Experiments Poke Holes In Quantum Physics 14
fenrissmurf writes: "The New York Times reports on new measurements of muons, done at the Brookhaven National laboratory. The muons didn't behave as expected, and scientists are saying that the "classical model" is now in doubt." We just posted another story about this, but the NYTimes article is good. There's another NYT article about a certain quantum force that I thought was interesting, too.
All this does to me (Score:1)
Re:Terrible title (Score:1)
Re:Terrible title (Score:1)
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Re:Terrible title (Score:1)
How about Standard model demonstrated to be substandard
or A good reason never to call your model the standard model
or Experiment guarantees theoretical physicists jobs for the next twenty years
dabacon
Because scientists like to be so right... (Score:1)
Re:Implications to relativity of the new measureme (Score:1)
CPT and Lorentz Tests with Muons, Robert Bluhm, Alan Kostelecky, and Charles Lane, Phys. Rev. Lett. 84, 1098 (2000).
The authors propose that it is possible to test special relativity by comparing g-2 measured during the sidereal day with the value from the sidereal night. We intend to do this analysis.
Re:Implications to relativity of the new measureme (Score:1)
Re:Implications to relativity [repost] (Score:1)
Forum: sci.physics
Subject: New muon anomaly - implication for relativity.
Date: 02/09/2001
Author: Robert Clark
The recent measurement of the magnetic moment of the muon has been interpreted as a possible suggestion of supersymmetry:
'Milestone' Study Challenges Basic Laws of Physics, Universe,
http://www.space.com/scienceastronomy/generalscie
The paper on the research is available on the experiments home page:
The Muon g-2 Experiment Home Page,
http://phyppro1.phy.bnl.gov/g2muon/index.shtml
However, as discussed in the article on Space.com the measurements are dependent on special relativity. There were measurements of the decay of muons as a test of special relativity in the 70's. They supported special relativity within the precision of the measurements, that is, the errors were within the accuracy of the experiments. This new research can be interpreted as providing a more precise test of special relativity.
In my opinion, the approximate nature of special relativity, that is, Lorentz invariance, for real physical bodies is inherent in the mathematics of modern physics, both in quantum field theory and in general relativity. It is interesting to note that quantum electrodynamics which attempts to meld quantum mechanics with special relativity is very accurate when applied to the hydrogen atom but less so when applied to heavier atoms. These new measurements also show that QED while accurate for the light electron is less accurate when applied to the heavier muon.
The approximate nature of Lorentz invariance is discussed in a preprint by Jacobson and Mattingly:
"There is also reason to doubt exact Lorentz invariance: it leads to divergences in quantum field theory associated with states of arbitrarily high energy and momentum. This problem can be cured with a short distance cutoff which, however, breaks Lorentz invariance.
"For these reasons we entertain the possibility that there is a preferred rest frame at each space-time point. In particular, we seek a viable effective field theory incorporating a breaking of local Lorentz invariance."
Spontaneously broken Lorentz symmetry and gravity, p. 1,
http://xxx.lanl.gov/abs/gr-qc/0007031
Note also that if it is confirmed that Lorentz invariance is only an approximation, then that strongly implies that light speed can be exceeded at sufficiently high energies:
Forum: sci.astro
Subject: Superluminal speeds as an explanation of cosmic ray anomalies.
Date: 11/17/2000
Author: Robert Clark
http://x74.deja.com/getdoc.xp?AN=694810422
--
______________________________________
"The more harshly you criticize someone else,
the more likely you are to be wrong yourself.
The cause is a mystery..."
-- Bob Clark
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and you want egg in your beer? (Score:2)
Then they would have to charge $$$ for it to pay for all that added labor.
You are getting exactly what you paid for dude. Stop complaining.
Re:Because scientists like to be so right... (Score:2)
BTW: This doesn't so much blow apart quantum physics as it does (hopefully) validate the supersymetry model of physics. Like said -- the people who do supersymetry are probably pretty happy about this. From the article (for those who don't bother to read it):
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Terrible title (Score:2)
Could we get the title of this story changed? This experimental result does not, in any way "poke holes in quantum physics". It (potentially) pokes holes in a very particular model that is based on quantum theory, but there is no suggestion that the quantum theory itself is being challenged.
Re:Implications to relativity of the new measureme (Score:2)
Thanks for the info and the ref. to the paper. I'll check that out. I would also be interested in finding out how your group can interpret these new results as a test of Lorentz invariance.
I also just saw a news release on some research that suggests the speed of light might vary and be frequency dependent over cosmological distances. It was meant to address the conumdrum of the anomalous gamma ray detection from Markarian 501 that was discussed in one of the articles I cited. One of the co-researchers is the highly-regarded general relativity theorist John Ellis:
Einstein in need of update?
http://www.eurekalert.org/releases/tam-ein02090
Space-Time Foam Effects on Particle Interactions and the GZK Cutoff
http://xxx.lanl.gov/abs/hep-th/0012216
The argument I'm presenting was taken from some debates I had on the sci.physics.relativity group a couple of years ago. Unfortunately, dejanews.com doesn't archive posts very far back anymore so those are no longer available.
A key point is philosophical/heuristic:
Is it reasonable that an equation of physics should be considered to be *exactly* true for the entire future of physics? Since we are not at the stage of having a final theory I don't think that is likely. However, note that the key idea that reaching and exceeding the speed of light would require infinite energy is based on the idea that the Lorentz transformation is *exactly* true, for if not you don't get the infinity by having a zero in the denominator.
One might argue that in the future Lorentz invariance will be replaced by a more accurate expression, but if it will not be *exactly* true at that time, surely it is not *exactly* true now.
I repeated this argument recently also in sci.physics.relativity and received the response that the conservation of energy is a counterexample to the idea that a physical equation should not be considered to be exactly true. However, remarkably, even conservation of energy is dependent on Einstein's transformation equations, so that deviations from these will also have an effect on how we interpret the conservation of energy. This is discussed in one of the papers that discuss violations of Lorentz invariance. I'll give you a reference if you like. The possibility that conservation of energy might also be violated is probably even a more jarring idea than that of violations of Lorentz invariance.
The mathematical reasons for doubting exact Lorentz invariance *for real physical bodies* are these:
The equations of both quantum field theory and general relativity have been found to be analogous to those of fluid mechanics. In fluid mechanics we also have the fact that for the approximate linear PDEs describing the fluid, exceeding the wave speed of the underlying medium would result in an infinite pressure. Naively, one might conclude no body can exceed the speed of sound in a medium. But of course mathematicians and engineers know these equations are approximations. These linear PDEs need to be replaced by the more accurate nonlinear PDE's that describe the fluid in transonic and supersonic situations.
One might take this to be just a coincidence that the most advanced equations of modern physics, quantum field theory and general relativity, both describe the vacuum with equations that are analogous to those of a material medium. But the predictions of those theories are also what one would expect for a medium. In quantum electrodynamics and quantum field theory in general we have the fact that you must make mass and charge renormalizations to describe the reactions of subatomic particles very close to the intense field of the nucleus.
The key fact about this in regard to this discussion is this: if Lorentz invariance is to be true, then *every* aspect of its predictions must hold, not just simply time transformations as measured by decay rates. If the *intrinisic* mass and charge have to changed when moving at high speeds close to the nucleus, then that signals Lorentz invariance is not holding in that situation. (Note this is not the "relativistic mass" change, and of course for Lorentz invariance to hold, charge must be invariant.)
One might say this is only true for subatomic particles close to the nucleus, but the equations of QED show in fact *this is true for a field of any intensity*, the corrections are just extremely small. This is discussed in papers describing how the speed of light is altered in regions of strong electrical and magnetic fields, which in itself is telling you that the vacuum has properties dependent on the energy content in a region that effect the *intrinisic* properties of bodies in that region.
When I had this discussion on sci.physics.relativity there was a fundamentally important fact about this being overlooked: not only do mass and charge renormalizations have to be made close to the nucleus, but THE DEVIATIONS IN MASS AND CHARGE GET WORSE AS THE SPEED OF THE PARTICLE INCREASES. I can not overemphasize the importance of this fact to the argument. As I said before the mass and charge renomalizations are signals of the failure of Lorentz invariance in these situations. That the deviations get worse with speed means the deviation from Lorentz invariance gets worse with speed. This is exactly what you would expect if it were true that this is analogous to the situation of a body traveling through a material medium and that given sufficient energy you can exceed the wave speed of the medium.
As I said the mathematics of general relativity also suggests Lorentz invariance should only be an approximation *for real physical bodies*. In general relativity is it said Lorentz invariance holds only "locally". This is defined to mean it only holds *at a point*, or equivalently it holds on a tangent plane. But in differential geometry on which GR is based, a property is said to hold locally, when it holds *exactly* on a small region of the manifold. According to differential geometry which is the mathematical theory deriving GR, Lorentz invariance does not hold locally using the definition used in that theory and in every field of mathematics that uses the concept of a manifold. In the primary reference work on GR _Gravitation_ by Wheeler, Misner and Thorne it says explicitly that in real space with curvature, containing real bodies inducing their own space-time curvature Minkowski space can not be expected to exactly hold. To me this is saying that Lorentz invariance does not hold exactly for real physical bodies in real space with curvature.
In the debates on sci.physics.relativity I only gave a heuristic reason that I think can probably be made rigorous that the fundamentally important fact that the deviations from Lorentz invariance get worse as the speed of the body increases also holds in general relativity: the fact that the effective "force" a body feels becomes greater as the speed of the body increases (this is discussed in the FAQ for the sci.physics.relativity group.) This suggests that the *intrinsic* mass of the body is increasing with speed. (Again this is not the "relativistic mass" correction.) However, I found an article in the American Journal of Physics that says this explicitly:
American Journal of Physics -- July 1985 -- Volume 53, Issue 7, pp. 661-663
Measuring the active gravitational mass of a moving object
D. W. Olson and R. C. Guarino
Department of Physics, Southwest Texas State University, San Marcos, Texas 78666
If a heavy object with rest mass M moves past you with a velocity comparable to the speed of light, you will be attracted gravitationally towards its path as though it had an increased mass. If the relativistic increase in active gravitational mass is measured by the transverse (and longitudinal) velocities which such a moving mass induces in test particles initially at rest near its path, then we find, with this definition, that Mrel=gamma(1+beta^2)M. Therefore, in the ultrarelativistic limit, the active gravitational mass of a moving body, measured in this way, is not gammaM but is approximately 2gammaM.
Note this "effective" mass of the body in a gravitational field is again not the simple "relativistic mass". To me this is again signaling that Lorentz invariance is only an approximation for real physical bodies.
Another article in AJP that appears to be saying this is by Steve Carlip:
American Journal of Physics -- May 1998 -- Volume 66, Issue 5, pp. 409-413
Kinetic energy and the equivalence principle
S. Carlip
Department of Physics, University of California, Davis, California 95616
According to the general theory of relativity, kinetic energy contributes to gravitational mass. Surprisingly, the observational evidence for this prediction does not seem to be discussed in the literature. I reanalyze existing experimental data to test the equivalence principle for the kinetic energy of atomic electrons, and show that fairly strong limits on possible violations can
be obtained. I discuss the relationship of this result to the occasional claim that "light falls with twice the acceleration of ordinary matter."
However, I'm only judging here by the abstract as I haven't had the chance to read this article yet. I also hasten to add that Dr. Carlip is a frequent contributor to the sci.physics.relativity group in which he argues against speeds surpassing the speed of light, so he would probably be opposed to the idea that Lorentz invariance is only an approximation.
These articles can be found by searching on AJP's site: http://ojps.aip.org/ajp/
Note I am suggesting that high speeds and energy content in a region can effect what are regarded as intrinsic properties. This of course implies these properties really are not intrinsic but are dependent on surrounding conditions. My view is that properties such as mass and charge will be found to be tensors dependent on the mass/energy distribution in their vicinity and indeed on that of the universe.
Bob Clark
Re:Because scientists like to be so right... (Score:3)
You may think its fun (and sometimes it really is), but no such thing happened here: we've been expecting the experiments to diverge from the Standard Model since the day it was written down in the 70s. More than that, we've been hoping to see that failure for 30 years.
The really embarrasing thing is that we've built a model that has been so incredibly successful (no experiment has yet been confirmed to be in conflict with the Standard Model, including this one) that we haven't seen it break down yet! Hopefully, once they've finished analyzing the data from their 2000 run, the g-2 group will be able to push the error bars down far enough that we can finally say we've seen the Standard Model fail. But we won't know for a year or so, unfortunately.
Re:Because scientists like to be so right... (Score:3)
This doesn't so much blow apart quantum physics as it does (hopefully) validate the supersymetry model of physics
This result doesn't actually favor any particular post-Standard Model physics scenario ... what it does say (if it holds ups) is that the successor model must provide a certain, definite correction to the muon anomalous g value. The paper mentions that this could be acounted for by a particular supersymmetric scenario with particular values of certain parameters; but, it could just as easily be accounted for by muon substructure at the 2TeV scale or other types of SM extensions. So, it really doesn't say anything other than "something else is (almost) definitely out there".
BTW, if you don't like the SM because it has 20 or so free parameters, you're going to absolutely hate supersymmetry: the absolutely minimal supersymmetric extension requires the specification of roughly 150 free parameters. Despite this, many people see it as the preferred extension of the SM for a number of extremely technical reasons that greatly outweigh the seven-fold ballooning of the parameter space.