Could a new proposed particle help to detect dark matter?

January 29, 2015, University of Southampton
A massive cluster of yellowish galaxies, seemingly caught in a red and blue spider web of eerily distorted background galaxies, makes for a spellbinding picture from the new Advanced Camera for Surveys aboard NASA's Hubble Space Telescope. To make this unprecedented image of the cosmos, Hubble peered straight through the center of one of the most massive galaxy clusters known, called Abell 1689. The gravity of the cluster's trillion stars — plus dark matter — acts as a 2-million-light-year-wide lens in space. This gravitational lens bends and magnifies the light of the galaxies located far behind it. Some of the faintest objects in the picture are probably over 13 billion light-years away (redshift value 6). Strong gravitational lensing as observed by the Hubble Space Telescope in Abell 1689 indicates the presence of dark matter. Credit: NASA, N. Benitez (JHU), T. Broadhurst (Racah Institute of Physics/The Hebrew University), H. Ford (JHU), M. Clampin (STScI),G. Hartig (STScI), G. Illingworth (UCO/Lick Observatory), the ACS Science Team and ESA

Researchers at the University of Southampton have proposed a new fundamental particle which could explain why no one has managed to detect 'Dark Matter', the elusive missing 85 per cent of the Universe's mass.

Dark Matter is thought to exist because of its gravitational effects on stars and galaxies, gravitational lensing (the bending of light rays) around these, and through its imprint on the Cosmic Microwave Background (the afterglow of the Big Bang).

Despite compelling indirect evidence and considerable experimental effort, no one has managed to detect Dark Matter directly. Particle gives us clues to what Dark Matter might be, and the standard view is that Dark Matter have a very large mass for fundamental particles, comparable to that of heavy atoms. Lighter Dark Matter particles are considered less likely for astrophysical reasons, although exceptions are known, and this research highlights a previously unknown window where they could exist and, with very general arguments from particle physics, derives some surprising results.

The research is published in Scientific Reports.

The proposed particle has a mass of 100eV/c^2, only about 0.02 per cent that of an electron. While it does not interact with light, as required for Dark Matter, it does interact surprisingly strongly with normal matter. Indeed, in stark contrast to other candidates, it may not even penetrate Earth's atmosphere. Earth-bound detection is therefore not likely, so the researchers plan to incorporate searches into a space experiment planned by the Macroscopic quantum resonators (MAQRO) consortium, with whom they are already involved. A nanoparticle, suspended in space and exposed directly to the flow of Dark Matter, will be pushed downstream and sensitive monitoring of this particle's position will reveal information about the nature of this Dark Matter particle, if it exists.

Dr James Bateman, from Physics and Astronomy at the University of Southampton and co-author of the study, says: "This work brings together some very different areas of physics: theoretical , observational x-ray astronomy, and experimental quantum optics. Our candidate particle sounds crazy, but currently there seem to be no experiments or observations which could rule it out. Dark Matter is one of the most important unsolved problems in modern physics, and we hope that our suggestion will inspire others to develop detailed particle theory and even experimental tests."

Dr Alexander Merle, co-author from the Max Planck Institute in Munich, Germany, adds: "At the moment, experiments on Dark Matter do not point into a clear direction and, given that also the Large Hadron Collider at CERN has not found any signs of new physics yet, it may be time that we shift our paradigm towards alternative candidates for Dark Matter. More and more particle physicists seem to think this way, and our proposal seems to be a serious competitor on the market."

Dark Matter may be a problem to be understood by crossing fields and looking for hidden possibilities.

Dr Bateman adds: "Also from this point of view, the paper comprises a milestone on the history of our department: for the first time there has been a publication involving authors from all three groups in Physics and Astronomy, which shows how valuable it can be to cross boundaries and to look beyond one's own field."

Explore further: On the hunt for dark matter

More information: "On the Existence of Low-Mass Dark Matter and its Direct Detection." Scientific Reports 5, 8058. www.nature.com/srep/2015/15012 … /full/srep08058.html

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77 comments

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dogbert
2.2 / 5 (16) Jan 29, 2015
With dark matter, absence of evidence is not evidence of absence -- ever. Just keep looking.

If you never find it, that is not a problem either. You can just say you are still looking.

At some point, the hypothesis should be considered falsified.
antialias_physorg
4.4 / 5 (20) Jan 29, 2015
With dark matter, absence of evidence is not evidence of absence -- ever. Just keep looking.

Since we have PRESENCE of evidence (lensing)...what's your point?
dogbert
2.3 / 5 (12) Jan 29, 2015
Since we have PRESENCE of evidence (lensing)...what's your point?


We have stars moving too fast to stay in their galaxies, galaxies moving too fast to stay in their clusters and light being bent more than we expect. Our models of gravity do not predict any of this.

Lensing is not evidence of imaginary matter. It is evidence that our models are faulty.

When your theory is falsified, you should devise a better theory. You should not create imaginary substance to normalize your theory.

We can say imaginary matter did it or we can say invisible angels are doing it. It is better to say that we don't understand what is happening and we will design better models.
movementiseternal
Jan 29, 2015
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Losik
Jan 29, 2015
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Losik
Jan 29, 2015
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vlaaing peerd
4.6 / 5 (14) Jan 29, 2015
By now we should indeed be asking ourselves why DM detectors haven't found anything yet. Crazy alternatives aren't that crazy anymore.

That said, in regards to some comments, stupid dumb crackpot alternatives are still stupid dumb crackpot alternatives.
vlaaing peerd
4.8 / 5 (16) Jan 29, 2015
Lensing is not evidence of imaginary matter. It is evidence that our models are faulty.


Lensing is an indication of gravity, but there isn't enough visible matter to cause that much. Rotation speed of galaxies confirm the lensing and the lensing confirms the roation speed is correct: we are not seeing something that is there.

What knowledge we have is that only matter can curve spacetime, so it must be matter of some sort.

It is better to say that we don't understand what is happening and we will design better models.


Hence the "dark" in dark matter. Any scientist in this field will be more than happy to acknowledge that they don't understand what is happening, but also tell you some sort of unknown matter is the most viable explanation and therefore should be researched.
axemaster
5 / 5 (10) Jan 29, 2015
I recommend reading the article, it's available without a paywall. Interesting stuff.
vlaaing peerd
5 / 5 (9) Jan 29, 2015
but no, you think our models being faulty is more logical to assume.

Tell me, which model should we revise or tune to fit all that extra gravity? Relativity?

That is the only theory that comes to mind when we are talking about this subject, but I can hardly imagine you think changing that instead of assuming we are dealing with matter we simply can't observe is more viable.

Losik
Jan 29, 2015
This comment has been removed by a moderator.
antialias_physorg
4.7 / 5 (15) Jan 29, 2015
Lensing is not evidence of imaginary matter.

Lensing is the evidence that there is something causing said lensing. And people are trying to find out what it is. Let's first try the plausible stuff before we go the less plausible. That's the sensible way to do science. Looking for a type of massive particle is the most sensible idea currently floating around (and also the most testable).

Well revise models if (and ONLY if) there is something that causes them to be revised. Not just because "let's make it fit".
dogbert
1.3 / 5 (13) Jan 29, 2015
antialias_physorg,

Dark matter is the kludge used to "make it fit".
We should not kludge our our models when they fail.
fourinfinities
4.4 / 5 (5) Jan 29, 2015
1. If they only weigh 100 Ev/c^2, why are they not produced in colliders?

2. Is there any astronomical x-ray signal at 100Ev?
ursiny33
1 / 5 (6) Jan 29, 2015
To find it you must theorize its purpose ,there is a mechanical connection of hydrogen all the way down the chart of all the lesser abundant elements, then it would be reasonable and logical for hydrogen to have a mechanical connection with more abundant dark matter, like a foundational particle whose purpose is to hold an assembly of opposite charged particles in a framed construction of neutrons and protons a netrual conductive particle for the base of an electric part construction, which has a mechanical process for the construction of these electric part assemblies into neutrons and protons thru induction, by having this dark matter in an induction environment a rotating negatively charged magnetic field bubble of a star which energizes the dark matter with an induction field environment where negatively charged electrons from that environment stick to it, and it collects positively charged high energy particles of the stars emissions to build a shell on it to make a proton,
antialias_physorg
4.7 / 5 (13) Jan 29, 2015

Dark matter is the kludge used to "make it fit".

No. Dark matter is simply a placeholder-lable for "that which causes the observed lensing". Nothing more, nothing less.
dogbert
1.9 / 5 (13) Jan 29, 2015
anti,

It is a kludge. Always has been. As evidenced that we create just enough in just the right places to normalize our models.

When is it scientific to prop up a model with place holders? And if it is just a place holder, why are we trying to find it.

Dark matter is simply a kludge because we don't want to admit that our models are not predictive on stellar scales. Dark matter does not improve prediction, but it allows us to pretend our models work.
Losik
Jan 29, 2015
This comment has been removed by a moderator.
dogbert
2 / 5 (8) Jan 29, 2015
No. We should try to find why or models fail and design better models.

Kludges only hide our ignorance. We should try to eliminate that ignorance.
Greenhorn
4.6 / 5 (10) Jan 29, 2015
dogbert. Not that long ago some would have said that the Higgs Boson was just a kludge to make a theory work but they kept looking for it and eventually found it. Perhaps the same process will occur with Dark Matter.
ppnlppnl
4 / 5 (4) Jan 29, 2015

Erm, but wait... if it interacts with normal matter then it should be dragged into stars as they form and form a large part of the mass of stars. If it interacts strongly enough then it will not separate from normal matter in galactic collisions. So...
big_hairy_jimbo
5 / 5 (11) Jan 29, 2015
Off topic, but I've decided to report every single post from movementiseternal, as it is the same junk post in every thread. So report it as SPAM people.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
antialias_physorg
4.6 / 5 (11) Jan 29, 2015
It is a kludge.

I think you need look up the word - because it makes absolutely no sense the way you use it.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
liquidspacetime
1 / 5 (7) Jan 29, 2015
There is evidence of dark matter every time a double slit experiment is performed; it's what waves.

Hi Tobias,

Dark matter has mass. Dark matter physically occupies three dimensional space. Dark matter is physically displaced by the particles of matter which exist in it and move through it.

The Milky Way's halo is not a clump of dark matter anchored to 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 Milky Way's halo is the deformation of spacetime.

What is referred to geometrically as the deformation of spacetime physically exists in nature as the state of displacement of the dark matter.

A moving particle has an associated dark matter displacement wave. In a double slit experiment the particle travels through a single slit and the associated wave in the dark matter passes through both.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
PhotonX
5 / 5 (11) Jan 29, 2015
OFF TOPIC
Off topic, but I've decided to report every single post from movementiseternal, as it is the same junk post in every thread. So report it as SPAM people.
Yes, that BS got old a long time ago. "Space dont expanding at all!" If he's going to keep rambling on the same nonsense, pointing to his weblog that rambles on some more of the same nonsense, he could at least learn proper English. Or get an f***ing clue.
.
"but you cant ever explain what curving space is!" Curving space is gravitational fields, no?
.
.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 29, 2015
This comment has been removed by a moderator.
Humbled1
1 / 5 (10) Jan 29, 2015
AP:

What makes you think that the "Force" represented by Dark Matter is Gravity at all?

Do you have any proof that gravity is the only force that bends light?

If there's an invisible undescribable particle, then maybe there's an invisible, undescribable Force, and moreover, maybe there's an invisible undescribable....

We already know planetary systems cannot form in the presence of Dark Matter of the type every major theory presents to try to explain the phenomena of galactic rotation and galactic cluster formations. Planets and Stars wouldn't exist in such an environment, and no Dark Matter has ever been observed on local scales...anywhere.

Every "missing mass" that has ever been discovered within the Milky Way has turned out to be another planet, star/black hole, Moon, or brown dwarf...every last one of them.

No evidence of an actual massive particle.

there is evidence of something unknown, but to say it is a particle is conjecture
Moebius
4.3 / 5 (8) Jan 29, 2015
If it is matter, I doubt it's a cloud of naked particles that pervades the galaxy in a loose clump that doesn't get sucked into all the gravity wells. If it's something that interacts with gravity so weakly to not get sucked into gravity wells, how can it hold the galaxy together?

It shouldn't even be called dark matter. There is no evidence it's matter. In fact there is probably more evidence right now that it isn't matter. No combination of known particles or matter can produce the effect so they have to invent new particles. It should be called if anything the dark matter effect and even that implies it's matter. I think we may need new physics to explain it, not particles.
PhotonX
5 / 5 (10) Jan 29, 2015
Do you have any proof that gravity is the only force that bends light?
So you're seriously asking for proof of a negative? Well, maybe no one will notice. People here probably don't know much about logical fallacies, shifting the burden of proof, that sort of thing. Sure, give it a try. Let's see how that goes. Meanwhile....
.
OFF TOPIC AGAIN
I can explain pushing force with one word and that word is movement!
-sigh- I guess I'll just switch it to 'Ignore user'. I hate doing that, but at least I won't have to worry about missing any incisive point. Everything are movement! Tree, rock, bush, air, galaxy, Universe, all movement. No gravity, none electricicity ether or thought, just movement! Movement is movement! No movement is no movement. Movement!!!
PhotonX
5 / 5 (9) Jan 29, 2015
It is a kludge. Always has been. As evidenced that we create just enough in just the right places to normalize our models.
No, a kludge is an inelegent solution to a problem. As in "It ain't pretty but at least it works." DM doesn't pretend to explain or solve anything, it's just an easier way of saying "that abnormality in the gravitational behavior of spinning galaxies." A label, a placeholder. Trying to define its characteristics by estimating its behavior in models is the way things get done, if that's what you mean by 'kludge' then you're using the term differently than I ever have.
Uncle Ira
3.3 / 5 (7) Jan 29, 2015
Do you have any proof that gravity is the only force that bends light?
So you're seriously asking for proof of a negative? Well, maybe no one will notice. People here probably don't know much about logical fallacies, shifting the burden of proof, that sort of thing. Sure, give it a try. Let's see how that goes. Meanwhile...!


If ol no-fate-Skippy does not pace him self, he's going to use all his backup plans on the same day. That's what happened when he was the no-fate-Skippy before he was the reset-Skippy and before that another Skippy I forget now. He get mad and says some ugly stuffs and thinks maybe he should change his clothes.

So today he is the delipinecho-Skippy and the Humbug-Skippy because everybody got on the reset-Skippy for the bad words. I wish I could remember the other Skippy that he was before the no-fate-Skippy.

You can always tell him because he likes to start off slow and work himself into the foolishments.
Losik
Jan 29, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 30, 2015
This comment has been removed by a moderator.
viko_mx
1 / 5 (4) Jan 30, 2015
@dogbert

"At some point, the hypothesis should be considered falsified."

When scientists have honest purely scientific approach. But this is a dogma that feed pretty families. Truth can also feed them but in addition it helps for the positive development of society.
movementiseternal
Jan 30, 2015
This comment has been removed by a moderator.
AmritSorli
1.7 / 5 (6) Jan 30, 2015
with proposing new partcles "out of blue" only more confusion will be created www.fopi.info
antialias_physorg
4.3 / 5 (12) Jan 30, 2015
It is a kludge.

No a kludge would be an (untenable) hypothesis.

Dark matter is NOT a hypothesis. It is a placeholder for any number of hypotheses (i.e. anything that could explain the observed effect...from WIMPs to axions to...whatever).
Each individual hypothesis has to be tested and when that test fails it will be discarded. But you can't disprove a placeholder (neither can you prove it).

Get over it. The term "dark matter" means NOTHING. It's just a bunch of letters. Subsititute "cheesecake" if you like. It makes no difference.
Whydening Gyre
4.5 / 5 (8) Jan 30, 2015
dogbert. Not that long ago some would have said that the Higgs Boson was just a kludge to make a theory work but they kept looking for it and eventually found it. Perhaps the same process will occur with Dark Matter.

To be exact, they didn't actually find it. They only found mathematically inferential evidence of it...
Whydening Gyre
4.3 / 5 (6) Jan 30, 2015
Off topic, but I've decided to report every single post from movementiseternal, as it is the same junk post in every thread. So report it as SPAM people.

Indeed.
He has been more "talkative" than usual in this particular thread...
Ya just wanna slap him and say shutup...
(Kinda like your grandma did when she took ya to church...)

dogbert
1 / 5 (5) Jan 30, 2015
antialias_physorg,

Dark matter is NOT a hypothesis. It is a placeholder for any number of hypotheses (i.e. anything that could explain the observed effect...from WIMPs to axions to...whatever).


You say it is a place holder while in the same sentence you restate that it is matter.

It is a kludge. The biggest problem with a kludge is what you just demonstrated, it closes out investigation of alternatives. People looking for dark matter are looking for dark matter. They are not trying to determine why our models of gravity fail. Thy simply assume that our models are correct and that we can normalize our models with our observations by creating imaginary matter.

> It's just a bunch of letters. Subsititute "cheesecake" if you like. It makes no difference.

The term imaginary fits and it does make a difference.
Whydening Gyre
3.7 / 5 (3) Jan 30, 2015
I think I have this dark matter concept straight in my head...

Can't see it...
It avoids matter locally, but still has mass...
That implies that empty space "weighs" something...
so...
maybe even gravity, itself, has mass...

(Dang.... I'm startin' to sound like ol' movementiseternal, there...)
movementiseternal
Jan 30, 2015
This comment has been removed by a moderator.
dogbert
5 / 5 (2) Jan 30, 2015
Whydening Gyre

maybe even gravity, itself, has mass...


An interesting concept.
antialias_physorg
5 / 5 (9) Jan 30, 2015
You say it is a place holder while in the same sentence you restate that it is matter.

No. No one ever said it is matter. Matter is just the only thing we know of that has a lensing effect so that is where we look first. No one said that that is the only hypothesis type worth looking at. No one.
(There have been also non-matter alternatives already proposed, like MOND (which has failed or at the very least also still requires unaccounted mass))

And please: look up the difference between 'kludge' and 'label'. Using a word wrong repeatedly doesn't make it right.

Thy simply assume that our models are correct

Because they work very well in most respects. Saying that a model has shortcomings isn't enough (that the standard model isn't complete is not news, BTW. You will find not a single scientists who claims otherwise). Unless you have something BETTER to replace it that's a worthless gripe.
movementiseternal
Jan 30, 2015
This comment has been removed by a moderator.
movementiseternal
Jan 30, 2015
This comment has been removed by a moderator.
antialias_physorg
4.4 / 5 (7) Jan 30, 2015
Why can't DM or the effects of what is perceived as DM be anti-gravity?

I don't know. However, I have seen no indication that anti gravity exists - and the lensing observed would speak for something that has positive gravity, not for negative gravity
To get the kind of lensing from anti-gravity would require a completely complementary distribution of 'anti gravity dark matter' to the dark matter distributions currently calculated...and I think such a distribution of repulsive matter would not be conducive to something like galaxies sticking together.
TimLong2001
1.7 / 5 (6) Jan 30, 2015
Problems such as dark matter, dark energy and "acceleration of expansion" are a result of assuming that the background red shift is a Doppler shift rather than a result of photon energy loss through various interaction mechanisms.
Whydening Gyre
3.8 / 5 (4) Jan 30, 2015
so... maybe even gravity, itself, has mass...


To enlarge upon this particular thought experiment;
Kind of like oil and water... They don't mix until you agitate them (and even then, not all that well). Maybe with something like - spin... or a combination of differing spins...

antialias_physorg
4.4 / 5 (7) Jan 30, 2015
The lensing effect observed you speak of and predicted by GR is strictly mass induced?

Nobody knows. Currently we only know of one thing for certain that produces lensing: Mass. So that's the sensible first guess at what the cause is.
Losik
Jan 30, 2015
This comment has been removed by a moderator.
antialias_physorg
4.4 / 5 (7) Jan 30, 2015
a photon has no mass. It has an energy (and a momentum). From the energy one can calculate an equivalent rest mass. But since a photon is never at rest that's just an abstract number.

Now whether the energy of a photon bends spacetime is a tricky question. If you go the (as yet hypothetical) graviton route then gravitons certainly interact with photons. But gravitons (being massless and therefore fixed to speed c) cannot be emitted by photons - so in that case photons aren't able to bend space themselves.

If photons do bend space then you should see two photons that travel past each other in opposite directions first blueshift one another and then redshift one another as they pass. The effect would be incredibly tiny, and I'm pretty sure no measurement to that effect has yet been made.
antialias_physorg
4.4 / 5 (7) Jan 30, 2015
When gravitational lensing is mentioned my thought is that light is being bent.

Well, the human mind is pretty bad at imagining bent space. But actually the photon takes the straight path. Always. It just appears bent to us (like looking at a straw that sticks out of water. It appears bent - but it actually isn't)

that spacetime is being bent/warped by mass and light is simply following that bent/warped space
Correct. The reason why, from the point of view of the photon, it always travels straight is a bit tricky. There's two ways to explain this.
1) The easy way (but wrong way) : If it were to follow a curve it would be accelerated sideways. But you can't accelerate a photon.
2) The correct, but not so intuitive one: The photon follows all paths - but the probabilities for all paths BUT the straight one cancel out.(see Feynman path integrals)
Whydening Gyre
3 / 5 (2) Jan 31, 2015
- but they're attracted to massive bodies, which have opposite gravitational charge, so that the dark matter gets concentrated around them.

So... why can't we see them from a local perspective?
Whydening Gyre
3 / 5 (2) Jan 31, 2015
- but they're attracted to massive bodies, which have opposite gravitational charge, so that the dark matter gets concentrated around them.

So... why can't we see them from a local perspective?

I meant IT...
bluehigh
2 / 5 (4) Jan 31, 2015
Perhaps 'lensing' is due to an absence rather than a presence.
Losik
Jan 31, 2015
This comment has been removed by a moderator.
antialias_physorg
4.5 / 5 (8) Jan 31, 2015
How the stars can lose mass with radiation of photons, after then?

E = mc^2 ?
Duh.
Losik
Jan 31, 2015
This comment has been removed by a moderator.
Whydening Gyre
3.7 / 5 (3) Jan 31, 2015
Well, exactly - after then the photons must also have an energy, if they carry out an energy. The zero rest mass energy cannot apply for them, if they're in motion.

What is it they say about this, again?
Oh, yeah ....
" A rolling photon gathers no mass..."
Or maybe it's a different metaphor....

antialias_physorg
4.1 / 5 (8) Jan 31, 2015
light while the light seeks out all possible paths as particles and as a wave thus the illusion of bending/warping.

Yes. And since light (more precisely: the speed of light) is the only constant 'standard ruler' in the universe (since c is always c no matter in what inertial reference rame you are) then it makes only sense to define things based on said constant ruler. Any other way of looking at stuff makes things depend on your point of view (i.e. stuff becomes realtive)
So the path light takes is straight. Always. Any bending we see is due to space being warped.

The thing that confuses people is that they try to see space as 3D with 'shortest duistance is just euclidian distance'. But spacetime is 4D...and shortest distance therein is defined by the path a photon takes.
omatwankr
1 / 5 (1) Jan 31, 2015
Hey Leave my bastard child \bowelmovementiseternal/ alone, he still learning to be as Asinine as my namesake used to be

go repulsive neutrons

o'wnker out
saposjoint
3.9 / 5 (7) Jan 31, 2015
Off topic, but I've decided to report every single post from movementiseternal, as it is the same junk post in every thread. So report it as SPAM people.

Indeed.
He has been more "talkative" than usual in this particular thread...
Ya just wanna slap him and say shutup...
(Kinda like your grandma did when she took ya to church...)



Yep. I've been reporting his garbage for quite a while, and since Zephir has a new sock, every one of Losik's as well.

Out, damned sock! Out I say! (He'll on;y come back...)
TechnoCreed
4.3 / 5 (6) Jan 31, 2015
Yep. I've been reporting his garbage for quite a while, and since Zephir has a new sock, every one of Losik's as well.

Out, damned sock! Out I say! (He'll on;y come back...)

Guess what would happen if everybody would put them on ignore. http://www.youtub...1LbC4Fvs
nevermark
4.4 / 5 (7) Feb 01, 2015
Dogbert should be have chosen the name PointyHairedManager for being pedantic.

Dark Matter is just a placeholder name for highly consistent effects that are easily and routinely measured in many ways. The dark matter effects are easily described using General Relativity by simply adding non-interacting matter. They explain galactic rotations, even differences of rotation over different radii within the same galaxy. They explain spacial curvatures that have separated from their galaxies after collisions. They were the missing ingredient in simulations of galactic evolution that now reproduce the distribution of galaxies we see. There is a lot more than that!

Nobody claims to know what dark matter is on the small scale, but it IS well understood on the large scale.

There is no Dark Matter conspiracy. There is no arbitrary fudge, as what is known about dark matter is highly constrained by evidence. Just a PoinyHairedManager arguing word games.
dogbert
3 / 5 (4) Feb 01, 2015
nevermark,

The dark matter effects are easily described using General Relativity by simply adding non-interacting matter.


Correct. You simply add sufficient dark matter as needed to normalize our models of gravity with what we observe which does not match our models. It is simply created on the spot.

Dark matter explains nothing because there is no predictability with Dark Matter. When you view something new, you have to add dark matter in just the amount needed in just the right places to normalize observation with our models.

Dark Matter is just a placeholder name ...


No it is not. If it were a place holder you would not have named it dark (invisible) matter. You would have called it a gravitational anomaly. Instead you identify it as matter which cannot be seen. You have already decided what it is.

It is imaginary because it is simply imagined.
nevermark
4 / 5 (4) Feb 01, 2015
dogbert,

The fact that it is called "dark matter" doesn't mean it is matter, just that modeling it as matter on a large scale fits what we see. Nobody disputes that it could be something different.

"Planetary Nebula" are not planetary. "Asteroids" are named after stars but have almost nothing in common. Quarks don't have "color". The "Big bang" was neither big nor a bang. "Black holes" are not holes.

Names are just sounds. They are neither "right" nor "wrong" and they change their meaning for all kinds of non-rational reasons.

Dark matter was postulated due galactic rotation but then turned out to explain galactic mashups, the web of lensing between galaxies, the distribution of galaxies after the big bang, etc. It has had a great deal of predictive power - in the large scale.

We just don't know what it is on the small scale yet. It might be something very different from "matter" and yet we might end up calling it "matter" anyway.
nevermark
3.7 / 5 (3) Feb 01, 2015
Correct. You simply add sufficient dark matter as needed to normalize our models of gravity with what we observe which does not match our models. It is simply created on the spot.


Are you really that uninformed of how dark matter was discovered, how well it explains many things on a large scale, how new evidence for it continues to accumulate, how absurd it is to think you can control long term, highly non-linear simulations with just a magic ingredient or two, or how many things in history got names before we completely understood them? The list is very long.

You are out of touch with how science works, not to mention basic facts about dark matter.
dogbert
5 / 5 (2) Feb 03, 2015
nevermark,
Are you really that uninformed of how dark matter was discovered...


It was not discovered. It was created when our observations of movement of stars in galaxies showed the stars moving so fast that they should leave their galaxy. When our models of gravity could not explain this, dark matter was created to normalize our observations with our models.

Not a single bit of dark matter has ever been discovered anywhere. Not a single bit of it has ever been found in any of our colliders either. Nor is dark matter found in our standard model of particle physics.

It was simply imagined and despite years of searching, not a single bit of it has been discovered anywhere.

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