Mystery Signal Could Be Dark Matter Hint In ISS Detector

astroengine writes Analysis of 41 billion cosmic rays striking the Alpha Magnetic Spectrometer particle detector aboard the International Space Station shows an unknown phenomena that is "consistent with a dark matter particle" known as a neutralino, researchers announced Thursday. Key to the hunt is the ratio of positrons to electrons and so far the evidence from AMS points in the direction of dark matter. The smoking gun scientists look for is a rise in the ratio of positrons to electrons, followed by a dramatic fall — the telltale sign of dark matter annihilating the Milky Way's halo, which lies beyond its central disk of stars and dust. However, "we have not found the definitive proof of dark matter," AMS lead researcher Samuel Ting, with the Massachusetts Institute of Technology and CERN in Switzerland, wrote in an email to Discovery News. "Whereas all the AMS results point in the right direction, we still need to measure how quickly the positron fraction falls off at the highest energies in order to rule out astrophysical sources such as pulsars." But still, this new finding is a tantalizing step in the dark matter direction.

Comments

ISIS is in space?

[ka9dgx]

How the heck did ISIS make it up into orbit to attack the space station? You can't trust the Russkies, can you?

Next thing you know ISIS will be on the moon, and we'll have to bomb them. ;-)

Re:ISIS is in space?

[Anonymous Coward]

NASA funding increased by 1000%

Re:ISIS is in space?

[iggymanz]

Her mother Nut is the sky god, you're saying she can't visit?

Huh?

[TFlan91]

>> the telltale sign of dark matter annihilating the Milky Way's halo

Sooooo when did dark matter become anti-matter? Or am I missing something?

Re:Huh?

[ls671]

Do you need anti-matter for "annihilating the Milky Way's halo"?

Dark matter could be made of black holes:

"There have been many candidates for this theorized "dark" matter, and in truth it is probably some combination of them: hot or cold gas, neutron stars, white or brown dwarfs, exotic particles and, yes, even black holes!"

https://van.physics.illinois.e...

Re:Huh?

[Bengie]

In the past year, all of those have been eliminated. Dark Matter has to be something that doesn't not interact with light in any way except via gravity. I'm pretty sure "gas" interacts with light. Black holes is the only thing that fits this restriction, but the gravitational gradient would be too much, and would require 80% of the universes mass to be tied up in black-holes at the edge of galaxies.

Re:Huh?

[Anonymous Coward]

You should have read the sentences right after where your quote stops:

"But we've been able to eliminate most of these as the primary variety in one way or another. If black holes constituted all of dark matter, for instance, we would expect to see gravitational lensing (the bending of light as it passes massive objects) when we look through the halo of our own galaxy at stars in other galaxies because we would expect there to be many black holes in that halo. We do not see such lensing, so we conclude that the dark matter we know to be present in galaxy is not black holes."

In other words, a lot of searches for microlensing and occlusion of stars within our galaxy have set an upper bound on the number of such items, and that upper bound is too small to cover a significant part of the missing dark matter. And that is without invoking the cosmological arguments for dark matter to be non-baryonic, and that there is more normal matter out that that we haven't even accounted for.

Re:Huh?

[Anonymous Coward]

In the past year, all of those have been eliminated.

Most of those were weakened, if not eliminated over a decade ago, going back almost to some early surveys in the 90s. Not just in the past year. More and more studies keep reducing upper bounds on the number of such objects, but for some time that upper bound has been too low.

Dark Matter has to be something that doesn't not interact with light in any way except via gravity.

Dark matter can still interact with light, it just must do so weakly in a way that would match current observations. There are several detectors looking for various dark matter candidates passing through the detectors that would involve electromagnetic interaction, but such processes would be so dim in outer space that you couldn't see them from any distance.

I'm pretty sure "gas" interacts with light.

It also is something that has been mapped out a lot, and is baryonic.

, but the gravitational gradient would be too much, and would require 80% of the universes mass to be tied up in black-holes at the edge of galaxies.

The gradient is not a problem, nor would they all be right at the edge of the galaxy. A model using a gas of very small black holes spread through out the galaxy and halo would explain rotation curves just fine, as would it explain other things like gravitational lensing if there were clouds of black holes in certain places between galaxies. The problem with black holes is not that they couldn't explain the missing gravity source, but that they would have been observerable in various surveys specifically looking for them and were not.

Re:Huh?

[radtea]

Sooooo when did dark matter become anti-matter? Or am I missing something?

Probably pretty much everything.

Matter and anti-matter are--up to a flip in charge and parity--the same thing. That is, if you take an electron (a matter particle), flip its charge and look at in a mirror you'll see a positron (an anti-matter particle).

So it is actually perfectly consistent, logically if not linguistically, for dark matter to be entirely anti-matter.

Exotic dark matter can also produce anti-matter when its particles collide with each other, which is what this report seems to be about. The significant thing is that the energy spectrum of the positrons that the AMS detector sees appear to have about the right energy spectrum for one particular type of exotic dark matter (which I personally have a pretty low prior for).

There are a whole bunch of follow-on papers from other people doing what scientists do, which is check for consistency between the exotic dark matter interpretation of this result and reality, in the sense that if this signal really is due to exotic dark matter there should be a number of different consequences (including the anti-proton signal the article mentions): http://arxiv.org/find/all/1/al...

Re:Huh?

[ls671]

I never mentioned large black holes and I was using the quote to demonstrate that we still do not know what is going on really yet.

Anyway, this seems recent enough ( April 30, 2014):
"Black hole atoms now join a long list of candidates for dark matter particles, from supersymmetric neutralinos, WIMPs and axions to warm sterile neutrinos and many more, Dokuchaev told Space.com. Verifying whether any of them is the real deal will require catching one first, he added."

http://www.space.com/25691-dar...

Re:Huh?

[iggymanz]

The hypothetical "neutralino" is a family of four particles the lightest of which is considered to be a dark matter candidate. Neutralinos are their own antiparticles (similar to how photons are), and a pair of them can sometimes annihilate to form other matter-antimatter pairs of particles.

Re:Huh?

[Anonymous Coward]

The idea being discussed there isn't necessarily pseudoscience, but is not mainstream and kind of an out there idea. That is rather distinct from black holes in general. Even the very article you linked raises issues:

But Frolov doesn't think that the idea quite works.

"Using [friedmons] for the explanation of the dark matter looks contradictory. Dark matter must be formed of WIMPs (weakly interacting massive particles), while friedmon atoms 'participate' in the electromagnetic interaction," he said.

"Possibly for this reason, Dr. Dokuchaev proposed to 'put' an electron orbit inside the friedmon. However, in this case the friedmon configuration will not be stabilized by an electric charge, and its external mass may be reduced to zero value," Frolov added. "Another unsolved problem of his model is the mechanism of the friedmon's formation. One can expect that in order to produce a sufficient number of friedmons to explain the dark matter, in the early universe there must exist large small-scale inhomogeneities. This is difficult to expect in the standard inflation models."

Other cosmologists also have doubts.

Re:Huh?

[ls671]

Please watch the TV Show Manhattan.

https://en.wikipedia.org/wiki/...

https://en.wikipedia.org/wiki/...

Yet, back then, at some stage, almost the whole scientific community was hyped on ThinMan which ended up being trashed. Implosion prevailed.

All I am saying is don't jump to conclusions and follow the scientific community hype too easily.

Re:Huh?

[Anonymous Coward]

Or if you are worried about hype, how about instead of citing movies or pop-sci internet articles, learning to read actual journal articles and review papers to see what the state of things are. Many of them are not that dense on such subjects once you get beyond a bit of jargon that an intro-level textbook covers, and the math can be light in many of the papers on the topic compared to other fields of physics. Then at least you won't be subject to following hype, or following the shadow of the hype by trying to pick up on the opposite... instead you could be making decisions for yourself based on the actual arguments and data involved.

Re:Huh?

[ls671]

Interesting, the "shadow of the hype" is still hype. You seem to be underestimating me.

Apart from that, you are basically saying the same thing as I do and rest assured I have been following your recommendations for quite a while, especially the part about: "you could be making decisions for yourself based on the actual arguments and data involved."

Re:Huh?

[Anonymous Coward]

Interesting, the "shadow of the hype" is still hype.

Not hype, but still influence by hype. People who seek out to do the opposite of something are still letting that something control them. I remember someone in undergrad that wore weird clothes, because they didn't want to be influenced by what was popular. Except when asked what happens if what they wanted to wear something that just happens to be popular, they said they would change it to be safe and got upset when suggesting that popularity was hence still influencing their wardrobe. tl;dr: seeking out something that is unhyped is not a solution to avoiding the influence of hype and potentially as dangerous.

That may not be applicable at all, but is a warning nonetheless.

You seem to be underestimating me.

I wish I was, and to help prove so it would help if you showed basic reading comprehension. You quote articles that contradict what you say, and now you even quote a post claiming to already follow those recommendations, even though they just recommended you not do what you did in your previous posts...

Re:Huh?

[Anonymous Coward]

The idea being proposed there is still pretty solidly in the WIMP category, as in something small enough it could enter into a particle detector and interactions be seen and matched against predictions. That is rather distinct from the MACHO theories that involve larger, "normal" matter objects that just don't interact with light strongly, and are now limited by observation. Assuming the issue with such objects interacting with electromagnetism strongly is ignored... otherwise their density would be rather limited by previous detector based searches. And there is still the question of where they come from, because creation schemes for large numbers of primordial black holes vastly over predict the number of intermediate sized black holes, and non-primordial creation schemes are sketchy at the moment. It is obviously an area of research, but has a lot of observations and failed predictions stacked or leaning against it as is.

Re:Huh?

[ls671]

1) I don't have anything to prove.

2) Learn to read between the lines ;-)

Cheers,

Re:Huh?

[reve_etrange]

I think they meant "annihilating in." Dark matter should have both anti- and regular variants, which would annihilate with each other, potentially producing an observable signal. Actually, the neutralino they're discussed is probably a Marjorana fermion, which is its own anti-particle.

Re:Huh?

[slashmydots]

You forgot the most realistic and easily proven dark matter theory. It's a math error! If the Star Ship Enterprise can't estimate total matter in the entirety of the universe, I don't think a Xeon can. You have to compensate for billion of years of light delay over an even scale while space is expanding the entire time that the light is traveling through it and be flawlessly accurate on the counts of individual atoms. You get one single thing wrong like mass vs perceived light bending around a black hole and you miss half the miss in every black hole in the universe. If there's a 100% black hole universe, you might have missed the whole damn thing. I mean come on! Oh look, lightning...it must be Zeus! Oh look, a floating thing with a light in the sky...must be aliens coming to visit! Can we go back to science and stick to the most likely explanation for once? Dark matter isn't real!

Re:Huh?

[Anonymous Coward]

So it is actually perfectly consistent, logically if not linguistically, for dark matter to be entirely anti-matter.

Dark matter is not anti-matter. However, if dark matter is a particle then that particle will have an anti-particle. In the case of the neutralino, it is its own anti-particle and thus it can annihilate with itself.

Re:Huh?

[Anonymous Coward]

Do you need ... black holes:

There have been many candidates for this theorized "dark" matter, and in truth it is probably some combination of ...lies, including this sentence.

Quoting out of context is disingenuous, but fun.

Re:Huh?

[Anonymous Coward]

That isn't "easily proven" at all. You don't know shit about this.

neutralino?!

[Lije Baley]

Does this mean they'll find the gravioli next?

So, what energy are we talking about?

[Grog6]

Are we talking about the fountain of 511keV positron/electron annihilation photons from the galactic poles, or are we talking some exotic gammas from an Neutralino annihilation?

Inquiring minds want to know... :)

Re:So, what energy are we talking about?

[skirmish666]

The smoking gun scientists look for is a rise in the ratio of positrons to electrons, followed by a dramatic fall

Enquiring minds should read the summary ;)

Re:So, what energy are we talking about?

[Anonymous Coward]

The positrons and electrons they are talking about are ones passing directly into the detector. They are not observing gamma rays from distant annihilation.

Re:So, what energy are we talking about?

[Grog6]

That was what was unclear; thanks.
idrtfa. :)

Wow, I thought you were dead.

[Grog6]

Great job on the whole moving out of the domes thing; how's R. Daneel?

Re: Wow, I thought you were dead.

[Lije Baley]

Daneel went back to Earth after I shacked up with Gladia. I suspect he's been trying out some new laws on my wife.

Re: Wow, I thought you were dead.

[Anonymous Coward]

Still working out the niggling details of that pesky 0th law at this point, I think.

Re: Wow, I thought you were dead.

[Grog6]

Cool beans; tell him I said hey; and he was right about those chicks. :)

Re: Wow, I thought you were dead.

[K. S. Kyosuke]

I suspect he's been trying out some new laws on my wife.

In your place, I'd become suspicious somewhere around the 69th law.

Annihilating the Milky Way's halo?

[wonkey_monkey]

the telltale sign of dark matter annihilating the Milky Way's halo

Is that supposed to be "annihilating in the Milky Way's halo"?

Re:Annihilating the Milky Way's halo?

[Anonymous Coward]

It's both since they are supposed to constitute most of MW halo.

Easily dissmissable

[crepe-boy]

Anyone who uses "phenomena" in the singular just can't be trusted.

Re:Easily dissmissable

[Anonymous Coward]

I'm dissmissing your opinion on the grounds of spelling errors.

Re:Easily dissmissable

[Anonymous Coward]

I'm dismissing your opinion on the grounds of cowardice.

Generally accepted

[retroworks]

Dark matter simply means matter that is too small to be detected by what humans have so far developed to see, but which gravity study suggests should be there. Seventy years ago, Pluto was probably "dark matter". Giving a name to "everything" we can't see and then finding evidence that there's something more is a bit curious. What hasn't been "seen" yet is "dark". We will eat away at "dark" matter one snapshot at a time.

Re:Generally accepted

[Anonymous Coward]

Giving a name to "everything" we can't see and then finding evidence that there's something more is a bit curious.

Except it isn't a name for everything or even some general, broad category of unknowns. It started as a potential solution of a specific unknown, and expanded to cover a small number of other situations that were found to be explainable by a single, common theory.

What hasn't been "seen" yet is "dark".

There is a lot of unseen stuff that doesn't get the dark label. The same models that predict that dark matter is non-baryonic also show that that we only see about a quarter of normal matter our there. In that case, the normal matter we don't see is not a part of dark matter, but just unseen stuff.

Re:Generally accepted

[MildlyTangy]

Dark matter simply means matter that is too small to be detected by what humans have so far developed to see, but which gravity study suggests should be there. Seventy years ago, Pluto was probably "dark matter". Giving a name to "everything" we can't see and then finding evidence that there's something more is a bit curious. What hasn't been "seen" yet is "dark". We will eat away at "dark" matter one snapshot at a time.

No, thats not correct. Dark matter is not matter that is "too small" to detect currently. Its matter that does not interact with electromagnetic radiation ( light, radio waves, gamma waves etc ) in any way, shape or form. We know its there from its gravitational interactions, that is correct. But it is not affected and does not affect electromagnetic radiation, or electric or magnetic fields. Its size is not the issue that makes it so difficult to detect.

Re:Generally accepted

[Anonymous Coward]

Its matter that does not interact with electromagnetic radiation ( light, radio waves, gamma waves etc ) in any way, shape or form.

This is pretty much flat out wrong, in the sense there are still plenty of dark matter candidates that involve some electromagnetism interaction. The interaction doesn't have to be zero, just very small to be below current detection thresholds. This can vary from being particles with a low chance of decaying into something that emits light to particles that have rare interactions with normal matter and light to annihilation producing gamma rays, but with low cross-section.

Re:Generally accepted

[reve_etrange]

That's why it's "dark," (pedantic AC corrections notwithstanding), but I would say its size is something that makes most dark matter candidates hard to detect. These particles are mostly predicted to be too massive for production at current accelerators.

Re:Generally accepted

[Anonymous Coward]

+4 Interesting. For a comment that doesn't even begin to be correct..

Well done, Slashdot. *slow handclap*

Re:Generally accepted

[Anonymous Coward]

Not correct. Dark matter particle candidates do not interact electromagnetically. If a dark matter particle decays then those decay products could be detectable but that does not imply that the dark matter particle interact electromagnetically.

Re:Generally accepted

[Anonymous Coward]

No, as other AC said, this is flat out wrong. Candidates like axions can interact with magnetic field and directly decay into photons, which is an EM interaction. Majorana fermions can still possess a toroidal moment which is extremely limiting to interacting with electromagnetism, but still allows it to interact. If particles were allowed to have a charge that is a small faction of the electron's charge, you could have very weak but difficult to observe electromagnetic interactions. Other particles could still interact through electromagnetism through loops in their Feynman diagram, which is rare but can happen, just like photon-photon scattering.

Re:Generally accepted

[Anonymous Coward]

Don't worry, it eventually got modded back down, and a reply that is also wrong go modded up to +5 instead.

Could be?

[Anonymous Coward]

It could be true, it might not be true...

When it is, let me know when it is...

Sorry, that was me

[Anonymous Coward]

I'm a fledgling celestine sorceror/warlock, I've been doing some groundwork adding funky new dimensions to life on earth. Dig that air man, this air is unbelievable!

Re:Sorry, that was me

[Anonymous Coward]

Which server do you play on? Have you hit level 90 yet?

Poor summary

[manu0601]

The summary makes little sense, but I suspect this is because nothing was really found. Awake me when you will have some real news.

Dark matter or supersymmetry verification

[jphamlore]

Which would be the biggest news for physics: A discovered candidate for dark mattery or discovery of a particle predicted by supersymmetry? I thought evidence from the LHC was casting doubt on many supersymmetry theories? Also Samuel Ting is fairly old which is a shame because it might be unlikely he could live long enough to be one of those rare scientists who are awarded multiple Nobel Prizes.

My speculation

[jandersen]

The fact is that we have too little evidence to guide us, and we can all speculate to some extent. My favourite, based on nothing more than my own wishful thinking, really, is that dark matter consists of not just 1 kind of particle, but of a whole 'phylum' (to borrow a word from biology) of particles that interact with themselves much like the particles we know; there may be several phylums (or phyla, if you prefer). The reason I like the idea is simply that it allows me to fantasize about a kind of parallel universe that we can't see - even life; a sort of ghost universe. Wouldn't that be cool :-) ?

Re:My speculation

[Anonymous Coward]

The fact is that we have too little evidence to guide us, and we can all speculate to some extent. My favourite, based on nothing more than my own wishful thinking, really, is that dark matter consists of not just 1 kind of particle, but of a whole 'phylum' (to borrow a word from biology) of particles that interact with themselves much like the particles we know; there may be several phylums (or phyla, if you prefer). The reason I like the idea is simply that it allows me to fantasize about a kind of parallel universe that we can't see - even life; a sort of ghost universe. Wouldn't that be cool :-) ?

I've been alternating between Spectrum and plane of matter as well as other terms to try and describe the exact same idea to other people as you just described here, nice. It looks to me like we are thinking about the same idea.

Each grouping of interactive and similarly sized matter, such as the ones on our traditional periodic table of elements, would have particle sizes vastly smaller than the grouping next larger up. At least the next smaller one compared to our familiar one would need to be composed of individually very small particles (possibly neutrino class). They would have their own types of potential chemistry etc depending on their structure related to each other. And yes, can't see why life couldn't come about on those planes, perhaps even more easily and even more vastly than on this "plane". Perhaps even preceding life on this plane.

In fact, at the rate that neutrinos are emitted from stars it would be tempting to say that the moving neutrinos from stars could serve a similar purpose as light for any creatures on such a plane, and there would be plenty of it. And even though the individual size of each particle there would be incredibly small and the overall mass in any location tiny, depending on the nature of their interaction with each other there might be a massive "amount" of those particles allowing for a full and detailed "landscape".

Can't help but wonder if such a physical phenomenon as these planes of dark matter might not account for peoples reports of ghosts and an astral plane etc. Thus changing what has here-to-fore been tossed to the side as mysticism and metaphysical into the full blown physical sciences.

Ask and ye shall receive:

[Hartree]

This not only discusses it, but has a link to the actual Phys Rev Letters paper. Jester (the blogger) thinks it may be a more mundane explanation, but still an interesting one.

http://resonaances.blogspot.co...