we are all doomed. Do you understand this ?
 

Catastrophe

The devil is in the detail
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I understand that you do not seem willing to disclose the source of your "information". ;)

Cat :)

To answer your question, I have to put my tongue in my cheek, and avoid words like unutterable nonsense, and say "no", I did not understand your most interesting post, and, again, ask you where you came upon such ponderable ideas, on which you base your assertions?

Yours, in anticipation,

Cat
 
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At what rate is the Universe expanding. Does it not seem reasonable to say "if the Universe is expanding our solar system is also expanding." Therefore would it be safe to assume eventually the expansion would disrupt
our orbit around our sun ?













'IF the
 

Catastrophe

The devil is in the detail
Feb 18, 2020
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Apparently, space is expanding. In some cases, gravity prevails, as in the local group including Andromeda coming together. It seems likely to me, that the Solar System comes into the same category.

I still politely await your advice of your sources of the less straightforward statements.

Cat :)
 
Jul 23, 2021
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The Universe just appears to be expanding Let me explain. The further out in space your satellites travel the more time is warped. You are looking at space trillions of light-years away. So time is of no essence. The further out you view the faster, it will appear to be expanding. Add heat, to the distance, and you get a warping of time. I hope this helps. " trillion is just a figure"
 
Jul 23, 2021
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"I am the source of my statements." Seeing they can not be disproven by you, or a team of this planet's scientists .
I will rest my case with the above statement. To bend the truth in your favor ,will indeed, not help, disproving the truth.
 
Jul 23, 2021
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yes, that is it delusional. Can a scientist be a gentleman? Scientists know little or nothing of what they observe.
I will leave you with this my friend watch out for the smoke rings,
 

Catastrophe

The devil is in the detail
Feb 18, 2020
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Restarted as agreed, together with continuations.

Dark matter: Agreed terms help sensible discussion
Universe - the definitive visual guide Gen ed Martin Rees Dark matter and dark energy DK 2012
There is far more dark matter in the Universe than that contained in stars and other visible objects. The invisible mass is called "dark matter". Its composition is unknown. Some might take the form of MACHOs (massive compact objects) - dark planet-like bodies - or WIMPs (weakly interacting massive particles) - exotic subatomic entities that scarcely interact with ordinary matter. . . . . . . . . . Cosmologists have proposed the existence of "dark energy", a force that counteracts gravity and causes the Universe to expand faster. The exact nature of dark energy is still speculative."

The Theory of (nearly) Everything BBC Focus Ed Daniel Bennett Searching for dark matter 2016
In terms of mass-energy "the Universe is 68% dark energy, 27% dark matter and 5% baryonic. If we discount the energy part, the numbers revert to - 85% dark matter (and) 15% baryonic matter."
"Has dark matter got anything to do with dark energy?
No. Dark energy is the name given to the mysterious entity thought to be accelerating the overall expansion of the Universe - a sort of anti-gravity. In contrast, dark matter can be thought of as gravitational glue that helps bind galaxies and clusters of galaxies together. We're literally in the dark as to what they are."
"Could dark matter be something else?
So far we've been assuming that dark matter is tangible, something that truly exists. But what if it doesn't . . . - a symptom of the fact that we don't understand gravity properly? That's exactly what proponents of a theory called Modified Newtonian Dynamics (MOND) advocate. . . . dark matter was introduced to account for the fact that stars in the Milky Way don't slow down the further they are from the galactic centre, unlike the planets of our Solar System. . . . . . . . . . The idea was first put forward by . . . Mordehai Milgrom in 1983. He suggested that the strength of gravity could become stronger where acceleration levels are small."

Astronomy Simulations zoom in on dark matter by Mark Zastrow February 2021
"Dark matter is a mysterious material that makes up more than 80% of all matter in the universe, This strange stuff permeates and surrounds every galaxy, and clumps of dark matter, called halos, are where galaxies tend to form. Now, supercomputer simulations have found that these cosmic clumps of dark matter look surprisingly alike, no matter their size - whether they encompass monstrous galaxy clusters or are mini-blobs the size of Earth. . . . . . . . . . While dark matter does not react with normal matter, it should give off a burst of gamma-ray light when it collides with its antimatter equivalent and the particles annihilate each other."

Endless Universe - beyond the big bang by Steinhardt and Turok Doubleday 2007
" . . . . . . dark matter and dark energy, rather unimaginative names for the two most surprising and enigmatic constituents of the Universe. The nomenclature is actually confusing because it suggests that the two are related, whereas the only thing they have in common is that they do not absorb or scatter light. Otherwise, their physical properties are completely different. And their roles in this history of the Universe. Dark matter dominated the past; dark energy will shape the future." . . . . . . . . .
"Most physicists think that dark matter consists of an ocean of elementary particles that are electrically neutral, so that they interact very weakly with ordinary matter, and do not scatter or absorb light. This would explain why the particles are not noticed even though the Earth is constantly moving through a sea of dark matter as it orbits the Sun."

The State of the Universe by Pedro G Ferreira Phoenix 2007
Dark and Exotic Matter
"Two main types of candidate for the missing matter have been proposed . . . . . . very heavy clumps of ordinary matter . . . and an altogether different kind of matter that does not emit or interact with radiation. (The neutrino - a failed candidate for dark matter.) . . . so we have to consider completely new types of particles . . . ." . . . . . . . . .
"The favoured candidate for dark matter drawn from supersymmetry theories is called the neutralino, a heavy, long-lived particle. Such particles would have to be heavy enough that even a small number of them would make an appreciable contribution to the mass density of the Universe. . . . . . . Neutralinos would be very weakly interacting and, if they existed, they would be constantly streaming through normal matter." . . . . . .
" . . . the WIMP (Weakly Interacting Massive Particles) candidate is in fact incredibly light, with a mass of less than one millionth that of the electron. Such a candidate, the axion, was postulated to solve a problem in the theory of strong interactions. . . . . . . . . . As with all other dark matter candidates, the mildness of the axion's interactions makes it incredibly difficult to detect." . . . . . . . . .
"The presence of dark matter is one of the main unsolved problems in cosmology. We are quite convinced that it exists, but we have no real idea of what it is or how to see it."


All About Space Issue 112 Dark Matter by Kulvinder Singh Chadha January 2021
"Dark Matter - where did it come from?
"Fritz Zwicky was a Swiss astronomer . . . . . . averaging the rotations of galaxies in the Coma Cluster . . . Zwicky noticed that their speeds were excessive . . . so much so, that the galaxies should have flown apart. there wasn't enough visible matter to gravitationally bind each galaxy together . . . he concluded that there must be a 'dark matter' component to them. . . . Six years later . . . Horace Babcock showed dark matter present in the Andromeda Galaxy . . . was more concentrated in the periphery of the disc . . . . . . the first indication that galaxies had dark matter haloes. . . . in the late 1970s, Rubin and Ford showed . . . that galaxies contained between 5 and 10 times more dark matter than luminous matter."
"The term 'dark matter' is a slight misnomer. It simply isn't dark; it's completely invisible, no matter which part of the electromagnetic spectrum it's observed in. Its only observed effect is gravitational . . . but this gives dark matter a dramatic character, one predicted by Einstein . . . ".
"No one has yet been successful in detecting dark matter, so how would someone look for dark matter filtered by cosmic bubbles? 'We consider the best prospects for finding evidence for our proposal are collider searches for the new [phi] particle, detection of dark matter annihilation products or detection of background gravitational waves."
"The puzzle of dark matter forces us to think in new ways, and even if these ideas turn out to be unrelated, they could provide the key to understanding some of the deepest mysteries in the Universe."
 

Catastrophe

The devil is in the detail
Feb 18, 2020
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Cosmic Dispatches Ed John Noble Wilford Mystery of the Missing Mass Norton 2002
"Dr Tyson's research has concentrated on dark matter in the form of exotic particles . . . . . . . . . if they exist, these subatomic particles must be sluggish and electrically neutral not to be producing detectable radiations; hence their designations as WIMPs, for weakly interacting massive particles."
"Some objects . . . . . . may make up another fraction of the dark matter. . . . . . . these are called MACHOs, for Massive Astrophysical Compact Halo objects. Astronomers estimate that the dark halo around Earth's home galaxy, the Milky Way, could contain ten times more mass than the visible part of the galaxy, and MACHOs could account for about half of that invisible mass."

All About Space Issue 109 November 2020 Dark Stars by Amanda Doyle
"Dark Stars, powered by dark matter, could be responsible for our existence, along with the appearance of today's universe."
"The Universe began with the big bang . . . . . . Matter began to clump together, pulling in ever more material through gravitational attraction. It may have been dark matter - the mysterious substance that has yet to be directly detected - that began to accumulate first. This then drew in the ordinary matter, the stuff we can see, such as hydrogen and helium. Together the dark and ordinary matter created what is known as a 'mini-halo', although the name is somewhat misleading, as minihaloes had masses around a million times that of our Sun.
It was in the minihaloes that the first stars were born 200 million years after the Big Bang." . . . . . . . . .
"The dark matter in the minihalo may have done more than bring elements together - it might also have been present deep within the first stars. These stars are known as 'dark stars', due to the dark matter within them, although they would actually have shone very brightly. . . . . . . . . . Dark matter does not interact with ordinary matter and it does not produce any light. We only know that it must be there as its immense gravitational force tugs on ordinary matter." . . . . . . . . .
"Dark stars could have reached masses up to a million times that of the Sun, with a luminosity a billion times brighter than that. . . . . . . . . . dark stars are so massive that they are fated to become a black hole. "

https://www.forbes.com › startswithabang › 2018/07/26

There's A Debate Raging Over Whether Dark Matter Is Real, But One Side Is Cheating Ethan Siegel, Senior Contributor Jul 26, 2018,10:00am EDT
"You'd wonder if we didn't have something fundamentally wrong. If we hadn't goofed something fundamental, like our theory of gravity. This is the heart of the debate over the existence of dark matter.
"On the scales of groups of galaxies, individual galaxy clusters, colliding galaxy clusters, the cosmic web, and the leftover radiation from the Big Bang, MOND's predictions fail to match reality, whereas dark matter succeeds spectacularly. . . . . . . . . . in the scientific realm, the evidence has already decided the matter, and 5/6ths of it is dark."

NASA Finds Direct Proof of Dark Matter - NASA
https://www.nasa.gov › home › hqnews › aug › HQ_06...

21 Aug 2006 — Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies. The discovery, using ...

Maybe 'dark matter' doesn't exist after all, new research suggests
https://www.nbcnews.com › science › space › maybe-d...

6 Jan 2021 — Now, an international team of scientists says it has found new evidence that perhaps dark matter doesn't really exist after all. In research ...

All About Space Are there other kinds of Dark Energy? by Robert Lea Issue 114 3/2021

"The expansion of the Universe is a phenomenon that can really only be measured by observing galaxies separated by massive gulfs of space. The further apart, the faster they race away from each other. And that effect is speeding up. Dark energy is the name given to the hypothetical force that is causing this acceleration. Think of it as . . . . . . providing a negative pressure that fills the Universe and drives objects apart at an increasingly rapid rate. But dark energy . . . . . . expands the very space between objects. Despite the fact it accounts for roughly 69% of the Universe's total energy, we know very little about this mysterious repulsive energy. . . . . . . However, cosmologists are aware of a number of prime suspects that could account for its effects. The leading candidate is the cosmological constant, lambda, which we associate with the vacuum space's energy. Other possible candidates are quintessence fields, proposed . . . to establish a fifth force responsible for the negative pressure that might cause the accelerated expansion of the Universe." Many flavours arise from this fifth force and "with so many potential candidates for dark energy, its reasonable to ask if dark energy might arise from more than one source (-) a question which cosmologists are really only beginning to consider." In the late 20th century, it was proposed that some form of matter-energy produced a repulsive force and, because of its elusive nature, it was termed dark energy. "This discovery has since been confirmed in a multitude of ways, including observation of the cosmic microwave background (CMB)." To account for the accelerating expansion, and vacuum energy, the cosmological constant was resurrected.
"Unfortunately, it still represents a massive headache for cosmologists, with the observed value delivered by astronomy being hundreds of magnitudes smaller than the value predicted by quantum field theory. . . . . . . The leading explanation for the cosmological constant is the vacuum energy contribution to the expansion of our Universe." It is speculated that it "could possibly be rectified by a multi source approach." . . . . . . . . .
Another approach is "a quantum field that permeates the entirety of space and evolves over time. . . . . . . considering multiple sources for this contribution could solve a multiple of problems presented by such a model."
It appears that more light needs to be shone on these complex issues, and those interested are recommended to consult the original paper.

Sky at Night The Key to unlocking Dark Energy by Colin Stuart September 2020

A short history of Dark Energy
"How do we know that the expansion of the Universe has been getting quicker of late? It's based on a type of exploding star, known as a Type Ia supernova. They detonate when a small, dead star, called a white dwarf, gorges on a nearby star until it becomes unstable. As this always happens at a similar stage, all supernovae of this type should explode with a similar brightness. This makes them great cosmic rulers, as dimmer ones must be further away."
"In 1998, two teams of astronomers were racing to measure the distances to these stellar explosions. They found that type Ia supernovae were consistently further away than they should be, suggesting the Universe had expanded more than we'd previously believed. The search for the culprit behind this accelerated expansion has remained one of cosmology's hot topics."
"Three of the astronomers behind the discovery shared the Nobel Prize in Physics in 2011, but others have called the results into question, pointing out that Type Ia supernovae aren't quite the reliable yardsticks we'd thought they were."

Dark Energy, what could it be?
"The most widely held answer is something called the cosmological constant (known by the Greek letter lambda). It originally appeared in Einstein's general theory of relativity as a way to counteract gravity and keep his notion of a static Universe that isn't expanding. Once Edwin Hubble showed the Universe was expanding in 1929, Einstein labelled his cosmological constant 'the greatest blunder of my life', Yet the idea gained renewed traction after the discoveries of 1998 hinted at the presence of dark energy. At its heart is the idea that even empty space contains energy, and the more that space expands, the more this energy dominates."
"It has had the same value everywhere in space throughout the Universe's history. Quintessence is the other leading dark energy contender. It says that dark energy is, in fact, a substance that pervades space, rather than a property of space itself. Its name means 'fifth essence' as it would be the fifth different component in the Universe after ordinary matter, light, particles like neutrinos and dark matter. Unlike the cosmological constant, the outward pressure exerted can evolve over time, which explains why the Universe's expansion has only started to accelerate relatively recently."

Work in progress. Last revision 30 August 2021 04.32 BST.
 
An interesting paper was on neutral neutrinos possibly being dark matter.
Wish i could find it online.

IMHO i think we are looking for dark matter/energy from the wrong source.
Add up temp matter/energy from fluctuation matter/energy creation and destruction across the universe and we have more than enough dark energy and matter to fill the missing need.
So illusive because it's only temp matter and energy but keeps filling the sky with a + temp.
 

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