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Neutrino Data Could Spell Trouble For Relativity
Science News has an exploration of the deeper implications of neutrino oscillation, one experimental confirmation of which we discussed last month. "The new findings could even signal a tiny breakdown of Einstein's theory of special relativity. ... MINOS [for Main Injector Neutrino Oscillation Search] found that during a 735-kilometer journey from Fermilab to the Soudan Underground Laboratory in Minnesota, about 37 percent of muon antineutrinos disappeared — presumably morphing into one of the other neutrino types — compared with just 19 percent of muon neutrinos. ... That difference in transformation rates suggests a difference in mass between antineutrinos and neutrinos. ... With the amount of data collected so far, there's just a 5% probability that the two types of particles weigh the same."
This isn't trouble, we already know there are problems with the theory, we just don't have any measurements that give us an idea of how to fix it (of course the theory works well enough in most cases). Any measurements like this that give us something unexpected are great things, they can give us a more accurate picture of how the world is, help the theory become more accurate. Always look for the flaws in your theory, for that is where the greatest discoveries are hidden.
Qxe4
It's already widely known that Relativity is just a model... much like the rest of physics. It's extremely accurate and useful for dealing with many areas, but breaks down somewhat when dealing with very very small things. Hence the great desire to develop a more unified theory! So, the summary is a little bit on the sensationalist side of the street.
The research is very important, though!
Let me try to find a lay-person analogy.
A chef theorized that there was a counter-part to bacon. We'll call it turkey bacon. We traditionally thought that Turkey Bacon was the direct opposite of Pig Bacon. Where Pig Bacon was delicious, Turkey Bacon was healthy. We decided to do some research on how Turkey bacon and pig bacon is received by the consumer. Recent taste test show that turkey bacon is not, in fact equally as healthy as pig bacon is tasty. This ruins the grand unified theorem of HTB (healthy tasty breakfast).
The only remaining explanation is there might, in fact, be a third type of bacon... i.e. a cow bacon or chicken bacon. If we discover this new type of bacon, it might completely revolutionize the Bacon Lettuce Tomato sandwich.
amirite?
Ok. I read the article and I'm still confused. I understand why different mass for particles and their antiparticles would violate CPT, which is obviously major. But I don't see how this violates special relativity. Why does this violate special relativity?
From the article, "there’s a 5 percent probability that the two types of particles weigh the same." Except, that would require a Bayesian statistical analysis and a prior. The thing to remember about confidence intervals is that the interval is random while the true value is stationary, so if you want to make statements about randomness, you have to make statements about the interval. Example, "An experiment conducted this way would find more muon antineutrinos than muon neutrinos disappear 95% of the time."
Second, we think there are infinities in the universe, and infinities tend to be catastrophic in the real world. In fact, classical mechanics met it's catastrophe in an infinity. It is unlikely that all the infinities that are created between quantum mechanics at the atomic scale and relativity at the universal scale can simply be normalized out, and black holes are not going anywhere until general relativity is fixed.
Then of course we havethe hacked dark matter née aether to make everything work out and match the theory. In light of these three things, any new data, especially new data the violates current theories, are not problem buy jewels. Jewels that will help us refine, and supposed depose, old theories. It is why we still train scientists, and laught at those that think the world is so boring that there is nothing left to be discovered. Fortunately for those that are curious, nature has new surprises every day. I would hate to live in a world where the special theory of relativity was gospel. Such a world would so boring that I would probably be thinking not of what wonders will come, but how life can be ended.
Especially since I squandered my youth solving those god forsaken equations.
"She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
Should I be preparing for Unforeseen Consequences?
If I recall correctly CPT presumes the correctness of Lorentz invariance. And Lorentz invariance is one of the bedrocks of relativity. In other words CPT comes about from assuming your theory is Lorentz invariant and if CPT were violated it would mean Lorentz invariance is violated as well (check out Physical Review Letters 89: 231602 by Greenberg, O.W, which shows CPT violation implies Lorentz violation).
There's always the possibility that this is just a variation of the Heisenberg uncertainty principle at work. Maybe it all works, we're just gumming it all up by trying to be "God".
:).
No, I'm not saying we shouldn't try, just that we may discover we're the variable.
I remember going crazy troubleshooting a circuit with an O-Scope and the freakin' thing would more-or-less work while I was monitoring the signals. Turns out it was a capacitance issue and the probe was introducing enough capacitance to make it work, but not consistently and seemingly 'random' - but really depending upon the relative position of the scope probe and how close to the tip I was choking it when measuring. Ever since then I've had a real appreciation for Werner
Someone either dropped those muon antineutrinos, broke them, and then swept the whole thing under the rug, or they sold them for chocolate frogs. "They were never there!" Yeah, right.
I would like to hope that these anti particles really are understood but my guess is that there is so much that is unknown that any conclusions are really shaky. Perhaps they just relocate to the absolute elsewhere without leaving a clue in their wake.
They are wrong on a universal scale. This has been proven, and indeed it is where things like relativity start to come in. We have measured things that go against the predictions that Newton's laws make. That would mean they've been falsified. ...
So why the hell do we still teach them?
Well because on the scale we normally work on, Newton's laws simply and accurately describe how things works. You can go out yourself and test them in any number of ways and you'll find that as accurate as you want to measure, they are dead on accurate. When dealing with the scale of things humans normally do, they are an excellent set of rules for calculations.
Thus more accurately put they aren't wrong, they are just a simplification that works within certain bounds. They do not fully describe motion and gravitation on every level, in every case. They break down for very large and very small scales. However they are an excellent simplification for anything less than, say, a planet in size and anything above the atomic level. That would include basically everything you are ever likely to work with.
So they are very much correct, all you have to do is put a couple constraints on their use.
Simplified models like that are wonderful too. Even if they don't explain everything, they allow for calculations to be done in an easy fashion on things we care about. Some day we may discover a truly complete law for motion, that covers all cases from the smallest to the largest. at all speeds, in all frames of reference and so on. There may be nothing left out. It also may be several pages of dense calculations. Instead of that, when dealing with a normal, human scale, we'll still use Newton's laws, something you can express in a couple characters and work out in your head if you are good. An exceedingly useful and accurate simplification.
A similar example would be the Ideal Gas law. When you look at it, it is clearly wrong. Reason is you plug in numbers for something like H2O at room temperature and the result is not what you actually get. It does not show it becoming a liquid. Yet again we use it. Why? Because so long as the substance you are talking about is a gas in the temperature and pressure range you are working at, the Ideal Gas law gives you a very easy, highly accurate, way to calculate things about it. It is a simplification, hence why it is called "Ideal Gas" instead of "Real Gas". That doesn't mean that it isn't accurate and useful within some constraints.
So I can see the same being true with relativity. While we have already found cases it doesn't explain (see quantum gravitation), that doesn't mean it isn't useful within certain constraints. As our knowledge progresses, we will know precisely what those are.
If the interactions of particles are thought of as a movie, CPT symmetry requires that whatever physics occurs during the show must be the same whether the film is run forward or backward (time), viewed through a mirror (parity) and repopulated with each particle being replaced by an antiparticle (charge).
This is unclear at best. CPT symmetry says that when the film is run backward AND seen through a mirror AND all particles are replaced with the anti-particles (and vice versa) then the physics should be the same.
If you change just one, for example by running the film backward but without the mirror or the the particle exchange, or if you change two, for example, running the film backward and with the mirror but no particle exchange, then the physics will change.
We don't see the world as it is, we see it as we are.
-- Anais Nin
about EXACTLY that sort of statistics abuse a couple of months back.
I think we need to reroute power through the main deflector dish to correctly mask the neutrino particle dispersion.
""there's a 5 percent probability that the two types of particles weigh the same." Except, that would require a Bayesian statistical analysis and a prior. "
Hallowed are the Ori
Found a pdf of calculus notes on northwestern.edu which shows what I was talking about.
For those unfamiliar, here's a (somewhat crude) explanation of neutrino oscillations.
The reason neutrinos oscillate is because their mass eigenstates are different from the flavor eigenstates. Essentially, a reaction will produce a particle with flavor F1, F2, or F3 being fixed depending on the reaction, but the particle may have mass M1, M2, or M3, which is (probably) randomly chosen. However, the particle then remains at M1, M2, or M3 and oscillates between the flavor eigenstates.
I don't know what reactions are used to produce the neutrinos and their antiparticles at MINOS (probably just pion decay), but it seems possible to me that the reactions may favor different mass eigenstates for antineutrinos than for neutrinos (particularly in light of CP violation, which causes K-meson anti-K oscillations to behave in some ways I find conspicuously similar).
I am of the school of thought that a "new" force is at work, likely a peculiar manifestation of the electroweak force.
because it exposes the fact that Slashdot members love to comment on articles no matter how little they understand them. Most of the comments are hilarious...basically nonsense disguised as insight because if you can comment on advanced particle physics then clearly you understand it and therefore clearly you are smart! LOL!
this idea. That a theory is just a tool for understanding and predicting reality. As long as you know where and when you can apply this tool and you use it in those circumstances it's a useful thing. (IE a hammer is great when you just need to hammer in a nail and don't expect it to be some super tool that can cut wood, turn a screw, measure an angle, etc.)
Did you know 80 to 90% of the moderators on slashdot wouldn't recognize a troll even if one dragged them under a bridge.
No. They're just resting.
It must have been something you assimilated. . . .
to the Soudan Underground Laboratory in Minnesota
Does that mean that there's also a Minnesouta Underground Laboratory in Sudan?
sic transit gloria mundi
string theorists say that we need, i think, 10 or 11 dimensions to get the math to work. could gravity be caused by everything expanding at a relative rate on one or a few of those extra dimensions that we don't see but feel?
This is not surprising. The neutrinos have begun mutating by the extreme solar wind, as we are closing to 2012...
hope someone is preparing the ark...
But a theory is more than just that, it's a mental model of reality, the context for sensory input. Einstein's General Relativity and Newton's Laws of Motion are fundamentally different: Newton took time and space to be a passive background, while Einstein made spacetime an active participant in events. The two theories don't just differ a little bit on their results, they represent fundamentally different ways of looking at reality.
But in a way your professor was right: a theory is "just a" tool for understanding reality, in the same way as you brains "just" allow you to think.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.
Only last night I was reading Edward Witten's article on this very subject, after visiting his little web page at SNS:
The Mass Question
I've been diving into Heim Theory for a while now, one of the so called "problems" with Heim's theory is that it predicts 5 types of neutrino's.
If this experiment is either (not) generating or (not) measuring one wrong type of neutrino, the error would be 20%...
I'd guess that describing subatomic particles is the realm of quantum mechanics, not relativity (which is about things that have lots of mass and/or move fast).
This article confuses things a bit, I think, in saying that this represents a problem for SR (or even GR).
SR say that the speed of light is the same in all frames of reference; that, in fact, is all it says, when you get right down to it. The principles of relativity, homogeneity and isotrpoy are assumed in both classical mechamics and QM as well, mostly, I suspect, because we can't really see why it should not be the case.
Where the problem is, really, is in QM - things like anti-particles are QM constructs, and so is the assumption that they weigh the same as their counterparts; the apparent observation, that anti-neutrinos have another mass than the neutrino, is very surprising for quantum mechanics and does not fit very well into the currently accepted theory.
Perhaps it is not so strange that QM may begin to show some cracks; SR and GR make very few assumptions about anything compared to QM. It is very hard indeed to see where one could sensibly make some changes, whereas is QM, there are so many little nooks and crannies where something murky could be hiding.
With the amount of data collected so far, there's a 5 percent probability that the two types of particles weigh the same
As someone pointed out, this merely means that assuming the masses are the same 1/20 experiments will find similar results due to measurement error. Considering how much data there is to back special relativity, I'm not the least worried about special relativity. I'll start paying attention when the error margin drops to one in a million or something. Seriously, using a 5 percent error margin for something that contradicts a fundamental law of physics is just ridiculous. Oh, and I measured some forces and accelarations in my garage and they're a bit off, so there's a 20% chance that Newton's F=ma is wrong.
Opus: the Swiss army knife of audio codec
The problem goes a bit deeper than this. CPT invariance is mathematically equivalent to Poincaré invariance. Breaking CPT means breaking symmetry under the Poincaré group (which is basically all translations, relativistic boosts and rotations). This is specially intriguing because particles are defined as irreducible representations of the Poincaré group. In other words, if Poincaré (or CPT) is broken, we cannot define a particle. This is one of the main problems with compatibility between quantum field theory and general relativity: in curved spacetimes there is no Poincaré symmetry, so there is no unambiguous definition of a particle and all hell breaks loose: even the definition of vacuum can't be done.
If those MINOS results are confirmed (and I assume they won't) QFT won't just needs adjustments: it will be wrong in a conceptual level. That would be VERY interesting, to say the least...
Science is fantastic in that it assumes that it will eventually be proven wrong. Unlike pseudo-science, there is hardly ever a "scientific consensus" - merely interesting ideas that run counter to accepted teachings.
The Greenberg et al 2002 paper says that CPT violations imply theories that are not Lorentz invariant, but also that :
Theories that violate CPT by having different particle and antiparticle masses must be nonlocal.
Now, the various EPR tests have shown that quantum mechanics cannot have a local hidden variable theory. So, if these results are true, I would expect to see a resurgence of hidden variable theories, of a nonlocal nature. Maybe they can even be clever and figure out how to how to do it in a way that preserves causality (as nonlocal theories in general imply that causality violations - i.e., time travel into the past - are possible.
If you try to calculate ab-initio stuff with heavy atoms, there are approximations for relativistic quantummechanics, where the behaviour of the nucleus is approximated in a different way.
This stuff is a ways above my head but maybe this article helps: http://iopscience.iop.org/1742-6596/104/1/012025/pdf/jpconf8_104_012025.pdf.
Dark matter is nothing like the aether. First and foremost dark matter is known to have a dramatically density distribution throughout galaxies, clusters, and the universe. The aether is pervasive, constant and defines a frame of reference. I you want to talk about something being aether like it would be CMB radiation which appears to define a unique reference frame, is isotropic, and homogeneous. Dark energy could be interpreted as aether like as well. However ALL of these fail to be similar to aether in one important sense: they do not provide a topology on which light or other wave propagate which was a major component of aether theories.
how do they work?
So, are there any GUT theories out there which predicted this outcome?
the growth in cynicism and rebellion has not been without cause
There's only one thing left to do: burn down the observatory so this will never happen again!
The author of the article is very confused.
Its common knowledge to philosophers that time isnt real, its a perception.
Stuff changes, humans use time to measure when changes happen(ed), that doenst make time exist in reality..
We can change stuff, and we can change our perception of stuff, but they are two separate things.
Changing how we perceive stuff doesnt change the stuff in reality.
I think more physicists should study philosophy....
Woah! Those neutrinos are some COOL DUDES!
With all these asymmetries appearing in the particle zoo, I just have to wonder, is it possible that the proximity of normal matter and the strength of the gravitational field be affecting these experimental outcomes? Is there any way to experimentally eliminate these kinds of effects?
It seems to me the jury is out until we run all these tests in a particle accelerator way outside of the galaxy.
-- thinkyhead software and media
Change is real. Time is only an inference.
-- thinkyhead software and media
Wow, if only this applied to programming.
The only reason it applies to physics is because we can't write our own laws. If we could that would be much more fun than trying to debug and understand what is already there.
It's extremely accurate and useful for dealing with many areas, but breaks down somewhat when dealing with very very small things.
No it does not. Special relativity (which is what the neutrino result probes) works just fine with the quantum world. Look up the Dirac, Klein-Gordon and Proca equations, not to mention particle physics as a whole. General relativity has issues with QM but, so far, not Special Relativity. If SR is found to be wrong the implications for physics are as profound as you can possibly get and equivalent to the effect that Newton and Einstein had on the field....which is why I fully expect that this will just turn out to be a statistical anomaly. Still we can hope...
"Just a model" is not what physicists seek.
That's true....but effective models is all that we have because we still don't know the 'true' physics of the Universe and probably never will, we will just have a really, really good model that always works.
Some of our models are basically there, like the "conservation" laws, which are based on rigorous mathematics.
Physics is NOT based on mathematics but on observation. Mathematics is the language and, like any language, can describe things which are not real. Hence the absolute requirement for observations otherwise how would you know what was real? Conservation laws are based on observation and, through the rigorous maths you mention, can be linked to the translational and rotational invariance of space-time i.e. the laws of physics today are the same they were yesterday and the same they are 1 km away. As long as we observe that to be true then conservation laws are here to stay but if tomorrow we find a spot of the universe with different physical laws all that changes.
Rarely here do I see a sig that is as relevant to the point you are making as yours is. So true.
But in a way your professor was right: a theory is "just a" tool for understanding reality, in the same way as you brains "just" allow you to think.
I don't think that's quite (pedantically *G*) accurate. A theory is a pure mental framework useful for translating reality into a context that human brains can understand. The human brain is the tool we use to develop theories... calling a theory a tool is somewhat of a stretch, as not all theories are useful as such, ie, don't lead to a change in our knowledge.
(I'm badly paraphrasing and misusing some of Iain M Banks' commentary from his novels but the gist of it's the same)
SB
It's old. The more humans I meet, the more I like my cats. At least they are honest.
Right - but the mental model you work with to figure out how much counterbalance and weight you need on a construction crane, or ballistics for firing large rounds from a warship doesn't need to include relativistic effects. You don't need to consider spacetime or einstein when doing these things... newton's model is just fine.
And let's be clear - both are just models. Relativity goes further to model more about cosmology and goes off on a bigger, deeper scale - but it's not the theory of everything, and we know that. It's still just a model.
So fundamentally - you apply the correct model to the correct situation. Neither newton nor einstein have the whole picture, nor could they, nor shoudl they - they just worked with the evidence and observations they were capable of making, and came up with models.
..perhaps interacting with matter, even subtly (via a magnetic field generated by matter), is entropic for antimatter, and there's no weight difference at all.