X Particle Might Explain Dark Matter & Antimatter 285
cold fjord writes "Wired Science has a story on a new theory that tries to explain dark matter, and the balance of regular matter with antimatter. This theory may even be testable. From the article: 'A new hypothetical particle could solve two cosmic mysteries at once: what dark matter is made of, and why there's enough matter for us to exist at all."
It's also (Score:4, Funny)
What gives the X-Men their powers.
Re:It's also (Score:4, Informative)
I was about to post:
It can solve two great outstanding problems in physics simultaneously? I nominate that we start calling it "the uncanny x-particle."
Re:It's also (And the PowerPuff Girls!) (Score:2)
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In one episode, it's revealed that Chemical X can be substituted with the vile sludge in a long-unflushed prison toilet XD
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The proposed particle, named simply “X,” has a separate antiparticle called “anti-X.”
Not to be confused with Evil-X [slashdot.org]
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Or Racer X.
ArXiv link (Score:5, Informative)
the paper (Score:5, Informative)
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Don't get into the science pool if you can't float (Score:4, Insightful)
"This theory may even be testable."
To be a theory it must be testable.
Re:Don't get into the science pool if you can't fl (Score:5, Insightful)
There's a difference between "testable in theory" and "testable in practice". Science proceeds from both ends towards the middle, where theoreticians and experimenters meet.
Theoreticians work on things that may not be testable in practice, now. They may be testable one day, and that actually happens: particle physicists build bigger colliders, astronomers get to see the views they couldn't before, paleontologists dig up the fossil they expected but didn't have.
It leaves the realm of science utterly when it's not testable even in theory. Between the two there's a gray area, where something may not be practical in the forseeable future, or may require so much time and space and energy that it's absurd to think it would ever become practical. Theoreticians run a minefield here, but it would be invalid to forbid them from going there. They might well find a way to take something absurd and make it realistic; it happens.
I'm glossing over a lot of epistemic niceties here, but the point is that a theory does not have to be testable at the moment to be science. If this one happens to be testable now or in the near future, yay; that lets us exclude a lot of territory that's currently in the mine field. But it likely would not have happened without other theoreticians having explored that space.
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That's actually one of the major problems with many of the current formulations of string theory; they're testable in theory, but in practice by the time we can throw that much energy around we probably won't care about the answer any more, one way or the other.
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Very much so. On the one hand, it's not really correct to dub string theory "not science" just because it's so far from testable. They're doing what theoretical physicists down when presented with a conundrum: they formulate equations and push them around hoping to find something that does give them a testable result.
The other hand, though, is that it's not anywhere near far advanced enough to merit the kind of attention it gets from the general public. There's a notion that they're looking for The Ultim
Re:Don't get into the science pool if you can't fl (Score:5, Insightful)
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Exactly!
I hope, one day, I have enough money to test out the "Race Car on a Train" Theory - to overturn General Relativity.
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At the moment, they are at #3. Unless they can get to both #4 and #5 then the 'theory' is and will remain idle speculation, suitable only for prompting bad jokes in ./
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Re:Don't get into the science pool if you can't fl (Score:4, Informative)
The axiom of choice is an axiom, not a theory. Coincidentally, this is why it is not called the theory of choice.
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It is, however, entirely suited to making bad jokes on ./, for example:
Q: What's yellow and sour and equivalent to the axiom of choice?
A: Zorn's Lemon!
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My theory, which is mine (Score:2)
To be a theory it must be testable.
Can I jut say here for one moment that I have a new theory about black holes? What is it that it is - this theory of mine. Well, this is what it is - my theory that I have, that is to say, which is mine, is mine. What is my theory? This is it. My theory that belongs to me is as follows.
This is how it goes. The next thing I"m going to say is my theory. My theory by MillionthMonkey Esq., Sir, brackets. This theory goes as follows and begins now. Black holes that swallow the earth can be made easily and for
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I can't believe I got suckered into reading that whole thing. I tip my hat to you sir...I tip my hat to you.
Re:Don't get into the science pool if you can't fl (Score:5, Funny)
To be a theory it must be testable.
Prove it.
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I think the phrase should probably technically "This theory may even be testable with current knowledge and technologies for an amount of money which exists."
You're right that all theories must be testable, but that doesn't mean we actually can test them.
"-able" as in plausably able (Score:2)
They don't mean testable as in "the theory makes predictions that could hypothetically be distinguished via experiment" in this case. They mean in the sense of "we may be able to test it", like with existing technology.
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There's testable in the sense of when I let go of this brick it will hit the ground in 1.3 seconds if my theory is correct and then there's testable in the sense of if we construct a 1000 mile high cylinder of neutronium and apply the entire industrial energy output of the earth to it for the next 10 years, this glass of water will boil if my theory is correct.
The latter is testable in the sense that there exists an experiment that would unambiguously falsify it. It's just that we don't have the technology
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> OTOH if the latter required a pegasus feather, it would not be testable.
Sure it would. It would just have to wait until biology has advanced to the point where we can manufacture a pegasus.
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Normally, but there is a lot of theories in Physics that MIGHT or MIGHT NOT be true, but can't be tested YET, including most of String theory and its weird and wonderful offspring.
Thats not to say they CANT be, but we dont know how to yet, and have to , for now, suffice with looking for mathematical models of string theory that fit with what we CAN observe.
Re:Don't get into the science pool if you can't fl (Score:5, Interesting)
Re:Don't get into the science pool if you can't fl (Score:5, Funny)
In fact, I challenge you to name even one theory that isn't testable.
P = NP.
Your move.
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Well are we necessarily talking about scientific theories or any theory at all? There are certainly theories which can't be tested.
Even in the scientific process, you come up with a theory first and from that devise a hypothesis that can be tested. Scientific theories where nobody can think of a way to test it won't generally get a lot of credence and don't become accepted, but they happen. But devising a theory and figuring out whether it can be proven are really two different steps.
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You may be confusing the colloquial "theory" with the scientific definition of a theory.
Unless I've been very, very misinformed, scientific theories that are actually worth calling theories are things which began as mere ideas, formed testable hypotheses, and have been rigorously tested and re-tested.
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Yeah, you've basically been very, very misinformed. Scientific theories are theories first. The theory of relativity was a theory, and from it various people devised testable hypotheses, which were then tested and verified. Since the hypotheses were verified, the theory was given a lot of credibility, but the theory was a theory as soon as it was formulated. Same with the theory of evolution-- it was a theory as soon as Darwin put it together.
Anyone who tells you different is a pedantic douchebag who's
Re:Don't get into the science pool if you can't fl (Score:5, Informative)
And String theory doesn't count. It's about as scientific as Astrology.
A Slashdotter or hundreds of physicists... who's a fellow to believe?
String theory (variants thereof) conforms to observations as well as any other theory. What's lacking is an observation where the predictions diverge.
Until such time as such an observation becomes possible, if you want to knock string theory you should argue on the basis of Ockham's Razor, not on perceived parallels with astrology.
Re:Don't get into the science pool if you can't fl (Score:5, Insightful)
There are about 10^500 possible string theories. We haven't yet found any that conform to all our observations. We don't know if it's even possible to search efficiently for that needle in the 10^500-big haystack, so string theory might be like the evil hall of mirrors in a bad B-movie: "yes, my childish nemesis, you falsified THIS one, but which one is the REAL string theory? HA HA HA!".
String theory may not be on a par with astrology, but IMHO it sullies the term theory. Anyone who has defended the theory of Evolution against fundies knows that's a bad move. It wouldn't be a bad idea to rename it string physics, even though arguably it's not physics yet either.
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No. 5 string theories, all which seem correct. That's why there is M-theory. Are you improperly referring to string vacua?
Anyways, read the wikipedia article for an overview. At least when you talk about whether or not it should be called a theory you won't look like an ignorant jackass.
If true, it's very nature would make it extremely hard to test at low energies.
Some would say impossible, but I hold out hope that some clever person will find a way to test it. Or at least it's properties.
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And String theory doesn't count. It's about as scientific as Astrology.
Oh come now, it's at least as scientific as alchemy.
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Astrology is easily falsifiable, so far string theory isn't.
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Astrology is testable. Get some astrologers and a pool of people. Find out what the astrologers are willing to predict that's testable, give them the birth information of the people, tally the predictions up, and see if they performed above chance level. The one time I heard of this being done, the astrologers didn't, which is what most people here would expect.
Astrology could be a scientific field, if it produced positive testable results.
I can answer that (Score:2)
So you put up a challenge and then immediately move the goal post using an ad hom attacks. Yeah. However, I will rebut your drivel with a simple fact:
This is physics, and in physics the 'term' theory is generally used for a mathematical framework.
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Spoken like someone who knows less than nothing about evolution.
Here's a trivial example: Find me fossil bunny in the Cambrian layer and you've just disproved evolution, and you'll likely get all sorts of awards very quickly (Nobel Prize, etc.)
Another trivial example: Just about anything a Creationist thinks evolution means. For instance, if we really did see a Crocaduck, that would pretty much be the end of the theory.
And yes, evolution makes testable claims. You can look at any of the phylogenetic trees -
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For instance, if we really did see a Crocaduck, that would pretty much be the end of the theory.
Yet, the theory persists despite the platypus.
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Many of us with actual scientific backgrounds would call them hypotheses, not theories.
Kindof Summary (Score:4, Interesting)
Equal amounts of X and anti-X were created in the Big Bang, and then decayed to lighter particles. Each X decayed into either a neutron or two dark-matter particles, called Y and . Every anti-X converted to an anti-neutron or some anti-dark matter.
But the hypothetical X particle would rather decay into ordinary matter than dark matter, so it produced more neutrons than dark matter. Anti-X preferred decaying into anti-dark matter, and so produced more of it.
Bold emphasis added is mine. Does this theory explain why "particle X" would rather decay into ordinary matter? Isn't that begging the question? How is that any different than moving to the larger set of all mass, and just saying "Hypothetical universe X would rather form more ordinary matter than dark matter". I understand they may be foregoing the DiffyQ's that perhaps stand behind their assertions for the word "rather" to provide for the layman, but this premise kills the theory for me unless there exist math/science/evidence/a reason besides the word "rather for this article.
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Re:Kindof Summary (Score:5, Informative)
CP violation has already been observed. This theory provides a mechanism whereby it can account for both dark matter and the matter-antimatter imbalance.
Re:Kindof Summary (Score:5, Funny)
+1 Proper use of "begging the question"
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Truly this day should go down in Slashdot history.
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Alright, so IANAPP, but, FTA:
[...]
Does this theory explain why "particle X" would rather decay into ordinary matter?
Does the quantum therory explains why fermions would (never/rather) not share the same quantum state with others?
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It seems it does, tough I didn't yet understand it enough to know.
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People versed in quantum field theory talk in a way that implies that it comes from the theory. I know that the spin, that was first postulated does come from the theory, that is certain, but I have never received a definitive answer from the exclusion principle. As I said, I don't know the theory to know the answer myself.
By the way, are you a physicist? Is that a definitive answer?
So... (Score:2)
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I don't think this theory requires any new quarks.
First LHC, now... (Score:2)
From TFA:
The signature of dark matter destroying protons “can be easily tested by the even bigger proposed underground detectors” planned to be built somewhere in Europe.
Should anyone interested in science just move to Europe now? Seems to be the place in the world where people actually care about science these days.
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So... your solution to providing access to higher education without limiting it to the rich, or saddling people with massive debt, is to either a) put people through the military (translation, have the government pay for it, anyway), or b) limit it to the top few percent who can gain access to scholarships.
Uhuh. Screwy, indeed.
So, just OOC, which one did *you* do?
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The Happy Fun Science Reporting Telephone Game (Score:2, Informative)
God damnit, no, it doesn't explain all dark matter. It explains how some antimatter could appear in cosmological equations as dark matter.
There's a lot of "dark matter" which really isn't all that dark (in the sense of "unknown") anymore. In cosmology, dark matter is just anything with mass which isn't conventionally visible from here. We can ballpark how heavy the universe should be based on the equations we've figured out for how the universe works in our neighborhood. Then we can turn around and observe
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Didn't they also find more stars in galaxies recently, even lowing their dependence on "dark matter".
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> Didn't they also find more stars in galaxies recently...
Yes.
> ...even [lowering] their dependence on "dark matter".
No. The masses of galaxies are not determined by counting stars.
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Didn't they also find more stars in galaxies recently, even lowing their dependence on "dark matter".
Well it means that we found a bunch of the 'normal' dark matter, as was expected to eventually happen, so in that sense yes we have less dependence on dark matter because some of it was only 'dark' as in 'unseen'.
For the "weird" dark matter, WIMPs or whatever this theory predicts, there are separate predictions on the amount of that which should exist. There were discrepancies in this prediction, though, in
More info here ... (Score:2)
man 3 XInternAtom
Testable (Score:4, Funny)
Physicists going old-fashioned on us, eh?
wimps (Score:3, Funny)
whenever two WIMPs meet up in space, they annihilate each other
I'm trying to picture this in my head, and failing.
It's called the X particle because (Score:2)
it's extreme... EXTREME!
i love how... (Score:2)
/.'s summary calls it a theory, when the wired article uses hypothetical. From what i understand, it only becomes a theory once the scientists have run out of other options (meaning, they have failed at breaking the hypothesis).
I posted something similar on Dec 2nd (Score:2)
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So Voyager is now sending scientific papers to 2010's Earth? Cool!
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Yeah, someone inverted the tetrion field and sent a tachyon pulse through the main deflector dish, and now we have particle of the week papers leaking from the fictional universe into the real one. If the dilithium matrix can hold out just a little longer, we have high hopes of getting an in-tact honest politician through the rift.
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I'll be at the Tomohawk room in Chippewa tomorrow night if you want to discuss it.
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I like you, you got moxie.
Here's a quarter, kid. Go buy a nicer shirt.
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I nominate Michael Krisotpeit as the 2010 /. Troll of the Year. We can send the award to all the fake addresses he keeps posting.
I swear, there hasn't been a troll this amusing since twitter. WHatever happened to him anyway?
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This thread seems to have uncovered the secret behind the copious presence of Dark Matter.
It appears to be fecal matter.
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I swear, there hasn't been a troll this amusing since twitter. WHatever happened to him anyway?
Someone at Microsoft gave him a call, said they wanted to have him meet with Bill Gates and Steve Ballmer to voice his complaints in person. Nobody saw him for a few weeks after that.
He's a janitor at MS now, he won't say what happened, he just keeps cleaning away with that thousand-yard stare, mumbling "I'm a PC and I have no complaints..."
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Your mind is like a steel trap, full of mice.
Now, g'way boy, you're botherin' me.
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You are mechanical.
Re:testable? (Score:5, Insightful)
Yes, but why?
That's the question that needs answering. We see that there is matter, obviously, but common sense (assuming the big bang is accurate, and it has held up pretty well over the years) says their shouldn't be.
So why does matter exist? Why didn't matter and anti-matter annihilate each other evenly? They've tested it in the colliders, and sure enough, matter and anti-matter are not created equally given the conditions necessary to create them.
This is a theory to explain why what is, is. This is how science works. You take an observable fact, create a hypothesis for why it might be so, and test the hypothesis. If it works as the hypothesis describes, you're closer to knowing why the observable fact is an observable fact. When you know a bunch of reasons why observable facts exist, you start to be able to predict new things that you haven't observed yet, and you can start looking for them. If you don't find them, your theory is bunk. If you do, your theory may still be bunk, but you at least know it is pretty good.
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Not to be a nit-pick, but in order for common sense to say there shouldn't be matter, you have to rely on both big bang theory AND dark matter theory. The fact that there is matter may not speak to big bang theory at all... it may speak to primarilly dark matter theory and the validity of that. There are other theories explaining gravitational di
Except it has nothing to do with dark matter (Score:2)
Yes, well, nice canned rant, except that wasn't the topic. For the "ignorant conspiracy theorists spewing about how dark matter is wrong because they don't understand it" room, you'll want to go down that hall, take the second left and it's the door at the end of the corridor.
This was about antimatter, which isn't even remotely the same as dark matter.
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Why you ask?
The answer is gravity can not push.
If you throw that out, all sorts of things open up but it make for a huge mess on modern physics.
But I'm okay with that until someone can explain the Pioneer space probes doing odd things using the gravity pulls model.
just put a crowbar by the testing lab (Score:5, Insightful)
just put a crowbar by the testing lab
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Cogito ergo sum.
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your comprehension skills are very telling.
ur mum's face fail.
you're an idiot.
Re:Who cares (Score:4, Insightful)
Wow, haven't been following physics much, eh?
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Why are we always in such a hurry to mod vague nerd cynicism as 'Interesting'?
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I know! They're more correctly referred to as "African-American holes".
Re:Who cares (Score:5, Insightful)
Yes, it's because it doesn't emit (except for the Hawking radiation) but it's still a name of ignorance: the existance of the singularity proofs Einstein's general relativity as wrong but we still lack a better theory to substitute it.
Actually it's the opposite.
The existence of singularities was a major prediction of General Relativity, and the source of much skepticism towards the theory. People didn't believe a thing like that could exist in our universe. The discovery of Black Holes with many of the predicted properties was (more) proof that GR was a damn good theory.
Not that we don't need a better theory to address known flaws, or that you couldn't in some way say Black Hole is a 'name of ignorance'. Certainly, there is a lot we don't know about them. If there is any problem with relativity wrt black holes, it's that since we can't look past the event horizon, we can't tell if there really exists a mathematical discontinuity in the universe or if something else is happening.
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If there is any problem with relativity wrt black holes, it's that since we can't look past the event horizon, we can't tell if there really exists a mathematical discontinuity in the universe or if something else is happening.
The problem I see with both special and general relativity is that it's an excellent mathematical method, but it's an ad hoc mathematical tool that cannot be extended beyond certain limits.
In relativity nothing can travel beyond light speed because that would imply an infinite energy, but that doesn't preclude some other mathematical solutions. However, if one assumes that space and time are quantized, then it seems like the existence of an absolute limit on the propagation speed of waves is necessary, from
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If it is of interest to anyone (this subject is of a great interest to me)
Re:Who cares (Score:5, Interesting)
In relativity nothing can travel beyond light speed because that would imply an infinite energy,
Not exactly. In Relativity nothing with rest mass can travel at the speed of light because that would imply infinite energy.
Nothing at all, not even information, can travel faster than light because that implies that you could create scenarios where from certain reference frames, effects appear to happen before causes. As in time travel, or causality violation, and both Relativity theories (and the rest of physics) assumes causality to hold.
Ten years after Einstein's death we discovered a universal velocity reference in the microwave background dipole, so one of the main tenets of special relativity is not true anymore.
Not true. All Special Relativity says is that there is no preferred reference frame, as in the laws of physics must appear to hold true according to every observer. There is not one "special" reference frame where causality only needs to hold for it.
There was never anything in Relativity saying that there couldn't be some convenient reference against which to measure your velocity. Which is all the CMB dipole really is, and in the sense of what it implies for Relativity is no different than arbitrarily deciding the Andromeda Galaxy is our reference.
I believe the future lies in information theory.
The present and recent past lies is information theory. Information theory, which arose from QM, is fundamental to explaining many situations encountered today, like limits on the efficiency of irreversible calculations or the decay rate of black holes. However there is nothing in Information Theory that suggests information can travel faster than light. Indeed, quite the opposite, and this limit is key to understanding things like quantum entanglement and why it cannot be used for information transfer.
Assuming observable events happen in the universe, and assuming that causality exists, i.e. that if some event causes another that relation will exist under all circumstances, then we can think on how information about different events is transported through the universe. Again, this would be a truly absolute limit, not one imposed by our limitations in measuring and calculation.
That's pretty much how it's already done -- assume causality holds for all reference frames, and you can see that information cannot travel faster than light.
However at the end of the day no matter how elegant a mathematical model you have constructed, there are going to be variables whose values in our universe must be determined experimentally. Like c. You can get c via direct measurement, you can calculate it based on other constants which must themselves be measured. Either way.
Yet as our measurements get more precise, the values for these constants becomes more precise, and doesn't suddenly change values to something outside the error bars on previous less precise measurements. We're still depending on measurement, but we aren't going to up-end physical theories at some point when we hit the 32nd digit of c and suddenly nothing works.
This only seems like a problem if it bothers you for some reason that you can't derive all physical constants from a mathematical model, and instead the only way to know what values to place in that model of the universe is by actually looking at the universe.
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Yeah, I originally said that the inside of the black hole beyond the event horizon was unknowable, but that seemed presumptuous and a little like begging the question.
I'm not sure Hawking radiation, if it exists, is going to tell us much more than the rate of virtual particle creation. Nothing is actually escaping the black hole, and it seems like the radiation would have very high entropy. But maybe someday...
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Unfortunately such reasoning is certainly suspect in general -- Aristotle did it by postulating that nature was designed with niches to fit the various animals perfectly because he was unaware of the theory of evolution which has animals evolving into those niches -- but often quite successful in particle physics. The neutrino was first postulated totally arbitrarily to help explain weak decays and wasn't discovered for decades after, but people generally accepted it existed because the theory worked nicely
Re:The box for Schrödinger's cat (Score:5, Informative)
"Dark matter" is not a theory. It is a label for a set of observed phenomena. Galaxies move as though they contained something that does not interact electromagnetically ("dark") but does interact gravitationally ("matter").
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NO. what the hell is wrong with you people? (Score:2)
To be a scientific theory it needs to make testable PREDICTIONS. a Scientific hypotheses needs to have a way to be testable. The way to be tested may or may not be doable at the time of the presentation of the scientific hypotheses.
The pedagogical definition means it needs bodies of evidence, not just falsifiability.
As I hope you know, the only test that counts are tests the try to falsify it.
BUT NONE OF THAT MATTERS. This is physics, and in physics the 'term' theory is generally used for a mathematical fr