'Dark core' may not be so dark after all: Scientists report new dark matter finding from merging galaxy cluster

Nov 29, 2012
These composite images taken by two different teams using the Hubble Space Telescope show different results concerning the amount of dark matter in the core of the merging galaxy cluster Abell 520. Dark matter is an invisible form of matter that astronomers believe is the underlying gravitational "glue" that holds galaxies together. In the top image observations of the cluster, taken by D. Clowe with the Advanced Camera for Surveys mapped the amount of dark matter in Abell 520. It reveals an amount of dark matter astronomers expect based on the number of galaxies in the core. The dark-matter densities are marked in blue, and the dotted circle marks the dark-matter core. The map is superimposed onto visible-light images of the cluster. In the bottom image a second team, led by James Jee, used the Wide Field Planetary Camera 2 to find an unusual overabundance of dark matter in the cluster’s core, denoted by the bright blue color at image center. The observation was surprising because astronomers expect that dark matter and galaxies should be anchored together, even during a collision between galaxy clusters. This discrepancy between the two results requires further observation and analysis, say researchers. The two dark-matter maps were made by detecting how light from distant objects is distorted by the galaxy clusters, an effect called gravitational lensing. Abell 520 is located 2.4 billion light-years away. Credit: (top) D. Clowe, (Ohio University, (bottom) J. Jee (University of California, Davis)

(Phys.org)—Astronomers were puzzled earlier this year when NASA's Hubble Space Telescope spotted an overabundance of dark matter in the heart of the merging galaxy cluster Abell 520. This observation was surprising because dark matter and galaxies should be anchored together, even during a collision between galaxy clusters.

Astronomers have abundant evidence that an as-yet-unidentified form of matter is responsible for 90 percent of the gravity within galaxies and clusters of galaxies. Because it is detected via its gravity and not its light, they call it "dark matter."

Now, a new observation of Abell 520 from another team of astronomers using a different Hubble camera finds that the core does not appear to be over-dense in dark matter after all. The study findings were published in The .

"The earlier result presented a mystery. In our observations we didn't see anything surprising in the core," said study leader Douglas Clowe, an associate professor of physics and astronomy at Ohio University. "Our measurements are in complete agreement with how we would expect dark matter to behave."

Hubble observations announced earlier this year by astronomers using Hubble's 2 suggested that a clump of dark matter was left behind during a clash between clusters in Abell 520, located 2.4 billion light-years away. The dark matter collected into a "dark core" that contained far fewer galaxies than would be expected if the dark and luminous matter were closely connected, which is generally found to be the case.

Because dark matter is not visible, its presence and distribution is found indirectly through its . The gravity from both dark and luminous matter warps space, bending and distorting light from galaxies and clusters behind it like a giant magnifying glass. Astronomers can use this effect, called , to infer the presence of dark matter in massive . Both teams used this technique to map the dark matter in the merging cluster.

Clowe's team used Hubble's Advanced Camera for Surveys (ACS) to measure the amount of dark matter in the cluster. ACS observed the cluster in three colors, allowing the astronomers to distinguish foreground and background galaxies from the galaxies in the cluster. From this observation, the team made an extremely accurate map of the cluster's dark matter. "With the colors we got a more precise selection of galaxies," Clowe said.

The astronomers estimated the amount of dark matter in the cluster by measuring the amount of gravitational "shear" in the Hubble images. Shear is the warping and stretching of by the gravity of dark matter. More warping indicates the presence of more gravity than is inferred from the presence of luminous matter, therefore requiring the presence of dark matter to explain the observation. "The WFPC2 observation could have introduced anomalous shear and not a measure of the dark matter distribution," Clowe explained.

Using the new camera, Clowe's team measured less shear in the cluster's core than was previously found. In the study the ratio of dark matter to normal matter, in the form of stars and gas, is 2.5 to 1, which is what astronomers expected. The earlier WFPC2 observation, however, showed a 6-to-1 ratio of dark matter to normal matter, which challenged theories of how behaves.

"This result also shows that as you improve Hubble's capabilities with newer cameras, you can take a second look at an object," Clowe said.

His team is encouraging other scientists to study its data and conduct their own analysis on the cluster.

Explore further: Australian researchers pioneer a 'Google street view' of galaxies

More information: iopscience.iop.org/0004-637X/758/2/128/

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HannesAlfven
1.9 / 5 (23) Nov 29, 2012
Re: "Because it is detected via its gravity and not its light, they call it "dark matter.""

Occam's Razor would traditionally suggest that we should look to the matters and forces we already have first, before inventing new forms. The error bars on the gravitational "constant" have been on the increase, rather than decline, as we have attempted to refine the value. Furthermore, we also know that, of the matter we can see, 99.999% of it is in the plasma state. In the laboratory, plasma exhibits three separate modes: arc, glow and dark. It can conduct in all three. Filaments of conducting plasmas exhibit long-range attraction, and short-range repulsion with one another. Thus, just like "dark matter", plasmas can exert force without emitting light.
Tuxford
1 / 5 (17) Nov 29, 2012
Let us review:
Dark matter may be largely absent within our galaxy, existing primarily in the galactic halo.
http://phys.org/n...sun.html
The halos may contain a few ejected stars;
http://phys.org/n...ies.html
or migrated stars.
http://phys.org/n...ays.html
The galactic halos likely also contain huge masses of hot gas. Why would our classic galaxy be unrepresentative?
http://phys.org/n...gas.html
And the dark matter cores do exist in center of massive galactic clusters, though, maybe not as dense as first believed.
http://phys.org/n...mic.html
http://phys.org/n...ion.html

All of these observations are consistent with LaViolette's SubQuantum Kinectics. Can the same be said of another theory??? If so, I am open to consideration.
VendicarD
2.8 / 5 (12) Nov 29, 2012
Wow, within months several galaxies worth of dark matter vanished.

It certainly is some whacky stuff. Where did it go, and how did it move so fast?
Q-Star
4.3 / 5 (12) Nov 29, 2012
Wow, within months several galaxies worth of dark matter vanished.

It certainly is some whacky stuff. Where did it go, and how did it move so fast?


You sound as if you think acquiring new data and refining results it a bad thing. What would be bad is there were no new things to observe and ponder over. It's called progress. It's how science is done,,, revolutions are rare, it's mostly tedious baby steps.
dogbert
2.2 / 5 (17) Nov 29, 2012
Hardly a day guides by that we don't find more imaginary matter.

Some day we may actually discover why our observations don't match our models of gravity. Until then, it appears that we will continue to create imaginary matter.
Q-Star
2.9 / 5 (17) Nov 29, 2012
Hardly a day guides by that we don't find more imaginary matter.

Some day we may actually discover why our observations don't match our models of gravity. Until then, it appears that we will continue to create imaginary matter.


Sort of like the imaginary electron? Proton? Neutron? Photon? No one has seen these mythical beasts either. What we do see is how they affect the reality we are trapped in.

What is dark matter? No one knows. But the effects are not "imagined", they are observed. Gravity is on solid ground, the best minds have tested it repeatedly. It's body of evidence is pretty much beyond dispute. So that makes a good case for being on the right track in assessing the effects of dark matter.

The question is not whether it is real or imaginary. It is real. The question is what IS it.

Electrons, Protons, Neutrons, Photons, Quarks, not one of them has been observed directly, are they imaginary too?
Lurker2358
2.8 / 5 (9) Nov 29, 2012
You sound as if you think acquiring new data and refining results it a bad thing. What would be bad is there were no new things to observe and ponder over. It's called progress. It's how science is done,,, revolutions are rare, it's mostly tedious baby steps.


I think he's mocking the way cosmologists are consistently inconsistent with their observations and publications of things like mass, distance, and luminosity. In this case an error of a half order of magnitude is ridiculous.

Electrons, Protons, Neutrons, Photons, Quarks, not one of them has been observed directly, are they imaginary too?


The truth you think you see may not be the Truth that is.

If true, uncertainty principle would actually make it impossible to accurately measure all of the properties of fundamental particles, because measuring one alters the others.

There could be any number of fundamental properties of particles which we don't know about which might explain a perceived gravity discrepancy
VendicarD
3.2 / 5 (11) Nov 29, 2012
On the contrary, it is a great thing. In this case showing that the dark matter equivalent of trillions of stars can just vanish overnight.

It is a pretty spectacular dark matter property.. Don't you agree?

"You sound as if you think acquiring new data and refining results it a bad thing." - Q-Star
Q-Star
3.7 / 5 (15) Nov 29, 2012
There could be any number of fundamental properties of particles which we don't know about which might explain a perceived gravity discrepancy


Is it possible? I'd be the first to say yes. But until I see a viable model and a theory that can be tested, I'll be skeptical. It's never enough to say "That is wrong", it must be accompanied with a reason that something else is MORE right.
Q-Star
4 / 5 (12) Nov 29, 2012
On the contrary, it is a great thing. In this case showing that the dark matter equivalent of trillions of stars can just vanish overnight.

It is a pretty spectacular dark matter property.. Don't you agree?



Not really, I agree that in the pursuit of knowledge, we sometimes makes mistakes.

But it was the first measurement of this cluster that had the folks scratching their head. This new assessment finds that the dark matter is more in line with what they first expected. In other words, "if you find unexpected results,,, look again to see if there was something wrong"

Good science, eh?
dogbert
3.4 / 5 (16) Nov 29, 2012
Q-Star
The question is not whether it is real or imaginary. It is real. The question is what IS it.


No, it is actually imaginary. The gravitational anomalies are real. They are all that has been observed. We have not observed dark matter. It does not show up in high energy collisions. It is supposed to comprise most of the matter in the universe, but we cannot isolate/capture/describe a single particle of it. A measure of its imaginary basis is that dark matter is not predictive. We must create dark matter on each observation in order to normalize our observation with our models of gravity. There is always just enough dark matter (never too much) in just the right places (never displaced from where it is needed) to account for the gravitational anomalies. This is because we just make it up as we go along.

The gravitational anomalies are real. The dark matter kludge is imaginary. This is not to say that dark matter is excluded from consideration, only current usage is imaginary
Q-Star
3.1 / 5 (16) Nov 29, 2012
No, it is actually imaginary. The gravitational anomalies are real.


What anomalies? Could you suggest another model that will explain it better? Remember, your model also has be able to live ALL the phenomena we observe, not just this one.

We must create dark matter on each observation in order to normalize our observation with our models of gravity. There is always just enough dark matter (never too much) in just the right places (never displaced from where it is needed)


You must not have read the article, the first measurements were found to TOO MUCH, this one found what they expected to find the first time.

The gravitational anomalies are real.


How does your model work? Separate physics for separate galaxies? We've been observing gravity on every scale for decades. No one has made a measurement that found any "anomaly". The best minds in physics and mathematics have been examining gravity for a century now. Guaranteed Nobel for the man who produces.
VendicarD
4.3 / 5 (13) Nov 29, 2012
I didn't observe a pick elephant in my pajama's this morning. That is how I knew it was really there.

No other mammal could have produced such a spectacular non-result, and I have no real explanation for why it wasn't there.

Hence it was.
Q-Star
3.1 / 5 (8) Nov 29, 2012
I didn't observe a pick elephant in my pajama's this morning. That is how I knew it was really there.

No other mammal could have produced such a spectacular non-result, and I have no real explanation for why it wasn't there.

Hence it was.


There is a theory and model that can't be disputed (or even doubted). Works for me, it does.
Urgelt
4.3 / 5 (12) Nov 29, 2012
I suppose VendicarD has a point.

The problem really comes back to an unfortunate naming convention. Are there gravitational anomolies unexplained by current gravitational theory? Yes. Is undetected matter responsible? Unknown. Are 'weakly-interacting massive particles (WIMPS) responsible? That hypothesis is not exactly a shoe-in. There's absolutely no evidence for it.

If we'd just called the phenomenon 'Expected Gravitational Anomoly,' then we wouldn't be railroaded into embracing WIMPS without evidence.

'Dark Energy' as an explanation for the accelerating expansion of the universe is an equally unfortunate term, because it railroads us into embracing another imaginary thing for which there is no evidence.

It's tempting to jump to a conclusion. (I prefer to jump to 'our theories of gravity are off', myself.) But in science, the right answer is to tolerate uncertainty pending better evidence, and pending better theories with better explanatory and predictive power.
dogbert
3.1 / 5 (16) Nov 29, 2012
Q-Star,
You must not have read the article, the first measurements were found to TOO MUCH, this one found what they expected to find the first time.


You just made my point. They measured too much lensing the first time, so they created enough dark matter to account for the lensing. Then they measured the lensing again and subtracted the excess dark matter to match the new observations.

At each point, enough dark matter is created to account for the gravitational anomalies.

Kludge; Fantasy.

We've been observing gravity on every scale for decades. No one has made a measurement that found any "anomaly".


Stars move too fast in galaxies. According to our gravitational models, the stars should be flung out of their galaxies. So we kludge dark matter.

Gravitational lensing is more than our models of gravity predict. So we kludge dark matter.

All of those observations which do not match our models represent a gravitational anomaly. In each case, we create imaginary matter
Q-Star
3 / 5 (14) Nov 29, 2012
In each case, we create imaginary matter


So you KNOW it's not dark matter. You KNOW something is wrong with gravity. What do you THINK might be the answer?

What model do you present that can be tested? It's never enough to say THAT is wrong. You must also present a reason at minimum, and an alternate solution that can be tested would be good.

Gravity is tested, about as well as any phenomenon we observe. So for me it only makes sense to shape the search for answer into a framework that includes gravity as we KNOW it to be.
VendicarD
3.7 / 5 (9) Nov 29, 2012
It should be pointed out that the astronomers who are looking at dark matter anomalies are fully aware that there may be alternate explanations.

Still the unfortunate name persists.

Personally, I work on the assumption that it is cold, very low density lightly ionized lumps of hydrogen ice with an average mass on the order of 1000 hydrogen atoms.

VendicarD
3.9 / 5 (7) Nov 29, 2012
Dark matter is evidence that it doesn't work as advertised on large distance scales, or perhaps conservation of momentum...

"Gravity is tested" - Q-Star
IronhorseA
1 / 5 (8) Nov 29, 2012

So you KNOW it's not dark matter. You KNOW something is wrong with gravity. What do you THINK might be the answer?

What model do you present that can be tested? It's never enough to say THAT is wrong. You must also present a reason at minimum, and an alternate solution that can be tested would be good.

Gravity is tested, about as well as any phenomenon we observe. So for me it only makes sense to shape the search for answer into a framework that includes gravity as we KNOW it to be.


The problem lies in that astronomers use Newtons formulation of gravity for calculating orbital velocities. Our best theory of gravity is General Relativity. However it's usually reserved for dense mass situations (black holes for example) or high speeds. However, research done using GR on ordinary concentrations of mass has produced results congruent with observation due to the non-linear nature of GR. Its not the last word but it does put an upper limit on the amount of 'dm'.
dogbert
3.3 / 5 (12) Nov 29, 2012
Q-Star,
So you KNOW it's not dark matter. You KNOW something is wrong with gravity. What do you THINK might be the answer? What model do you present that can be tested? It's never enough to say THAT is wrong. You must also present a reason at minimum, and an alternate solution that can be tested would be good.


Not at all. I don't know why our models of gravity do not match our observations. Neither do the people who create imaginary matter. My point is only that when you do not know, you say "I do not know". You do not pretend that you know something you do not know.

Dark matter is a kludge. The problem with any kludge is that the people who use it soon begin to believe in their own fantasies. You exemplify that pattern. You believe in dark matter because the kludge is presented consistently as if it were real.
rah
2.6 / 5 (15) Nov 29, 2012
Excuse me, this article is a joke people. There has never been any confirmation of anything known as dark matter. So what you're looking at is a picture of a part of Abell 520 with a dotted circle in it. You can feel free to add your own mark-ups and sound effects, John Madden style.
binghamjames
3 / 5 (8) Nov 30, 2012
Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious.

- Albert Einstein
binghamjames
2.3 / 5 (6) Nov 30, 2012
Dark Matter Now Tied to Global Warming !! News at 11:00 Lol
binghamjames
2.7 / 5 (7) Nov 30, 2012
Maybe Dark Matter represents that point where our quantifiable physical reality meets or "interferes" with another type of physical reality. We can't measure it, since it isn't really part of our physical realm. After all, I feel there simply has to be a point where this is the case since we know our reality isn't infinite. So since this type of matter or reality seems so elusive and non-quantifiable, whose to say this isn't the case here?
yash17
1 / 5 (5) Nov 30, 2012
Dark matter & black holes are same one type. They are compressed atom structure matter. They exist in extremely high pressure & temperature.
Ober
1.8 / 5 (5) Nov 30, 2012
Well, what if a galactic black hole, actually anchors spacetime for it's galaxy? Is there dark matter, that is not associated with a Black Hole and it's galaxy? What I'm trying to suggest is that I suspect DM to be anomalous, due to a lack of understanding of Galactic Black Holes. If we can invent missing matter and give it galactic wide distribution to explain an anomaly, then why not consider inventing new properties of Black Holes that do the same. For example, a Black Hole is already DARK, and we suspect the laws of physics breakdown at the internal singularity. So if the laws breakdown, hey why not invent some new ones, but attach them to the BLACK HOLE!!!! Seems obvious to me that the massive monster in the center of most (if not all) Galaxies, is the dominant force in a Galaxy. This is where people should be looking. This is where the anomaly is standing out like Rhino Balls!! (I'll be interested to see how this post gets rated :-) )
ValeriaT
1 / 5 (6) Nov 30, 2012
IMO the dark matter is a lightest form of matter observable and matter is formed with space-time curvature only. It may contain huge amount of neutrinos, but even more lightweight "particles" (axions), which are merely density fluctuations of vacuum. In AWT the vacuum is so dense, so that even its tiny temporal density fluctuations have inertial and gravitating effects. So it can be formed with mixture of heavier particles and pure curvature of space-time quite easily and most of models of it are correct and wrong at the same moment.
The change of visible matter density in the dark matter core is intriguing and it could mean, that the new galaxy is just about to form there - and we can observe it like the miniature analogy of Big Bang. Maybe it's just observational artifact, because the sensitivity of observational methods just increases - but if not, then we have a rare opportunity to follow the galaxy formation from its very first moment.
ValeriaT
1 / 5 (6) Nov 30, 2012
Because in dense aether model the cold dark matter is formed with shielding of superluminal gravitational waves (a flux of tachyons), it can be quite dynamic and it can be formed far away from other material objects from "nothing" like the quantum wave. Note that during solar eclipses the Allais effect and various gravitational anomalies manifest itself without noticeable delay. So far the research of this phenomena belongs nearly exclusively into "parallel science". The observation of dynamic dark matter could therefore reconcile the finding of mainstream and alternative physics.
ValeriaT
1 / 5 (5) Nov 30, 2012
If we compare the dark matter intensity (which is easy to do for example in Photoshop), we will see, that the later image contains not only higher density of dark matter at central area, but even a lower mass density of dark matter in another areas. It eliminates the assumption, that the previous observation was biased toward lower values due the insufficient sensitivity of dark matter detection. It seems, that the dark matter is really emerging before our eyes inside of Abel galaxy cluster - and it emerges fast.
Claudius
1.7 / 5 (6) Nov 30, 2012
This seems to be a case of trying to pound a square peg (observations) into a round hole (dark matter theory.) Repeat as necessary.
DavidW
1.7 / 5 (6) Nov 30, 2012
Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious.

- Albert Einstein


Nothing will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet.

ALBERT EINSTEIN

So, if you haven't done that first you probably shouldn't be quoting him or at least put in a disclaimer that you disagree with his ethics and support needless killing instead and have a different idea as to what will do the most good. Understanding what we call dark matter was not what he said was what we needed to do for ther most good.
Torbjorn_Larsson_OM
4.7 / 5 (7) Nov 30, 2012
Ah, I remember that anomalous result mentioned. But spurious results tend to go away.

@ HannesAlfvèn, yash17, Ober, ValeriaT:

And that is exactly how the area went, from trying on normal matter, including black holes and neutrinos, to having it rejected. And later, in the standard cosmology with DM, having these types of observations unambiguously tested.

HA, Ironically the same thing would apply to EU/PC religion, in which case it is easily seen not to be a result of "matters and forces we already have" as it is non-predictive. No quantified models are ever presented, just verbiage.

Conversely, since such pseudoscience religion belief is based on pattern recognition it is easy to identify it as social "matters and forces we already have" way before actual science.

@ Tuxford, Claudius: The only known predictive theory that those observations are consistent with is dark matter of standard cosmology.

Tuxford, a spurious term is not a "theory".
Torbjorn_Larsson_OM
4.1 / 5 (8) Nov 30, 2012
@ Urqelt: There is no uncertainty in DM/DE, since the observations are well tested as such and all the competing theories have fallen by now.

We don't know all there is to know about it, but that can be observed for all areas of science.

@ VendicarD: Not professional physicists or astronomers with physics background, which are after all those who do the theories. DE/DM is a done deal, check the peer review literature.

Standard cosmology with DM/DE preserves energy on the pertinent scales, locally as well as globally. It is well known that a medium scale expanding spacetime volume does not conserve entities such as energy (hence redshift, say).

@ rah, binghamjames: You are making false claims, read the article on existence and observation (constrained "measure"). So who are the joke here?
Q-Star
3.1 / 5 (7) Nov 30, 2012
If we compare the dark matter intensity (which is http://i45.tinypi...xwfr.jpg for example in Photoshop), we will see, that the later image contains not only higher density of dark matter at central area, but even a lower mass density of dark matter in another areas. It eliminates the assumption, that the previous observation was biased toward lower values due the insufficient sensitivity of dark matter detection. It seems, that the dark matter is really emerging before our eyes inside of Abel galaxy cluster - and it emerges fast.


Uuh,,,? They are reporting a DECREASE from the earlier findings, not an increase. So you sort of have it backwards.
Lurker2358
1 / 5 (4) Dec 01, 2012
Nothing will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet.

ALBERT EINSTEIN


Livestock, game, and fish, etc, provide a means of storing food in a form which doesn't spoil, until it is needed to be harvested. Cattle can graze on their own, and only need supplemental feeding if it's a drought or winter. Fish and Game take care of themselves, and cost nothing to raise or harvest. In fact, they'd be much cheaper if not for licensing laws (but then you'd have poaching running rampant).

If all we had was fruits, vegetables, and grains, it would be far more difficult to preserve and transport enough food for the whole world in a cost effective manner.
ValeriaT
1 / 5 (3) Dec 01, 2012
They are reporting a DECREASE from the earlier findings, not an increase. So you sort of have it backwards
It doesn't matter in my point - the other areas of picture exhibit the opposite trend instead. So I'm opened to deduction, the changes in dark matter density aren't artifact of some experimental bias, but a real change, which happened in timespan of few years at the immense distance. Such a coherent change in dark matter density would require some superluminal interaction between the clouds of dark matter, which could point to the "new physics".

Now we can just ignore this finding - or we can try to reconcile it with another similar observations, done previously. Which would be more scientific approach in this case?
Q-Star
3.3 / 5 (7) Dec 01, 2012
It doesn't matter in my point -


Do you even have a point?

the other areas of picture exhibit the opposite trend instead. So I'm opened to deduction, the changes in dark matter density aren't artifact of some experimental bias, but a real change, which happened in timespan of few years at the immense distance. Such a coherent change in dark matter density would require some superluminal interaction between the clouds of dark matter, which could point to the "new physics".


Time span of few years? Change in dark matter density?

The data for both conclusions are one and the same. It's an article about REASSESSING the same data.

But I will admit, this is the best photograph of DARK matter yet. Don't ya think so?
ValeriaT
2.3 / 5 (3) Dec 01, 2012
The data for both conclusions are one and the same. It's an article about REASSESSING the same data.
The later paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile, not just Hubble data. Without it such an articles would serve as a random number generators: the distribution of dark matter is quite different in each version. I hope, the later article is more reliable.
this is the best photograph of DARK matter yet
A photograph? Best? In which criterion?
Q-Star
2.5 / 5 (8) Dec 01, 2012
Best? In which criterion?


Why best in the criterion that it can be seen at all.
ValeriaT
3 / 5 (6) Dec 01, 2012
What you can see at the above pictures isn't photo of dark matter, but the interpretation of minute shifts in position and shape of galaxies behind it. It's solely computer generated picture and you should keep it on mind when you extrapolate some conclusions from it.
yyz
3.7 / 5 (9) Dec 01, 2012
"What you can see at the above pictures isn't photo of dark matter, but the interpretation of minute shifts in position and shape of galaxies behind it"

The images refer to the mass distribution in A520 based on weak lensing observations. The new analysis of mass distribution in A520 by Clowe et al notes that the observed DM discrepancy in previous studies arises in part due to selection effects in the limited FOV of the HST images: http://arxiv.org/abs/1209.2143

In your professional opinion, based upon your (nonexistent) published weak lensing studies if A520, what accounts for the "minute shifts in position and shape of galaxies" observed? Pixie dust at the outer edge of the solar system?

If you don't believe it's DM you are in opposition to ALL weak lensing studies of A520 including:

http://arxiv.org/abs/0706.3048

http://hubblesite.../pdf.pdf

(Those are the original papers describing anomalous DM distribution in A520 based on W-L observations)
kevinrtrs
1.4 / 5 (10) Dec 02, 2012
You sound as if you think acquiring new data and refining results it a bad thing. What would be bad is there were no new things to observe and ponder over. It's called progress. It's how science is done,,, revolutions are rare, it's mostly tedious baby steps.

So how come there's been no improvement in the estimated age of the earth? WHy has it remained stagnant at its current value for the past 60 years already? Where is the good science in that? Where is the good science in determining the age of the earth in the first place - currently it's based on the dubious assumption that meteorites and the earth were made out of the same stuff and hence the age of the meteorites can be used to determine the age of the earth. That's a whole lot of bad science because the assumption is completely indefensible.
kevinrtrs
1 / 5 (8) Dec 02, 2012
This observation was surprising because dark matter and galaxies should be anchored together, even during a collision between galaxy clusters.

Quite clearly the assumptions underlying the theory of dark matter is out of whack with reality, hence this "surprise".
One should remember that anything to do with dark matter is based on inference. There is no direct way to observe the unobservable and so people have to rely on the calculations they make based on certain assumptions about star and galaxy movement in order to arrive at the conclusion of the influence of dark matter. In this case the results of the calculations are simply way off beam from the expectations.
ValeriaT
1 / 5 (3) Dec 02, 2012
The dark matter was originally found with lensing effects of galaxies and rotational curves of stars in it. So that the physicists believed, that the dark matter is something, which cannot exist without observable matter. The later observations of so-called dark galaxies, i.e. blobs of dark matter lensing without observable galaxies at their center demonstrated though, that the dark matter can exist as an independent entity. It makes trouble for theories, which explain it with adjusting general relativity equations. Instead of it, it supports the theories, which do consider the existence of massive particles for it. But if the distribution of DM can change and propagate with superluminal speed, then both theories will have a problem and we should rethink the whole stuff from even more general perspective.
ValeriaT
1 / 5 (4) Dec 02, 2012
In AWT the gravity propagates faster than light, because its caused with shielding of superluminal gravitational waves in accordance to ancient deDuillier/LeSage gravity model. But the same shielding applies to nearby massive objects, the shielding of which diminishes this gravity effect. Whereas the gravity shadow concentrates the particles of energy around massive objects, i.e. the photons, the shielding of another massive objects increases the concentration of gravitational waves and its solitons, i.e. the neutrinos. In AWT the neutrinos are similar solitons of gravitational waves, like the photons are solitons of EM waves. Therefore during solar eclipses and planetary conjuctions the concentration of gravitational waves and neutrinos is raising rapidly along connection line of these objects. This effect occurs with superluminal speed and its not constrained to the immediate vicinity of massive objects.
ValeriaT
1 / 5 (3) Dec 02, 2012
In the universe the dark matter is concentrated along fibers, in the nodes of which new galaxies are forming. Such a behavior can be modelled with hyperdimensional extensions of general relativity as so-called the Gregory-LaFlamme instability. Roughly speaking, when massive galaxies accidentally appear at the single line, a new fiber of dark matter is formed between them. This fiber gains its density gradually, because the neutrinos are condensing from gravitational waves and CMBR photons gradually there. When the critical density is reached, a gravitational collapse will happen and the fiber will coalesce into droplet like the fiber of slimy fluid. This droplet is so called the dark galaxy and it may grow in size until the nearby galaxies remain collinear. Under such a situation a sudden collapse of neutrinos and photons will ignite the quasar formation and new galaxy is formed in the empty space
ValeriaT
1 / 5 (3) Dec 02, 2012
The problem of dark matter from mainstream physics perspective is, it's complex hyperdimensional system. The gravitational waves and neutrinos interact with photons and heavier particles of matter here. When fiber of dark mater is formed, it attracts another matter into it. Therefore the bottom-up mechanism of large galaxies formation is always followed with up-bottom mechanism based on classical accretion. In this way the small galaxies are formed with gradual condensation of matter rather than with evaporation of matter from quasars. You cannot find a general model, which will describe them all. The dark matter is behaving both like field propagating with superluminal speed, both like clouds of classical interstellar gas, both like charged plasma clouds. The behavior of neutrinos in gravity field is nontrivial: these particles aren't attracted to it, but they're still dragged with it. And so on - there is pile of new physics in it and it will take years to describe it schematically.
NOM
3.4 / 5 (5) Dec 02, 2012
there is pile of new physics in it
There is a pile of something, but it aint physics.
aroc91
3.9 / 5 (7) Dec 02, 2012
Quite clearly the assumptions underlying the theory of dark matter is out of whack with reality, hence this "surprise". One should remember that anything to do with dark matter is based on inference. There is no direct way to observe the unobservable and so people have to rely on the calculations they make based on certain assumptions about star and galaxy movement in order to arrive at the conclusion of the influence of dark matter. In this case the results of the calculations are simply way off beam from the expectations.


Quite clearly the assumptions underlying the theory of creationism is out of whack with reality, hence this "surprise".
One should remember that anything to do with creationism is based on inference. There is no direct way to observe the unobservable and so people have to rely on the calculations they make based on certain assumptions about the Bible in order to arrive at the conclusion of the influence of God.
dogbert
2 / 5 (8) Dec 02, 2012
aroc91,

Why did you feel the need to discuss religion ( actually attack ) on this site and on an article having nothing to do with religion?
Raygunner
1 / 5 (1) Dec 02, 2012
Just some fog on the lens...
yash17
2.3 / 5 (3) Dec 02, 2012
Dark matter in cosmos plays prominent role to cause low redshift galaxies/quasars to spread away in mighty space; the case with friends expect space expanding. On other fact, abundant of dark matter intrudes galaxies and becomes the source of CMBR and the source of clouds constructing new stars in galaxies. This dark matter case is waiting for science evidence/ observation.
Q-Star
2.6 / 5 (5) Dec 02, 2012
Dark matter in cosmos plays prominent role to cause low redshift galaxies/quasars to spread away in mighty space; the case with friends expect space expanding. On other fact, abundant of dark matter intrudes galaxies and becomes the source of CMBR and the source of clouds constructing new stars in galaxies. This dark matter case is waiting for science evidence/ observation.


Oh wow, their are actually two of these? What wondrous things the cosmos presents. Two, I wouldn't have believed it possible,,, until I saw the empirical, experimental, reproducible, and verifiable proof right here in this quantum state that we are observing.

(Sorry Dr. Pauli, that "exclusion principle" thingy has failed miserably. You'll have to return the prize,,, without interest of course.)
Q-Star
2.6 / 5 (5) Dec 02, 2012
So how come there's been no improvement in the estimated age of the earth? WHy has it remained stagnant at its current value for the past 60 years already? Where is the good science in that?


Maybe it has remained stagnant because it is close to truth? I know,, what a concept, right?


Where is the good science in determining the age of the earth in the first place - currently it's based on the dubious assumption that meteorites and the earth were made out of the same stuff and hence the age of the meteorites can be used to determine the age of the earth.


Get out more, read more, you might find that there just may, possibly, perhaps, in some conceivable strange idealistic world,,,, dozens of DIFFERENT methods of dating the earth without the need of meteorites?

VendicarD
2.3 / 5 (4) Dec 03, 2012
yup. We can just presume that the dark energy is negative and the dark matter is positive, and have the two cancel, but there is zero evidence that this is the case.

It is nice presumption based on the existing laws of energy conservation, but then those conservtion laws have been changed a couple of times so, it is not clear to me that they can't be changed again making your relationship 0 to 0 proportion false.

Another problem of course is tha the computed energy of the vacuum which seems to be verified by measurement, doesn't mesh with general relativity, by what is it? 90 orders of magnitude?

And then you have the problem of explaining the relative proportions... 75/20/5 approx.

Your explanation ain't a done deal.

"Standard cosmology with DM/DE preserves energy on the pertinent scales, locally as well as globally. It is well known that a medium scale expanding spacetime volume does not conserve entities such as energy (hence redshift, say)." - Torbi
VendicarD
4 / 5 (4) Dec 03, 2012
For the same reason that there has been no improvement in the estimated age of you.

"So how come there's been no improvement in the estimated age of the earth?" - KevinTard
rubberman
2.3 / 5 (3) Dec 03, 2012
Gravitational lensing indicates dark matter....a merging galaxy cluster...OK. My ignorance of physics again at risk here, but, if you point a telescope at the center of gravity for multiple merging galaxies. Why does the lensing have to be caused by dark matter? The merging galaxies are merging to a center of gravity...between each other, it's only logical that if you aim a telescope in this vicinity, gravitational lensing will occur.
ValeriaT
1 / 5 (2) Dec 03, 2012
The origin of dark energy goes to Einstein and Schrodinger. Einstein believed in steady-state Universe (in the same way, like me, BTW) - but his equations required its expansion. Einstein got upset with it (in his time no observational evidence of expanding universe had been given yet) - so he did a something, which could be considered as a sorta cheat - he introduced a constant into his equations, which would balance the expansion factor. But the finding of red shift with Hubble demonstrated the foolishness of such blind formal approach very soon and Mr. Einstein did lost the opportunity to claim this finding as a prediction of his theory.

Alex Harvey at New York University in New York adds an interesting twist to the tale. Harvey has unearthed and re-interpreted a note by Erwin Schrodinger about Einstein's addition of the constant and also studied Einstein's reply.
ValeriaT
1 / 5 (2) Dec 03, 2012
This blunder has lead the Einstein to the proclamations like "If the facts don't fit the theory, change the facts". But the connection of dark energy to the quantum mechanics is more interesting here. Einstein didn't like the quantum mechanics and he dismisses it saying: "The course taken by Herr Schrodinger does not appear possible to me because it leads too deeply into the thicket of hypotheses."

Recently we discussed here the approach of Aristotle, who refused the hypothesis, that the body of different mass would fall with the same speed. He simply observed the different things in real life: the feather falls faster than hammer. Later the proponents of geocentric system refused the Copernican model with the same argument: "it too hypothetical model - every one can see, the Sun is encircling the Earth, not vice-versa". Einstein refused the aether model later in the same argument: "we do need such a model for our theories". But is it really true? Or the history just repeats again?
ValeriaT
1 / 5 (2) Dec 03, 2012
At the water surface the ripples are scattered with distance and their wavelength gradually increases. But because waves of long wavelength are of low energy and even more prone to scattering, this effect accelerates with distance, until all ripples don't scatter in the Brownian noise of the underwater. From perspective of observer floating at the water surface his "2D universe" would simply end there, so he could claim the Universe beginning.

The same effect occurs with surface ripples at the short distance scale, where all ripples get blurred with Brownian noise. This model therefore points to the deep connection of the scattering of light in vacuum at the short distance scale, which is responsible for quantum uncertainty and for scattering of light at the cosmological scale, which manifest itself with dark energy, dark flow and another effects at the cosmic scale.
Q-Star
3 / 5 (6) Dec 03, 2012
Why does the lensing have to be caused by dark matter? The merging galaxies are merging to a center of gravity...between each other, it's only logical that if you aim a telescope in this vicinity, gravitational lensing will occur.


The center of mass of a cluster of galaxies, may or may not be the "visual" center of the cluster. Say you have 100 galaxies in a cluster, all moving around a common center of mass, the velocities of the individual galaxies making up the cluster when analyzed, point to a certain center of mass for the entire cluster. But if you map the galaxies using only the light you receive from them, they may OR may not be centered on the same point in space that the center of mass is. This is one of the SEVERAL DIFFERENT methods (which all agree) used to infer dark matter.
Q-Star
2.6 / 5 (5) Dec 03, 2012
Gravitational lensing indicates dark matter....


Don't engage with Dr. Gobbledegook. He's neither a physicist, philosopher or Czech. The only way he get people in this life to engage with him is by trolling the forums on the internet. (Negative attention is better than no attention.)

I was sucked in myself, until he over played his role. Or the amphetamines started to wear off causing him to slip into and out of character.

You can learn a lot by observing a person's syntax and time-stamps. (And sometimes they are even smart enough to give their IP addresses by answering "fan" mail.)
FrankHerbert
3.2 / 5 (9) Dec 03, 2012
Dogbert is a stealth religionist that doesn't have the convictions to actually stand up for his beliefs. In this sense, he is worse than Kevinrtrs.

It's obvious to anyone that has read the comments on this site for more than a few weeks that Kevin brought up creationism without invoking the word, a kind of dogwhistle. Aroc91 was responding to this.

Just ignore Dogbert. At least Kevin believes strongly enough to defend it outright (most of the time). Dogbert is too afraid to stand up for his own insane beliefs.
rubberman
2.3 / 5 (3) Dec 03, 2012
But if you map the galaxies using only the light you receive from them, they may OR may not be centered on the same point in space that the center of mass is. This is one of the SEVERAL DIFFERENT methods (which all agree) used to infer dark matter.


So, to paraphrase, DM is inferred as having effect if the calculated baryonic mass based on observation would place the center of gravity in one spot, but the actual center of gravity based on the galactic motion is not where it should be? Interesting, and understandable.

I have been considering your theory in the other thread (you posted in response to my remark about DE), of Spacetime being expanded, I couldn't have described it better myself. If it is by the mechanism I believe is responsible, the spacetime at the COG of merging galactic clusters is a very, turbulent region.
Q-Star
3 / 5 (6) Dec 03, 2012
DM is inferred as having effect if the calculated baryonic mass based on observation would place the center of gravity in one spot, but the actual center of gravity based on the galactic motion is not where it should be?


It's but one method to infer DM.

The observable baryonic matter is not enough to explain the observed dynamics.

Those who promote "rethinking" gravity would have you believe that it is the simplest approach. But they neglect to add that it would also require "rethinking" thermodynamics. And "rethinking" electromagnets. And "rethinking" mechanics. And "rethinking" quantum dynamics.

Or instead of "rethinking" all branches of physics, you could first make sure that the simplest explanation is the best avenue of investigation,,, undiscovered particle?

I have been considering your theory


Not mine, Einstein, Lemaitre, Friedman, Hubble, & most others, through today. It's the heart of Hot BB, Cold Inflationary models. What IS DE? Sure Nobel there
Q-Star
3 / 5 (6) Dec 03, 2012
Expanding space has been observed and acknowledged for almost a century. (1920's)

What's new, since the late 90's is the observations of "accelerated expansion". This is when all the "theorizing" about dark energy started. The "accelerated expansion" is observed directly, what's driving it? No one knows. Best, simplest explanation is vacuum energy which is counter to gravity. But there as yet not been a model that can tested experimentally.

Dark matter is on much firmer ground. It's been modeled so that different methods of inferring it, all reach the same results. Electromagnetically. Gravitationally. Thermodynamically. Every established sub-discipline gives consistent results. When the quantum guys find the "particle" it will be settled. And they seem to be closer and closer every year.

It's (dark matter) new science, they've only noticed it within the last 70 years (late 30's). It wasn't until the last 25 years that the technology to explore it began to be developed.
aroc91
5 / 5 (5) Dec 03, 2012
aroc91,

Why did you feel the need to discuss religion ( actually attack ) on this site and on an article having nothing to do with religion?


It wasn't a discussion. It was a facetious remark at kevin's expense. We all know your bias here. You've been outed as a creationist many times over.
dogbert
1 / 5 (5) Dec 03, 2012
FrankHerbert,
Dogbert is a stealth religionist that doesn't have the convictions to actually stand up for his beliefs. In this sense, he is worse than Kevinrtrs.


There is nothing stealth about my belief in God. No need to insult anyone.

I merely asked aroc91 why he brought up religion on a scientific site on a thread which is not concerned with religion.

I might ask you the same thing. I know you hate God, but shifting discussion away from the topic to religion is not appropriate.

If the article concerns religion or philosophy, then a religious discussion might be OK, but not this continual hate mongering.
FrankHerbert
3.2 / 5 (9) Dec 03, 2012
I know you hate God


You have to believe something exists in order to hate it.

QED
dogbert
1 / 5 (5) Dec 03, 2012

You have to believe something exists in order to hate it.


The logical question to such a statement is why you hate God when you don't believe he exists.

Your hate speaks for itself. QED

But again, this is not the proper place to spar about religion.
FrankHerbert
2.7 / 5 (7) Dec 03, 2012
I obviously don't believe as I am an atheist. I also don't hate the god of Abraham because the god of Abraham does not exist.

QED

PS: The hate you are sensing is directed at you, not your imaginary friend.
ValeriaT
1.8 / 5 (5) Dec 03, 2012
The "accelerated expansion" is observed directly, what's driving it? No one knows.
And is anyone interested about explanation, when it could threat the job carriers and social credit of many physicists at least a bit? I don't think so. We are living in hypocritical world and you're portion of it. The mainstream science is an industry feeding many people and all progress in it may appear just with the speed, which wouldn't threat the size and significance of this industry. Of course, many findings and ideas are attracting another money and job opportunities into it - such a findings and theories are welcomed heartily.
yash17
1 / 5 (3) Dec 03, 2012
"And is anyone interested about explanation, when it could threat the job carriers and social credit of many physicists at least a bit? I don't think so. We are living in hypocritical world and you're portion of it. The mainstream science is an industry feeding many people and all progress in it may appear just with the speed, which wouldn't threat the size and significance of this industry."

There it is. That's what we face today. On many forums, they even block the facts written given, if that fact could kill current existing theory; the theory we should have left, base on additional latest facts (accumulated additional data from 1998 to 2012).
ValeriaT
2 / 5 (4) Dec 03, 2012
accumulated additional data from 1998 to 2012
The situation is more complex at the case of global warming than the cold fusion, because the denial of global warming helps nearly as many people, as its support. We have "green" lobby and "fossil" lobby and both lobbies are roughly of the same power by now. But because the development of "green" technologies and climatic research brings more jobs places than the fossil fuel research (this technology is already developed well), the scientists are more opened to "green technologies" - despite these technologies just accelerate the devastation of rain forests and draining of raw material resources instead of fossil fuel sources.