Talk:Lorentz covariance

message: I think it should be mentioned that E*B is not a lorentzscalar, but rather a pseudoscalar. As well for the dual Fieldtensor G and the Levi-Civita-Symbol. —Preceding unsigned comment added by 85.176.230.49 (talk • contribs) 
:Feel free to perform the necessary edits. --Masud (talk) 00:01, 13 October 2008 (UTC)
thread_title: Pseudoscalar

message: I don't think this is true.  One can imagine a non-uniform universe in which Lorentz covariance is true.
:: Lorentz covariance is part of a broader concept of cosmological principle, that the universe, when viewed on sufficiently large distance scales, has no preferred directions or preferred places. Poincaré covariance is the extension to the Poincaré group.
Roadrunner 02:22, 23 Jul 2004 (UTC)
thread_title: Mistatement

message: This article is quite impossible to understand unless you have a degree in physics. Couldn't we add something like "Imagine a volleyball match, where the ball contiuously moves between... " or something like that to all the "Due to the ambiguity and indifference of the Lorentz-Eintein-Buggyman co-ordinated octopus, the Buron and Woron particles behave similarly due to the incoprehensible... " type paragraphs? —Preceding unsigned comment added by 203.122.73.116 (talk • contribs) 09:22, 23 June 2005 (UTC)
replies: text: I really liked your opening paragraph, it made you ask the right questions in the technical body of the article.  But there is more softening of the intro that needs to be done. Expressing the big picture with well-understood examples (like your volleyball example) is especially important in technical articles like this.  Pb8bije6a7b6a3w (talk) 19:15, 3 May 2013 (UTC)
thread_title:  Comprehensible? I don't think so. 

message: I am convinced that such a (misleading) discussion of LQG, one particular theory that has problems with Lorentz covariance, much like with many other requirements, does not belong to the page about such an important topic as Lorentz invariance. It's not just my opinion, see also Prof. Sean Carroll, . All the best, Lubos --Lumidek 11:46, 26 October 2005 (UTC)
replies: text: I whole heartedly agree. Can we move this material to a separate article (or merge it into the Loop quantum gravity article)? -- Fropuff 15:16, 26 October 2005 (UTC)
replies: text: It came from loop quantum gravity, a while back, when that needed concision. I suggest a separate page for the issue. Charles Matthews 16:02, 26 October 2005 (UTC)
thread_title:  NPOV for Loop Quantum Gravity section 

message: It would be nice if somebody could explain why gravity is exempted from this rule. —Preceding unsigned comment added by Megacz (talk • contribs) 11:33, 8 January 2006 (UTC)
replies: text: Because gravitational physics does not obey Lorentz covariance; general relativity is the present standard theory of gravitation that uses general covariance (a 'generalisation' of Lorentz covariance). Hope this helps. MP   (talk) 12:30, 8 January 2006 (UTC)
thread_title:  Why "Non-Graviational?" 

message: *I'd say yes (Lorentz symmetry), not that there is much here to merge.---CH 00:41, 20 March 2006 (UTC)
thread_title:  To merge or not to merge? 

message: I quote from the article:
:"Lorentz covariance requires that in two different frames of reference, located at the same event in spacetime but moving relative to each other, all non-gravitational laws must make the same predictions for identical experiments."
I'm fairly certain this isn't true on at least two accounts. Firstly, Lorentz covariance applies only to two different inertial frames of reference. And secondly, not all predictions are the same: even in Galilean relativity, we predict different values of kinetic energy in different reference frames. The situation is similar in special relativity: various physical quantities (energy, momentum, B-field etc) transform (note this is NOT the same!) as components of various spacetime vectors.
I will be more than happy to make the necessary changes, iff someone agrees with what I've had to say.
--Masud 09:34, 26 September 2006 (UTC)
thread_title:  Is this even true? 

message: I wish to take issue with the following quote:
The laws of physics are exactly Lorentz covariant but this symmetry is spontaneously broken. In special relativistic theories, this leads to phonons, which are the Goldstone bosons. The phonons travel at LESS than the speed of light. In general relativistic theories, this leads to a massive graviton (note that this is different from massive gravity, which is Lorentz covariant) which travels at less than the speed of light (because the graviton devours the phonon).
The helicity of a graviton is ±2, and the helicity of a longitudinal phonon is 0. A massive graviton would be a spin-2 particle at rest. So, a massive graviton can only emerge if we also have a U(1) gauge boson with helicity ±1. I am taking the liberty of removing the devouring part.
Fizz2010 (talk) 13:07, 17 March 2010 (UTC)
thread_title:  Gravitons eating phonons 

message: Keep an eye out for discussion of this paper, it might well be something to include>
http://prd.aps.org/abstract/PRD/v83/i12/e121301
Constraints on Lorentz Invariance Violation using integral/IBIS observations of GRB041219A
One of the experimental tests of Lorentz invariance violation is to measure the helicity dependence of the propagation velocity of photons originating in distant cosmological obejcts. Using a recent determination of the distance of the gamma-ray burst GRB 041219A, for which a high degree of polarization is observed in the prompt emission, we are able to improve by four orders of magnitude the existing constraint on Lorentz invariance violation, arising from the phenomenon of vacuum birefringence.  — Preceding unsigned comment added by 83.108.206.235 (talk) 19:57, 1 July 2011 (UTC)
thread_title:  Constraints 

message: What's a "Lorentz Tensor"? See the section by this name. This is not common nomenclature that I am aware. The designation is applied but not defined.  — Preceding unsigned comment added by 67.142.168.21 (talk) 18:47, 9 June 2013 (UTC)
replies: text: Fixed  — Quondum 20:50, 9 June 2013 (UTC)
thread_title:  "Lorentz Tensor" 

message: While at one point in time it was common to define, e.g, vectors, tensors, densities, in terms of the transformation properties of their components, the modern perspective is to define them in terms of products of the tangent and cotangent bundles, and covering spaces of those products. This perspective exists not only in the literature of Mathematics but also the literature of Physics. It may be easier for the layman to understand a definition in terms of components, but there should at least be a note that the approach is dated. Shmuel (Seymour J.) Metz Username:Chatul (talk) 21:49, 13 June 2018 (UTC)
thread_title:  NPOV: manifolds and objects on them