Mystery Signal Could Be Dark Matter Hint In ISS Detector 55
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.
ISIS is in space? (Score:1, Offtopic)
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. ;-)
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Her mother Nut is the sky god, you're saying she can't visit?
Huh? (Score:1)
>> 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?
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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... [illinois.edu]
Re:Huh? (Score:5, Informative)
Re:Huh? (Score:4, Informative)
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.
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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... [space.com]
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Please watch the TV Show Manhattan.
https://en.wikipedia.org/wiki/... [wikipedia.org]
https://en.wikipedia.org/wiki/... [wikipedia.org]
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.
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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."
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1) I don't have anything to prove.
2) Learn to read between the lines ;-)
Cheers,
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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
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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 si
Re:Huh? (Score:5, Informative)
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.
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neutralino?! (Score:2)
Does this mean they'll find the gravioli next?
Wow, I thought you were dead. (Score:2)
Great job on the whole moving out of the domes thing; how's R. Daneel?
Re: Wow, I thought you were dead. (Score:2)
Daneel went back to Earth after I shacked up with Gladia. I suspect he's been trying out some new laws on my wife.
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Cool beans; tell him I said hey; and he was right about those chicks. :)
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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.
So, what energy are we talking about? (Score:2)
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... :)
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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 ;)
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That was what was unclear; thanks. :)
idrtfa.
Annihilating the Milky Way's halo? (Score:2)
the telltale sign of dark matter annihilating the Milky Way's halo
Is that supposed to be "annihilating in the Milky Way's halo"?
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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 se
Re:Generally accepted (Score:5, Informative)
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.
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Poor summary (Score:2)
Ask and ye shall receive: (Score:2)
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... [blogspot.com]
Dark matter or supersymmetry verification (Score:2)
My speculation (Score:2)
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 parall