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Cosmic Antimatter Excess Confirmed

Soulskill posted more than 2 years ago | from the good-news-for-warp-core-engineers dept.

Space 113

sciencehabit writes "In 2008, the Italian satellite PAMELA picked up an unusual signal: a spike in antimatter particles whizzing through space. The discovery, controversial at the time, hinted that physicists might be coming close to detecting dark matter, an enigmatic substance thought to account for 85% of the matter in the universe. Now, new data from NASA's Fermi Gamma-ray Space Telescope confirm the spike (abstract)."

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Dark matter or antimatter? (4, Insightful)

Anonymous Coward | more than 2 years ago | (#38146620)

I'm confused, is this about antimatter or dark matter?

Re:Dark matter or antimatter? (2, Informative)

buchner.johannes (1139593) | more than 2 years ago | (#38146636)

The answer is in the second paragraph of the article.

Re:Dark matter or antimatter? (5, Funny)

Anonymous Coward | more than 2 years ago | (#38146702)

The answer is in the second paragraph of the article.

Well, don't keep us hanging in suspense here! What does the second paragraph of the article say?!?

Re:Dark matter or antimatter? (5, Informative)

justin12345 (846440) | more than 2 years ago | (#38146756)

"Theorists generally believe that when two dark matter particles collide, they should annihilate each other to produce ordinary particles, such as an electron and its antimatter twin, a positron. Thanks to Einstein's iconic equivalence between energy and mass, E=mc2, each of those particles should emerge with an energy essentially equal to the mass of the original dark matter particle."

I suspect that the author doesn't know that "dark matter" isn't a synonym for "antimatter". The above paragraph, if true, would make the universe a very explode-y place.

Re:Dark matter or antimatter? (5, Interesting)

mattie_p (2512046) | more than 2 years ago | (#38146776)

"Theorists generally believe that when two dark matter particles collide, they should annihilate each other to produce ordinary particles, such as an electron and its antimatter twin, a positron. I suspect that the author doesn't know that "dark matter" isn't a synonym for "antimatter". The above paragraph, if true, would make the universe a very explode-y place.

Some dark matter candidates are, according to theory, their own anti-particle. The only reason it is not a more explode-y space is that dark matter interacts very weakly with other matter, including itself, and therefore has not been identified yet.

Re:Dark matter or antimatter? (5, Funny)

rossdee (243626) | more than 2 years ago | (#38147076)

"Some dark matter candidates are, according to theory, their own anti-particle"

In related news, Herman Cain is his own worst enemy.

Re:Dark matter or antimatter? (-1)

Anonymous Coward | more than 2 years ago | (#38147726)

"Some dark matter candidates are, according to theory, their own anti-particle"

In related news, Herman Cain is his own worst enemy.

Was that a 'darkie' joke? Really? Racist.~

Re:Dark matter or antimatter? (1)

St.Creed (853824) | more than 2 years ago | (#38151664)

I read that as a joke on the Republicans. You know, the Sith :)

Re:Dark matter or antimatter? (0)

Anonymous Coward | more than 2 years ago | (#38148092)

This sentence made me believe the author has no idea what they're talking about.

"Physicists hope they might use the accumulating data on antimatter to home in on the mass of the weakly interacting massive particle (WIMP), which is thought to be the fundamental dark matter particle"

Re:Dark matter or antimatter? (1)

JoeMerchant (803320) | more than 2 years ago | (#38148552)

Some dark matter candidates are, according to theory, their own anti-particle. The only reason it is not a more explode-y space is that dark matter interacts very weakly with other matter, including itself, and therefore has not been identified yet.

That would make dark matter very lonely. If it interacts weakly, wouldn't there need to be more of it to account for the effects that dark matter was invented to explain?

Re:Dark matter or antimatter? (3, Informative)

Surt (22457) | more than 2 years ago | (#38149138)

It was mainly invented to explain why the amount of gravitational effects observed exceed the amount of mass visible. If dark matter has normal gravity, but interacts with other matter in an otherwise very limited fashion, then, no, there wouldn't need to be more of it.

Re:Dark matter or antimatter? (3, Interesting)

dmartin (235398) | more than 2 years ago | (#38149382)

Some dark matter candidates are, according to theory, their own anti-particle. The only reason it is not a more explode-y space is that dark matter interacts very weakly with other matter, including itself, and therefore has not been identified yet.

That would make dark matter very lonely. If it interacts weakly, wouldn't there need to be more of it to account for the effects that dark matter was invented to explain?

Gravity is incredibly weak for individual particles. The reason we notice it in everyday life is because there are a lot of particles in the Earth pulling us the same way and all those little bits add up. This is the bit that we rely on to explain the galactic rotation curves (and to explain the cold spots in the CMB). If the dark matter only interacted gravitationally then it would almost impossible for us to make any direct detection of this sort (but it is also difficult to explain how so much of it was produced).

The idea of the WIMP is that the dark matter, in addition to interacting gravitationally, also interacts via another force called the weak force. While these interactions would have to be somewhat small so that the dark matter did not all explode, or collide too much with itself, it would still be much much stronger than the gravitational interactions on a per particle basis -- but would not "add up" the same way. [As a very simple analogy, the electric forces between protons and electrons are very strong compared to their gravitational attraction, but on large distances matter is almost neutral because opposite charges attract]

This idea is appealing to physicists because
    1) if true, we have hope of detecting the dark matter and verifying its existence and
    2) it tells us (very broadly) that we would produce the right amount of dark matter as the universe was cooling (the so-called WIMP miracle)

Re:Dark matter or antimatter? (1)

Anonymous Coward | more than 2 years ago | (#38149948)

I'm missing something here. I thought one of the greatest (theoretical) achievements of the last century was the unification of electromagnetism and the weak (nuclear) force (i.e. they are mediated by the same charge carrier). How does dark matter fit in with this view, if it does not interact EMically yet does respond to the weak force?

Re:Dark matter or antimatter? (4, Informative)

sheepe2004 (1029824) | more than 2 years ago | (#38146892)

Why is this modded +4 informative? The quoted text doesn't confuse dark matter and antimatter. The universe isn't explode-y because (if the theorists are right) dark matter interacts very weakly and so collisions are very rare.

Re:Dark matter or antimatter? (1, Interesting)

justin12345 (846440) | more than 2 years ago | (#38147024)

Just think about the amount of energy that would be present in such a system. If two (nebulously defined) particles of dark matter can annihilate (probably the wrong word) each other to produce a particle of antimatter and a particle of matter, it follows that the dark matter particles must be as massive as regular matter/antimatter. So they wouldn't be very weakly interactive. And that's even assuming that absolutely no mass is converted to energy when the particles "annihilate" one another, which is unlikely.

If that statement were true dark matter would be anything but dark. You would haver massive strongly interactive particles dumping a huge amount of matter, antimatter, and energy (not to be confused with dark energy) into the universe. Then the matter and antimatter reacts, releasing still more energy. Such a reaction would be pretty easily observed. By comparison, WIMPs should be near massless, but abundant, and hence dark.

Re:Dark matter or antimatter? (3, Informative)

MrZilla (682337) | more than 2 years ago | (#38147256)

I think you are confusing "massive" and "strongly interacting".

The whole point of "dark matter" is that it interacts gravitationally with ordinary matter, but almost never in any other way. So, having massive dark matter particles means a higher gravitational field around them, but nothing else.

I agree with your other point however, that having two of these dark matter particles annihilating directly to a electron/positron pair seems.. strange. Normal matter/antimatter annihilations always (afaik) produce "energy" (i.e. photons).

But a good thing is that if annihilation of dark matter produces electron/positron pairs, then smashing electrons and positrons together in an accelerator should produce dark matter.

Re:Dark matter or antimatter? (2)

marcosdumay (620877) | more than 2 years ago | (#38147318)

The photons were probably simplified out of the explanation. If the article would report everything, it would be talking about momentum, and virtual particles too. They probably annihilate into a photon, that produces a pair of electron/positron, and that pair is separated by Earth's magnetic field.

Also, they probably didn't detect the positrons, but some photon generated by its annihilation.

...but no anti-protons (3, Informative)

Roger W Moore (538166) | more than 2 years ago | (#38150692)

If the article would report everything, it would be talking about momentum, and virtual particles too.

It would not report on virtual particles because the annihilation takes place in the galactic core where the densities of DM are highest and virtual particles can only exist for the tiniest fractions of an instant not the ~50k years needed to make it from the core.

The question you should be asking is where are all the anti-protons? Since DM particles generally need to have masses roughly ~100 or more times the mass of the proton their annihilations should be capable of producing all stable anti-particles below this. Hence most models predict an excess of anti-protons as well as positrons but no satellite has seen any evidence of this. So if this positron excess is due to DM (and that is a BIG if!) we may have to start looking at some of the more exotic DM models (e.g. Arkani-Hamed et al. Phys Rev D (2009) vol. 79 (1) pp. 015014) which some of us are already looking for with the LHC.

Re:Dark matter or antimatter? (5, Informative)

Anonymous Coward | more than 2 years ago | (#38147338)

Anything which can produce photons also can produce electron-positron pairs, just with lower probability. However dark matter particles should not produce photons directly because they don't interact electromagnetically (the defining property of dark matter!), and annihilating (directly) into photons would be an electromagnetic interaction (photons are not "pure energy", no matter how often you read that). Rather as weakly interacting particles, I'd expect them to produce virtual Z0s which then could decay into (real) electron-positron pairs, assuming sufficient energy (I'd expect the dominant decay channel to be into neutrinos, though).

Re:Dark matter or antimatter? (1)

MrZilla (682337) | more than 2 years ago | (#38149306)

Thanks for the explanation. I must admit my particle physics is very weak (not that that will stop me from commenting..)

I can not remember ever having seen an example where an annihilation produces anything other than photons, but I guess it's usually simplified that way for us laymen. Anyways, it makes sense now that I think about it.

Re:Dark matter or antimatter? (4, Insightful)

geekoid (135745) | more than 2 years ago | (#38149396)

(not that that will stop me from commenting..)

and that is what's wrong with the world.

I don't know jack abut the subject, but I'll be damned if that stopped me from commenting like I'm an expert.

Re:Dark matter or antimatter? (1)

justin12345 (846440) | more than 2 years ago | (#38149772)

Take a step back, take a deep breath, and get a little perspective. You're complaining about a lack of expertise on a website that allows anonymous posting, where the standard is semi-anonymous posting. No experts to be found there. You are commenting in a thread about dark matter, which is called dark because very little is known about it. No experts on that either. You are also commenting in a sub-thread which only purpose is to call into question whether the author of the article is confused by the terminology "dark matter" and "antimatter". There isn't a shred of expertise anywhere in sight.

And that's all ok. The idea is to have a discussion, there is nothing to prove here. Discussion like this is the beginning of problem solving, not the final step. No one is going to write an article about the significant advances in particle physics made by geekoid (135745) or anyone else posting on Slashdot.

Re:Dark matter or antimatter? (1)

heinousjay (683506) | more than 2 years ago | (#38151110)

I don't know jack abut the subject, but I'll be damned if that stopped me from commenting like I'm an expert.

And that is what's really wrong with the world, people who add their own little extra "facts" to make a point that wasn't really there in the first place. OP never insinuated any sort of expertise, and you are not the arbiter of who is allowed to comment.

Re:Dark matter or antimatter? (1)

izomiac (815208) | more than 2 years ago | (#38151842)

Was the world really that much better during feudal times, where only the elite were educated and therefore the only opinions that counted?

Re:Dark matter or antimatter? (1)

justin12345 (846440) | more than 2 years ago | (#38147476)

You're right, I was using the term "strongly interactive" incorrectly.

Re:Dark matter or antimatter? (1)

cyberchondriac (456626) | more than 2 years ago | (#38148476)

I think you are confusing "massive" and "strongly interacting".The whole point of "dark matter" is that it interacts gravitationally with ordinary matter, but almost never in any other way. >

Well, that explains a lot. This is why we can't find the elusive Higgs boson, they're obviously all out there in deep space hiding as dark matter!

Re:Dark matter or antimatter? (1)

sheepe2004 (1029824) | more than 2 years ago | (#38147258)

I'm not a particle physicist but, from wikipedia: [wikipedia.org]

The main theoretical characteristics of a WIMP are:
Interaction only through the weak nuclear force and gravity, or at least with interaction cross-sections no higher than the weak scale;
Large mass compared to standard particles (WIMPs with sub-GeV masses may be considered to be light dark matter).

Re:Dark matter or antimatter? (1)

yndrd1984 (730475) | more than 2 years ago | (#38147290)

If two particles of dark matter can annihilate each other to produce a particle of antimatter and a particle of matter, it follows that the dark matter particles must be as massive as regular matter/antimatter.

Well, some particular kind of 'regular' matter/antimatter particle, yes.

So they wouldn't be very weakly interactive.

Why?

Re:Dark matter or antimatter? (1)

Anonymous Coward | more than 2 years ago | (#38147072)

Why is this modded +4 informative? The quoted text doesn't confuse dark matter and antimatter.

Probably because the people modding are fully aware that "antimatter" is a specific type of particle, and "dark matter" is a phrase we use instead of saying "a bunch of shit we don't have any clue about yet."

Re:Dark matter or antimatter? (4, Funny)

Joce640k (829181) | more than 2 years ago | (#38147574)

Why is this modded +4 informative?

Because it saved millions of slashdotters from having to read TFA.

Re:Dark matter or antimatter? (0)

Anonymous Coward | more than 2 years ago | (#38149490)

It's modded up because the it quoted the text. This is informative. The fact that the quoter's understanding is a bit muddy diminishes the value, but it's still informative.

Re:Dark matter or antimatter? (1)

Lumpy (12016) | more than 2 years ago | (#38146922)

"I suspect that the author doesn't know that "dark matter" isn't a synonym for "antimatter". The above paragraph, if true, would make the universe a very explode-y place."

Ohhh! I'm gonna sing the doom song!!!!

Re:Dark matter or antimatter? (2)

Black Parrot (19622) | more than 2 years ago | (#38146990)

I thought the general view is that dark matter doesn't even interact with itself, except gravitationally.

Re:Dark matter or antimatter? (4, Informative)

miketee (513478) | more than 2 years ago | (#38147030)

Clearly, the author DOES differentiate between Dark matter, and antimatter (and matter). They use the terms to refer to different things: 2 Dark Matter particles BEFORE a collision, and a matter + antimatter particle AFTER it. If you meant that the particle/antiparticle pair would instantly annihilate (and the large amount of DM would cause many such annihilations), remember that the DM particles *collided*. IANA Physcist, but wouldn't momentum be conserved, and the 2 new particles move apart with the conserved momentum, preventing annihilation? Also there is the weak interactivity that others have mentioned.

Re:Dark matter or antimatter? (1)

mcgrew (92797) | more than 2 years ago | (#38149218)

The above paragraph, if true, would make the universe a very explode-y place.

I'd say it is an "explodey" place. Hell, there's a hydrogen bomb only eight light seconds away, and it's been exploding for over four billion years. Almost every twinkle in the night sky is a incredibly huge fusion explosion.

Re:Dark matter or antimatter? (4, Informative)

Pope (17780) | more than 2 years ago | (#38149634)

Eight light minutes, actually.

Re:Dark matter or antimatter? (1)

buchner.johannes (1139593) | more than 2 years ago | (#38150000)

The above paragraph, if true, would make the universe a very explode-y place.

I'd say it is an "explodey" place. Hell, there's a hydrogen bomb only eight light seconds away, and it's been exploding for over four billion years. Almost every twinkle in the night sky is a incredibly huge fusion explosion.

The street is an "explodey" [what is that word!?] place. There is a car 1 meter away, and it has been exploding oil for an hour now. Almost every noise you hear in a street is a powerful explosion.

There is no reason to make it sound so scary. It is an ensemble of continuous, small, explosions that amass to a continuous energy output (not "explodey").

Re:Dark matter or antimatter? (4, Funny)

mattie_p (2512046) | more than 2 years ago | (#38146706)

I'm really confused. Dark matter is made out of spikes? Do they stab at thee from hell's heart or something?

Re:Dark matter or antimatter? (1)

Muad'Dave (255648) | more than 2 years ago | (#38147782)

That's Khaaaaaaan!!!

Re:Dark matter or antimatter? (1)

Greyfox (87712) | more than 2 years ago | (#38149618)

What's it matter?

Hmm wait...

What's it, matter?

Great (0)

Anonymous Coward | more than 2 years ago | (#38146624)

Somebody forgot to flush again.

Its not that simple.. (-1, Troll)

dev825 (2515054) | more than 2 years ago | (#38146658)

The distribution of positrons they are talking about can be found here [evenweb.com]
While I do notice the trend upward as energy increases its not that clear. You know, its easy to shape statistics results when you know what it should look like.
Damn lies!

Re:Its not that simple.. (2, Informative)

Anonymous Coward | more than 2 years ago | (#38146698)

goatse alert

Re:Its not that simple.. (1)

nitehawk214 (222219) | more than 2 years ago | (#38149252)

goatse alert

Indeed, any poster named in the pattern dev000 and a link to evenweb is a troll.

Mod Up (0)

Anonymous Coward | more than 2 years ago | (#38149936)

I do believe that this information should be more prominent.

Just the emissions of an alien real estate agent.. (3, Funny)

ibsteve2u (1184603) | more than 2 years ago | (#38146668)

...zipping by to see if we've eliminated ourselves yet.

What I am afraid of (2, Funny)

G3ckoG33k (647276) | more than 2 years ago | (#38146686)

What I am afraid of, if anyone ever cared... ;)

What I am afraid of is that some people will use this as evidence of otherworldly forces (any Slashdot reader), supreme beings (any Slashdot reader), Batman (a DC comic), demons (a variety of delusions), Thor (The Norse God), Bogeyman (an American tell tale), Akhenaten's Ra (Akhenaten the monotheistic precursor to the Abrahamitic monotheistic "Yahweh"), Santa Claus (The Coca Cola version of a Norse tradtion), Green Lantern (a DC superhero), Sherlock Holmes (a Doyle detective), King Kong (a Hollywood movie), or whatever has sprung out of man's mind.

Dark Matter. Ok, calm down, we won't bite.

Re:What I am afraid of (-1)

Anonymous Coward | more than 2 years ago | (#38146862)

Omg, is evidence of G3ckoG33k!
All hail G3ckoG33k!

Bow for now (0)

Anonymous Coward | more than 2 years ago | (#38146886)

Until My Kingdom cometh.

Re:Bow for now (2)

Black Parrot (19622) | more than 2 years ago | (#38146996)

Until My Kingdom cometh.

Ah, so when he wrote "supreme beings (any Slashdot reader)", you must be the reader he had in mind.

Re:What I am afraid of (1)

inasity_rules (1110095) | more than 2 years ago | (#38146884)

You live with the strangest of fears... Even if your fears are realized, so what?

If my fears are realized, so what? (0)

Anonymous Coward | more than 2 years ago | (#38146932)

If my fears are realized, so what?

Well, for a starters, we could have the a leader of strongest military force on Earth seriously believing in superstitious matters, again.

It could influence world politics (1)

Anonymous Coward | more than 2 years ago | (#38146988)

"You live with the strangest of fears... Even if your fears are realized, so what?"

It could influence world politics. Imagine some part of the world where some would argue that their well being was given by some otherworldly power, and, that at least some fuck-ups would believe. It could create a situation where we would have a seriously lethal conflict that could go on for decades. inasity_rules, would that be a situation you wouldn't object to, the killing of innocents for any profound reason at all...

Re:It could influence world politics (2)

Surt (22457) | more than 2 years ago | (#38149210)

You feel that there isn't a sufficient amount of irrationality out there to generate wars now, but after dark matter is discovered, there will be a big increase?

Re:What I am afraid of (1)

Anonymous Coward | more than 2 years ago | (#38147478)

What, you didn't notice the paragraph further down the article?

"As a technical feat, it is beautiful," says Harvard University physicist Doug Finkbeiner. Still, he says it's too soon to say whether the new data say anything about dark matter. [...]The new paper is "a wonderful confirmation of the PAMELA result," he says, "however the positron signal will likely be there whether the positrons come from dark matter annihilation, or from pulsars, or from tooth fairies."

(emphasis added)

Re:What I am afraid of (1)

Ricwot (632038) | more than 2 years ago | (#38147526)

Surely a world with Sherlock Holmes would provide a good deterrent to criminals, or at least make their exploits really interesting reading for those of us who still read newspapers?

Re:What I am afraid of (1)

Muad'Dave (255648) | more than 2 years ago | (#38147792)

I'm worried about midichlorians.

Re:What I am afraid of (1)

garaged (579941) | more than 2 years ago | (#38147882)

They did not do any harm to Anakin....oh wait!

Re:What I am afraid of (1)

mcgrew (92797) | more than 2 years ago | (#38149096)

No reason to, there are none in our galaxy, although I understand that the aliens in a far distant time in a galaxy far, far away have plenty.

Why are we discussing this? (5, Funny)

gringer (252588) | more than 2 years ago | (#38146690)

It doesn't matter

Re:Why are we discussing this? (5, Funny)

migla (1099771) | more than 2 years ago | (#38146728)

>It doesn't matter

What's the matter with you? As a matter of fact, it does. One semantically related question is which of the two mats is more mat than the other - which one is matter? Probably the person who lays mats for a living, the matter, could answer that.

Re:Why are we discussing this? (1)

shikaisi (1816846) | more than 2 years ago | (#38147958)

No, you've missed the point here; what concerns him is which of the particles is glossier than the other, and which is matter.

Re:Why are we discussing this? (2)

Saintwolf (1224524) | more than 2 years ago | (#38146736)

but it does anti-matter ;)

Re:Why are we discussing this? (3, Informative)

muon-catalyzed (2483394) | more than 2 years ago | (#38146942)

> It doesn't matter
yes it matters, particle physics is very important as are cosmic radiation studies, recetly Soudan 2 (underground proton decay particle detector) measure that 10000 relativistic muons are hitting every 1m2 of earth per minute (avg.), now we got this new type of cold fusion confirmed http://en.wikipedia.org/wiki/Muon_catalyzed_fusion [wikipedia.org] , exciting times!

Re:Why are we discussing this? (1, Insightful)

Tukz (664339) | more than 2 years ago | (#38146962)

woooosh

Re:Why are we discussing this? (4, Funny)

Black Parrot (19622) | more than 2 years ago | (#38146998)

woooosh

Well, dark matter *is* hard to detect.

Re:Why are we discussing this? (1)

Tukz (664339) | more than 2 years ago | (#38147084)

I see what you did there.

Re:Why are we discussing this? (0)

Anonymous Coward | more than 2 years ago | (#38147112)

Use a flashlight.

Re:Why are we discussing this? (0)

Anonymous Coward | more than 2 years ago | (#38148314)

I think I just saw some

Re:Why are we discussing this? (1)

babywhiz (781786) | more than 2 years ago | (#38148364)

Matters to me. My WoW toon is Antimatter, and my real name is Pamela. Talk about a brain esplosion.

Re:Why are we discussing this? (0)

Anonymous Coward | more than 2 years ago | (#38151036)

L13z! Tehr r no gurlz on teh interwebs.

Quantum Fluctuation Origins of Universe Theory (2)

Grindalf (1089511) | more than 2 years ago | (#38146828)

Ha, it's regional asymmetry and you know it ...

Opinion (-1)

Anonymous Coward | more than 2 years ago | (#38146918)

Quite extra ordinary don't you think. I have heard of this case but it is strange how so many years ago it is still mentioned, I am sure there must have been other happening related to the dark matter in the meantime! Vacation Rental [vacationrentalnet.com]

Anti-matter vs. dark matter (2, Insightful)

walter_f (889353) | more than 2 years ago | (#38146948)

In my opinion and in contrary to what the original posting suggests, anti-matter should not be viewed as particularly "dark".

E.g., anti-Hydrogen, consisting of an anti-proton and a positron, will readily absorb a quantum of energy (a photon, which happens to be one of the particles that are their own anti-particles) and re-emit a photon again, just like "plain old" hydrogen. Thus, a cloud of anti-hydrogen should be observable as easily (or difficultly) as a cloud of hydrogen, assuming their masses, their viewing distances and all other parameters like temperature, density etc. being equal.

So there should be no difference in observability here, due to the fact that photons are citizens of both realms, of "nornal" matter as well as of anti-matter, and will interact with mass particles of both realms in the same way.

Obviously, "dark matter" looks like a very different beast...

Re:Anti-matter vs. dark matter (5, Informative)

sheepe2004 (1029824) | more than 2 years ago | (#38146994)

I'm guessing you didn't RTFA? They are not saying that antimatter is dark matter.

They have detected a large and unexpected amount of antimatter.
Dark matter collisions (theoretically) can create large amounts of antimatter.
So one possible explanation for the antimatter is that two dark matter particles collided.

Re:Anti-matter vs. dark matter (0)

Anonymous Coward | more than 2 years ago | (#38151584)

So in order to fuel our warp drives, all we need to do is to collect dark matter and convert it? Since there's a lot more dark matter than regular matter (or antimatter for that matter), it would provide a lot of energy.

On a related note: That explains why the group Dark Materia wrote the song "The Picard song"...

Re:Anti-matter vs. dark matter (1)

expo53d (2511934) | more than 2 years ago | (#38147058)

Interestingly enough, we could all be made up of antimatter. If after the Big Bang, the amount of anitmatter was greater than matter, we be made (assuming me happened to exist) out of anitmatter, but call the anitmatter "normal matter", and call the real matter "anitmatter".

Re:Anti-matter vs. dark matter (2, Insightful)

Anonymous Coward | more than 2 years ago | (#38147094)

Interestingly enough, we could all be made up of antimatter. If after the Big Bang, the amount of anitmatter was greater than matter, we be made (assuming me happened to exist) out of anitmatter, but call the anitmatter "normal matter", and call the real matter "anitmatter".

That's gibberish. You might as well says that cats might really be called dogs. They're not. Which is matter and which is anti-matter (or any other labels) depends on what names people have given them. There isn't a "right" answer outside of what people have come up with.

Re:Anti-matter vs. dark matter (1)

Anonymous Coward | more than 2 years ago | (#38147174)

You're the only that anti-matters here, dude.

Re:Anti-matter vs. dark matter (2, Funny)

Anonymous Coward | more than 2 years ago | (#38147188)

Interestingly enough, we could all be made up of antimatter. If after the Big Bang, the amount of anitmatter was greater than matter, we be made (assuming me happened to exist) out of anitmatter, but call the anitmatter "normal matter", and call the real matter "anitmatter".

Yeah! And how come we call them fingers if we never see them fing?

Re:Anti-matter vs. dark matter (1)

Cragen (697038) | more than 2 years ago | (#38147446)

Ha! Reminds me of the time I went to a talk by a Tibetan lama. He asked a question of the audience and requested that everyone who thought the answer was "yes" to "raise your arms." I had to do a mental double-take to get back to the question. :) (In the USA, our expression is "raise your hands".) Good to get my brain nudged from its nap every now and then.

Re:Anti-matter vs. dark matter (0)

Anonymous Coward | more than 2 years ago | (#38147248)

What makes you think this isn't exactly what happened?

Stop quibbling. It is an obvious mistake, chaps (0)

Anonymous Coward | more than 2 years ago | (#38147144)

The abstract is all about matter and antimatter (and why there seems to be an excess of the first one). It has nothing to do with dark matter at all. The phrase "Theorists generally believe that when two dark matter particles collide, they should annihilate each other to produce ordinary particles (...)" is just a plain mistake... oh, wait, there are actually TWO mistakes there. The news from Science Now is all confused. Geoffrey Koch, get yourself a course on physics. -Ignacio Agulló

To quote the philosopher Homer: (2)

orphiuchus (1146483) | more than 2 years ago | (#38147234)

What is mind?
No matter.
What is matter?
Never mind.

Re:To quote the philosopher Homer: (1)

geekoid (135745) | more than 2 years ago | (#38149496)

The laugh after that was awesome. Note: That laugh only happened on the TU episodes.

It seems nobody asked that yet... (1)

marcosdumay (620877) | more than 2 years ago | (#38147348)

So... Are there any theories on how to create a dark matter powered electricity generator?

Re:It seems nobody asked that yet... (1)

geekoid (135745) | more than 2 years ago | (#38149504)

Fists, create the Universe..
the rest is QED.

Alternate explanation (3, Interesting)

AdrianKemp (1988748) | more than 2 years ago | (#38147374)

Antimatter galaxies (or at least clumps) seem like they could also plausibly explain this. That's not an outright endorsement of the theory but I can't help but think that they've got insufficient evidence to show causal link.

They're saying:
1. lots of energy released (presumably when dark matter interacts)
2. anti-matter is created

An equally plausible interpretation is:
1. the anti-matter already exists
2. the interactions with small amounts of matter cause the energy release

I may have missed it, but I don't see anything to rule that possibility out. The primary objection to the anti-matter galaxy theory is that we don't see a lot of annihilation events; This could just as easily be those exact events.

Re:Alternate explanation (1)

marcosdumay (620877) | more than 2 years ago | (#38150248)

They are detecting those events on the Earth magnetic field, not some distant point of the Universe. So, I guess no, if it was an ati-matter galaxy, we'd have detected it already.

Re:Alternate explanation (1)

AdrianKemp (1988748) | more than 2 years ago | (#38150432)

Wait, unless I've missed something you just made an incredibly silly argument. They've detected something for the first time; whatever the explanation for the event is, saying "they'd have detected it already" is broken.

Re:Alternate explanation (1)

marcosdumay (620877) | more than 2 years ago | (#38150866)

That anti-matter was detected here, on Earth's magnetosphere. If it comes from some anti-matter cluster, it would be newby and we'd be able to see it annihilating with the nearby matter, what means, with us. Or better, we'd probably not be able to see anything anymore.

Re:Alternate explanation (1)

AdrianKemp (1988748) | more than 2 years ago | (#38151048)

Can you point to where that's said? From what I read they used the earth as a filter to block out noise, I saw nothing regarding the events happening locally

Re:Alternate explanation (1)

marcosdumay (620877) | more than 2 years ago | (#38151406)

"They found a way to do so, using Earth itself as a particle filter. "You can basically look in certain directions from which only electrons or only positrons will get through the Earth's magnetic field," Vandenbroucke says. "

So, altough their model says the interesting events happened farther away, the anti-matter that they are detecting is quite here.

Re:Alternate explanation (0)

Anonymous Coward | more than 2 years ago | (#38151352)

Antimatter galaxies (or at least clumps) seem like they could also plausibly explain this.

Nope. Electrons and positrons at these energies don't travel far enough to come from another galaxy: they slow down and stop as they lose energy through synchrotron radiation.

The primary objection to the anti-matter galaxy theory is that we don't see a lot of annihilation events; This could just as easily be those exact events.

You've got the first part right, but not the second. If there were pockets of anti-matter, we'd see gamma-rays from annihilation events around the edge of the pocket. PAMELA isn't seeing gamma-rays from antimatter annihilation events; it's seeing antimatter from (possibly) dark matter annihilation events.

Neutralino Annihilation (4, Informative)

Stirling Newberry (848268) | more than 2 years ago | (#38147738)

The most promising wimp is a particle known as the neutralino. This is a hypothesized particle which would exist in either super-symmetrical theories. Super-symmetry says that in an unbroken general theory, every boson - a particle like a photon with an integer spin - has a fermion - 1/2 spin - partner, with the difference being that the fermion has a spin of 1/2. Since we don't seen bosons and fermions of the same energy, if, and it is still if, there was super-symmetry, it is a broken symmetry.

The neutralino would be a composite particle, composed of the super-partners of the guage bosons and the higgs - that is wino (w partner), higgsino (higgs parnter), bino (partner of the weak hypercharge). Since the symmetry is broken, we don't see the original super-partners, only their super-imposed forms with the same mass eigenstate.

When particles annihilate, they produce a set of particles that have a quantum number of 0. Any particles with the same mass-energy as the original colliding pair of particle and anti-particle can be produced. If mass energies are low, this means that the result will be mostly photons, because photons have no mass, and are only energy. That is, they have a low total mass energy. But any particles can be produced, so long as the result totals to 0, and has the same mass energy.

Neutralinos, as you would guess, from the term WIMP, are weakly interacting, and massive. That means that when a neutralino annihilates another, particles with greater mass energy can be produced.

In a 1994 paper Drees et al [aps.org] calculated neutralino decay into gluons. One of the co-authors here Kamionkowski went on to publish more on dark matter and neutralinos. There have been other papers on other possible decay products from neutralino annihilation, because, of course, if annihilation produces unstable particles, or anti-particle pairs, it can keep going until it reaches an end state of stable products. However, not all anti-particle pairs produce annihilate, and if the products are stable, they go bouncing on their merry way.

This means that anti-protons and positrons above the background, and at certain energy levels could be the signature of neutralino dark matter.

Or to roll things back: one of the few ways, other than gravity, we can detect WIMPS is from their annihilations. To determine if, and if so, what, WIMPs are composed of, we have to look at the decay products of those events. The Pamela data shows that there is an excess of positrons, however, it does not show that this excess is from WIMP annihilation. The search for this spectrum is important for both large and small reasons: large because cosmology evolves based on mass, and small because neutralinos, if detected, tell us about the final broken super-symmetrical extensions to the Standard Model, and in turn tell us about the super-partners, and, in turn, about the partners. For example, we have not seen a higgs boson, but a neutralino is an eigenstate of a higgsino fermion, which implies a higgs boson to be partnered with. Back in the 1990's Drees et al published

mod down (0)

Anonymous Coward | more than 2 years ago | (#38148792)

the way this post terminates strongly implies copypasta. please mod down.

Laser of pure anti-matter (0)

Anonymous Coward | more than 2 years ago | (#38148162)

What we need is a Laser of pure anti-matter.

Then we can mount it on a shark.

Consider this (0)

Anonymous Coward | more than 2 years ago | (#38148796)

OK, recently physicists claim to have discovered that the speed of light is not the absolute top end it was once thought to be, now if that holds true then would that not mean that E is not equal to MC squared? We are expecting a certain quanta of matter but that quanta is based upon the false perception about the fundamental components of the equation? I might have missed something here but there it is anyway

brains, dna, antimatter, and dark matter (0)

crowlogic (940856) | more than 2 years ago | (#38149376)

It's all around us and has far more to do with consciousness than any most scientists and theologians can fathom. http://tgd.wippiespace.com/public_html/genememe/asymmetries.pdf [wippiespace.com] one important thing to note in that paper is "Note that matter antimatter asymmetry in the scale of entire genome has largest positive value for human genome and negative value only for yeast genome: this case the magnitude of the asymmetry is largest." and it's no coincidence that this coincides with http://www.physorg.com/news/2011-11-scientists-fountain-youth-yeast.html [physorg.com] announced yesterday "Collaborations between Johns Hopkins and National Taiwan University researchers have successfully manipulated the life span of common, single-celled yeast organisms by figuring out how to remove and restore protein functions related to yeast aging." Also see http://tgd.wippiespace.com/public_html/articles/newcosmo.pdf [wippiespace.com]

Wait Wait Wait... (1)

DarthVain (724186) | more than 2 years ago | (#38149390)

I was under the impression that anti-matter came from dilithium crystals, not dark matter.

Now red matter apparently makes black holes, which I guess are kinda dark.

Anyway none of this makes any sense to me. I think we need some new TV show that has this sort of information in it.

I mean if the hydrospanner ain't broke, don't fix it.

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