Dark matter core defies explanation

Mar 02, 2012
This composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. The natural-color image of the galaxies was taken with NASA's Hubble Space Telescope and with the Canada-France-Hawaii Telescope in Hawaii. Superimposed on the image are "false-colored" maps showing the concentration of starlight, hot gas, and dark matter in the cluster. Starlight from galaxies, derived from observations by the Canada-France-Hawaii Telescope, is colored orange. The green-tinted regions show hot gas, as detected by NASA's Chandra X-ray Observatory. The gas is evidence that a collision took place. The blue-colored areas pinpoint the location of most of the mass in the cluster, which is dominated by dark matter. Dark matter is an invisible substance that makes up most of the universe's mass. The dark-matter map was derived from the Hubble Wide Field Planetary Camera 2 observations by detecting how light from distant objects is distorted by the cluster of galaxies, an effect called gravitational lensing. The blend of blue and green in the center of the image reveals that a clump of dark matter resides near most of the hot gas, where very few galaxies are found. This finding confirms previous observations of a dark-matter core in the cluster. The result could present a challenge to basic theories of dark matter, which predict that galaxies should be anchored to dark matter, even during the shock of a collision. Credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University)

(PhysOrg.com) -- Astronomers using data from NASA's Hubble Telescope have observed what appears to be a clump of dark matter left behind from a wreck between massive clusters of galaxies. The result could challenge current theories about dark matter that predict galaxies should be anchored to the invisible substance even during the shock of a collision.

Abell 520 is a gigantic merger of located 2.4 billion light-years away. is not visible, although its presence and distribution is found indirectly through its effects. Dark matter can act like a , bending and distorting light from and clusters behind it. can use this effect, called , to infer the presence of dark matter in clusters.

This technique revealed the dark matter in Abell 520 had collected into a "dark core," containing far fewer galaxies than would be expected if the dark matter and galaxies were anchored together. Most of the galaxies apparently have sailed far away from the collision.

"This result is a puzzle," said astronomer James Jee of the University of California in Davis, lead author of paper about the results available online in The . "Dark matter is not behaving as predicted, and it's not obviously clear what is going on. It is difficult to explain this Hubble observation with the current theories of and dark matter."

Initial detections of dark matter in the cluster, made in 2007, were so unusual that astronomers shrugged them off as unreal, because of poor data. New results from NASA's confirm that dark matter and galaxies separated in Abell 520.

This composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. Credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University, California)

One way to study the overall properties of dark matter is by analyzing collisions between galaxy clusters, the largest structures in the universe. When galaxy clusters crash, astronomers expect galaxies to tag along with the dark matter, like a dog on a leash. Clouds of hot, X-ray emitting intergalactic gas, however, plow into one another, slow down, and lag behind the impact.

That theory was supported by visible-light and X-ray observations of a colossal collision between two galaxy clusters called the Bullet Cluster. The galactic grouping has become an example of how dark matter should behave.

Studies of Abell 520 showed that dark matter's behavior may not be so simple. Using the original observations, astronomers found the system's core was rich in dark matter and hot gas, but contained no luminous galaxies, which normally would be seen in the same location as the dark matter. NASA's Chandra X-ray Observatory was used to detect the hot gas. Astronomers used the Canada-France-Hawaii Telescope and Subaru Telescope atop Mauna Kea to infer the location of dark matter by measuring the gravitationally lensed light from more distant background galaxies.

The astronomers then turned to the Hubble's Wide Field Planetary Camera 2, which can detect subtle distortions in the images of background galaxies and use this information to map dark matter. To astronomers' surprise, the Hubble observations helped confirm the 2007 findings.

"We know of maybe six examples of high-speed galaxy cluster collisions where the dark matter has been mapped," Jee said. "But the Bullet Cluster and Abell 520 are the two that show the clearest evidence of recent mergers, and they are inconsistent with each other. No single theory explains the different behavior of dark matter in those two collisions. We need more examples."

The team proposed numerous explanations for the findings, but each is unsettling for astronomers. In one scenario, which would have staggering implications, some dark matter may be what astronomers call "sticky." Like two snowballs smashing together, normal matter slams together during a collision and slows down. However, dark matter blobs are thought to pass through each other during an encounter without slowing down. This scenario proposes that some dark matter interacts with itself and stays behind during an encounter.

Another possible explanation for the discrepancy is that Abell 520 has resulted from a more complicated interaction than the Bullet Cluster encounter. Abell 520 may have formed from a collision between three galaxy clusters, instead of just two colliding systems in the case of the Bullet Cluster.

A third possibility is that the core contained many galaxies, but they were too dim to be seen, even by Hubble. Those galaxies would have to have formed dramatically fewer stars than other normal galaxies. Armed with the Hubble data, the group will try to create a computer simulation to reconstruct the collision and see if it yields some answers to dark matter's weird behavior.

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determinist
2.1 / 5 (19) Mar 02, 2012
Apparently 'dark matter' is still the realm of philosophy. Intuition tells me (and I have the greatest respect for science) that there is a relationship between space and matter which we can't seem to understand. To answer these questions is to know the face of science god. I hope that I live to see it.
Parsec
4.5 / 5 (21) Mar 02, 2012
One unexplained phenomena does not a theory destroy. Nor does it move a theory from science into the realm of philosophy.

I suspect the answer to this particular anomaly is more data and time. Obviously if more data suggests that our dark matter theories are either incorrect or invalid, then we will need to come up with different explanations for what we see. I suspect however that this will not happen in this case.
Deesky
4.3 / 5 (23) Mar 02, 2012
I suspect the answer to this particular anomaly is more data and time.

Exactly. In fact, it's anomalous observations like this that lead to new insights and that spur further research and observations. I only see this as a positive, on the road to identifying the nature of dark matter.
dogbert
2.1 / 5 (31) Mar 02, 2012
It is apparent that we are missing something in our understanding of gravity at stellar distances.

We may never understand these anomalies if we continue to create imaginary matter to explain our observations.
jamesrm
3 / 5 (13) Mar 02, 2012
"Some dark matter may be what astronomers call "sticky."" sounds very "Ad hoc"

No amount of experimentation can ever prove me right; a single experiment can prove me wrong. (paraphrased) Albert Einstein

Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve. Karl Popper
Deesky
3.9 / 5 (22) Mar 02, 2012
t is apparent that we are missing something in our understanding of gravity at stellar distances.

We are missing the true nature of DM, yes, but we do know a lot already.

It's conceivable that DM isn't just a single thing as the label may imply. Just as is the case with baryonic matter, dark matter may come in a number of flavors which may manifest different properties. That's just a guess.

We may never understand these anomalies if we continue to create imaginary matter to explain our observations

There is nothing 'imaginary' about DM (unlike your god fairy). The evidence for it is overwhelming and multifaceted. It's just a matter of time before its true nature is discovered and observations, such as in this article, will help us to do so.
Deesky
3.4 / 5 (17) Mar 02, 2012
"Some dark matter may be what astronomers call "sticky."" sounds very "Ad hoc"

No amount of experimentation can ever prove me right; a single experiment can prove me wrong. (paraphrased) Albert Einstein

Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve. Karl Popper

Your quote-mining tells me that you don't really understand how science works and how it makes progress, nor the body of evidence that exists for dark matter.
Benni
2.4 / 5 (14) Mar 02, 2012
We may never understand these anomalies if we continue to create imaginary matter to explain our observations.


But you know, it's the challenge of trying to make sense of things we are not able to presently understand that drives the human mind to reach beyond what is presently known & find a new level of understanding the universe around us.

We're trying to discover why stars inside each galaxy orbits the central core in unison with respect to one another. The way I best understand this is to create a circle on a piece of paper, I place a bunch of dots inside that circle to represent a spiral galaxy. In the very center of that circle I would place the largest dot on the paper, then puncture the point of my pencil through the paper at that dot and spin the paper, and as I observe every dot (star) inside the circle move in unison to one another, that is my simplified view of the manner stars are positioned inside of galaxies.

cont'd......
Benni
2.6 / 5 (15) Mar 02, 2012
cont'd....

.....but the problem we're confronted with, is, the dots on my paper are constrained from randomnly repositioning themseves due to their connection of the solid surface between the dots. Stars inside galaxies seem to have some similar connection to one another and only a "solid" of some kind (like the paper on which I placed my dots) seems to be the answer. For me, this scenario simplifies the argument for the existence of "dark matter", our challenge is to figure out why we can accelerate rockets & satellites through interstellar space without some force of friction to slow them down or even to cause them to burn up as if they were moving through something as ordinary as our dense atmosphere.
Caliban
1 / 5 (2) Mar 02, 2012


Maybe the collision of these galactic clusters brought together enough dark matter to cause the formation of a supermassive dark matter black hole?

Certainly bears thinking about...
Deesky
3.9 / 5 (15) Mar 02, 2012
Maybe the collision of these galactic clusters brought together enough dark matter to cause the formation of a supermassive dark matter black hole?

Certainly bears thinking about...

Not really. From what we do know about DM, it's weakly interacting and is not strongly self-attracting, which means it cannot form dense concentrations for black holes to form.
Mayday
1.5 / 5 (8) Mar 02, 2012
It seems to me that we vastly overestimate the size/importance of things that glow in our photographs of space. Remember that those bright dots are much, much tinier than the photo indicates. And the distances between them are extraordinarily vast. To me, it seems fairly straight-forward that broadly dispersed gas and dust could easily outweigh (out-mass?) the stuff that glows. Our photos of the cosmos greatly distort any accurate perception of scale (and we do so love shiny objects). Perhaps gas accreting into stars at all is the dominant anomaly in these photos.
Vendicar_Decarian
2.6 / 5 (8) Mar 02, 2012
This blob of dark stuff must be dark anti-matter.
hylozoic
1 / 5 (5) Mar 02, 2012
Steady state or BUST strikes again!
Tausch
2.2 / 5 (10) Mar 02, 2012
Reverse all this research and pretend we are creatures to which only dark matter is visible to us. Map that dark matter.

Let that map dictate what we must deduce/invoke for creatures that have the same visible spectrum as we are pretending not to exhibit.

Does that deduced/invoked mapping of the visible spectrum of light emitting matter match the real photographic records?
210
2.3 / 5 (6) Mar 02, 2012
This blob of dark stuff must be dark anti-matter.

Vendi...why do you say this?

word-
Vendicar_Decarian
3.6 / 5 (14) Mar 03, 2012
Since the properties of dark matter are completely unknown and since even the existence of dark matter is entirely unproven I feel free to speculate wildly and without reservation.
MorituriMax
3.9 / 5 (15) Mar 03, 2012
dogbert flatulated,
It is apparent that we are missing something in our understanding of gravity at stellar distances.

We may never understand these anomalies if we continue to create imaginary matter to explain our observations.

Are you as vocal in saying we should abolish the zero? After all, it doesn't really exist, it's just a place holder. Just like dark matter is a placeholder for something we haven't identified yet. But we can identify the indirect results of "dark matter" ie, something that doesn't reflect light but does have a gravitational effect on space around it. What would YOU call it? Or would you just throw your hands in the air and give up any further research into WHAT is causing gravitational lensing yet doesn't appear in a form we can visually see?
TabulaMentis
1.3 / 5 (14) Mar 03, 2012
Dark matter is preatomic space junk created by spacetime fabric (dark energy). It looks very much like quarks, except much smaller. There are many types (flavors, etc.) of preatomic particles (dark matter).
StarGazer2011
2.2 / 5 (15) Mar 03, 2012
hmm... if the Abell 520 galaxies have been 'stripped of their dark matter' can we check if the cores of these galaxies are rotating more quickly than the edges? If they are, that would be a great piece of supporting evidence for DM, if not, well...
Au-Pu
2.8 / 5 (6) Mar 03, 2012
dogbert nay have been closer to the truth than he realises.
It is certainly worth considering.
dogbert
2.3 / 5 (18) Mar 03, 2012
MorituriMax,
we can identify the indirect results of "dark matter" ie, something that doesn't reflect light but does have a gravitational effect on space around it. What would YOU call it?


I would call gravitational lensing gravitational lensing. I would call the movement of stars about a galaxy the movement of stars about a galaxy. When it is apparent that our theories of gravity do not match out observations, I would say that out theories of gravity do not match our observations. And I would try to determine why our theories and our observations do not match.

Creating an imaginary substance to explain away these anomalous results does not bring us understanding. It just allows us to be comfortable in our ignorance.

Continued ...
dogbert
2.2 / 5 (20) Mar 03, 2012
MorituriMax,

We are supposed to be surrounded by dark matter and moving through it constantly, yet no one has found a single particle of it. Our particle colliders do not indicate the presence of dark matter. Suns should accumulate the stuff and should burn differently when they accumulate it, but they don't. Our Standard Model, though imperfect, has predicted many things, but it does not predict dark matter. In fact, there is no indication of dark matter at all anywhere. We just use the concept because we don't understand what we observe.

We should try to correct our understanding instead of making up imaginary substances to reconcile our observations with our theories.

Something which should show you that dark matter is not real is that there is always just enough of it -- and never too much -- in just the right places to account for our observations. That is, we just make it up on the spot. It is imaginary but we live in a real world.
jamesrm
2.2 / 5 (5) Mar 03, 2012
"Your quote-mining tells me that you don't really understand how science works and how it makes progress, nor the body of evidence that exists for dark matter."

Now we know how little evidence it take for you to draw sweeping conclusions.

NO EVIDENCE FOR A DARK MATTER DISK WITHIN 4 kpc FROM THE GALACTIC PLANE
http://iopscience.../1/L122/

http://en.wikiped...rk_fluid
Crazy_council
1 / 5 (2) Mar 03, 2012
I think that what we see as dark matter/energy/flow is all linked or an affect of whatever the fabric of the universe/space is. Specificaly, If, whatever makes up space time has any spinn or ossilation ( like i think strng theory proposes ), then any small interaction between this and normal matter would maybe cause the affects we see.

to me, space fabric or strings are more likely to be 2d objects trying to resolve themselves in a 3d enviroment. I know it sounds bonkers, and i dont understand the maths of 2d object in 3d space enough to put any figures on the spin rate.
Modernmystic
1.4 / 5 (18) Mar 03, 2012
Why do we always look for a purely naturalistic explanation for what we see in the universe? If you look at the dark side of the Earth from space and discount intelligence from your theories you'd be hard pressed to square your theories of electromagnetism with all the lights you see coming from the land masses...

Whenever we don't see isotropy wherever we look we automatically assume nature is askew. What we forget is that intelligence changes and engineers its environment for its purposes, at least on this planet.

On the flip side, what if there is a large clump of dark matter between us and our LOS to Abell 520 that DOESN'T have any luminous matter aggregating around it? Wouldn't that magnify the lensing? Granted it would be a fluke to be just on the right angle, but don't flukes happen?
CardacianNeverid
3.6 / 5 (14) Mar 03, 2012
Now we know how little evidence it take for you to draw sweeping conclusions.

NO EVIDENCE FOR A DARK MATTER DISK WITHIN 4 kpc FROM THE GALACTIC PLANE
http://iopscience.../1/L122/ -jamesTard

From your reference it says:

"We assume that the dark halo could be UNDETECTABLE with our method, but the dark disk, recently proposed as a natural expectation of the CDM models, SHOULD be detected. Given the good agreement with the visible mass alone, models including a dark disk are LESS likely, but within errors its existence cannot be excluded"

Sounds like a slam dunk against dark matter, not!
CardacianNeverid
4.1 / 5 (17) Mar 03, 2012
Whenever we don't see isotropy wherever we look we automatically assume nature is askew. What we forget is that intelligence changes and engineers its environment for its purposes, at least on this planet. -NotSoModernMystic

The null hypothesis is your friend unless proved otherwise.
Lurker2358
1.6 / 5 (7) Mar 03, 2012
GMK, where K is the constant of integration.

If the K is negative, space contracts, "Dark Matter."

If K is positive, space expands, "Dark Energy."

the fallacy of mathematics is that an integral is not a discreet solution.

An integral is a family of infinite solutions for K from negative infinity to infinity. We just have a bad habit of assuming K is always zero.

Since K is a constant, then this explains star orbits around galaxies perfectly when "Kb - Ka = K" is net negative, since it would introduce a linear attraction proportional to mass over galactic distances. K may be a number slightly greater than zero, but probably less than 1.

"Dark Energy" happens when "Kb - Ka = K" is a net positive number.

Linear gravity and linear anti-gravity is hidden in the Newton's Law in the form of the constant of integration.

Wow.

The constant doesn't cancel itself, since when you do antiderivative with respect to R, the mass changes from a to b, which means GMKb != GMKa...
Modernmystic
1.6 / 5 (14) Mar 03, 2012
Whenever we don't see isotropy wherever we look we automatically assume nature is askew. What we forget is that intelligence changes and engineers its environment for its purposes, at least on this planet. -NotSoModernMystic

The null hypothesis is your friend unless proved otherwise.


I totally agree, isn't observation how we start to do that one way or the other? Something isn't right here so why not look at all the possibilities?
Modernmystic
1.5 / 5 (16) Mar 03, 2012
I think I know why physicists discount intelligence from their models. It's something they can't predict, and hence can't get grant money for...
naqe
2 / 5 (5) Mar 03, 2012
It seems to me that perhaps we aren't giving EM enough credit. Perhaps the universe is held together by EM instead of G, or perhaps the relationship between the two are much more different than we believe. No matter what, we live in extremely exciting times =)
Benni
1.7 / 5 (11) Mar 03, 2012
It seems to me that perhaps we aren't giving EM enough credit. Perhaps the universe is held together by EM instead of G,


No, "energy (EM) does have measurable gravity (G), we know this because instrumentation can measure the gravity field of energy(photons).

Photons do not have "rest mass", but have what is generally referred to as "mass equivalence", this because photons can exist only at "lightspeed", meaning they can never come to "rest". It is this "mass equivalence" through which energy fields (photons) generate measurable gravity. Photons do eventually transform into "mass" in accordance with quantum mechanics & the the laws of conservation of energy.
TimESimmons
1 / 5 (6) Mar 03, 2012
It is apparent that we are missing something in our understanding of gravity at stellar distances

You are. http://www.presto...ndex.htm
bewertow
3.2 / 5 (9) Mar 03, 2012

Since K is a constant, then this explains star orbits around galaxies perfectly when "Kb - Ka = K" is net negative, since it would introduce a linear attraction proportional to mass over galactic distances. K may be a number slightly greater than zero, but probably less than 1.

"Dark Energy" happens when "Kb - Ka = K" is a net positive number.


Lurker just finished "baby's first calculus" course and now he thinks he knows better than some of the most brilliant scientists in the world who have spent decades researching this topic.

You are so arrogant and stupid it's mindblowing.

jibbles
1 / 5 (2) Mar 03, 2012
if the self-interacting hypothesis is borne out, it would be mindblowing, imo. for then the possibility for dark matter to form dark stars, dark chemistry, and perhaps even dark life exists.
Benni
2.1 / 5 (11) Mar 03, 2012
if the self-interacting hypothesis is borne out, it would be mindblowing, imo. for then the possibility for dark matter to form dark stars, dark chemistry, and perhaps even dark life exists.


The much sought after parallel universe concept? It could exist right alongside ours & the only way we would know it is by the gravitational forces we exert on each other, thus explaining the present over-abundance of gravity we measure in the universe that can't be accounted for.
Vendicar_Decarian
3.4 / 5 (5) Mar 03, 2012
"Our particle colliders do not indicate the presence of dark matter." - DogBerTard

They don't detect neutrino's either. Or Neutrons for that matter.

They are inferred.

Vendicar_Decarian
2 / 5 (4) Mar 03, 2012
You have been watching way too much StarTrek Benni.

"It could exist right alongside ours & the only way we would know it is by the gravitational forces we exert on each other" - Benni

"it" ???

There is no physical theory that I know of that postulates a single alternate universe.

Vendicar_Decarian
3.3 / 5 (7) Mar 03, 2012
"No, "energy (EM) does have measurable gravity (G), we know this because instrumentation can measure the gravity field of energy(photons)." - Benni

Gravity is such a weak force, that the gravitational force from any individual particle (neutron, photon etc) has ever been measured. Bags of photons that contain enough energy for their gravitational field to be measured do not exist.

"Photons do not have "rest mass", but have what is generally referred to as "mass equivalence"" - Benni

There is a strong theoretical basis to believe this, but there have been no measurements to test it directly.
Vendicar_Decarian
3.4 / 5 (5) Mar 03, 2012
"I think I know why physicists discount intelligence from their models. It's something they can't predict.." - Modern

If it were truly intelligent and therefore logical then it would be predictable.

Perhaps you mean to say that your God's mind is random and therefore unpredictable.
Vendicar_Decarian
3.9 / 5 (7) Mar 03, 2012
"Why do we always look for a purely naturalistic explanation for what we see in the universe?" - Modern

Because magical thinking invariably ends in failure.
Lurker2358
2.1 / 5 (7) Mar 03, 2012

Since K is a constant, then this explains star orbits around galaxies perfectly when "Kb - Ka = K" is net negative, since it would introduce a linear attraction proportional to mass over galactic distances. K may be a number slightly greater than zero, but probably less than 1.

"Dark Energy" happens when "Kb - Ka = K" is a net positive number.


Lurker just finished "baby's first calculus" course and now he thinks he knows better than some of the most brilliant scientists in the world who have spent decades researching this topic.

You are so arrogant and stupid it's mindblowing.



I guess you think it's coincidence that the discarded "K" would represents units EXACTLY appropriate to explain DM and DE?

Some people, I swear.

You are right that technically, the K is supposed to cancel due to the fundamental theorem, but that is "on paper".

Lots of stuff works "on paper" that doesn't work in reality, and vice versa.
Lurker2358
1.7 / 5 (6) Mar 03, 2012
Take Imaginary numbers.

In nature, as far as we know, Imaginary numbers in certain physics equations "work" because they represent properties that always cancel themselves out, so that they are never "observed" directly, for this I'd cite neutrinos.

The constant of integration cancels itself out, in theory, in the fundamental theorem, but that is "on paper".

In reality, the K and -K may exist in the background, beyond our direct observation, much like the imaginary numbers represented in a neutrino.

Why you find that offensive? The units of GMK are exactly what is needed to explain some of the anomalies we've labeled as DM and DE, and it appears as a direct consequence of the original formula for Newton's law of gravity...
Lurker2358
1.7 / 5 (6) Mar 03, 2012
Further, due to the Speed of Light postulate, "K" and "-K" may occur over distances large enough to become partially or totally causally disconnected from one another, preventing them from cancelling one another in the "real world" the way they "should" in an on-paper integral. Thus explaining why the same constant can produce negative expansion locally, i.e. "DM gravity" in galaxies or galaxy clusters, but positive expansion, i.e. "DE" globally across the universe.
Estevan57
1.9 / 5 (22) Mar 03, 2012
"No single theory explains the different behavior of dark matter in those two collisions. We need more examples." From the article.

If the astronomers have trouble explaining the difference between theory and observed data, perhaps we should consider the theory not completely proven, just like they do.

There doesn't have to be a conspiracy theory behind every unproven theory in science. They did have "numerous examples" and listed three, of scenarios that would make the data more complicated than originally thought.

Have we gone to "dark" numbers and "dark" mathematics now?

I blame the government, any government.

The first picture of galaxies make a dandy desktop picture.
Lurker2358
1.7 / 5 (6) Mar 03, 2012
Further.

If matter and anti-matter can be asymmetric, then why not "GMKb vs GMKa"?

Note that the asymmetry only needs to be a few percent to explain observed phenomena.

M^3/S^2

An acceleration (or deceleration) in a rate of change in volume of space.

corresponding nicely to an acceleration or deceleration of matter moving THROUGH space...

All arriving from the same formula as different terms given by the anti-derivative of the same equation.
Benni
1.8 / 5 (10) Mar 03, 2012
"Photons do not have "rest mass", but have what is generally referred to as "mass equivalence"" - Benni

There is a strong theoretical basis to believe this, but there have been no measurements to test it directly.


Instead of "mass equivalence", I should have used the term "rest mass equivalence", maybe this would bit a little more cogent.

You are totally wrong about there being no measurements to test the "rest mass equivalence" of photons. Gravity only acts as a force on something with mass, this is what gravitational lensing is all about, we can see it without even bothering to measure it, that's even better, it's indisputable.

Black holes are formed because gravity prevents photons from escaping the surface of that collapsed star. Another case in point exhibiting the "rest mass equivalence" of photons.
Lurker2358
1.8 / 5 (5) Mar 03, 2012
Now see, consider relativity and the speed of light postulate.

It is, according to the theory, impossible for "information" to get from a to b instantaneously, unless they are exactly co-located in space-time.

Because of this, Ka and Kb can have different values, because "information" cannot be exchanged between "events" at those locations instantaneously, but is limited by the speed of light.

Moreover, the value of the "M" in GMK could have changed due to events such as fusion, fission, and annihilation events in the surrounding region of space during the time the "information" travels from a to b, thus further introducing local asymmetries into GMKa vs GMKb.

Textbook calculus assumes "information" travels from a to b instantaneously.

If the speed of light postulate is true, then that isn't possible in the real world, and Ka and Kb are therefore slightly different, though in most cases the difference may be too small to ever observe.
Callippo
1.3 / 5 (4) Mar 03, 2012
This observation doesn't defy explanation - it simply points to the particle models of dark matter. It supports some WIMPs models too, but I do presume, the dense cloud of neutrinos is capable to explain it as well.
technodiss
4.5 / 5 (2) Mar 03, 2012


It's conceivable that DM isn't just a single thing as the label may imply. Just as is the case with baryonic matter, dark matter may come in a number of flavors which may manifest different properties. That's just a guess.

Dark plasma? dark Bose Eisenstein condensate? dark antimatter? i think i've got my next set of sci-fi stories. thanks!
i wonder if a new model of super symmetry will include dark elementary particles.
dark time!
Vendicar_Decarian
3 / 5 (2) Mar 03, 2012
I sympathize with your hypothesis, but realize that this "test" only shows that the path of light can be bent by a gravitational field. It does not show that light emits a gravitational field.

Theoretically it must. But that theory has not been put to the test.

You claim was that it has been tested. And that is false.

"Gravity only acts as a force on something with mass, this is what gravitational lensing is all about, we can see it without even bothering to measure it, that's even better, it's indisputable." - benni
Vendicar_Decarian
5 / 5 (1) Mar 03, 2012
We don't know if black holes exist either.

They are just speculation.

"Black holes are formed because gravity prevents photons from escaping the surface of that collapsed star." - Benni

There certainly seems to be compelling evidence that something like black holes exist.
Vendicar_Decarian
5 / 5 (1) Mar 03, 2012
"It is, according to the theory, impossible for "information" to get from a to b instantaneously, unless they are exactly co-located in space-time." - Lurker

There is no universally shared simultaneity in general or special relativity. However dr**2 - dt**2 is a shared metric between events.

Benni
2.3 / 5 (9) Mar 03, 2012
I sympathize with your hypothesis, but realize that this "test" only shows that the path of light can be bent by a gravitational field. It does not show that light emits a gravitational field.

Theoretically it must. But that theory has not been put to the test.

You claim was that it has been tested. And that is false.


Wrong, energy & mass are simply transformed states of one another, being such, the Law of Conservation of Energy dictates that gravity also cannot be lost in the transformation process. If you lose gravity converting mass to energy you "destroyed" something, or vice versa, a fundamental violation of all the laws of thermodynamics. I learned this in 2nd semester physics.
TabulaMentis
1.7 / 5 (6) Mar 03, 2012
I think that what we see as dark matter/energy/flow is all linked or an affect of whatever the fabric of the universe/space is. Specificaly, If, whatever makes up space time has any spinn or ossilation ( like i think strng theory proposes ), then any small interaction between this and normal matter would maybe cause the affects we see.

to me, space fabric or strings are more likely to be 2d objects trying to resolve themselves in a 3d enviroment. I know it sounds bonkers, and i dont understand the maths of 2d object in 3d space enough to put any figures on the spin rate.
You are getting warm!
Lurker2358
1.7 / 5 (6) Mar 03, 2012
Benni:

Although it's not properly taught, gravity technically does not operate as a "force". It operates as a bias in space-time, supposedly.

Even in the newtonian formula you see:

F = GMm/r^2

But if you remove "m" you get:

A = GM/r^2

and now you find that everything, not just massive particles, is accelerated according to the equation. Just as you have said.

Thus, properly applied, the Newtonian equation should bend photons' flight path.

The mass of the smaller "object," being "m," does not affect it's own acceleration towards "M" and thus we can see that a "massless" particle should be accelerated towards "M" at the same speed as a massive particle.

"Force" is therefore irrelevant, since the "mass" of the "m" term cancels itself anyway, since the acceleration is independent of the second object's mass or lack thereof. And this works both ways. "M" is irrelevant when determining by how much the larger object is accelerated towards the smaller.
Lurker2358
1 / 5 (3) Mar 03, 2012
But since light's "speed" cannot be changed, then "acceleration" must function by changing it's vector components, as seen in any reference frame, such that the vector sums of it's motion is always 299292458m/s, but it is "acclerated" and therefore "bent" by changing the values of the individual vector components.

thus it's direction, the "vector" components of velocity, can change while the "speed" component, which is the scalar sum of the vectors, does not change.
Vendicar_Decarian
3.5 / 5 (11) Mar 03, 2012
Dark matter as it turns out comes in 3 flavors. Chocolate, Vanilla and Lemon.

The bullet cluster provides an example of the Vanilla type, and this new observation is the Lemon form. The chocolate form is completely invisible since it is extra dark chocolate.

15 percent of the universe it made from the Vanilla form, 10 percent the Lemon form, 5 percent the extra dark chocolate form and 5 percent coming from normal matter.

This progression corresponds to first 4 terms of the ZnifPikl Wadflad projection of an 11 dimensional manifold onto an infinite dimensional non-conformal zeta baloon.

StarGazer2011
1 / 5 (3) Mar 03, 2012
If the galaxies of Abell 520 have been 'stripped of their dark matter' then, if DM theory is useful, their rotation should have changed to match DM-free gravitiational theory. Looks like DM just became falsifiable.
Lurker2358
1.9 / 5 (8) Mar 03, 2012
If the galaxies of Abell 520 have been 'stripped of their dark matter' then, if DM theory is useful, their rotation should have changed to match DM-free gravitiational theory. Looks like DM just became falsifiable.


Not really.

There's no "control" in any such experimental measurement.

i.e.

How do you know there just isn't "extra" dark matter there, etc?

Maybe the galaxies have plenty Dark Matter, and there's "extra".

Or...maybe Dark Matter doesn't exist at all, and the effect is exactly what I've described above.

Or...maybe Vendi is right and this is all ridiculuos nonsense.

What seems more likely? A mathematical error or missing term in our existing laws which simultaneously produces units sufficient to explain both DM and DE?

Or an invisible pixie dust particle that just happens to be unobservable, and always in exactly the right place and time, and also doesn't explain DE at all, but only DM?

If you want to take the law of parsimony, my theory is simpler.
Vendicar_Decarian
3.5 / 5 (4) Mar 03, 2012
Measuring the rotational profiles of the galaxies in this cluster is an excellent idea. And the bullet cluster too.

If there is sufficient resolution and optical brightness it is probably underway right now.

If not, then there is a potential nobel in the doing.
Lurker2358
1.7 / 5 (6) Mar 03, 2012
Now you could test for Relativity-based asymmetries or other asymmetries between my postulated GMKa and GMKb terms via simulation of known galaxies' star motions, so it IS falsifiable, but you'd need a very, very powerful computer to do a simulation, since as I've pointed out, you really need to do the vector sums for all terms for all particle pairs. Though since stars make up 98% of ordinary matter in galaxies, just modeling the stars as point masses should be close enough to keep a margin of error smaller than the DM phenomenon itself.

Thus, if you can show that relativistic effects, both by speed of light limits directly as well as dilation effects, produce asymmetry between Ka and Kb over interstellar distances or in and between galaxies, within a couple sigmas, then this could explain some or all of the missing mass.

For a proof of concept, testing it on modeling a few individual galaxies or one or two galaxy clusters should suffice.
TabulaMentis
1.8 / 5 (5) Mar 03, 2012
Dark matter as it turns out comes in 3 flavors. Chocolate, Vanilla and Lemon.

The bullet cluster provides an example of the Vanilla type, and this new observation is the Lemon form. The chocolate form is completely invisible since it is extra dark chocolate.

15 percent of the universe it made from the Vanilla form, 10 percent the Lemon form, 5 percent the extra dark chocolate form and 5 percent coming from normal matter.

This progression corresponds to first 4 terms of the ZnifPikl Wadflad projection of an 11 dimensional manifold onto an infinite dimensional non-conformal zeta baloon.
I will take an extra large of the extra dark chocolate with a cherry on top.
Lurker2358
1.6 / 5 (7) Mar 03, 2012
Will be SO funny if Rossi's cold Fusion device is real.

That should really throw a monkey wrench in cosmology when stars can suddenly fuse Nickel and other stuff without necessarily exploding, and planets' cores can fuse Nickel, instead of needing long-lived heavy radioactive isotopes.

They'll have to throw out almost everything anyone thinks they know about stars and supernovas and other similar stuff. LOL.

God I hope Rossi isn't hoaxing.
Vendicar_Decarian
4.3 / 5 (6) Mar 03, 2012
Given that his 1 megawatt demo was a failure, what hope is there?

"God I hope Rossi isn't hoaxing." - Lurker

I grow giant purple dinosaurs in my basement. I sold one to an unnamed collector just last week.

Would you like to purchase a time machine? I make those too.

Billy_Madison
1.3 / 5 (6) Mar 03, 2012
Galaxies collided.... What if the black holes in the middle of these galaxies combined and formed larger black holes that caused either A.) dark matter to clump together B.) the gravitational lensing is caused by different black holes and not dark matter.
Tuxford
1.7 / 5 (12) Mar 03, 2012
If the galaxies of Abell 520 have been 'stripped of their dark matter' then, if DM theory is useful, their rotation should have changed to match DM-free gravitiational theory. Looks like DM just became falsifiable.

I predict that it will be shown that most/all galaxies will be shown to have lost their dark matter. In the presence of matter, the dark matter conversion to matter is enhanced. That is, dark matter is the precondition to the formation of matter. Dark matter halos and tenuous gas clouds will likely be shown to surround all galaxies. But within galaxies, the matter will dominate.

Nevermind the need to explain galactic rotation. That is simply a product of red/blue shift observations, which has likely be over-respresented as a result of a single cause. Other factors are at work. And no galactic rotation has ever been confirmed optically by star displacement.
Modernmystic
1.7 / 5 (12) Mar 04, 2012
"Why do we always look for a purely naturalistic explanation for what we see in the universe?" - Modern

Because magical thinking invariably ends in failure.


When I say naturalistic I don't mean God Vendi...I simply mean that it could be intelligence.

We know of at least one example of such, why is it a stretch to hypothesize another?
Shinichi D_
2.1 / 5 (7) Mar 04, 2012
And no galactic rotation has ever been confirmed optically by star displacement.


That is the most pathetic reasoning. "it's not observable in a human lifetime, so it doesn't exists."
Just because a human lifetime is not enough to go trough how many times creationalists were proven wrong, doesn't mean they weren't. Or that they are right.

http://www.youtub...=related
Vendicar_Decarian
3.5 / 5 (4) Mar 04, 2012
"When I say naturalistic I don't mean God Vendi...I simply mean that it could be intelligence." - Modern

Since as you say we have only one example of such, and several thousand years of observation, the probability of that is very low.

Hence the presumption of natural cause.
StarGazer2011
1.7 / 5 (11) Mar 04, 2012
@Lurker2358 :
I dont disagree, its my personal intuition that lensing and rotational anomalies are caused by separate phenomena and i dont think that DM actually exists, i understand it as a kludge to fit theory to observation, simmilar to ptolemaic epicycles.
And you are right that there isnt a control as such, and DM adherents can 'explain away' using the types of arguments you posit (extra DM in the Abell 520 cluster allowing DM to have its cake and eat it too is the most obvious).
If it turns out the Abell 520 galaxies are rotating in a way consistant with standard gravitational theory being correct then that would support DM.
If the cores are still rotating at the same rate as the periphery then that would cause good scientists to consider that lensing and galactic rotational anomolies may be caused by separate phenomena.
Whatever the result, the data would be interesting at the very least.
Callippo
1 / 5 (3) Mar 04, 2012
its my personal intuition that lensing and rotational anomalies are caused by separate phenomena and i don't think that DM actually exists
They can be both caused with caused with dense clouds of neutrinos, which are both moving collectively like cohesive fluid, both cause gravitational lensing. Why not? Actually, the more manifestations of DM, the more we can be sure, it does exist.
bluehigh
2.2 / 5 (13) Mar 04, 2012
Gravity only acts as a force on something with mass


Actually, mass has property that we detect as a gravitational field. Gravity does not act on mass. Mass acts on mass.

... and Vendi the Dinosaur was not purple, if was a kinda off grey pinkish hue. I named it Deesky and it died after only a few weeks. I reckon feeding it just cabbage and carrots was a bad diet.

I'll have a go of one your time machines as long as you don't bullshit me about backward travel. I just want to slow my rate of change in time, that way I watch the future evolve. Can I run it on a couple of AA cells?
Au-Pu
2 / 5 (4) Mar 04, 2012
Perhaps we should revisit the work of an Indian scientist of the late 19th and early 20th centuries i.e. BOSE
One of his molecular theories may be better applied at the sub atomic level.
Worth a thought?
Benni
1.6 / 5 (7) Mar 04, 2012
Gravity only acts as a force on something with mass


Actually, mass has property that we detect as a gravitational field. Gravity does not act on mass. Mass acts on mass.


It's been a few years since 1st semester Newtonian physics, so maybe my memory has failed me. Is this a quote of his?
MrGrynch
1.6 / 5 (7) Mar 04, 2012
Dark matter is a concept that was invented, and I mean that literally. It never existed in previous models. It was anomalous observations, which did not match existing dogma, that made this invention necessary in order to save it. There is no requirement to find it or define it in reality. Until plasma cosmology is given its due, there will always be doubt in the existing model and the inability to define and detect dark matter will only strengthen this need.
TabulaMentis
1.7 / 5 (6) Mar 04, 2012
Dark matter is a concept that was invented, and I mean that literally. It never existed in previous models. It was anomalous observations, which did not match existing dogma, that made this invention necessary in order to save it. There is no requirement to find it or define it in reality. Until plasma cosmology is given its due, there will always be doubt in the existing model and the inability to define and detect dark matter will only strengthen this need.
Sure the title "Dark Matter" was invented by us humans. The correct title for dark matter is preatomic particles and preatomic energy. It is called "Preatomic" because it is before atoms which also includes neutrinos. And people need to forget about Calabi-Yau space particles being dark matter. Furthermore, Plasma Cosmology will not get the job done either! Think "Preatomic."
dogbert
1.8 / 5 (9) Mar 04, 2012
Think "Preatomic."


Better yet, think "kludge".
TabulaMentis
1.7 / 5 (6) Mar 04, 2012
Better yet, think "kludge".
Nope, think "Preatomic."

P.S.: If you are religious and believe in life after death, then think "Post-atomic."
Vendicar_Decarian
4 / 5 (4) Mar 04, 2012
"Can I run it on a couple of AA cells?" - BlueHigh

I was going to design the time machine to run on pixie dust, but getting some was too difficult, so it is powered by a lump of dark matter instead.

Look for it in the little compartment under the seat. If you can't see it, you have just found it.

SR71BlackBird
1 / 5 (2) Mar 04, 2012
I would very much like to know if Dragan Slavkov Hajdukovic's proposal on the polarization of the quantum vacuum could offer an explanation to this anomaly. http://arxiv.org/abs/1106.0847
Billy_Madison
1 / 5 (3) Mar 05, 2012
I still believe there is a simple explanation to this... When masses of galaxies collide, the dark matter conglomerates together. Even though the non-dark matter masses get slung apart, the dark matter stays clumped together. It's like the remnants of a party no one has cleaned up. Maybe a battlefield of the galactic civil war between two opposing galaxy cluster masses, and what's left in the picture is the wounded/dead no one cared to retrieve, would be a better analogy.
Pyle
2.2 / 5 (5) Mar 05, 2012
BlackBird - testing of the foundation of that theory seems close at heand as we capture more anti-matter. If it has negative gravity then Hajdukovic's ideas may warrant development.

dogbert's point should be thought on. He comes back to it every time DM rears its head and I have yet to see a valid argument against him. DM is a plug. We postulate it exists because of our anomalous observations and then say, "Look how well our observations match our plug!"

Angry Canadian seems to have left out the bananas so I doubt his theory will gain much traction.

This article is great. Lisa has done a great job, again, of finding a great paper and bringing it to us armchair physicists. Bravo.

(Damn, couldn't find anywhere to mention my favorite pet theory. Maybe its ship has sailed.)
TabulaMentis
1.9 / 5 (8) Mar 11, 2012
@Pyle:

I think this article on Physorg.com is the best I have heard of yet to explain the lack of anti-matter (Fermilab results add to confidence in explaining less antimatter amounts):

http://www.physor...nts.html

MOG and MOND do not explain it all. It is time to reconsider DM and DE.
Callippo
1 / 5 (3) Mar 11, 2012
IMO the neutrinos are good candidate for missing antimatter. They're behaving like Falaco solitons of longitudinal waves at the water surface, i.e. like the bubbles with respect to transverse waves of light with negative gravitational potential. Such a bubbles still deform the space-time in such a way, they induce the gravitational lensing (the water surface appears undulated and expanded even for transverse waves, which are passing trough Falaco solitons), but these bubbles are repelled with places where the gravitational potential is changing. The whole trick is, such form of antimatter is very diluted, so it escaped the attention of physicists. But what we should actually expect from antimatter exhibiting antigravity? Such form of matter cannot form large compact objects. We should be prepared, that the lightweight particles of matter can play the role of antiparticles at the same moment.
Callippo
1.4 / 5 (7) Mar 11, 2012
In AWT are all particles formed with mutual interference of longitudinal and transverse waves and the longitudinal waves are behaving like mirror word of the negative curvature of space-time. Therefore all particles can be observed like the massive bubbles with the antimaterial hole at the center, which differ with thickness of their walls. Well and the neutrinos are smallest lightweight bubbles, so that their antimatter behavior becomes dominant. The typical property of antimatter is, it's attracted to places, where gravity is shielded, i.e. into places BETWEEN massive objects, i.e. into fibers of cold dark matter, where the longitudinal waves of vacuum are dominant. For example the Allais effect during solar eclipse is just the moment, when huge amount of neutrinos fills the gravitational shadow, which is formed behind the moon. It's typical aetheric physics, which still waits for its understanding.