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Matter, Anti-Matter, and a New Subatomic Particle?
sciencehabit writes "Physicists may have finally figured out why the universe contains more matter than antimatter. The key lies in a flaw in the relationship between the two and a potentially new subatomic particle. 'Other researchers, however, say the results, published today in Nature, should be interpreted cautiously. It could all be an effect produced by run-of-the-mill particles'."
Anyone remember the particle-of-the-week on Star Trek? Yeah. Modern physics feels like that sometimes.
Where does dark matter fit into that cosmological view?
Does it ever seem as if they are fudging in new particles and forms matter to account for discrepancies in math or observation? Well, it IS tax season...
Is if they could figure out the reasons behind a similar type of disparity in the chirality of naturally occurring amino acids.
Just callin' it like I see it.
Matter, Antimatter and it doesn't matter. I knew it all along.
So. We now have the ancient joke out of the way, let's start the discussion.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
A flaw in God's perfect creation?!?!
This space available.
Ive always wondered, as there seems to be an opposite for everything in Physics, why we dont call it lite matter?
"Persistance is Fertile" - Me. I can quote myself if I want to.
When that much matter and antimatter are brought together... aye, that we will.
then go ahead and mix a little of matter and antimatter together.
I prefer the "u" in honour as it seems to be missing these days.
Why do we assume there is more positive matter than negative matter? It seems to me that we might have a bias here, considering we're made out of positive matter...
Would that be, um, flour? The universe is held together by flour?
(Thought I should attempt to reflect the Luddite perspective. Everybody else commenting on this post is being far too intelligent and rational.)
I've calculated my velocity with such exquisite precision that I have no idea where I am.
So did Garrett Lisi predict the new particles? Do they fit into the E8 algebra thing that his theory is based on?
Erm, sorry about the typo.
I attended a lecture on the CP violation in B and anti-B meson decay at Virginia Tech in 1998. The theory and maths pointed to asymmetry in the binding force of the (respectively) anti-down and down quarks involved. The amount of asymmetry was calculated to be a few parts in a billion. It hadn't then been seen, but the exact nature of the experimental set-up had been worked out (that was the nature of the lecture). Now it has been seen. Now that it has, why pull an unknown particle rabbit out of the quantum hat? What happened to a perfectly good hypothesis derived from known factors which predicted exactly this?
Astronomers noticed an anomaly. They dreamed up dark matter to explain it. Actually, they dredged it up -- the concept had been applied to other phenomena and always found not to be involved if it even existed. Then they set about looking for other signs that matched the theory, and in a fit of circular reasoning claimed it supported the hypothesized existence of the dream-stuff. Now that they're getting away with it so well that The Teaching Company even has a 12 hour lecture series on it for sale, it's encouraging others to invent all manner of invisible widgetons to blame it on, because hey, anyone can do science, but how many people get to dream up something imaginary and get taken seriously? Dream-stuff is sexy even if it doesn't exist. It gets you noticed. It gets you published, and if the publication is more a question than an answer, well, it's invisible or massless or some other quality which makes it unseen by everyone except you and your imagination.
I'm not buying until I see how they dismiss the previous workable theory based on entirely known quanta that predates this supposed discovery by 10 years.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
Without this "flaw" matter and anti-matter would have cancelled out almost perfectly early on in the Big Bang leaving nowhere near enough matter (or anti-matter) to form galaxies or stars. So this "flaw" is what allows us to exist. I would not call it a flaw, but rather a design feature. Without breaking this symmetry the Universe would be a really boring place, in much the same way that a tree is more interesting than a cube even though the cube has far more symmetry.
See by example http://arxiv.org/abs/math-ph/0502042 (http://www.jp-petit.org/science/f300/a301.htm)
There is more matter than anti-matter because otherwise we'd call anti-matter matter and matter anti-matter.
If (theory != sense)
then create.newParticle();
Else
publish.newTheory();
Why do you think it is that pi often is needed in calculations? Because someone is using the wrong coordinate system. But pi is not a rational number. It is not the ratio of two integers.
Its the same problem with particle physics. Using the same logic, having to find more and more particles to satisfy some mathematical model makes it pretty obvious that you are in the wrong paradism. People will claim that we have proof that this or that particle exists, but what is a particle to begin with? What exactly is an electron or proton? We have no idea YET.
All this paper shows is that there is a difference between CP violation in the charged B mesons and the neutral B mesons. This is somewhat unexpected and while you cannot rule out something new it is also true that they cannot rule out QCD (strong force) effects.
The problem the strong force is that it is so strong at low energy that our normal technique to calculate what is going on (called perturbation theory) does not work because, rather than small perturbations, the strong interaction causes huge changes. This means that theorists have to make approximations in order to calculate anything and so their results may well just show a flaw in their assumptions rather than a flaw in our understanding of physics.
An excellent example of this was with my grad student experiment which was also measuring CP violation but with kaons. Before our measurement the theorists were saying that there was absolutely no way at all they could have a certain parameter (epsilon'/epsilon) to have a value greater than 1e-3 and it would likely be a lot lower. So, we measured it at around 1.7e-3 and, lo and behold, the theorists adjusted their models and suddenly it was in agreement with theory.
So while this might be an indication of something new I am not yet convinces that it is anything more than an incorrect assumption in a QCD calculation somewhere. Such calculations are fantastically difficult and while in this case there are things that will make it easier, it is not yet convincing evidence.
"run-of-the-particle-accelerator particles"?
...Feynman-Stueckelberg interpretation of antiparticles is literally correct (antiparticles are "basic" particles, only moving backwards in time) and we are seeing less antimatter because if, after Big Bang, we are floating "with the flow", futurewards, then we are less likely to meet particles going "upstream", counter to our own temporal direction (yes, I understand it is yet another self-centric anthropic argument, but still...). Ideal balance of matter and antimatter we would probably observe if we were left at the point of Big Bang, but instead we moved in time, since. Consequently, there is probably another, predominantly antimatter (anti-, relative to us, otherwise probably very similar) Universe propagating toward "before Big Bang" in direction symmetric to ours, as well as "ring of light" multiverse, aka background radiation to us.
The universe is held together by flour?
The universe is held together by Duct Tape. Except air conditioning ducts, because of the enormous quantities of Schrodinger particles emitted by shed cat hair. You need to use metallized tape to hold those together. Heavy-metallized if you have more than two cats.
I am Sparticus!!!
If there are any physicists out there, can they explain how we know the universe is predominantly matter? What's to say that the andromeda galaxy isn't 100% anti matter (i.e. all positrons and neg-protons.. negtons?). Is anti-matter unstable, even in a regular matter free environment? Or is there some other mechanism that shows the galaxies we observe are mostly matter?
With an improved class library you can do both of those with one variable....
if (theory != sense)
theory.createNewParticle(BS)
else
theory.publishNewArticle(BS);
Why carry around variables for "theory" and "publish"? Don't they belong together?
This all just proves that all we know is, really, that we know nothing.
There is definitely at least one mathematical system where pi has a precise value that could be used as the base unit in geometries. In such a system, the area of a circle would be knowable with the same absolute precision as the area of a square.
Unfortunately, the human mind is not constructed in a way that can comprehend such a system. It would always appear to us to be based on something that is inherently irrational, no matter how it is presented. That is, in fact, one of the defining limitations of what it is to be human. Any being capable of working with such a mathematical system would be alien. Maybe a demon; maybe a god. But definitely not human.
As a corollary, because of our limitation with regard to rational processes, we cannot know, we can never know, whether the mathematical system described above actually exists, or is completely imaginary. We can only say that it is outside of the scope of rational human activity. We can, however, conceive of its possibility— so whatever its reality is, it casts a shadow within our scope, and we need to acknowledge that.
To get back to GP post's point: I think what he is saying is that continually adding new beasts to the particle physics menagerie is like trying to find the area of a circle with absolute precision by continually adding more digits to the value of pi. Another way of expressing this:
High energy physics needs a Copernican revolution, because it is getting too costly to add yet more epicycles onto the backs of the leptons and baryons. Those imaginary beasts are already carrying a greater load of such refinements than any reasonable and prudent lay person would rationally accept. Which is why physics has begun to take on a religious aspect: most of us are having to base our lives on the beliefs that the priest-physicists tell us to believe, because we have no hope of being able to work through the intricate logics about how many leptons can dance on a point of a pin...
The fascination with string theory is that it offered the promise of a Copernican revolution. But it looks like it will not fulfill that promise. We need something else, another approach. We need a way to think about physics that is more accessable and has fewer of the trappings of an elite priesthood dictating beliefs— today's dogma— to the engineers and technologists who make our lives work.
Re: there aren't any more electrons than protons
If there were more electrons than protons, their charge would need to be balanced by positrons, so we'd see gamma ray peaks indicating annihilation of electrons by positrons. We don't.
OTOH, this is based on other theories. E.g. it presumes that the net charge is neutral. There are lots of good reasons to believe this, but a direct proof is obviously impossible. (We couldn't even do a direct proof that your hand was neutral...but there are lots of good reasons to believe that it's at least approximately neutral. E.g., it doesn't fly apart.) There are a indefinite number of quibbles possible, but each one known can be answered in a plausible and relatively consistent manner. So it's probably true. Absolute truth is only the province of theology. Even mathematical theories have, occasionally, been proven wrong. And proofs of theories are frequently shown to be wrong.)
I think we've pushed this "anyone can grow up to be president" thing too far.
Baryons are hadrons (particles composed by quarks), specifically three quarks, and the proton and neutron are the lightest and most stable of baryons.
The Baryogenesis theory, as proposed by Sakharov, describes a set of three conditions which all had to be met together in order to have a matter-asymetric universe. A baryogenic reaction sets off from a baryon-symmetric state to produce a final state which has a greater content of particles than anti-particles; or, in effect, no anti-particles and a "small" ammount of matter particles (in comparison to the number of annihilation photon "sea" which might be interpreted as the Cosmic Background Radiation). According to Sakharov, a potencially baryogenic reaction has to satisfy all of three conditions:
- It must violate the baryonic number, i.e., the number of baryons in the final state must differ from the initial state. This might seem a trivial requirement, but under the current (very successful) Standard Model of Particle Physics, it is not.
- It must violate CP (charge-parity) symmetry. In other words, the physics of the reaction/decay must be different from its charge-conjugated (and parity-conjugated) counterpart. Specifically, the rate of a baryogenic reaction must differ from the reaction involving the corresponding anti-particles, due to a non-trivial theoretical result known as "CPT theorem".
- It must happen away from equilibrium (thermal and "chemical"). In other words, the reaction rate must be faster than the time it takes for the mixture between initial and final state domain contents to mix and reach equilibrium.
The first two conditions are mostly related to particle physics, and the third is more oriented to cosmology and especially the macroscopic treatment of the universe with (relativistic) thermodynamics. IMHO, the trickiest is to find a decay that satisfies the first condition, since in the Standard Model of Particle Physics this should not happen directly (technically, the baryon number operator does not show up explicitly in the Standard Model Hamiltonian).From what I've gathered, this is the job of looking for a "new" particle whose decay can, not only, satisfy the three Sakharov conditions, but also give the correct predictions. The matter-to-radiation content is fairly precise: it's very small, but not null, about 1 matter particle (think "hydrogen atom") per 10 billion (1010) cosmic background radiation photons. It's one thing to find a particle whose decay satisfies the Sakharov conditions, especially one that violates the baryon number conservation "directly" (i.e., as a "first order" process); it's another thing entirely to justify that that same decay is enough to give that particle-to-photon ratio within an order of magnitude.
My sig is better than your sig.
Dark matter: the twentieth century answer to phlogiston, or germ theory? We really won't know for a while.
While hidden variables cannot form the basis for a testable scientific theory, they work perfectly well for meta-physics. Not everyone is a philosophical materialist. Oh, and meta-physics doesn't necessarily mean God. The "hyper-dimensional space alien simulating our universe on a computer" is also very popular. The trick for metaphysicians is to realize that such theories are not "science", in the traditional sense of methodological materialism and testable hypothesis, however true they may or may not be. The trick for scientific materialists is to realize that testable theories are not the only source of truth. There are historical records, and personal testimony for example. Don't reject them too quickly, because you rely on them - you can't verify every experiment yourself.
One way to avoid the weak washout is to have the GUTs generate a net density of leptons, which the additional weak interactions would then recycle into baryons.
I'm not sure why, but reading the weak washout section, i'm reminded of space filling (self-dithering) Hilbert Curves. Would anyone know of a similar line of enquiry to this end? I know analysis is the hardest part of chaotic systems, but it would be interesting to see if anyone has practically explored an underlying mathematical order.
We also know the value of pi with absolute precision. The only problem is that we don't know how to express it. There is definitely at least one mathematical system where pi has a precise value that could be used as the base unit in geometries. You're talking from your ass.
How does that work? Am I missing something here?
"We might have possibly known about it all along, we might not have. Nevertheless, the discovery is potentially very exciting!"
The world seems to be perfectly at peace without knowing the complicated explanations behind the dominating presence of matter over anti-matter. I mean, all is well that ends well, so what's the matter!