Fermi observations of dwarf galaxies provide new insights on dark matter

Apr 02, 2012 b yFrancis Reddy
This dwarf spheroidal galaxy in the constellation Fornax is a satellite of our Milky Way and is one of 10 used in Fermi's dark matter search. The motions of the galaxy's stars indicate that it is embedded in a massive halo of matter that cannot be seen. Credit: ESO/Digital Sky Survey 2

(PhysOrg.com) -- There's more to the cosmos than meets the eye. About 80 percent of the matter in the universe is invisible to telescopes, yet its gravitational influence is manifest in the orbital speeds of stars around galaxies and in the motions of clusters of galaxies. Yet, despite decades of effort, no one knows what this "dark matter" really is. Many scientists think it's likely that the mystery will be solved with the discovery of new kinds of subatomic particles, types necessarily different from those composing atoms of the ordinary matter all around us. The search to detect and identify these particles is underway in experiments both around the globe and above it.

Scientists working with data from NASA's Fermi Gamma-ray have looked for signals from some of these hypothetical particles by zeroing in on 10 small, faint galaxies that orbit our own. Although no signals have been detected, a novel analysis technique applied to two years of data from the observatory's Large Area Telescope (LAT) has essentiall"In effect, the Fermi LAT analysis compresses the theoretical box where these particles can hide," said Jennifer Siegal-Gaskins, a physicist at the California Institute of Technology in Pasadena, Calif., and a member of the Fermi LAT Collaboration. Earlier today, she discussed the latest results of space-based searches in an invited talk at a meeting of the American Physical Society (APS) in Atlanta, Ga.

, or Weakly Interacting , represent a favored class of dark matter candidates. Some WIMPs may mutually annihilate when pairs of them interact, a process expected to produce -- the most energetic form of light -- that the LAT is designed to detect.

"One of the best places to look for these faint gamma-ray signals is in dwarf spheroidal galaxies, small satellites of our own Milky Way galaxy that we know possess large amounts of dark matter," Siegal-Gaskins explained. "From an astrophysical perspective, these are downright boring systems, with little gas or star formation and no objects like pulsars or supernova remnants that emit gamma rays."

In addition, many dwarfs lie far away from the plane of our galaxy, which produces a broad band of diffuse gamma-ray emission that all around the sky. Selecting only dwarf galaxies at great distances from this plane helps minimize interference from the Milky Way. y eliminated these particle candidates for the first time.

The team examined two years of LAT-detected gamma rays with energies in the range from 200 million to 100 billion electron volts (GeV) from 10 of the roughly two dozen dwarf galaxies known to orbit the Milky Way. Instead of analyzing the results for each galaxy separately, the scientists developed a statistical technique -- they call it a "joint likelihood analysis" -- that evaluates all of the galaxies at once without merging the data together. No gamma-ray signal consistent with the annihilations expected from four different types of commonly considered WIMP particles was found.

This video is not supported by your browser at this time.
Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientific instrument. This animation shows a gamma ray (purple) entering the LAT, where it is converted into an electron (red) and a positron (blue). The paths of the particles point back to the gamma-ray source. The LAT maps the whole sky every three hours. (Credit: NASA's Goddard Space Flight Center)

For the first time, the results show that WIMP candidates within a specific range of masses and interaction rates cannot be dark matter. A paper detailing these results appeared in the Dec. 9, 2011, issue of Physical Review Letters.

"The fact that we look at 10 dwarf galaxies jointly not only increases the statistics, but it also makes the analysis much less sensitive to fluctuations in the gamma-ray background and to uncertainties in the way the dark matter may be distributed around the dwarfs," said Maja Llena Garde, a graduate student at Stockholm University in Sweden and a co-author of the study.

For any given properties of a dark matter particle, the distribution of the particles has a significant impact on the expected gamma-ray signal, a wrinkle that often is handled inadequately, if at all, in previous studies.

The motions of a dwarf galaxy's stars trace out the profile of the massive dark matter halo in which they're embedded, but these tiny galaxies often have very few stars to track. The result is uncertainty in the way dark matter is distributed along the line of sight to the dwarf, which affects the expected flux of gamma rays detected by the LAT. By addressing uncertainties in the dwarfs' dark matter profiles, the LAT team's results are among the most accurate.

"An important element of this work is that we were able to take the statistical uncertainties from an updated study of the dwarf stellar motions and factor it into the LAT data analysis," said Johann Cohen-Tanugi, a physicist at the Laboratory of the Universe and Particles at the University of Montpellier 2 in France and a member of the research team.

"This treatment constitutes a significant step forward, and we hope that future studies will follow our example," noted co-author Jan Conrad, a physics professor at Stockholm University.

The team is in the process of following up the two-year analysis with new ones that will incorporate additional observing time, improvements made to the LAT's sensitivity and the inclusion of higher-energy gamma rays. Additionally, sky surveys now ramping up may discover new that can be included in future studies.

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Pyle
2.8 / 5 (11) Apr 02, 2012
HAHAHAHAHA
The result is uncertainty in the way dark matter is distributed along the line of sight to the dwarf, which affects the expected flux of gamma rays detected by the LAT.

Basically they didn't find what they weren't sure they were looking for, but they are very sure they didn't see what they weren't sure they should have been expecting.

All in all very solid science!!!

Unfortunately without a better clue our theorists waffle quite a bit trying to gather observational confirmation of their hypotheses.

dogbert
2.6 / 5 (16) Apr 02, 2012
One of the few studies seeking to find dark matter which admits it did not find it. The article still presumes it exists, but the study failed to find it.

I wonder when we will stop presuming something which we cannot find exists.
Teneca
1 / 5 (7) Apr 02, 2012
IMO the dark matter is formed mostly with neutrinos, the another components are axions and positrons and ionized atom nuclei (which are positively charged too, so they defy the gravity). But because the neutrinos play a role of supersymmetric counterpart of photons in dense aether model (the photons are solitons of transverse waves, whereas the neutrinos are soliton of gravitational, i.e. longitudinal waves of vacuum), their rest mass can change in wide range depending on their frequency/energy - they're chameleon particles.
mattytheory
4.9 / 5 (14) Apr 02, 2012
Maybe, dogbert, when they have built experiments that can directly test all of the hypotheses. However, since scientists have yet to accomplish this feat, DM theories will persist. And, even if all DM theories are disproven, there is still the effect that DM purports to account for that will need to be explained, somehow, by another theory.

Also, if you had actually read the article, you would notice "For the first time, the results show that WIMP candidates within a specific range of masses and interaction rates cannot be dark matter". Simply, the experiment has shown evidence against only certain theories about certain WIMPS in a certain mass range.

Personally, I have always been suspect of the DM and DE theories. They just seem strange to me. Then again, I am a layperson. So I will trust that the learned population (ie: the scientists that spent years going to school and spent many more years researching, formulating, and testing their theories) know what they are doing.
StarGazer2011
3.9 / 5 (14) Apr 02, 2012
Im no fan of the DM hypothesis, esspessially the WIMP version, but this seems like pretty solid science to me. Kudos to LAT team.
TabulaMentis
1.7 / 5 (6) Apr 02, 2012
Personally, I have always been suspect of the DM and DE theories. They just seem strange to me. Then again, I am a layperson. So I will trust that the learned population (ie: the scientists that spent years going to school and spent many more years researching, formulating, and testing their theories) know what they are doing.
The best way to figure out things one does not know is to create a bottom-up and a top-down single line diagram with all of the possiblities and delete what does not fit. My models call for DE and DM. After all, what else would it be, Tinker Bell and the Seven Dwarfs?
Pyle
3.6 / 5 (9) Apr 02, 2012
matty, the problem with directly testing all of the hypotheses is that for most of them we don't even know what that means. DM, and DE for that matter, are plugs to explain our cosmological observations. We have some equations that work when we input some mysterious "dark matter" but we don't really know the properties of it other than it makes galaxies move the way galaxies appear to move.

Part of science is challenging the established explanations of things and providing evidence to refine the models. In the case of Dark Matter, to many of us, it seems that not enough challenging has been done. Especially given that there aren't any "micro" observations that support that DM even exists. We search and search for "particles" that could be DM while other explanations languish in obscurity.

Ok, I just want more work done on MOG, but everybody should be entitled to a pet theory.
Twin
3.3 / 5 (10) Apr 02, 2012
DM Theory assigns the observed effects to matter.
Just because all "known" gravity is associated with matter, it does not follow that all gravity is associated with matter.
The very name of the theory limits the investigation of it's causes.
middley
5 / 5 (3) Apr 02, 2012
We can't rule out Thetans.
Twin
4.2 / 5 (5) Apr 02, 2012
That MIGHT be stretching my point just a little.
determinist
1 / 5 (4) Apr 02, 2012
DM Theory assigns the observed effects to matter.
Just because all "known" gravity is associated with matter, it does not follow that all gravity is associated with matter.
The very name of the theory limits the investigation of it's causes.


Great point! Also the 'knowledge' of the scientific community may keep them in the box. I have a feeling (intuition) that we need to go to the next level for the DM or DE solution. Historically, the body science has been quite presumptuous, has it not?
Short bloke
2.5 / 5 (2) Apr 03, 2012
Twin. If you go to the General Science Journal and download free the research paper on Matter and Associated Mysteries; download number4039, you will find that gravity influences every particle of matter or antimatter, dark or otherwise. All logical reasons are provided.
With regards the research on Dwarf galaxies; the researchers are being honest when making their report, and that should be appreciated.
CardacianNeverid
4.3 / 5 (12) Apr 03, 2012
HAHAHAHA. Basically they didn't find what they weren't sure they were looking for, but they are very sure they didn't see what they weren't sure they should have been expecting -gomerPyle

DM properties are continually being refined. This research is a fine example. And when we get to the bottom of it, I'm sure you'll shout "Surprise, Surprise, Surprise!"

IMO the dark matter is formed mostly with neutrinos...But because the neutrinos play a role of supersymmetric counterpart of photons in dense aether model [snip] -TenecaTard

Wot, another sockpuppet ZephirAWT/beelize54/rawa1/Callippo/Kinedryl???

Just because all "known" gravity is associated with matter, it does not follow that all gravity is associated with matter -TwinTard

Energy, too.

I have a feeling (intuition) that we need to go to the next level for the DM or DE solution. Historically, the body science has been quite presumptuous, has it not? -indeterminateTard

No, tard boy. DM and DE are unrelated.
rah
2 / 5 (4) Apr 03, 2012
I am really thankful that no false coloring was added to any images which accompanied this report. There has been an epidemic of false colorizing images in the last few years. It has bordered on fraud but hopefully it may be being stopped. Next up, having people with no new subject knowledge show some manners when posting their comments.
rah
4 / 5 (4) Apr 03, 2012
We can't rule out Thetans.

Here, take all my money please. Am I better?
CardacianNeverid
3.6 / 5 (10) Apr 03, 2012
I am really thankful that no false coloring was added to any images which accompanied this report. There has been an epidemic of false colorizing images in the last few years. It has bordered on fraud but hopefully it may be being stopped. -rahrahTard

You realise, my dim little fellow, almost all astronomical pictures are 'false' colored? It not only depends on which filters are used (which don't necessarily mirror what the eye can see) but also to highlight frequencies outside of the visible spectrum, like X and gamma rays. What a tard - oh pardon my manners, that was impolite.

bluehigh
2.7 / 5 (7) Apr 03, 2012
you will find that gravity influences every particle of matter or antimatter
- Short bloke

That is twisted. You would need to find a gravitational field that exists without Mass (or equiv Energy) to validate that statement.

Every particle of matter influences the geometry of space-time and is perceived as gravitational force.

bluehigh
3.2 / 5 (9) Apr 03, 2012
What do you call that Vendi, when you jumble around the letters of one word to make another. eg: Vendicar Decarian and Cardacian Neverid? Theres a word for that. Don't let the virtual split personality manifest into a problem or is it too late?
Pardon manners, impolite!! What have they done to you?

MarkyMark
5 / 5 (1) Apr 03, 2012
We can't rule out Thetans.

Here, take all my money please. Am I better?

Yes my readings show a definate benifitial improvement. To take advantage of this i advise you enter into one of ower monthly donation plans that simple and for your convenience transfers your monthly wage packet to a special account where we take a pre-aproved donation from your wage packet before transfering it to your public account.

This will ensure that you can attend regular Thetan Measurements and treatment and a limited membership into ower Scientific Cul-er Church.
Husky
5 / 5 (1) Apr 03, 2012
so, they finally found my hidden dyson sphere.
jsdarkdestruction
5 / 5 (4) Apr 03, 2012
DM Theory assigns the observed effects to matter.
Just because all "known" gravity is associated with matter, it does not follow that all gravity is associated with matter.
The very name of the theory limits the investigation of it's causes.


no it does not. have you heard of mond or mog? both are alternatives proposed to account for the dark matter effect.
Kinedryl
not rated yet Apr 03, 2012
No, tard boy. DM and DE are unrelated
Says who? Another tard boy? There are peer-reviewed theories, they're the two sides of the same stuff.

http://www.scienc...4056.htm
Vendicar_Decarian
0 / 5 (35) Apr 03, 2012
"Theres a word for that." - BlueHigh

It's called "fandom".

Fandom is a term used to refer to a subculture composed of fans characterized by a feeling of sympathy and camaraderie with others who share a common interest.
Vendicar_Decarian
0.2 / 5 (37) Apr 03, 2012
Dark matter - Speculation - Low density plasma consisting of ionized particles high density hydrogen ice perhaps 1000 molecules in mass surrounded by a low density electron gas.
StarGazer2011
1 / 5 (2) Apr 03, 2012
Dark matter - Speculation - Low density plasma consisting of ionized particles high density hydrogen ice perhaps 1000 molecules in mass surrounded by a low density electron gas.


Holy Jeebus, i agree with Vendicar! :)
bluehigh
1 / 5 (1) Apr 03, 2012
Aha .. excellent Vendi, so you like Pineapples too.

What is 'hydrogen ice'?
Graeme
not rated yet Apr 03, 2012
Vendicar_Decarian > AFIK those hydrogen ion clusters are not stable with multiple positive charges. But they have been made with over 100 atoms in them, and with one positive charge. This should still show some kind of absorption or emission spectrum that can be detected. So it should be possible to rule in or out in future. Hydrogen snow clouds would only be possible if it was really cold.
elginz
2 / 5 (4) Apr 03, 2012
Why is th obvioius simple solution to dark matter being ignored. Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.
Kinedryl
not rated yet Apr 03, 2012
Heck there could be galaxies of this stuff out there.
These bodies can be and are observed, but they're rather rare. http://www.univer...covered/
sirchick
5 / 5 (2) Apr 03, 2012
Why is th obvioius simple solution to dark matter being ignored. Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.


Would it not be more obvious to think the top scientists have probably considered the possibility and tried to observe it ?
TabulaMentis
1 / 5 (1) Apr 03, 2012
IMO the dark matter is formed mostly with neutrinos.
You are halfway correct. Follow those neutrinos and you will find DM.

We can't rule out Thetans.
It would take a lot of Thetan particles to create a soul.

No, tard boy. DM and DE are unrelated.
DM is a product of DE. I am now convinced you and your alias twin are members of the KGB.

No it does not. Have you heard of mond or mog? Both are alternatives proposed to account for the dark matter effect.
You need to keep up with the latest news on MOG and MOND. What you are proposing is not possible.
elginz
not rated yet Apr 03, 2012
Why is th obvioius simple solution to dark matter being ignored. Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.


Would it not be more obvious to think the top scientists have probably considered the possibility and tried to observe it ?

elginz
2.3 / 5 (3) Apr 03, 2012
Just because scientests have tried to observe the non-reflective ordinary matter but have failed doesn't mean it doesn't exist. To say that if you try to obseve something but can't, thus proving it doesn't exist is thinking out or the dark ages.

Why is th obvioius simple solution to dark matter being ignored. Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.

Would it not be more obvious to think the top scientists have probably considered the possibility and tried to observe it ?


Kinedryl
4 / 5 (2) Apr 03, 2012
Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.
The dark matter is routinely detected with its gravitational lensing effects or rotational curves of galaxies. The physicists aren't therefore dependent on the reflectivity of non-reflective bodies at all.
elginz
1 / 5 (2) Apr 03, 2012
I'm sorry, did I fail to mention that non-reflective ordinary matter would behave ordinarly when it comes to gravity?

Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there. The dark matter is routinely detected with its gravitational lensing effects or rotational curves of galaxies. The physicists aren't therefore dependent on the reflectivity of non-reflective bodies at all.

eezee
not rated yet Apr 03, 2012
LOL, did bacteria only come into existence once the micorscope was invented?

I'm sorry, did I fail to mention that non-reflective ordinary matter would behave ordinarly when it comes to gravity?

Non-reflective bodies of ordinary matter we simply can't see or detect. Heck there could be galaxies of this stuff out there.
The dark matter is routinely detected with its gravitational lensing effects or rotational curves of galaxies. The physicists aren't therefore dependent on the reflectivity of non-reflective bodies at all.


Ventilator
not rated yet Apr 03, 2012
Considering the fact that Dark Matter is difficult to find, and gravity reveals its presence, could Dark Matter be cold, absolute zero matter that's essentially stalled out? Just a thought I had, might be wrong but it seems quite possible to me.

While I like the Dark Matter low density speculation by Vendicar, it seems more likely that without the actual gravitational effects that Dark Matter has on what's around it, we can't truly know what DM might be.
Pyle
not rated yet Apr 03, 2012
TabulaMentis:
You need to keep up with the latest news on MOG and MOND. What you are proposing is not possible.
Huh? With respect to MOND, yes, they poked holes through it, but in the end it was just a fudge factor anyway.

With MOG it is an entirely different creature. MOG is a modification of the Einstein field equations, introducing a fifth force to counteract gravity at smaller distances. Even more so than with GR the MOG field equations are unwieldy. It is parameterless, meaning there isn't some arbitrary constant to fit it to observations as with MOND. Right now, my understanding, is that work on MOG is stalled because it doesn't receive any attention and the tests to differentiate it from GR aren't within our technical grasp yet.

Ultimately the switch to other theories won't gain momentum until we exhaust our search for DM. Much as our continuing failure to find the Higgs is leading to alternative hypotheses for the origin of gravity.
Teneca
1 / 5 (2) Apr 03, 2012
In dense aether model the particles are similar to foamy cups at the stormy water surface. They're essentially a solitons formed with mutual interference of surface and underwater waves, whereas the surface ripples prevail. But we can have another kind of solitons, so-called the Falaco solitons. These solitons deform the water surface in the opposite way, because they're formed mostly with underwater waves. Note that, with respect of surface ripples, both types of solitons deform the water surface and increase its specific area in such a way, the surface ripples are passing more slowly trough both of them - both kinds of solitons appear like massive bodies and they exhibit the same form of gravitational lensing. In aether model these solitons correspond particles and antiparticles and the dark matter is formed preferably with antiparticles.
TabulaMentis
1 / 5 (1) Apr 03, 2012
@Pyle:

The one thing I like about John Moffat's MOG is the idea of a fifth force, but in the form of a Z2 boson. However, replacing DE entirely with MOG will not work, IMO. IMO the Higgs field is created by DE and it is only of a matter of time before the Higgs boson is found.
Teneca
2.3 / 5 (3) Apr 03, 2012
In aether model the gravity force results in similar way, like the shielding force, which collides the boats together at the stormy sea. The shielding of surface ripples is analogous to the Casimir force, which manifest itself at short distances. And the shielding of underwater waves corresponds the gravity force. Because underwater waves are spreading a way faster, than the surface ripples, this shielding manifest at the larger distances. Between massive objects a relative deficiency of underwater waves exists, which pulls them together. But other massive objects are applying and they're shielding the underwater waves too - which creates a relative abundance of underwater waves, which do manifests with increased concentration of Falaco solitons around massive objects, i.e. dark matter. At the water surface these effects are very minute because of its low energy density, but the energy density of material objects and vacuum is way higher, so these effects are way more pronounced there.
Pyle
not rated yet Apr 03, 2012
@TM:
The work on MOG is incomplete, but I don't see how it can progress without scientists working on the problem. There is a limit to what a theorist, a mathematician and a few doctoral candidates can accomplish.

I'm not sure I fully understand the DE/Higgs field work being done despite trying to plow through it. The connection between expansion and gravity would make sense given the weak/electro/strong/gravity connections made evident through M theory.

Your earlier conflating MOND and MOG is off though. They are fundamentally very different. MOND, in Moffat's words, is "phenomenological" and the attempts to fit theory around the MOND parameter are "contrived".

MOG, however, is a fully relativistic modification of GR that has been shown to be at least roughly consistent with the universe around us (local gravitational effects, galaxy rotation, clusters, gravitational lensing, power spectrum, etc.) w/o Dark Matter. (Still needs DE for expansion.)
CardacianNeverid
5 / 5 (2) Apr 04, 2012
You are halfway correct. Follow those neutrinos and you will find DM -TabulaMental

References?

It would take a lot of Thetan particles to create a soul -TabulaMental

Or exactly none.

DM is a product of DE -TabulaMental

So sure you are, hrmmm? The crazy is strong with this one.

I am now convinced you and your alias twin are members of the KGB -TabulaMental

Nyet!

Have you heard of mond or mog? Both are alternatives proposed to account for the dark matter effect
You need to keep up with the latest news on MOG and MOND. What you are proposing is not possible -TabulaMental

Well, that at least is true - Huzzah!
CardacianNeverid
4.8 / 5 (5) Apr 04, 2012
Just because scientests have tried to observe the non-reflective ordinary matter but have failed doesn't mean it doesn't exist. To say that if you try to obseve something but can't, thus proving it doesn't exist is thinking out or the dark ages -elginzTard

You have no idea what you're babbling about. It is NOT possible for ordinary but so far undiscovered normal matter to produce effects we observe.

Why is th obvioius simple solution to dark matter being ignored -elginzTard

Because it is stupid beyond belief, tard boy. Ferchrissakes, just do a basic wiki search!
CardacianNeverid
5 / 5 (2) Apr 04, 2012
With respect to MOND, yes, they poked holes through it, but in the end it was just a fudge factor anyway -gomerPyle

So you acknowledge one fudge, but...

With MOG it is an entirely different creature. MOG is a modification of the Einstein field equations, introducing a fifth force to counteract gravity at smaller distances -gomerPyle

...but you don't think that inventing a whole another force of nature isn't an even bigger fudge?
Vendicar_Decarian
0.1 / 5 (35) Apr 04, 2012
Interstellar Solid Hydrogen (Hydrogen Ice)

http://arxiv.org/abs/1105.1861

Spectroscopic Evidence of Interstellar Solid Hydrogen

http://www.mpa-ga...2085.pdf

Interstellar Solid Hydrogen: How Much and Where?

http://www.nature...7a0.html
bluehigh
1 / 5 (1) Apr 04, 2012
Thank you for the links, Mr Decarian.

I am now convinced you and your alias twin are members of the KGB.
- 007

I repeat. How come you get all the good gigs Vendi?
KGB fandom too!

Shinichi D_
not rated yet Apr 04, 2012
Just an idea. Could DM be a feature of space itself? I mean, maybe the fabric of spacetime isn't "springy" at certain scales, but rather behaves like a memory foam? It carries a dent, massive objects leave behind.
Kinedryl
1 / 5 (1) Apr 04, 2012
Just an idea. Could DM be a feature of space itself? I mean, maybe the fabric of spacetime isn't "springy" at certain scales, but rather behaves like a memory foam? It carries a dent, massive objects leave behind.

Dark matter is hyperdimensional stuff and it gives the vacuum fluid a slimy behaviour of non-Newtonian fluids. The fibres of dark matter around galaxies exhibit Rayleigh-Plateau and Gregory-Laflamme instabilities typical for hyperdimensional non-Newtonian fluids (they're connecting the galaxies with fibbers in similar way, like the droplets of slime are connected with fibers of slime) (1, 2)
Pyle
not rated yet Apr 04, 2012
@Imitation Canadian:
...but you don't think that inventing a whole another force of nature isn't an even bigger fudge?

Nope. Not a fudge.

Taking gravity at a certain scale and adding an arbitrary constant to modify the force strength so that the formulas still work for galaxy rotation is a fudge.

Adding some mysterious substance that is invisible and can't be detected except by its gravity and adding it in just the right amount to explain our observations is a fudge.

Adjusting Einstein's field equations, adding a fifth force to those equations, is much more than a fudge. Did the early precursors to MOG look more like a fudge? Maybe. But where the theory stands stands now is as an overlooked alternative that will, IMO, still be waiting for confirmation or rejection once we decide there isn't any mysterious dark matter out there that can explain our anomalous observations of galaxy rotation curves and gravitational lensing.
Pyle
not rated yet Apr 04, 2012
@Angry Canadian:

blather about solid hydrogen


Don't the CMB measurements from WMAP (5 and 7 year analyses) suggest that your solid hydrogen idea isn't the right answer?

(Note that MOG was shown to be not inconsistent with the power spectrum measured in the CMB.)
Vendicar_Decarian
0 / 5 (35) Apr 04, 2012
Yes. I have Anna Chapmen cooking me dinner right now.

"I repeat. How come you get all the good gigs Vendi?
KGB fandom too!" - BlueHigh

http://www.google...p;ty=107
brodix
1 / 5 (1) Apr 07, 2012
Here is one for the speculative category:
What is gravity, but spatial contraction associated with mass.
Mass and energy are convertible. E=mc2.
When we convert mass into energy, it creates a noticable expansion; Think nuclear explosion.
So what happens when energy converts to mass? Does it create some form of contraction?
Could gravity be due, not so much to the static existence of mass, but the active creation of it?
Obviously stars are converting lots of mass into energy and radiating it out over billions of lightyears, but they also have significant gravity fields. Could this be due to the creation of ever more dense and complex atomic structure, ie, that they are also converting energy into mass?
So on the perimeters of galaxies, where all this interstellar gas is collapsing into stars, could the gravity fields be due, not to the current existence of mass, but the rather active creation of it?
brodix
1 / 5 (1) Apr 07, 2012
continued:
We think of photons as point particles, because that is how they interact with atomic structure. When released from atoms, could it be that light expands and then contracts back when absorbed? This might explain the wave behavior.
So light released expands(C squared) and if absorbed it contracts, would this create a vacuum we experience as gravity?
Shootist
1 / 5 (1) Apr 07, 2012
DM Theory . . .
The very name of the theory limits the investigation of it's causes.


No it does not. Dark = cannot be seen. Matter = galaxies angular momentum is greater than the mass visible matter can account for.

Good name.

HannesAlfven
1 / 5 (4) Apr 07, 2012
Dark matter is the indirect product of faulty cosmic plasma models. Hannes Alfven invented MHD in the early 1940's. After three decades of working with plasmas in the laboratory, he came to see these models as "pseudo-pegagogical". But, those ideas he created remained wildly popular. And despite advocating a more modern view of cosmic plasmas repeatedly, and even within his Nobel acceptance speech in 1970, there is simply no desire amongst establishment astrophysicists to consider taking a step back, in order to collectively move forward.

David Talbott's Edge Magazine article did a fantastic job of covering this subject ...

http://www.scient...e_09.pdf

When cosmic plasmas are modeled as laboratory plasmas - with some small resistance, E-fields and double layers - gravity simply stops being the dominant force. Birkeland currents can transport the electric force to infinite distances.
Twin
1 / 5 (1) Apr 07, 2012
"No it does not. Dark = cannot be seen. Matter = galaxies angular momentum is greater than the mass visible matter can account for."

Matter = assumption that matter is the cause of the anomalous gravitational effects.
A2G
1 / 5 (2) Apr 07, 2012
"Matter = assumption that matter is the cause of the anomalous gravitational effects."

Even saying "gravitational effects" is already making assumptions. It is not now clearly understood why what we see in space looks the way it does. What if gravity is not the real force responsible? What if everyone is looking at the whole thing entirely wrong because of how the questions are always framed?

jsdarkdestruction
not rated yet Apr 08, 2012
No it does not. Have you heard of mond or mog? Both are alternatives proposed to account for the dark matter effect.
You need to keep up with the latest news on MOG and MOND. What you are proposing is not possible.

Um, it already happened. Mog and mond have been proposed as an alternative to unseen matter being the cause of the dark matter effect. so that pretty obviously shows the statement that dark matter as a term is stopping people from looking at alternatives to the dark matter effect that do not involve unseen matter of some sort.
jsdarkdestruction
5 / 5 (1) Apr 08, 2012
"No it does not. Have you heard of mond or mog? Both are alternatives proposed to account for the dark matter effect.
You need to keep up with the latest news on MOG and MOND. What you are proposing is not possible."

Um, it already happened. Mog and mond have been proposed as an alternative to unseen matter being the cause of the dark matter effect. so that pretty obviously shows the statement that dark matter as a term is stopping people from looking at alternatives to the dark matter effect that do not involve unseen matter of some sort is false.

fixed it.
Tennex
not rated yet Apr 08, 2012
IMO the general relativity is not flawed, because it's initial principles are wrong, but because they're not used consequentially. At the case of Einsteinian field equations it's understandable, because Einstein had no time and rigor experience to derive complete formulation of his theory, due the complexity of the resulting equations. For example, only few people do realize, that the general relativity cannot account to attraction of infinitely large slabs: because there is no curvature of space-time, there cannot be some attractive force - no matter, how the slabs are actually heavy. Which indeed makes a problem, because it would mean, that the gravity of large massive spheres should cease to zero with increasing size of these spheres: which is apparently in disagreement with practical observations.
Tennex
5 / 5 (1) Apr 08, 2012
The math of Einstein's theory is very complex, but some caveats of it may be understood even with laymans. For example, the Einstein's relativity says, the curvature of space-time is equivalent to energy of gravity field. But this energy is not applied anywhere in the theory, although the same relativity implies, that every energy corresponds some mass by famous E=mc^2 equation. The energy of gravity field should therefore manifest like sparsely divided matter and it should account to the resulting gravity too. This contribution is neglected in field equations, because it would make them too complex. Because the field around massive bodies is essentially flat at their center (the gravitational force is zero there in the same way, like at the distant vacuum), the maximal gradient of gravity field is not at the center of massive objects (as general relativity implies) - but around their surface. The mass/energy density of gravitational field should be therefore maximal there too.
Tennex
5 / 5 (1) Apr 08, 2012
From some modifications of relativity (Yilmaz, Beckenstein) follows, the mass density of gravitational field could account to the dark matter, which manifests itself just OUTSIDE of massive objects too. The rotational curves of stars are violating the relativity just at the perimeter of galaxy, the inner region fills the relativity well. One problem is, the mass of gravity field violates the another postulate of relativity, the equivalence principle. If we take the spheres of the same mass but of different radius, then the mass of gravity field will be larger around smaller more dense sphere, because the gradient of gravity field is larger here. This component of gravity field is therefore dependent on the size of objects, not on their mass only - which is in direct contradiction with equivalence principle, in which the gravitational action of mass shouldn't be different from its inertia. Therefore the rock-steady relativists tend to neglect these modifications of relativity.
Tennex
3 / 5 (2) Apr 08, 2012
But what experiments actually say? Many observations do indicate, the above interpretation may be actually correct, because the Pioneer anomaly and/or various fly-by anomalies attributed to dark matter manifest itself just for smaller bodies, but not for larger planets. If they would manifest for large planets, we would detect it already, because we are capable to measure their motion in very precious way.

Therefore the relativistic physics is in certain schizophrenia. It already has the models, which could be derived from general relativity with incorporating of additional equations (which do follow from general relativity as well, after all) and which fit the various observations well - but it cannot accept them, or the final solution would violate the fundamental postulates of general relativity, like the equivalence principle. After all, like the dark matter itself.
Tennex
not rated yet Apr 08, 2012
BTW The various extensions of quantum mechanics, like the string theory suffer with the same schizophrenia, just in dual extent. For example, the recent observations of superluminal neutrinos could be explained with assumption of extradimensions, on which string theory is based. But the superluminal neutrinos do violate another postulate of string theory, on which the string theory is based too: the postulate of Lorentz invariance.

As we can see, we have another theory, which cannot be applied for the recent observations, just because these observations do violate another postulate of it.
HannesAlfven
1 / 5 (1) Apr 08, 2012
Re: "IMO the general relativity is not flawed, because it's initial principles are wrong, but because they're not used consequentially."

History of science brings clarity where confusion reigns. Look at the timeline, and it becomes completely clear that Einstein had no idea whatsoever that space was filled with charged particles when he originated Relativity. Astrophysicists changed the universe's preferred state for matter, and have attempted to convince the world that there would be no consequences for this. But, they did this by altering the very concept of a cosmic plasma, such that they are essentially superconductors which cannot sustain an E-field, and which have magnetic fields frozen into them.

Not only is large-scale space filamentary -- which Alfven predicted 30 years before it was observed, based entirely upon the observation of the pervasiveness of cosmic plasma -- but we also see an inordinate amount of synchrotron radio waves, and even magnetic fields everywhere.
HannesAlfven
1 / 5 (1) Apr 08, 2012
The conventional theories did not predict any of this apparently electromagnetic universe. And we've now made it to the point where it is admitted that the ionosphere, and even the Birkeland Currents which feed the aurora, contain double layers.

People need to think very hard about this: A double layer is a sandwich of plus and minus charge, side-by-side. Are astrophysicists trying to convince us that these structures are rare? We didn't have to leave the Earth very far to see them. Chances are they are everywhere.

Double layers violate quasi-neutrality, guys.

Furthermore, quasi-neutral plasmas still conduct electricity. That's why we use the word "quasi-neutral", instead of "neutral" -- to differentiate the case when a plasma contains equal numbers of plus and minus from the situation when condensed matter does: A plasma's conductivity is a function of its ionization -- not its quasi-neutrality.

The confusion in cosmology is confusion over electricity over plasma.
HannesAlfven
1 / 5 (1) Apr 08, 2012
The widespread refusal amongst scientists to question the assumptions and approximations which go into their models is starting to have real-world consequences. This is becoming very serious stuff here, for we now have a group of very vocal extremists who are trying to convince everybody that humans are causing the warming we observe.

And yet, how can anybody claim any confidence with the climate models so long as this far more fundamental debate persists? How one models the cosmic plasmas completely determines one's cosmology, as well as the cause for the warming. When the cosmic plasma models are permitted to conduct electricity, as happens in the laboratory, these currents can do things of enormous consequence. A number of papers have been written on this "electric joule" heating.

We see widespread evidence that the cosmic plasmas can and do conduct very large electrical currents. How is it possible that people think they can just ignore this problem in the models?
Tennex
not rated yet Apr 08, 2012
these currents can do things of enormous consequence .. How is it possible that people think they can just ignore this problem in the models?
Because you still have no testable predictions for it.
HannesAlfven
1 / 5 (1) Apr 08, 2012
Re: "Because you still have no testable predictions for it."

I'm sorry to get riled up, but what in the world is this nonsense? You see the synchrotron; you see the magnetic fields; you see the filamentation; you see the double layers and the Birkeland Currents as wide as the Earth connecting the Sun and the Earth EVERY FEW MINUTES. Gerrit Verschuur has even seen the critical ionization velocities for hydrogen and helium, associated with those filaments. We see the ionization happening, and it is exactly where it was expected -- in the filaments.

What in the WOLRD are you looking for still, in order to simply accept that we need to fund this SCIENCE? You see every single indicator of electricity associated with the cosmic plasmas. The only thing which has yet to be observed is the electron drift feeding into the Sun. But, there's no way in hell we'll see that until we actually design a mission to observe it. Electron drifts are incredibly difficult to observe.
Tennex
not rated yet Apr 08, 2012
OK, let make these things more specific - the distance between galaxies is thousands of light years, the particles of plasma will usually move with speed at least one hundred-times lower, than the speed of light and the density of plasma between them is in order of one atom per cubic meter.

Now I'm asking you again.. which effects do you expect to observe with such plasma current?
HannesAlfven
1 / 5 (1) Apr 08, 2012
@Tennex

Plasmas are known to scale over many orders of magnitude. There should be nothing extraordinary in claiming that the scaling of fractals also applies in nature. What this means is that we can model an astrophysical plasma within the laboratory, and it will fairly closely resemble the scaled-up version (except that gravitational effects must be taken into account). We see this in plasmas. Plasmas with fractal-like appendages are called heteromacs. Heteromacs even occur as petroglyphs on rock art; it's one of the categories of petroglyphs. Your analogy seems to assume that none of this is occurring.

This is why we see similarities between the structure of neuronal networks and strings of galaxies: Because this is the shape of electricity.

Furthermore, when plasmas violate quasi-neutrality with double layers, we can see extreme differences in plasma density over very short distances. The double layer contains the charge like a skin.
HannesAlfven
1 / 5 (1) Apr 08, 2012
Keep in mind that plasma filaments exhibit long-range attraction and short-range repulsion with one another. This attractive force between the filaments is the electric force. In other words, the electric force permeates enormous regions of space, over Birkeland currents, at very great distances from the condensed matter. The gravity resulting from the tiny islands of condensed matter could never come close to approximating the pervasive power of the electric force. Gravity is simply far too weak a force. And this is why cosmologists have such an energy deficit problem with their models.
Au-Pu
3 / 5 (2) Apr 09, 2012
Pyle's first post was on the money.
The Big Bang Theory is missing about 80% of the matter it needs to support the theory.
Observations show anomalies in certain galaxies and this has been attributed to the influence of this allegedly "missing" matter.
They refuse to question seriously if their Big Bang Theory may be wrong. They also refuse to question whether if their BBT is wrong then their understanding of gravity may also be faulty.
Instead they reach for a band aid, call it Dark Matter and all is well with the Universe.
Then there is the problem of accelerating expansion that doesn't fit either so they reach for another band aid (it is amazing how much assistance Johnson & Johnson have rendered to science through their band aids) and we now have Dark Energy.
Could it be that somewhere along the path we have taken a wrong turn and we are too stubborn to admit that we may have got it all wrong and that we need to start all over again?
Why are we locked to the anthropomorphized BBT?
Shinichi D_
5 / 5 (2) Apr 09, 2012
Au-Pu:
We exactly know that the BB and GR are not fully correct in their current form. They don't work at the quantum level for example. You on the other hand ignore how much predictions were made and how coherent they are at larger scales.
As for DM and DE. Think of them like placeholders. Like the early versions of the periodic table. It had "holes" in it. But Mendeleev knew , that someting is going to fit those places. And we found those elements later.
Whatever new theory you are going to present - and don't forget, it has to explain why an apple would hit you on the head if you sit under the tree and why light from distant stars bend when passing near our sun, AND the rotational anomalies of galaxies - that part of it, that something, that will explain galactic rotation, that is called now dark matter. Until we - or you - find a more fitting name.
Pyle
not rated yet Apr 10, 2012
Zephyr!
You have outdone yourself!!! That was sweet!

Dark Matter affecting our grey matter! I love it. Why not?

Now when all the other gravitation models boast about their explanatory powers you can one up them with an explanation for the Peace at Halys! No other gravity theory has that!
Pyle
not rated yet Apr 11, 2012
Alas. My previous post was made irrelevant by the moderators removal of a sockpuppet post.

The gist of the removed post was that WIMPs gather behind aligned planets. The increase in DM causes people to act crazy during eclipses. Very funny, and I thought worth preserving in the record. If they don't whack my post too.

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