Special Relativity Between Reality and Illusion

CarlB

Homework Helper
samalkhaiat said:
Generalization of my statement is (as I said before) meaningless, because it is a common BELIEF among physicists. The SM, string theory and supergravity represent a solid ground for this belief.
You're saying that the justification for physicists believing what they believe is that they believe it. If we were talking about religion or politics, you'd be calling this circular reasoning.

The best argument for special relativity is that it has gotten us this far, why should we consider abandoning it now. But the same argument applies against every revolution that has ever been done in physics. Lee Smolin's new book goes to great length describing how difficult every one of the previous revolutions.

samalkhaiat said:
Having said this, I do, however, want you to tell me where, in physics, do I find a Lie symmetry that gets larger in the low energy limit?
The first and most obvious example is the optics of crystals. The presence of birefringence (and "trirefringence") give optical evidence of anisotropy in the crystal and is a hint of the structure of the crystal.

A crystal in the cubic system exhibits no birefringence and so appears to possess SO(3) symmetry to photons (of low enough energy). But at x-ray energies, the symmetry is broken (to a discrete symmetry).

Lee Smolin's latest book describes the ether theory of the late 19th century as a "matter" theory because it tried to explain everything in the world as matter. The ether was invisible matter that carried the vibrations of light. Since light travels at a very high speed, it was thought that the ether must be very stiff. Light moving in a crystal follows the analogy perfectly.

For the case of the substance which moves when light travels, the analogy to the crystal is that as long as our energies are low, the Poincare symmetry will appear to be a continuous one. But at high enough energies, it is also possible that the symmetry will be broken to a discrete symmetry. In this case, the breaking would be by the appearance of a preferred reference frame and the reduction of Poincare symmetry to the symmetries that existed before the invention of SR.

samalkhaiat said:
NO, because this was a result from a mathematically sound theory with countless experimental verifications. By "mathematically sound" I mean logical consistency and ability to explain a number of known facts.
Classical mechanics was a mathematically sound theory with countless experimental verifications. It had logical consistency and was able to explain a number of known facts. So why search for a new theory outside its bounds?

samalkhaiat said:
Like most physicists, I think science is going in the right direction.
I've been enjoying Lee Smolin's new book "The Trouble With Physics". He makes it very clear that at any given time, very few physicists are worried about the direction of the field. Instead, they just calculate. But Smolin also points out the difficulties that attend the present situation and he makes a pretty good argument that something radical needs to be done.

samalkhaiat said:
If you think that physics needs to be rewritten, then DO IT and show us a solid results. Don't just sit there and [throw] garbage on us.
I have great respect for your knowledge of physics and appreciate your spending time here defending what is commonly believed to be true. Earlier, I gave an alternative interpretation of relativity, that it is a consequence of an anthropic principle and you didn't respond to it. As far as showing you a solid result, as long as you refuse to imagine that anything other than what you've been taught is true, it would be a waste of time. Besides, it doesn't belong on this forum.

Do you agree that if the naive ether theory of the late 19th century (i.e. Gallilean invariance, the straw man that SR defeated) were true, then the biochemistry of living organisms would depend on their orientation? Do you agree that if gravitation and acceleration were not equivalent then biochemistry would depend on the gravitational potential that a planet experiences? Do you agree that both of these effects would tend to make it more difficult for life to survive? Do you agree that one can make a first principles argument for SR and GR on the basis of the anthropic principle? Do you agree that if our foundation for believing SR and GR is the anthropic principle, then it is reasonable to explore physics ideas that treat SR and GR as only very good approximations? What I'm curious here is exactly which step in the above reasoning you find fault with.

Carl

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samalkhaiat

CarlB said:
David Bohm, of Bohmian mechanics fame, believed otherwise.
I know Bohm well enough to tell you that he never believed in "accidental relativity". He BELIEVED in (what he called) a "field" theory of "unbroken whole" which (when formulated) contains relativity and quantum theory. His notion of "implicate order" does not mesh well with any "accidental" symmetry.
"On the meaning of non-Lorentz invariance of processes involving individual beables". The index lists page 292 for "preferred frame" and page 290 for "Lorentz ether" which reads on my comments on the Lorentz Ether Theory directly.
Bohm spent the last 30 years of his life (at Birkbeck college) trying to formulate his "field" theory. He experimented with many, but never found the appropriate mathematical system for his (philosophical) concepts.
This is the reason for the "speculative" material of the last 4 chapters of his book with Hiley.
What Bohm & Hiley said in chapter 12, regarding QM versus relativity,is the following:
IF QM does not break down at some fundamental level, and IF a metric tensor field CAN BE defined on such level, then a LARGE quantum fluctuations could prevent this metric from having diagonal form, i.e. spacetime may cease to be Minkowskian and Lorentz group ceases to be fundamental.
Now, it is equally possible that it is the QM that breaks down at such level. In this case, Lorentz symmetry may continue to be fundamental.
I believe, the book discusses this possibility in chapter 14.

Also see page 346 which shows up in the index. As I recall, this is where he discusses the possibility of future experiments showing violations of Lorentz symmetry.
Not just in the book, but even in private coversations, Bohm & Hiley never explained or proposed such a "future" experiment.
In chapter 14 ,I think, they claim that their "field theory" (when formulated properly) COULD go beyond both relativity and QM. I know their method of introducing "arbitrary forces & momenta" into Bohm's equation of motion of QM. I also know that the method does not work.

Bohm has an important physical effect named after him, the Aharonov-Bohm effect. I don't see how you have the standing to call his ideas rubbish. There are still a lot of physicists working on his ideas.
:rofl: :rofl: :rofl:
Nice one.
I heppened to be the last person, to whom, Bohm spoke physics just one hour befor his death on Oct.27th.1992.

You never presented a view similar to that of Bohm or/and (my ex supervisor) Hiley. I suggest you read AND understand the book you mentioned.

As for the A-B effect, let me tell you that it is a Birkbeck College effect, this is because; 1) Bohm worked (even after retirement) at Birkbeck for 31 years, and most importantly; 2) the effect was first discovered at Birkbeck in 1949 by R. Siday (who died from alcohol abuse). For 10 years, the poor man work went unnoticed until Bohm and his student Aharonov "REDISCOVERED" the effect in 1959 at Bristol university.
After Bohm's death, Hiley promised to speak out and make this fact known to people. Apart from one paragraph in one of his articles in the royal socity, Hiley seems to have forgotten the promise he made in his professorship lecture in 1996.

SO PEOPEL, THE A-B EFFECT SHOULD BE CALLED THE SIDAY'S EFFECT.

Agreed. You've made a series of clearly true statements but I'm not sure what your point is. I'm going to guess that your logic is to point out that quarks are subparticles of protons and neutrons and yet quarks obey Lorentz symmetry just like neutrons and protons do. Therefore, perhaps by a sort of induction, all deeper subparticles must also obey Lorentz symmetry.
The point is this; We have NO good reasons (experiment or good theory) to believe in:
1) Lorentz non-invariant physics.
2) quark is or can be a bound state of some "stuff".

In order to believe in some idea, say preons, physicists need to see two things (for me No1 is enough):
1) mathematically sound theory (logical consistency & explanatory power)
2) experimental evidence.
Well, regarding preons and/or Lorentz violation, we have niether (1) nor (2). So, according to Occam's razor, we are better without them.

Let's apply your logic to the neutrons and protons themselves. Back before quarks were accepted would you have argued that all known particles carry integral electric charges and therefore quarks must too? Would you have argued that all known particles can be found in a free state and therefore quarks must too?
Larger than SU(2) symmetry ,SU(3), led naturally to fractional charges. Most physicists accepted the quark model when it was first proposed
(I would have done the same thing), because
1) it is based on mathematically sound theory
2) soon after the introduction of the quark model, many experimental verifications began to appear.
So, if I was arround in 1963, I would have said what S Coleman said about the quark model:
"It is too d... successful"

It is unwise to compare "the quark model and its success" with "preons and their failures" because

1) preon models are based on mathematically "full of garbage" theories with no experimental evidence.
2) they can not even explain the need for proposing them in the first place.
3) they can not achieve their goal (they end up with more particles than it is in real life)
4) THEY ARE UGLY AND SMELL WRONG.
5) the best of them (the one that pridicts some thing) leads to wrong pridictions, therefore it is wrong.

Do you have an outline of a proof that it is impossible for a non Lorentz invariant preon model to produce Lorentz invariant bound states? Or are you saying it's impossible only because you've never heard of it?
The very fact "I never herd of it" makes this particular model one of many irrelevant garbage arround.

However, I am very interested to see how "Lorentz non-invariant" dynamics (Lagrangian) "produces" a "Lorentz invariant bound state". So, I want you to write down the Lagrangian of this model and show me how it leads to Lorentz invariant bound state. I believe you know how to use LaTex, so I will be waiting to see that Lagrangian next time you post, OK?

regards

sam

CarlB

Homework Helper
samalkhaiat said:
However, I am very interested to see how "Lorentz non-invariant" dynamics (Lagrangian) "produces" a "Lorentz invariant bound state". So, I want you to write down the Lagrangian of this model and show me how it leads to Lorentz invariant bound state. I believe you know how to use LaTex, so I will be waiting to see that Lagrangian next time you post, OK?
What you're asking for is too complicated to put into a single post, nor does it belong on this thread. A first step on getting to where I described is to construct Lorentz invariant propagators from a non Lorentz invariant theory. Will you accept that as a first step or do you insist on having a whole textbook typed into a post?

By the way, regarding Bohm's opinions. You can claim whatever you want to about what the man told you etc. But why would you think he would talk to you about Lorentz invariance when you exhibit this attitude towards it? You can put whatever (self-serving) words you want to into a dead man's lips but you cannot deny his very clear writing on the subject.

Carl

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samalkhaiat

CarlB said:
What you're asking for is too complicated to put into a single post, nor does it belong on this thread. A first step on getting to where I described is to construct Lorentz invariant propagators from a non Lorentz invariant theory. Will you accept that as a first step or do you insist on having a whole textbook typed into a post?
I am happy to see the lagrangian, just the lagrangian. Is this too complicated for you? Just write to me a Lorentz non-invariant Lagrangian

By the way, regarding Bohm's opinions. You can claim whatever you want to about what the man told you etc. But why would you think he would talk to you about Lorentz invariance when you exhibit this attitude towards it? You can put whatever (self-serving) words you want to into a dead man's lips but you cannot deny his very clear writing on the subject.
By the way I never put a single word in Bohms lips. Everything I have said can be easily verified and checked.
You do need to read and understand Bohm & Hiley book. And You do need to know that discrete symmetries are not Lie type symmetries.

sam

CarlB

Homework Helper
samalkhaiat said:
I know Bohm well enough to tell you that he never believed in "accidental relativity".
The quote you are answering is my statement in response to your quote:
samalkhaiat said:
It is IMPOSSIBLE, even for God, to distinguish between inertial frames full stop.
I never said Bohm believed in accidental relativity. You set up a straw man here.

samalkhaiat said:
What Bohm & Hiley said in chapter 12, regarding QM versus relativity,is the following: IF QM does not break down at some fundamental level, and IF a metric tensor field CAN BE defined on such level, then a LARGE quantum fluctuations could prevent this metric from having diagonal form, i.e. spacetime may cease to be Minkowskian and Lorentz group ceases to be fundamental.
samalkhaiat said:
Now, it is equally possible that it is the QM that breaks down at such level. In this case, Lorentz symmetry may continue to be fundamental. I believe, the book discusses this possibility in chapter 14.
So here's the evidence. You believe a version of what Bohm and Hiley believed. I believe a different version. You have a belief as to what is in Bohm & Hiley's book, "The Unidivided Universe". I have a different belief. What kind of experiment can we run to determine who is wrong and who is right (if either)? It seems that we should read chapter 14 and see what it says about Lorentz invariance. Should be easy enough.

I've got the book in my lap. Here's the early references to Lorentz invariance in Chapter 14: Regarding the GRW extension of QM, "Therefore it seems likely that further new developments of this approach may lead to the need to assume a deeper non-relativistic level, rather as we have had to do in our own interpretation as explained in chapter 12, section 12.8." No mention of Lorentz invariance from there until they discuss extensions of their own theory in section 14.6. I quote the last 5 paragraphs of the book:

TheUndividedUniverse said:
Our proposed ontological explanation of the quantum theory has, as we have seen, also led to a certain paradox. For it implies nonlocality and this would seem to contradict relativity which is regarded as a theory that is equally as fundamental as quantum theory. But as we have seen in chapter 12, section 12.7, it is possible to propose a deeper theory of the individual quantum process which is not relativistically invariant and which nevertheless leads to Lorentz invariant consequences for all statistical results, as well as for the large scale manifest world. In this theory there is a preferred coordinate frame in which the instantaneous transmission of impulses is in principle possible, so that there is no contradiction with nonlocality for individual quantum processes. In other words, we say that underlying the level in which relativity is valid is a subrelativistic level in which it is not valid even though relativity is recovered in a suitable statistical approximation as well as the large scale manifest world.

In our discussion of this idea we have already suggested one way in which the theory might imply new experimental consequences. Thus although there is no inherent limitation to the speed of transmission of impulses in this subrelativistic level, it is quite possible that quantum nonlocal connections might be propagated, not at infinite speeds, but at speeds very much greater than that of light. In this case, as explained in chapter 12, we could expect observable deviations from the predictions of the current quantum theory (e.g. by means of a kind of extension of the Aspect-type experiment).

It would seem then that already in this case a subrelativistic level would simultaneously be one that goes beyond the current quantum theory. But the notion of a general subquantum mechanical level would have to go beyond the current quantum theory in a much more thoroughgoing way. To explore such a possibility, it is useful to consider once again the stochastic form of our ontological approach. We recall that in this approach a particle follows a trajectory that is random, but is modified by a suitable osmotic velocity along with the action of the quantum potential. At the level of Brownian motion of atoms, for example, similar random trajectories are regarded as approximations to actual trajectories in which this randomness does not prevail at indefinitely short distances. Rather there exists a characteristic length, the mean free path, below which simple causal laws begin to have a dominant effect. This free path reveals itself in many experiments, e.g. those of diffusion, conductivity of heat, etc. Similarly we may propose that in our theory there is a minimum free path below which the trajectory ceases to be random. As the atomic free path is the first sign of a 'subcontinuous' domain in which the laws of continuous matter would break down, so the free path in our trajectories would be the first first sign of a subquantum domain in which the laws of quantum theory would break down. It is implied of course that this would begin to occur for wavelengths of the order of the 'free path'.

The next sign of a breakdown of the quantum theory would be the discovery of some yet smaller dimension whose role might be analogous to the dimension of the atom in the atomic explanation of continuous matter. We do not yet know what this dimension is, but it seems reasonable to propose that it could be of the order of the Planck length, where, in any case, we can expect that our current ideas of space-time and quantum theory might well break down. The 'free path' would then be some multiple of this length.

At present further progress only seems to be possible through the use of the imagination to suggest new concepts that might permit a more precise formulation of these ideas. In this regard the situation is not very different from what it is in string theory, which is at present guided by speculative use of mathematical concepts, that also have little or no contact with experiment. As we have pointed out in section 12.8 of chapter 12, it took over 2000 years before the atomic theory of Democritus could achieve a more precise formulation. But we may reasonably hope that with the more rapid progress of science in the present era, it will take considerably less time.

In short, there is absolutely no indication of Lorentz symmetry getting saved by some sort of quantum breakdown in this book. The authors imply future experiments might show violations of Lorentz symmetry and even outline ways it could happen. The book is filled with references to the necessity of a preferred reference frame. And yet you claim to have known the authors well. What you're doing is filling another man's books with your own ideas just like you put your own ideas onto his lips. And you think that I'm the one who's disconnected from reality?

Carl

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samalkhaiat

CarlB said:
You believe a version of what Bohm and Hiley believed. I believe a different version. You have a belief as to what is in Bohm & Hiley's book, "The Unidivided Universe". I have a different belief. What kind of experiment can we run to determine who is wrong and who is right (if either)?
One experiment is to write down the Lagrangian of that Lorentz NON-INVARIANT theory you talked about, which I am still waiting to see.

Saying that "O(3) symmetry" breaks down to a "discrete symmetry" indicates clearly that your knowledge about physics and mathematics is very very poor.
So you already did run that experiment.

sam

CarlB

Homework Helper
samalkhaiat said:
One experiment is to write down the Lagrangian of that Lorentz NON-INVARIANT theory you talked about, which I am still waiting to see.
You haven't mentioned anything about "The Undivided Universe" nor the opinions of Bohm and Hiley on special relativity. I have shown that your opinion: It is IMPOSSIBLE, even for God, to distinguish between inertial frames full stop. was not only not shared by all physicists, but it wasn't even shared by the physicists who taught you. And you wrote: Not just in the book, but even in private coversations, Bohm & Hiley never explained or proposed such a "future" experiment. but I showed extensive quotes from their book showing that this is not the case. Look, if you want people to believe your opinions about what opinions are shared by "all physicists", then you might try explaining how it came to be that you didn't even know the opinions of two physicists that you claim were close to you. No one can verify what David Bohm told you "one hour before he died". Anyone can verify what is written in Bohm's books, and that is compatible with what I wrote about his opinions.

Now if, after reading extensive quotes from Bohm & Hiley, you're willing to admit you were wrong about their opinions with regard to preferred reference frames, then we can continue. But if you are so stubborn that even simple things like what is in chapter 14 of "The Undivided Universe" evade you, then I have no further discussion with you. Admit your error and we will continue.

On the subject of the possibility of physical situations having more Lie symmetry at low energies than high, you wrote: "Look Carl, if you want to look for violation of some Lie symmetry, then you should look at low energy phenomena (at large length scale)." and "The correct statement is; the standard model could be an effective theory of more symmetric one. And this "deep" theory must show, in certain limit, all the symmetries of the SM."

In return, I gave you a common physical example where an apparent Lie symmetry at low energies breaks down at high energy, namely where the O(3) symmetry of the interactions of low energy photons with a cubic symmetry crystal break down to the discrete symmetry of the crystal lattice at high energies.

If you want to continue discussing physics you need to confront my example with something deeper than: "Saying that "O(3) symmetry" breaks down to a "discrete symmetry" indicates clearly that your knowledge about physics and mathematics is very very poor.

Your comment says absolutely nothing about physics or mathematics. What you've written is just an ad hominem attack of no use to anyone.

Now if you want me to comment further on this, you need to either adimt that in the example of photons in cubic crystals, an apparent continuous symmetry breaks down to a discrete symmetry at high energies, the reverse of the expected symmetry behavior of the standard model, as I claimed existed (many more examples exist). If you don't like my use of terminology, then correct the terminology. If you don't agree with the physics, then correct the physics. If you think the mathematics is wrong, the say what you think is right.

But if you really want to explain something, not just to me, but to anyone else reading this thread (perhaps your students), then lay off the ad hominem attacks. And the human memory is a treacherous thing. If you're going to argue through the use of name dropping, you need to make sure that the written record supports your memory.

Carl

samalkhaiat

CarlB said:
You haven't mentioned anything about "The Undivided Universe" nor the opinions of Bohm and Hiley on special relativity.
Look, I have never read the book! But I DO know exactly what Bohm & Hiley did put in each chapter. YES, This well I know the two men and their "opinions".
However, I am not a "Bohmian". I donot believe in or share the same philosophical views of Bohm (or Hiley). This is why I DONOT agree with their speculations in some parts of the book.
I even have my doubts about the whole mathematical structure of (what peopel now call) Bohmian mechanics.

Bohm saw GOD in his quantum potential, but was very unhappy with the fact that his god (QP) could not account for or explain the existence of photon and other relativistic particles.
For many years, research students at Birkbeck were trying to do two things;
1) Finding the relativistic version of Bohm's equation (i.e doing what Dirac did to Schrodinger equation)
2) Deriving Bohm's Eq. from the integral Schrodiger Eq.

$$i\hbar \frac{\partial{\phi(p)}}{\partial{t}}= \int d(\bar{p}) H(p,\bar{p}) \phi(\bar{p})$$

(i.e proving that Bohm's Eq is equivalent ro Schrodinger's)

After 6 mohths of work on this program, I realized that such task is (at least for me) impossible to accomplish (still is an open question). This failure forced me to abandon my earlier interest in the interpretations of QM and choose to do my phd on the mathematical formalisim of field theory instead.
The day, I made this decision, I said to Hiley
"mathematics forces me to believe that photon and other relativistic particles are too fast for Bohm's GOD to see and explain. It seems to me that quantum potential is FUNDAMENTALLY non-relativistic concept. something that disappears completely in the relativistic domain. This together with the fact that Bohm's Eq can only be derived from the differential(x-space) Schrodinger Eq, suggests a place for Bohm theory somewhere between Newton's mechanics and Non-relativistic QM".
After that day, Hiley started introducing me to people by saying (with smile): "this is .... who has been annoying me for some time"

Now if you want me to comment further on this, you need to either adimt that in the example of photons in cubic crystals, an apparent continuous symmetry breaks down to a discrete symmetry at high energies, the reverse of the expected symmetry behavior of the standard model, as I claimed existed (many more examples exist). If you don't like my use of terminology, then correct the terminology. If you don't agree with the physics, then correct the physics. If you think the mathematics is wrong, the say what you think is right.

But if you really want to explain something, not just to me, but to anyone else reading this thread (perhaps your students), then lay off the ad hominem attacks. And the human memory is a treacherous thing. If you're going to argue through the use of name dropping, you need to make sure that the written record supports your memory.
The relavent symmetry groups of "photon" interaction (even when it interacts with cows) are SO(1,3) & U(1), NOT (S)O(3).

1) The symmetry of regular solids(crystalls) is classified by the so-called point groups. They are;
the cyclic group $$C_{i}$$ and
the dihedral group $$D_{i}$$ ,with i = 2,3,4 and 6.

2) the symmetry group of an atom is the rotation group SO(3).

Tiny knowledge in group theory tells us

$$\left(C_{i},D_{i}\right) \subset SO(1,3)$$

This says that symmetry groups of the macroscopic (low energy) system, the crystall, are subgroups of the symmetry group of the microscopic (high energy),(deep level) system, the atom. Isn't this what I said?
Do you want me to rephrase? OK

The above relation means that low energy "effective" theory (of crystall) is less symmetric than its corresponding high energy "deep" theory (of atom)
, apart from the words atom and crystall, this was exactly my statement.

How about another rephrase? so you understand my statement first and find "that" contradicting "example"

When atoms (small, high energy things) join to form a crystall (large, low energy thing), the symmetry group of atomic physics "breaks down" to its subgroups, i.e to the symmetry groups of crystall physics.

Eventhough my statement was about Lie symmetry groups and its Lie subgroups, your "discrete symmetry example" does support, not contradict, my statement that;
Micro-world seems to be associated with larger symmetry group than that of the Macro-world.
Do you get it now?
You should have put some efforts and understood this statement before bringing about your crystall .

Physicists had very good reason to enlarge Poincare' group and to go from
SU(2) all the way up to SU(5) & SO(10).

sam

oh, what happened to that Lorentz non-invariant Lagrangian?:rofl:

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CarlB

Homework Helper
samalkhaiat said:
Look, I have never read the book! But I DO know exactly what Bohm & Hiley did put in each chapter. YES, This well I know the two men and their "opinions".
The book itself is the only tangible evidence of what is in the book. Your memory is intangible. I trust the book. It's quite clear. I'm amazed that you're willing to tell me what is in it without reading it, and even more amazed that you're willing to admit it.

The memory plays tricks on all of us. People believe what they want to believe. The written word is far better evidence.

samalkhaiat said:
Isn't this what I said?
Your physics is correct, but you still talk around the example. In your answer, you've completely avoided discussing the subject at hand, which is the difference between the low energy behavior of photons in crystals and the high energy behavior of photons in crystals. Let me repeat it again.

Consider the physics of photons in cubic symmetry crystals. Low energy photons see no crystal at all. For them, the symmetry of the region they operate in is the full Lie group of rotations and translations in 3 dimensions. It is only as the energy of a photon increases that it begins to interact with the crystal and discovers that the symmetry is not so complete.

Instead of this example, you are defeating a straw man. Yes, I agree that the symmetry of an atom is greater than the symmetry of a crystal. But the example is not the atom. The example is the photons and the photons alone. The crystal, and its atoms, are only providing the background for the photon, they are not of concern.

samalkhaiat said:
Physicists had very good reason to enlarge Poincare' group and to go from SU(2) all the way up to SU(5) & SO(10).
Well, the proton didn't decay, did it. If symmetry were the solution to all elementary particle problems there wouldn't be all those string theorists running around loose out there.

samalkhaiat said:
oh, what happened to that Lorentz non-invariant Lagrangian?
You can have it after you admit that (a) Bohm and Hiley very clearly wrote in favor of a preferred reference frame in the book "The Undivided Universe", and (b) the photons in cubic system crystals provide a physical example of how a system (in this case the photons in cubic crystals) can have a Lie symmetry broken at high energies rather than low. Until we get through these, no more. This is enough.

I am glad to see you back. I've got some more to talk with you about, I'll put it in another post.

Carl

CarlB

Homework Helper
CarlB said:
Since the standard model is only an effective theory, any of its symmetries could be accidental.
samalkhaiat said:
The correct statement is; the standard model could be an effective theory of more symmetric one. And this "deep" theory must show, in certain limit, all the symmetries of the SM.
Here is a quote from Lee Smolin's latest book, "The Trouble with Physics":

LeeSmolin said:
(p 315) One of the great seers is Holger Bech Nielsen of the Niels Bohr Institute. He was an inventor of string theory, and he has many other key discoveries to his credit. But for many years he has been isolated from the mainstream for advocating what he calls random dynamics. He believes that the most useful assumption we can make about the fundamental laws is that they are random. Everything we think of as intrinsically true, such as relativity and the principles of quantum mechanics, he thinks are just accidental facts that are emergent from a fundamental theory so beyond our imagining that we might as well assume that its laws are random. His models are the laws of thermodynamics, which used to be based on principles but now are understood as the most likely way that large numbers of atoms in random motion will behave. This may not be right, but Nielsen has come remarkably far in his antiunification program.
Here are some Holger Nielsen preprints:

http://www.arxiv.org/find/hep-th/1/au:+Nielsen_H/0/1/0/all/0/1

One that reads directly on our discussion is this one:

Derivation of Poincare Invariance from general quantum field theory
C.D. Froggatt, H.B. Nielsen
Annalen der Physik, Volume 14, Issue 1-3 , Pages 115 - 147
Special Issue commemorating Albert Einstein
Starting from a very general quantum field theory we seek to derive Poincare invariance in the limit of low energy excitations. We do not, of course, assume these symmetries at the outset, but rather only a very general second quantised model. Many of the degrees of freedom on which the fields depend turn out to correspond to a higher dimension. We are not yet perfectly successful. In particular, for the derivation of translational invariance, we need to assume that some background parameters, which a priori vary in space, can be interpreted as gravitational fields in a future extension of our model. Assuming translational invariance arises in this way, we essentially obtain quantum electrodynamics in just 3 + 1 dimensions from our model. The only remaining flaw in the model is that the photon and the various Weyl fermions turn out to have their own separate metric tensors.
http://www.arxiv.org/abs/hep-th/0501149
http://www3.interscience.wiley.com/cgi-bin/abstract/109884430/ABSTRACT

By the way, this is NOT my example of how one can obtain Poincare invariance from a QFT that does not possess it. To get MY example, you have to play nice by admitting that Bohm and Hiley wrote a book that very clearly presented their belief that there is a preferred reference frame, and by admitting that photons in crystals are an example of a Lie symmetry that breaks at high energy rather than low.

Carl

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samalkhaiat

CarlB said:
We are not yet perfectly successful. In particular, for the derivation of translational invariance, we need to assume that some background parameters,

By the way, this is NOT my example of how one can obtain Poincare invariance from a QFT that does not possess it
Write down that Lagrangian which you do not know or have.:tongue2:

you have to play nice by admitting that Bohm and Hiley wrote a book that very clearly presented their belief that there is a preferred reference frame,
NO, They suggested a line of thoughts which they admit it could be wrong, because it is based on speculations.

and by admitting that photons in crystals are an example of a Lie symmetry that breaks at high energy rather than low.
School kids know that when they talk about photons in crystalls, in chairs and in cows the symmetry is the Lorentz's SO(3,1).

I can only admit that you have shown everybody that your knowledge about physics and math is infinitesmal. I will be here from time to time to let everybody knows this fact about you.

bye

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