Dark Energy Survey creates detailed guide to spotting dark matter 

April 13, 2015
Mass map with images of two galaxy clusters and a cosmic void

Scientists on the Dark Energy Survey have released the first in a series of dark matter maps of the cosmos. These maps, created with one of the world's most powerful digital cameras, are the largest contiguous maps created at this level of detail and will improve our understanding of dark matter's role in the formation of galaxies. Analysis of the clumpiness of the dark matter in the maps will also allow scientists to probe the nature of the mysterious dark energy, believed to be causing the expansion of the universe to speed up.

The new maps were released today at the April meeting of the American Physical Society in Baltimore, Maryland. They were created using data captured by the Dark Energy Camera, a 570-megapixel imaging device that is the primary instrument for the Dark Energy Survey (DES).

Dark matter, the mysterious substance that makes up roughly a quarter of the universe, is invisible to even the most sensitive astronomical instruments because it does not emit or block light. But its effects can be seen by studying a phenomenon called gravitational lensing – the distortion that occurs when the gravitational pull of bends light around distant galaxies. Understanding the role of dark matter is part of the research program to quantify the role of , which is the ultimate goal of the survey.

This analysis was led by Vinu Vikram of Argonne National Laboratory (then at the University of Pennsylvania) and Chihway Chang of ETH Zurich. Vikram, Chang and their collaborators at Penn, ETH Zurich, the University of Portsmouth, the University of Manchester and other DES institutions worked for more than a year to carefully validate the lensing maps.

"We measured the barely perceptible distortions in the shapes of about 2 million galaxies to construct these new maps," Vikram said. "They are a testament not only to the sensitivity of the Dark Energy Camera, but also to the rigorous work by our lensing team to understand its sensitivity so well that we can get exacting results from it."

Mass map with locations of galaxy clusters

The camera was constructed and tested at the U.S. Department of Energy's Fermi National Accelerator Laboratory and is now mounted on the 4-meter Victor M. Blanco telescope at the National Optical Astronomy Observatory's Cerro Tololo Inter-American Observatory in Chile. The data were processed at the National Center for Supercomputing Applications at the University of Illinois in Urbana-Champaign.

The dark matter released today makes use of early DES observations and covers only about three percent of the area of sky DES will document over its five-year mission. The survey has just completed its second year. As scientists expand their search, they will be able to better test current cosmological theories by comparing the amounts of dark and visible matter.

Cross correlation of mass and light

Those theories suggest that, since there is much more dark matter in the universe than , galaxies will form where large concentrations of dark matter (and hence stronger gravity) are present. So far, the DES analysis backs this up: The maps show large filaments of matter along which visible galaxies and galaxy clusters lie and cosmic voids where very few galaxies reside. Follow-up studies of some of the enormous filaments and voids, and the enormous volume of data, collected throughout the survey will reveal more about this interplay of mass and light.

"Our analysis so far is in line with what the current picture of the universe predicts," Chang said. "Zooming into the maps, we have measured how dark matter envelops galaxies of different types and how together they evolve over cosmic time. We are eager to use the new data coming in to make much stricter tests of theoretical models."

Explore further: Scientists find rare dwarf satellite galaxy candidates in Dark Energy Survey data

More information: View the Dark Energy Survey analysis: deswl.github.io/page1/vikram_p … er/vikram_paper.html

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liquidspacetime
1.4 / 5 (9) Apr 13, 2015
In terms of dark matter, there are two notions which are incorrect. One is that dark matter is a clump of stuff traveling with the matter. The other is that dark matter does not interact with matter.

Dark matter fills 'empty' space. Dark matter is displaced by matter.

The Milky Way moves through and displaces the dark matter.

The Milky Way's halo is the state of displacement of the dark matter.

The state of displacement of the dark matter is otherwise known as the deformation of spacetime.

The Milky Way's halo is the deformation of spacetime,
baudrunner
1.2 / 5 (11) Apr 13, 2015
The map shows a spatial field which is scaled in inch-long units of 100 million light years. Given that there is general understanding that space is curved and that it has a mutable and variable density, it seems logical to assume that there is substantial distortion of the spatial volume between us and all those galactic clusters, and across the field of view, which is a half-billion light years across.

Now just stop and think of those distances. What in the world can one possibly conclude from the observations? Nothing, that's my opinion.
nevermark
3.7 / 5 (12) Apr 13, 2015
Two comments above express gross misconceptions with the boldness of the clueless. Why do science sites attract the willfully scientifically illiterate? Why does anyone want to be willfully ignorant, much less broadcast that?

There was a study on Internet trolls. I would love to see a study on the troll subtype that clutters science comment threads. I suspect the character flaws they found in regular trolls take more specific forms in the science deniers, haters, and self-proclaiming uninformed contrarians. These people are trying to meet some emotional need and science pricks it.
liquidspacetime
1.7 / 5 (6) Apr 13, 2015
It is amazing that mainstream physics is incapable of bringing itself to the understanding 'empty' space has mass which is displaced by the particles of matter which exist in it and move through it.

It is amazing that mainstream physics is incapable of bringing itself to the understanding in a double slit experiment it is the dark matter that waves.
TheOrphan
2.5 / 5 (2) Apr 13, 2015
Which came first the Matter or the Dark Matter ?

Or in other words, is the Dark Matter a product of the Galactic masses or are the masses a product of the Dark Matter ?

If Gravity changes the state of super-void, how can we determine the difference between state changed super-void and dark matter particle masses ?

One possibility is dark matter particle mass would could occlude or amplify gravity.
hillmeister
4.4 / 5 (7) Apr 13, 2015
Trolls are so predictable. I knew they were going to comment on the article before I even read it. Dark matter seems to attract trolls. xD
liquidspacetime
1.6 / 5 (7) Apr 13, 2015
People who consider themselves knowledgeable about mainstream physics are so predictable. They are incapable of understanding in a double slit experiment it is the dark matter that waves; yet they act like they know what they are talking about.
liquidspacetime
1.7 / 5 (6) Apr 13, 2015
Physics is as simple as the following:

Q. Why is the particle always detected traveling through a single slit in a double slit experiment?
A. The particle always travels through a single slit. It is the associated wave in the dark matter that passes through both.
teaching4word
1 / 5 (6) Apr 13, 2015
The hildebegeschnauser troll effect that matter was always here is taken missy
Taken missly by almost all mainstream scios
Trolls on phys.org worked out
When commets implode under the Planck length
They don't fill the intergalactic slot machine.
They're still there and will show us gravity, just splashing about like a smear campaign. We learn
teaching4word
1 / 5 (3) Apr 13, 2015
In particle physics experiments, energy can go into The framework or hole corresponding to a certain particle and if there is not enough energy to fill that hole, less than its corresponding particle, energy seems to have disappeared, but it only lasts for a tiny fraction of a second.Even when particles are not seemingly here, their framework can be. Particles only show when enough energy to create them goes into their corresponding framework. Energy can seem to disappear for an instant. Dark matter may be energy that is not going into any discrete hole for any particle we know. We have also predicted, mathematically, particles with energies many orders of magnitude above those which we have observed.
liquidspacetime
1.7 / 5 (6) Apr 13, 2015
de Broglie said it is the "subquantic medium" that waves in a double slit experiment.

How are you not able to understand that *is* the dark matter?
rfwhiteaker
4.7 / 5 (3) Apr 13, 2015
Dark matter is still a term used to explain many ideas and theories in astrophysics. As of this day dark mass are just words to explain the unknown until really proven.

I believe that we are seeing forces that cannot be measured by us (yet) in action. There are physics that exist inside black holes and beyond the bubble of our own universe that we do not understand. So much is still hidden from our simple eyes and minds.

The dimensions that we perceive now are finite or we could not understand them. Anything or any possibility that is truly infinite we may never be able to understand.
Mimath224
4.5 / 5 (2) Apr 13, 2015
Trolls are so predictable. I knew they were going to comment on the article before I even read it. Dark matter seems to attract trolls. xD

I like this, at least it shows DM 'interacts ' with something, Ha!
As a layman I'm a bit confused about the wording in the article...'Analysis of the clumpiness of the dark matter in the maps will also allow scientists to probe the nature of the mysterious dark energy...' Since DM and DE refer to different 'things' I'm wondering how DM would help to determine DE. Tried the article link for more info but it doesn't seem to work for me...can anyone help? Thanks
TheOrphan
5 / 5 (1) Apr 14, 2015
Here's the pdf MiMath ...
http://deswl.gith..._des.pdf

From what I can tell they are using DES surveys to map mass in given Galaxies.
teaching4word
not rated yet Apr 14, 2015
One star... I spent five years on an MSci and got a first to learn that. You ungrateful....
And the part about energy disappearing is from class. The bigger particles are mathematically predicted, just crossed out like anomalies. Just like antimatter before Dirac.
teaching4word
not rated yet Apr 14, 2015
de Broglie said it is the "subquantic medium" that waves in a double slit experiment.

How are you not able to understand that *is* the dark matter?


I think the word you're looking for would be oscillates unless it's more than one word that needs to be changed.
vidyunmaya
not rated yet Apr 14, 2015
Sub: Comprehension- Cosmic Function of the Universe
The Invisible-Visible matrix modes involve Cosmic Flow distribution in four-flow pattern. See Super-imposition-as well -my paper- COSPAR-2013.
The concepts of Dark Energy need to comprehend above sequential modes in Nature under Cosmic Pot Energy of the Universe-STSCI -2003 by V Nanduri and Carnegie 2003
http://www.scribd...del-2003
http://www.scribd...rse-2003
Gravitational assumptions and Dark matter concepts do not hold much promise at this scale -of Supernovas observations under Ellepticals
Space Cosmology Vedas Interlinks-Cosmology Definition-1 By Vidyardhi Nanduri
http://www.youtub...youtu.be
Introduces Cosmology Defintion, coverpages of 7 books,Purpose of interlinks -all in brief
liquidspacetime
not rated yet Apr 14, 2015
'Interpretation of quantum mechanics by the double solution theory - Louis de BROGLIE'
http://aflb.ensmp...p001.pdf

"When in 1923-1924 I had my first ideas about Wave Mechanics I was looking for a truly concrete physical image, valid for all particles, of the wave and particle coexistence discovered by Albert Einstein in his "Theory of light quanta". I had no doubt whatsoever about the physical reality of waves and particles."

"any particle, even isolated, has to be imagined as in continuous "energetic contact" with a hidden medium"

The hidden medium of de Broglie wave mechanics is the dark mattrt. The "energetic contact" is the state of displacement of the dark matter.

"For me, the particle, ... may be likened in a first approximation, to a moving singularity."

A particle may be likened in a first approximation to a moving singularity which has an associated wave in the dark matter.
gculpex
not rated yet Apr 14, 2015
sounds like aether again.....
liquidspacetime
not rated yet Apr 14, 2015
In the following two articles the aether is what waves in a double slit experiment.

'From the Newton's laws to motions of the fluid and superfluid vacuum: vortex tubes, rings, and others'
http://arxiv.org/abs/1403.3900

"This medium, called also the aether, has mass and is populated by the particles of matter which exist in it and move through it" ...

... and displace it.

'EPR program: a local interpretation of QM'
http://arxiv.org/abs/1412.5612

"Wave particle duality is described as the compound system of point particle plus accompanying wave (in the æther)."
Mimath224
not rated yet Apr 14, 2015
TheOrphan have got the PDF, thanks for the info. Will it read soon
Benni
1 / 5 (1) Apr 14, 2015
Orphan-Mimath:

When Einstein did his calculations for (weak) gravitational lensing in his 1916 thesis on General Relativity, he did not insert a fudge factor like DM to correctly calculate the degree of "bend" that would occur when starlight passes near the disk of the sun, he used his now famous Einstein Field Equations for gravity to predict the exact "lensing effect" calculated from the observable mass of the sun. A few years later it was observed all without the use of cosmic fairy dust.

The paper presented in the link is dominantely focused on "weak lensing" that occurs near galaxy clusters. Well big surprise there, after all you need to go where the gravity is, either giant Ellipticals or something with a near equivalent inherent mass like galaxy clusters. Then for absolutely no reason begins a discussion of lensing effects created by DM to create the observed weak lensing effects. What's the matter with the author of this link, has he never heard of Einstein's GR?

jeffensley
2.3 / 5 (3) Apr 14, 2015
DM theory aside, we should at least be able to use the above map to mark locations where matter/light does not behave how current physics predicts it should. After that it's human imagination. BUT, considering the recent questions about expansion, maybe we don't need to be spending too much intellectual energy trying to prove a phenomena that only exists because of flawed interpretations of observations.
liquidspacetime
not rated yet Apr 14, 2015
... maybe we don't need to be spending too much intellectual energy trying to prove a phenomena that only exists because of flawed interpretations of observations.


Exactly. Here we have evidence of curved spacetime, in the Milky Way's halo, but for some unexplainable reason mainstream physics is incapable of understanding they have what they are looking for: physical evidence of curved spacetime.

All mainstream physics needs to understand is the Milky Way is moving through and displacing the dark matter and many of the fundamental questions facing physics today are answered.

The Milky Way's halo is the state of displacement of the dark matter.

The state of displacement of the dark matter is otherwise known as curved spacetime.

The Milky Way's halo *is* curved spacetime.
liquidspacetime
not rated yet Apr 14, 2015
Incorrect assumptions in mainstream physics:
- Dark matter is a clump of stuff that travels with matter
- Matter does not interact with dark matter

Correct the above and correctly understand what occurs physically in nature.

Dark matter fills 'empty' space and is displaced by matter.

What ripples when galaxy clusters collide is what waves in a double slit experiment; the dark matter.

Einstein's gravitational wave is de-Broglie's wave of wave-particle duality; both are waves in the dark matter.

Dark matter displaced by matter relates general relativity and quantum mechanics.
Benni
1 / 5 (1) Apr 14, 2015
maybe we don't need to be spending too much intellectual energy trying to prove a phenomena that only exists because of flawed interpretations of observations.


......and just what are these "flawed interpretations of observations" you allude to?
liquidspacetime
not rated yet Apr 14, 2015

......and just what are these "flawed interpretations of observations" you allude to?


Thinking dark matter is a clump of stuff traveling along with the matter. Thinking matter does not interact with dark matter ... for starters.

Dark matter fills 'empty' space and is displaced by the matter which exists in it and moves through it.

In a double slit experiment it is the dark matter that waves. What de Broglie referred to as the "hidden subquantic medium" *is* the dark matter.

The Milky Way's halo is not a clump of stuff traveling along with the Milky Way. The Milky Way is moving through and displacing the dark matter. The Milky Way's halo is the state of displacement of the dark matter. The state of displacement of the dark matter is otherwise referred to as curved spacetime.

The Milky Way's halo *is* curved spacetime.
Benni
1 / 5 (1) Apr 14, 2015
DM theory aside, we should at least be able to use the above map to mark locations where matter/light does not behave how current physics predicts it should


So how does the above map indicate locations where matter/light is not behaving in accordance with current physics? The topic is about lensing in the presence of galactic clusters, gravity fields in perfect accord with GR & Einstein's calculations for gravitational lensing versus mass. The mass of our Sun contains exactly the gravity Einstein needed to perfectly calculate gravitational lensing without the need for inclusion of unidentified mass.

The real question becomes a matter of why it is there is this crying need to find DM in places where it is not needed to explain gravitational lensing. When you read through all the noise of these DM narratives, you get the impression that galactic structures exist only where there is DM. Well, how come our solar system can exist within our galaxy with undetectable DM?

liquidspacetime
not rated yet Apr 14, 2015
DM theory aside, we should at least be able to use the above map to mark locations where matter/light does not behave how current physics predicts it should


Current physics predicts the greater the mass of the dark matter the greater the lensing of the light.

What is incorrect in mainstream physics is in thinking the lensing of the light is caused by the mass of the dark matter.

The lensing of the light is caused by the state of displacement of the dark matter.

The state of displacement of the dark matter *is* curved spacetime.
liquidspacetime
not rated yet Apr 14, 2015
Another way to think of it is to understand spacetime has mass.

And the 'dark matter' does exist in our Solar System and it is detected.

The Sun displaces it. It's state of displacement *is* curved spacetime.
Benni
1 / 5 (1) Apr 14, 2015
And the 'dark matter' does exist in our Solar System and it is detected
How was it detected?

The Sun displaces it. It's state of displacement *is* curved spacetime.
The Sun displaces DM? How does it do this & what do you mean by "displacement"?
jeffensley
1 / 5 (1) Apr 14, 2015
......and just what are these "flawed interpretations of observations" you allude to?


My understanding (which is admittedly limited) is that dark matter/energy was mainly devised as an explanation for expansion, to account for behavior that simple observations of bodies emitting some form of electromagnetism didn't. Stepping back once again, the expansion theory is mainly founded up on the redhshift of light. Perhaps there's an alternate explanation for that phenomena? This is purely theoretical of course but when all we are going on is light wavelength, we should leave room open for the possibility that we are "seeing" it wrong. Some theories can crumble like a house of cards when the observation they are based off of proves faulty.

http://phys.org/n...rse.html
jeffensley
1 / 5 (1) Apr 14, 2015
Somehow this link got omitted from my previous post. It doesn't discount our interpretation of redshift altogether but it illustrates some weaknesses and suggests the possibility that expansion isn't happening as quickly as we thought.

http://phys.org/n...ast.html
liquidspacetime
not rated yet Apr 14, 2015
How was it detected?


You understand the notion of curved spacetime, correct? You understand the Earth orbits the Sun because the Sun curves spacetime, correct? Curved spacetime physically exists in nature as the state of displacement of the dark matter.

So, since you are able to understand the Earth orbits the Sun because the Sun curves spacetime you are at the same time understanding the Sun displaces the dark matter which causes the Earth to orbit it.

The Sun displaces DM? How does it do this & what do you mean by "displacement"?


A submarine moves through and displaces the ocean water. The Sun moves through and displaces the dark matter. The dark matter behaves like a supersolid and pushes back. The pushing back *is* gravity.
jeffensley
1 / 5 (1) Apr 14, 2015
So you're saying that dark matter is basically what holds 3-dimensional "space" apart. Is that the accepted definition or your theory? I've always had the impression that dark matter was like an undetectable celestial body with mass, whose gravity was influencing visible bodies.
liquidspacetime
5 / 5 (1) Apr 14, 2015
I am saying that dark matter fills 'empty' space and is displaced by the particles of matter which exist in it and move through it.

I am saying that we are fish who refuse to understand we exist in water.

Dark matter is now understood to fill what would otherwise be considered to be empty space.

'Cosmologists at Penn Weigh Cosmic Filaments and Voids'
http://www.upenn....nd-voids

"A long standing mystery on where the missing dark matter is has been solved by the research. There is no empty space in the universe. The intergalactic space is filled with dark matter."

Another way to think about it: Spacetime has mass.
jeffensley
1 / 5 (1) Apr 14, 2015
Thanks for the link. Very interesting. So what this suggests (to my brain anyway) is that gravity works differently depending on the "medium". A void doesn't transmit the force of gravity the way it should if it dispersed itself evenly across space. It needs particles (masses) to communicate across space? So the phrase "nature abhors a vacuum" takes on a different meaning with voids. By abhorring it means it actually avoids it as opposed to attempting to fill it? I'm just thinking out loud, trying to better understand. Maybe like a little oil in water...except like you said, we can't see the water, only the oil (matter as we know it).
liquidspacetime
1 / 5 (1) Apr 14, 2015
I avoid the term 'void' as where there is no matter, there is dark matter. As far as we know, there is no 'space' which doesn't have mass. Either the space contains the mass associated with the matter or the space contains the mass associated with the dark matter.

Let me try a visualization.

Think of the Universe as being filled with a supersolid (which is the dark matter). Think of the particles of matter as moving through and displacing the supersolid. The supersolid pushes back and exerts inward pressure toward the particles. When you get to something as large as the Earth, the supersolid displaced by the Earth which is pushing back and exerting inward pressure toward the Earth *is* gravity.
jeffensley
1 / 5 (1) Apr 14, 2015
Makes sense... thank you for the visualization. But my analogy holds right? Like oil and water, matter and dark-matter don't directly interact except at their interface, where they exert "pressure" on each other? So dark matter wants to fill every gap in matter, even the spaces between an electron and its nucleus and the only thing that keeps it together is its electrostatic attraction? Wow, so that explains why the greater the density, the greater the differential, dark matter being squeezed out from between atoms... the greater the gravity. Still.... it's hard for me to picture an invisible liquid pushing down on me at all times.
liquidspacetime
not rated yet Apr 14, 2015
Yes, your analogy holds. As of today, I think the displacement takes place at the quark level. The more quarks which exist within a volume the less dark matter exists in the volume the greater the displacement of the dark matter from the volume the greater the pressure exerted toward and throughout the volume by the dark matter.
Returners
1 / 5 (1) Apr 14, 2015
Anything regarding DE or DM is suspect in light of the recent paper on Type 1a supernova actually being more than one type. Until further study is done to recharacterize the nature of these events and the measurements made using them we should consider DE and DM discussions suspect.

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