Slashdot Mirror


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."

38 of 279 comments (clear)

  1. Not trouble... by phantomfive · · Score: 5, Insightful

    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
    1. Re:Not trouble... by jd · · Score: 4, Insightful

      Since every theory is a simplified model, every theory has problems. Sometimes the model works just fine at the resolution and scope for which it is intended (eg: Hooke's Law). It's the cases where you know it's broken within the bounds it should be working for, but you don't know where or why, that are the exciting ones. In the case of relativity, we know it's incompatible with QM at some level that includes gravity but may extend beyond that. We now know that it also has problems with neutrino mass. It may be that relativity can be fixed - at least for neutrinos - but either relativity or QM (or maybe both) =must= break down entirely within their intended scope in a way that is irretrievable. But nobody knows which, when, why or how.

      But this is the fun of science! Science would have no purpose if it weren't for the ferreting out of the glitches and flaws in theories, fixing them and testing them to destruction all over again. We learn so little by being right in comparison to what we learn when we're wrong.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    2. Re:Not trouble... by Zixaphir · · Score: 5, Insightful

      But this is the fun of science! Science would have no purpose if it weren't for the ferreting out of the glitches and flaws in theories, fixing them and testing them to destruction all over again. We learn so little by being right in comparison to what we learn when we're wrong.

      Wow, if only this applied to programming.

      --
      "Now I am become Death, the destroyer of worlds"
    3. Re:Not trouble... by raving+griff · · Score: 3, Insightful

      Well, just as we cannot say with certainty that a law that has not yet been unproven is correct, we also cannot say with certainty that a law that has not yet been unproven is incorrect. Assuming the universe operates on some form of natural law (that is, assuming that all events are not entirely random and arbitrary), then the laws of the universe are finite and therefore describable.

      The issue is not that we cannot be right, because it is possible that we can find one that is right; the issue, rather, is that we have no way of irrevocably confirming a law. We may only watch the evidence increase while waiting on the possibility of an event that disproves it.

    4. Re:Not trouble... by mangu · · Score: 5, Insightful

      bugs tend to... go over looked, especially in projects that are hobby-based in nature, like many FLOSS programs.

      This happens in commercial software as well. When you buy the next "improved" version they get paid, fixing the current version gives them costs without revenue.

  2. Relativity is just a model by onionman · · Score: 4, Insightful

    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!

    1. Re:Relativity is just a model by bertok · · Score: 3, Insightful

      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!

      That's a gross misunderstanding of the problems of relativity.

      "Just a model" is not what physicists seek. The aim is to seek laws of physics that are absolute, inviolable, and a complete description of space, time, and mass-energy. Some of our models are basically there, like the "conservation" laws, which are based on rigorous mathematics.

      The problem with relativity isn't that it's "just a model", it's that it is explicitly known to be incomplete. It simply doesn't "extend" down to small scales. This was known by Einstein himself, he sought to complete his theory, but failed.

    2. Re:Relativity is just a model by onionman · · Score: 4, Insightful

      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!

      That's a gross misunderstanding of the problems of relativity.

      "Just a model" is not what physicists seek. The aim is to seek laws of physics that are absolute, inviolable, and a complete description of space, time, and mass-energy. Some of our models are basically there, like the "conservation" laws, which are based on rigorous mathematics.

      The problem with relativity isn't that it's "just a model", it's that it is explicitly known to be incomplete. It simply doesn't "extend" down to small scales. This was known by Einstein himself, he sought to complete his theory, but failed.

      Sorry, but I'm a mathematician... so everything you physicists do is just a model to me. Ever since I realized (via Goedel) that there aren't even any complete and consistent theories for logic, I sort of figured that there would never be a complete and consistent theory for physics. (Let me know if you find one.) In the mean time, I'm still really impressed with the work physicists do! I really should finish working through Gravitation some day... that's cool stuff.

    3. Re:Relativity is just a model by Anonymous Coward · · Score: 5, Funny

      Sorry, but I'm a mathematician... so everything you physicists do is just a model to me.

      An instant link to xkcd is required here. I hate doing this (linking to xkcd), but you brought it on yourself :)

    4. Re:Relativity is just a model by Muad'Dave · · Score: 3, Funny

      mathematics is just applied logic, and logic is just applied philosophy... ... and philosophy is just applied physics ...

      Kirk: "Everything Harry tells you is a lie. Remember that! Everything Harry tells you is a lie!"

      Harry: "Now listen to this carefully, Norman: I AM LYING!"

      Norman: "You say you are lying, but if everything you say is a lie then you are telling the truth, but you cannot tell the truth because everything you say is a lie, but... you lie, you tell the truth, but you cannot for you l... Illogical! Illogical! Please explain! You are Human! Only Humans can explain their behavior! Please explain!"

      beeeeeeeeeep......thump.

      That's what you just did to my brain by closing the loop. Thanks! :-)

      http://memory-alpha.org/wiki/Induced_self-destruction
      http://www.youtube.com/watch?v=EzVxsYzXI_Y

      --
      Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
    5. Re:Relativity is just a model by jbezorg · · Score: 3, Funny

      Relativity is just a model.

      Just like Camelot.

      --
      I've lost all my marbles except one & It's fun to test angular & centripetal acceleration in my skull
  3. So basically... by Anonymous Coward · · Score: 5, Funny

    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?

    1. Re:So basically... by mog007 · · Score: 3, Funny

      I believe your bacon analogy is far superior to the often used car analogy.

    2. Re:So basically... by hsthompson69 · · Score: 3, Funny

      Except pig bacon is healthy, and delicious. Contrary to USDA guidelines, saturated fat is good for you, and cereals and grains are bad for you. Bacon is, simply put, health food. You just need to avoid orange juice, muffins, or anything else that is going to raise your blood sugar levels and therefore your insulin levels.

      Now, admittedly, there are some types of bacon that are dipped in chocolate, or sugar, or pancake batter, or some other evil condiment, but on its own, bacon is a perfectly healthy food.

    3. Re:So basically... by Hognoxious · · Score: 5, Funny

      The car analogy works as a reasonble approximation at vehicular scales but breaks down at the edible level.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    4. Re:So basically... by Linker3000 · · Score: 4, Funny

      I'm waiting for the Higgs Bacon.

      --
      AT&ROFLMAO
  4. How does this violate special relativity? by JoshuaZ · · Score: 4, Insightful

    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?

  5. statistics fail by gumbi+west · · Score: 3, Informative

    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."

    1. Re:statistics fail by Parlyne · · Score: 4, Informative

      The correct statistical statement here would be that an experiment like this one would show a splitting between particle and anti-particle properties at least this large 5% of the time even if there were no difference at all.

  6. There is already trouble by fermion · · Score: 5, Interesting
    Here are three things I see to be a consistent form of trouble. First, obviously as we exist, there was not an equal amount of matter and anti-matter created at the big bang. Furthermore most kludges that have been devised to explain this discrepancy have been less that stellar and have tended not to match real data very well, unless they have been tweaked to arbitrarily match real data.

    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
  7. So... by fuzzyfuzzyfungus · · Score: 5, Funny

    Should I be preparing for Unforeseen Consequences?

  8. CPT = Lorentz Invariance by SciBrad · · Score: 5, Informative

    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).

    1. Re:CPT = Lorentz Invariance by thrawn_aj · · Score: 3, Funny

      Drunk-modding again? =p
      Someone please fix this to informative or insightful. Someone on /. actually cited a PRL ref correctly to prove his point - will wonders never cease? I think I'm gonna cry.

    2. Re:CPT = Lorentz Invariance by JSBiff · · Score: 5, Funny

      Well, you see, the modder had to preserve Slashdot CRM ( Correctness, Relevance, Modding) Invariance which states that Comment Correctness, Comment Relevance, and Comment Modding, when assigned a boolean value (e.g if the Comment is factually correct, it is assigned the value of 1, else 0) of 1 or 0, then multiplied together, must never be 1. So, since we had a correct, relevant comment, the modding must be incorrect to preserve the Invariance.

    3. Re:CPT = Lorentz Invariance by 0111+1110 · · Score: 3, Interesting

      A CPT violation has major implications for the special theory apparently due to what SciBrad said. Is Lorentz invariance similar to Lorentz Covariance? To get closer to why this is relevant to the special theory take a look at the wiki for Lorentz transformation.

      The Lorentz transformation was originally the result of attempts by Lorentz and others to explain observed properties of light propagating in what was presumed to be the luminiferous aether; Albert Einstein later reinterpreted the transformation to be a statement about the nature of both space and time, and he independently re-derived the transformation from his postulates of special relativity.

      Now, IANATP, but this seems core. We are getting back to the Michelson-Morley experiment for god's sake. I always figured the general theory would be the first to show cracks since it has a lot less solid experimental data behind it. But everyone is always going on about how the special theory is one of the most proven theories in all of science. So this could be big. Very big. Of course, it's a lot easier to just massage the data a little or start positing magical new forces to explain the discrepancy:

      To save CPT and Einstein's theory -- assuming they need saving -- Ann Nelson of the University of Washington in Seattle favors the introduction of a new force. "It's a less radical idea" than throwing out Einstein's theory of special relativity, she notes. The force Nelson envisions would endow matter with a new kind of charge that would allow it to interact differently with neutrinos than antineutrinos.

      It's a lot easier than tossing out your beloved theory or trying to build it up from scratch based on solid scientific evidence to support each individual tenet. I think the latter is what needs to be done, but it will take time. We need to re-figure out what we know absolutely. IOW, what aspects of special relativity are not contradicted by a CPT violation? If the Lorentz Transformation is called into question then so is science fiction's much beloved time dilation And what about the Twins Paradox? Yikes. This could be big. It is exciting when a major (and the special theory is about as major as it gets) scientific theory is contradicted, even in part because it means we could be on the verge of a major discovery. A real discovery based on experiment as opposed to flights of fancy, the angels dancing on pin heads inside the minds of theoretical physicists and then rationalized ex post facto quantitatively with systems of equations. Let us not forget the lesson of Ptolemy's cycles and epicycles. They predicted the motion of the planets better than Copernicus's theory, at least initially. But if Einstein is Ptolemy, who is Copernicus?

      --
      Quite an experience to live in fear, isn't it? That's what it is to be a slave.
    4. Re:CPT = Lorentz Invariance by JoshuaZ · · Score: 4, Informative

      It's a lot easier than tossing out your beloved theory or trying to build it up from scratch based on solid scientific evidence to support each individual tenet. I think the latter is what needs to be done, but it will take time. We need to re-figure out what we know absolutely. IOW, what aspects of special relativity are not contradicted by a CPT violation? If the Lorentz Transformation is called into question then so is science fiction's much beloved time dilation And what about the Twins Paradox? Yikes.

      Time dilation has been observed in a number of different contexts, most famously by putting atomic clocks on airplanes and measuring the resulting slow down as they fly around the globe. Even if SR fails, time dilation is still an experimentally verified fact.

    5. Re:CPT = Lorentz Invariance by Parlyne · · Score: 3, Informative

      Lorentz covariance means that a quantity changes in a way given by the appropriate Lorentz transformations under boosts or rotations. Lorentz invariance means that a quantity is unchanged under boosts or rotations. So, Lorentz invariance is a subset of Lorentz covariance which applies to frame-independent quantities like proper time, electric charge, or rest mass. As for explaining these results, I think you'll find that a large majority of particle physicists (both theorists and experimentalists) will tell you that a 95% confidence level is actually very low. It means that a value (here something characterizing the difference between neutrinos and antineutrinos) differs from 0 by only twice the uncertainty in its value. In particle physics, its usually a bad idea to trust a result until there's enough data that deviation from 0 is at least five times the uncertainty in its value. (In fact, there have been cases where effects that had deviations from 0 of about 4.5 times their uncertainty that still turned out only to be statistical flukes.) But, those uncertainties tend to decrease in such a way that the uncertainty multiplied by the square root of the number of data points you're calculating the value from stays constant. So, this is rather slow to attain. If, however, with a great deal more data, this effect still seems to be there, there are still some ways out. Essentially, you have to posit that somewhere between the production of the neutrino and its detection there's something unaccounted for which treats neutrinos and antineutrinos differently. Maybe there have been details overlooked about how propagating through matter (rather than antimatter) affects neutrinos (although this seems unlikely). There's also a paper I've run across recently which suggests that the standard treatment of neutrino oscillations misses a small dependence on the details of the physics by which the neutrinos are detected. (Personally, I'm waiting for people who know quite a bit more about quantum measurement and about neutrino oscillations to weigh in on this one.) It's only once everything of this sort has been ruled out that we face the prospect of actual, honest-to-goodness CPT violation.

    6. Re:CPT = Lorentz Invariance by TapeCutter · · Score: 4, Informative

      "Time dilation has been observed in a number of different contexts"

      Indeed! Without taking time dialation into account GPS locations would systematically drift about 10km/day.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
  9. Perhaps it isn't Einstein's fault ... by bkeahl · · Score: 3, Interesting

    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 :).

  10. Newton's laws would be a great example by Sycraft-fu · · Score: 5, Insightful

    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.

    1. Re:Newton's laws would be a great example by JSBiff · · Score: 4, Interesting

      I wish I could find the URL now, but I remember reading once about relativity (don't remember now if it was special or general), the author showing how some of the classical mechanics formulas are basically the first few terms of Taylor Polynomials which represented the values given by relativity, so basically, as you said, they are accurate when sufficiently near 0, but the farther you move away from 0, the more the error accumulates without the 'missing' terms. Really wish I could find it now.

    2. Re:Newton's laws would be a great example by IICV · · Score: 5, Interesting

      Actually! I was looking this up at one point for some reason I forget, but:

      You cannot explain the yellowish color of gold* without relativity. If you just use classical chemistry, it should be silvery-white, just like silver. It's also the reason why mercury is one of two elements that are liquid at room temperature; relativistic forces screw with the electrons, making them bind more weakly. Although the reasons why these things happen do come from a level outside of your bounds (it has to do with electrons, which are smaller than atoms) the effects are things everyone takes for granted.

      Gold would not be golden if it weren't for relativity! I just find that so amazing.

      *It's also how you explain the yellowish color of cesium, but that's not something most people are familiar with.

    3. Re:Newton's laws would be a great example by Anonymous Coward · · Score: 3, Interesting

      How about that quantum tunneling makes electrical switches work at all? That's something everyone takes very much for granted every day.

    4. Re:Newton's laws would be a great example by JSBiff · · Score: 3, Informative

      Oh, one other point - a large part of why we teach them in High School and basic undergraduate physics classes is that they don't require a lot of math beyond algebra and trig, and maybe a little calculus (some knowledge of integration and differentiation can still be useful even with Newton's Laws), but when you start looking at the more accurate models of relativity and things, it starts to take knowledge of much more advanced math, which High School students and undergrads(well, most of them anyhow) won't know or understand.

  11. CPT Symmetry by DrJimbo · · Score: 4, Informative
    The fine article said:

    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
  12. Cloaking device malfunction?! by SOOPRcow · · Score: 5, Funny

    I think we need to reroute power through the main deflector dish to correctly mask the neutrino particle dispersion.

  13. Found a source by JSBiff · · Score: 5, Interesting

    Found a pdf of calculus notes on northwestern.edu which shows what I was talking about.

  14. Re:I think I had an astronomy prof that talked abo by ultranova · · Score: 4, Informative

    That a theory is just a tool for understanding and predicting reality.

    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.