LHCb Experiment Observes New Matter-Antimatter Difference 129
An anonymous reader writes "Matter and antimatter are thought to have existed in equal amounts at the beginning of the Universe, but today the Universe appears to be composed essentially of matter. By studying subtle differences in the behavior of particles and antiparticles, experiments at the LHC are seeking to cast light on this dominance of matter over antimatter. Now the LHCb experiment has observed a preference for matter over antimatter known as CP-violation in the decay of neutral B0s particles. The results are based on the analysis of data collected by the experiment in 2011."
I'm Definitely Antimatter (Score:5, Funny)
Now the LHCb experiment has observed a preference for matter over antimatter known as CP-violation
If the pro-matter people are violating CP laws, I want nothing to do with them.
Just Say No to matter!
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You vile soulless lapdog! Those Civil Protection jackboots must be disobeyed as often as possible!
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But by preferring antimatter to matter, you're also violating CP laws. Down with matter-ism!
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I'm proud to say I'm a matterist, and I don't care who knows it.
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Re: I'm Definitely Antimatter (Score:1)
You're saying it just doesn't matter?
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We need more restrictive CP laws so that it'll be harder for them to be violated in the future.
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Just Say No to matter!
I've been saying "no" my whole life and I still don't matter.
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But you don't matter.
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A: Becuase it breaks the flow of a message (Score:5, Informative)
Re:A: Answering a question (Score:2)
before it's asked is even worse
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who asked what was worse?
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So, in other words...it...breaks the flow of a message?
You see what I did there?
Re:What if light travels REAL SLOW (Score:5, Insightful)
What if monkeys can actually talk but refuse to do so because they don't want us to know?
What if quarks are actually microscopic doughnuts, and we can fly through them into an alternate universe where Snooki is president?
What if... ah, screw it, if you can't see where I'm going with this by now there's no hope for you.
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What if space is matter and there's no such thing as a vacuum?/quote
NASA is going to be PISSED!!!
Re:What if light travels REAL SLOW (Score:5, Funny)
What if space is matter and there's no such thing as a vacuum?/quote
NASA is going to be PISSED!!!
Slashdotter discovers simple $5 trick that makes NASA scientists FURIOUS! Click your age to discover this trick for yourself!
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James Dyson is going to be even more pissed. Freeman Dyson probably will be too. Why is the AC trying to piss off all sorts of Dysons?
Re:What if light travels REAL SLOW (Score:5, Funny)
James Dyson is going to be even more pissed. Freeman Dyson probably will be too. Why is the AC trying to piss off all sorts of Dysons?
He's probably hoping all the Dysons come to see him at the same time and angrily surround him.
He will then claim that he has the only Dyson sphere made out of real Dysons.
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What if space is matter and there's no such thing as a vacuum?
That's it! All we have to do is dephlogisticate a large quantity of rocket fuel and we'll reach the aether!
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Imagine if a photon travels not much faster than an electron (a few cms a second)...
Electrons can and often do travel much faster than that, but they go round and round in tiny circles and only drift through a conductor at an aggregate speed of a few cm per second. An electron's actual speed is, as with all physical things, based on its energy. You might as well imagine how fast rocks travel.
equal amounts at the beginning of the Universe (Score:1)
Matter and antimatter are thought to have existed in equal amounts at the beginning of the Universe
yes, both zero at the beginning.
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/sarcasm. Right, the universe just spontaneous came into existence.
From the Laws of Thermal Dynamics we know energy can not be created nor destroyed.
Einstein showed us all Matter is Energy.
Therefore the Universe has ALWAYS existed in one form or another.
Q.E.D.
Re:equal amounts at the beginning of the Universe (Score:5, Insightful)
You say "QED" like science is a closed method of understanding like logic is. The scientific method makes acknowledgement that its results are only accurate in as far as the controls we've been able impose in our experimentation and observation hold. We have never tested the laws of thermodynamics in conjunction with a singularity, and thus anything we say about their behavior there is an extrapolation. Extrapolation isn't induction, and what you just said isn't a proof.
Re: equal amounts at the beginning of the Universe (Score:2)
All physical laws breakdown before Big Bang.
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See, but that's a positive assertion that's actually quite unprovable. We know there are a subset that cannot operate as we define them today because contradictions would arise, but that's not the same as them. There may be underlying rules/laws to the ones we use today that would continue to make sense under those conditions.
I'm not saying there are, but you're the one making a positive assertion.
Re: equal amounts at the beginning of the Universe (Score:5, Insightful)
This is incorrect. All currently known laws become meaningless as all your variables go towards infinity. This doesn't mean there are no laws - simply that we lack the theory to describe them in such extreme conditions.
It's the "what's infinity * infinity? Infinity!" - it doesn't really describe anything real. Of course, this situation changes dramatically if we could show that the variables didn't go to infinity, but were bounded in some fashion. Presently, we can't though.
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Hmm, parts of this are accurate and really not contrary to my point, and parts are downright crazy, incorporating some sort of bizarre nationalism, a fundamental misunderstanding of the scientific method, and directionless babble about how wrong I(or was the GP?) am about something non-specific. I have a feeling that if I could parse your underlying point out from that word-salad I'd disagree, but I can't even say that for sure.
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/sarcasm. Right, the universe just spontaneous came into existence.
From the Laws of Thermal Dynamics we know energy can not be created nor destroyed.
Einstein showed us all Matter is Energy.
Therefore the Universe has ALWAYS existed in one form or another.
Q.E.D.
you are forgetting zero point energy where a negative and a positive particle spontaniously (for lack of a better word) spawn and then annihilate each other leaving the balance at zero. this does not violate thermodynamics as the balance is maintained. Is it possible that the universe is nothing more than a very large zero point even where the antimatter will eventually annihilator all the matter?
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There is a lack of symmetry in the creation of matter and anti-matter.
How do we know this? How do we know that a distant galaxy isn't completely made of antimatter? Does anti-hydrogen fusion in an antimatter star produce a different spectrum than normal hydrogen in a normal matter star?
When the Big Bang happened, both matter and antimatter were created. A goodly amount of it found its opposite and annihilated back to energy. However, the universe was expanding at the time. Eventually the universe would be big enough that a particle and antiparticle could fly away from
Good question! (Score:5, Informative)
How do we know this?
We know this by looking for gamma rays produced by matter/anti-matter annihilations. The solar wind does not annihilate with out atmosphere so we know the sun is made of matter. This same wind does not annihilate with the interstellar medium in the galaxy so that is made of matter. No other star has visible annihilation lines with this medium either so we can be sure the entire galaxy is made of matter. Further out out galaxy does not create annihilations with the medium in the local super cluster of galaxiesand neither does any other galaxy so we know that the local super cluster is all made of matter.
To go further afield is harder since at this point the distances rule out detecting gamma rays from the incredibly sparse intergalactic medium (at least this was true several years ago - perhaps astronomers can do better now?). So instead what you can do is look at galactic collisions. No colliding pair of galaxies emits gamma radiation consistent with annihilation events so either the universe is really perverse and somehow no pair of colliding galaxies is ever a matter/antimatter pair OR there are no anti-matter galaxies out there to collide with. So while it is impossible to rule out that there might be one or two anti-matter galaxies hiding in some distant corner of the universe there are clearly far, far more matter galaxies than anti-matter ones.
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There is a lack of symmetry in the creation of matter and anti-matter.
How do we know this? How do we know that a distant galaxy isn't completely made of antimatter?
Basically because from things like the cosmic background radiation and other evidence, we can determine what the original conditions of the universe were like. In the time of primordial nucleosynthesis, about three minutes after the big bang, things were becoming cool enough for matter and anti-matter to form. In this time, things were still pretty well mixed and it was too hot for a nucleus to capture electrons or positrons, so matter and anti-matter were recombining as they were drawn to each other and an
First Law of Thermodynamics (Score:4, Informative)
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The big bang as we currently assume it is clearly not symmetric under translation in time. There's a clear distinction between "before big bang" (doesn't exist) and "after big bang" (does exist). Therefore Nöther's Theorem doesn't predict energy conservation at the big bang.
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The big bang as we currently assume it is clearly not symmetric under translation in time.
Careful - I have heard some speculation from cosmologists that time may have existed prior to the Big Bang in which case energy may well have been conserved. However if the Big Bang created time and without time there is no concept of energy then obviously in these circumstances energy cannot be conserved. However my response was to the OP's claim that thermodynamics had no law about energy conservation which is clearly untrue.
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How was "as we currently assume it" not careful enough?
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How was "as we currently assume it" not careful enough?
We do not assume that the Big Bang was asymmetric under translation in time: it might have been or it might not have been. There is no data to justify an assumption one way or the other hence "careful".
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Without the universe there's no concept of causality and no concept of time. ...
The universe could still have come into existance all on its own.
Time is the dimension upon which we measure change. Without a dt, dv doesn't happen. Without time, how does the universe change from non-existing to existing?
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> how does anything exist if there is no space?
So the number 2 does't exist? Infinity doesn't exist?
You seem to be greatly confused about meta-physics. Physical reality is only a tiny subset of much larger reality that scientists are generally clueless about.
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So the number 2 does't exist? Infinity doesn't exist?...Physical reality is only a tiny subset of much larger reality that scientists are generally clueless about.
Perhaps I am being overly scientific here but that "larger reality" is in your head, which is a complex physical system operating in our physical reality and hence any thought you may have is part of our physical reality - it's the quantum state of your brain. Hence the number two represents an abstract concept designed to be relevant to our universe. Frankly if you have no space and no time then I'm not convinced that the number 2 does exist or have any meaning - 2 what?
Clearly the universe came from s
Re:equal amounts at the beginning of the Universe (Score:5, Interesting)
/sarcasm. Right, the universe just spontaneous came into existence.
From the Laws of Thermal Dynamics we know energy can not be created nor destroyed.
Einstein showed us all Matter is Energy.
Therefore the Universe has ALWAYS existed in one form or another.
Q.E.D.
Indeed, the curvature of the universe corresponds to negative energy, which can make the energy budget zero. See "A universe from nothing" by Lawrence Krauss (talk [youtube.com] here) on why the energy budget can be zero.
One aspect in the big bang is that you can borrow energy from quantum mechanics if you give it back within a short time (the time needs to be shorter the more energy you borrow). Combine this with extremely fast inflation and you can run away with the energy you borrowed.
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One aspect in the big bang is that you can borrow energy from quantum mechanics if you give it back within a short time (the time needs to be shorter the more energy you borrow). Combine this with extremely fast inflation and you can run away with the energy you borrowed.
So you are saying the early universe was just like our financial system? ;-)
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The second law of thermodynamics applies within our universe. Who knows what laws governed the creation of that universe in which that law applies? Maybe there's something outside what we naively call "the universe" from which the energy came?
Re:equal amounts at the beginning of the Universe (Score:5, Interesting)
Matter and antimatter are thought to have existed in equal amounts at the beginning of the Universe
yes, both zero at the beginning.
Creation of matter from zero matter is a violation of the second law of thermodynamics. Not that I say that you are wrong, just that it doesn't seem likely that both are right.
The simple answer to that is that the second law of thermodynamics is a statistical law, not an absolute one. Entropy in a system can increase with time, but the overall trend is always for entropy to increase. You can see the universe as a temporary statistical blip.
The more accurate answer is to observe that there are issues with the understanding of time itself implied by your observation. On the usual model of the big bang, time itself came into existence at the big bang. Because there was no "before" the big bang, the rate of change of entropy is undefined at the point of the big bang -- it would be the gradient at a singularity, and there's no such thing, so the second law of thermodynamics is meaningless at that point. (And of course even that is a simplification, because phrases like "came into existence" assume time's arrow, which is pretty hotly disputed).
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My theory is, that matter and antimatter did exist in equal amounts. Matter travels one direction in time, antimatter travels the other direction. So the two forms of matter headed of in different temporal directions, and the original matter and antimatter will never meet. Antimatter can be created in high energy interactions though, which explains why there is some around, but that isn't the original antimatter.
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If that were the case, then reactions that produce anti-matter would be detectable before they occur.
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CP (Score:5, Funny)
"CP-violation"
Right. Like I'm going to click on that link.
I know /. editors love CERN (Score:4, Informative)
but the headline is a bit grandiose - there is nothing new about CP violation. CP violation has been known for a very long time and there are at least three other examples of it prior to LHCb report. Also, as CERN notes, others were not able to accumulate sufficient statistics to make the observational claim. Perhaps "CERN's LHCb confirms CP violation in another particle" my be both a more accurate way of describing it and also less "omg, ponies!"
Re:I know /. editors love CERN (Score:5, Informative)
For the electroweeak force yes, but not in the QCD Lagrangian. B+ meson CP violation is the new part.
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this is still the same CKM quark mixing. finding CP violation in the QCD lagrangian would be *really* big news.
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Sometimes I think people are just trolling /. by posting random letters that look like physics, then I spend some time on Wikipedia and realise how little I know.
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Car Analogy (Score:2)
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But this was predicted years ago, right? (IIRC there are two commonly predicted CP violations) This is "just" experimental confirmation?
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I think the headline is correct, LHCb has observed CP violation in an experimental domain where it had not been observed before. The headline does not claim that LHCb has discovered CP violation.
How do we know (Score:2)
What type of matter most of the universe is made of? Past this particular gravity well of our sun, how do we tell that the rest of the planets and stars are not anti-matter planets and anti-matter stars?
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Well, let me start by saying I don't know anything about this field. However, it seems to me that the interstellar medium is that kind of combination of really close to a vacuum and really big that still allows for quite a lot of particles out there hitting the edge of our solar system (I believe we're close to (or already are) getting actual measurements from probes we've sent out that have already left or will soon leave the solar system). Where these collisions occur, we'd expect matter-antimatter pairs
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But matter grouts together with indistinct borders that are not often crossed.
We are in the The Milky Way galaxy, it is probably fair to say that it is made of a vast majority of matter.
But how do well know that the Andromeda Galaxy is not made of a vast majority of antimatter.
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Read the AC comment before mine, it says about about what I was going to say. Certainly within galaxies and galaxy groups, there are enough interactions that we would see the results of the matter-antimatter annihilation if there were significant amounts of both, especially gamma rays at the energy of electron-positron annihilations. And many cosmic ray particles come from a long ways out, maybe even intergalactic, I think -- if there was a lot of antimatter out there we would see more antimatter in the i
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The universe would still exist even if it was empty; there'd just be no-one around to observe it (unless you want to get ridiculously philosophical about that). So no, it wasn't required to be that way, it's just lucky for us that it was.
There may well be other universes (sidebar: there are several different classes of things you can call "universes") where there is no matter or antimatter, but there are probably no conscious beings in there.
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Yes, from an "anthropic principle" perspective you've pretty much got to somehow end up with a universe with a matter/antimatter imbalance in order to have folks to see it. The interesting physics question, however, would be to understand how said necessary matter imbalance was produced. For example, perhaps matter and antimatter behave exactly the same, and we're just in a local "bubble" where early-universe statistical fluctuations coughed up a bit more matter. On the other hand, maybe we can find differe
CP violation (Score:2)
Meanwhile.... (Score:3)
Meanwhile, in a parallel universe: "...experiments at the LHC are seeking to cast light on this dominance of antimatter over matter."
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Except they call it the CHL.
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No, the headline would be exactly the same. THAT's curious.
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> Meanwhile, in a parallel universe: "...experiments at the LHC are
> seeking to cast light on this dominance of antimatter over matter."
Actually, they would consider their form of matter to be "matter" and "the other kind" would be "anti-matter".
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...that we are definitely made of matter. If we were made of anti-matter, wouldn't matter actually look like anti-matter to us, only because it isn't what we're made of?
Not really. We have defined an electron (matter) as the electron-particle that has a negative electric charge. A positron (anti-electron, antimatter) is an electron with a positive charge. Same goes for protons etc, and we know for certain that we and all the matter around us are composed of the 'matter' version.
Also, if matter and anti-matter existed in equal amounts at the beginning, wouldn't the remaining particles, regardless of what they are (after all the self-annihilation and whatnot) be considered matter by default?
No, because if they were equal in quantity, the left over particles would be a 50-50 mix of matter and antimatter, but this is not the case in reality.
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We have defined electron as matter only because it is part of what we're made of. If however, atoms were composed of positrons instead of electrons, wouldn't electrons be considered anti-matter?
Perhaps, but that's the thing. Super symmetry doesn't exist, so things would work differently in the anti-matter dominated universe.
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Christopher Walken approves of the parent post. (Score:2)
We could call them this-matter and that-matter and the physics wouldn't change.
You can go with this or you can go with that [youtube.com]