Exploring Quantum Mechanics without Representation: A Textbook Approach

In summary, the conversation revolves around finding a textbook that presents quantum mechanics without relying heavily on representations and instead focuses on the physical and mathematical aspects of the operators. The books "Modern Quantum Mechanics" by Sakurai and "Classical and Quantum Mechanics via Lie algebras" by Neumaier and Westra are suggested as potential options. The importance of avoiding non-peer reviewed material, such as Neumaier's paper, is also emphasized.
  • #1
Gerenuk
1,034
5
Does someone know a textbook that treats QM without relying on representations much? I mean like saying "lets show that this commutator (momentum and position etc.) is reasonable and then derive everything from that without ever talking about representation much".

Moreover is it possible to justify these fundamentals in this form? I only know the vague Schroedinger argument for the wave function exp(ikx), but this is an argument about a representation and not the operator?!
 
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  • #2
Essentially the Dirac formalism uses an interpretation-independent formalism which replaces both matrix mechanics and wave mechanics.
 
  • #3
Of course, it provides the tools for representation-free treatment, but so how do you set up QM with it?

I mean something more explanatory than just quoting Schroeding again and saying <x|p>=exp(ikx). Maybe rather a statement about the operators themselves rather than the basis functions? I suppose anything in QM is just guess, but I prefer guesses about operators rather than basis functions. And ideally a total treatment of everything else starting from operators.

(btw: similar to the algebra of ladder operators!)
 
  • #4
Quantum mechanics can be formulated/presented axiomatically using this representation-free formatlism and this is done in serious books like Galindo and Pascual or Prugovecki who put a lot of mathematical rigor in their statements.

Or perhaps you mean a formulation purely in terms of operators, like the algebraic one of Segal ?
 
  • #5
I don't know these more advanced formulations, but it's quite likely that I mean one of those. What's the names of these books and do you know some more? I might have a glance at them in the library. Thanks!

I don't need mathematical rigor really, but I'm fine with what's common to physicist by saying "it works and is well behaved" :)
 
  • #6
Sakurai's "Modern Quantum Mechanics" doesn't rely much on any particular interpretation of QM. In particular, he explains how the relationship between momentum and position operators can be understood in terms of momentum being the generator of rotation.
 
  • #7
SpectraCat said:
Sakurai's "Modern Quantum Mechanics" doesn't rely much on any particular interpretation of QM.
The thread is about (absence of) REPRESENTATION, not interpretation. :-p
 
  • #8
Gerenuk said:
I don't know these more advanced formulations, but it's quite likely that I mean one of those. What's the names of these books and do you know some more? I might have a glance at them in the library. Thanks!
The algebraic approach is presented e.g. in "Mathematical theory of quantum fields" by H. Araki. But I doubt that's the sort of thing you want. You would just be replacing stuff about representations of groups with stuff about representations of C*-algebras.

Perhaps you could explain in more detail what it is that you don't want to see? Don't most books already avoid talking about representations of groups? Did you mean something other than "representations of groups" when you said "representations"?

Did you perhaps just mean that you don't want the book to emphasize a specific Hilbert space? In that case, maybe Sakurai is a good choice.
 
  • #9
Thanks for the suggestion!
Maybe you are right. This book could be rather mathematically rigorous, which isn't my primary goal. It would probably be too tedious for me.

Thinking of the Dirac representation, I don't want to see statements about the wave vectors, but rather about the operators infront of them. Like the ladder operator derivation where you tell the commutator and everything else follows from that once you postulate a creation operator. Ideally you never mention the specific basis functions.
Best would be if QM would follow from some sensible axioms which explain the position and momentum operator physically and mathematically.

I hope to find such treatment in the books of Dexter. But what are these books called? :)
 
  • #10
What you are describing is pretty much exactly how Sakurai handles the subject of QM. This is why I suggested it, because I found it to give exactly the treatment that you are asking for .. focus on the operators and underlying physics, rather than the eigenvalues and wavefunctions. Reading it really helped fill gaps in my understanding of QM that I didn't even know were there.

Have you looked at that book?
 
  • #11
I don't have easy access to a library at the moment.
I remember learning from Sakurai a lot. Not quite sure if I missed some part.
 
  • #12
Gerenuk said:
Of course, it provides the tools for representation-free treatment, but so how do you set up QM with it?

I mean something more explanatory than just quoting Schroeding again and saying <x|p>=exp(ikx). Maybe rather a statement about the operators themselves rather than the basis functions?

You can find a fully developped operator approach to quantum mechanics in my book

Arnold Neumaier and Dennis Westra,
Classical and Quantum Mechanics via Lie algebras,
2008, 2011. http://lanl.arxiv.org/abs/0810.1019
 
  • #13
Gerenuk, one thing you should definitely avoid, is the paper by Arnold Neumaier. It’s not peer reviewed, and it’ll never be.

Please take a visit to http://arnold-neumaier.at/" :

"I learned to see chance as the innovative potential of the Creator, both in small things (Prov. 16:33) that may be insignificant and in decisive situations (Ps. 139:13). I learned to see that (when one looks at the bottom line of arguments of chance, where they can be checked through calculations that can be compared with experiments) chance is simply the scientist's way to account for influences beyond one's control, that cannot be modeled by deterministic laws but appear to have a degree of surprise. (And indeed, one can find technical definitions of the concepts of `innovation' and `surprise' in some treatises of statistics. I recently wrote a formal paper about surprise.)"

On the same page Neumaier declares:
"The way protein molecules fold into their biologically active state is determined by the same mechanism: different possible conformers compete for survival, and the law of large numbers guarantees that most of the molecules will be in the shape corresponding to the smallest energy - forcing the shape to be in a well-defined form that allows the molecule to be used as a biological machine.
...
The possibilities of life are built in into the delicate mixture of deterministic and stochastic laws of nature; which possibilities are realized are determined by the creativity of God, combined with the properties of the environment that carries out the plans of God through self-organization processes governed by the second law of thermodynamics."

Besides the complete crackpot nonsense about "protein folding" and "the law of large numbers" (since it requires a time http://en.wikipedia.org/wiki/Levinthal%27s_paradox" to arrive at its correct native conformation), Neumaier has his own QM interpretation called the "Thermal Interpretation", and the rest you can figure out by yourself...

Some have http://www.askwhy.co.uk/truth/810NeumaierCoprolalia.php" about Arnold Neumaier, and personally it feels a little bit awkward he got the affirmation as a PF Science Advisor...? :bugeye:
 
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  • #14
DevilsAvocado said:
Gerenuk, one thing you should definitely avoid, is the paper by Arnold Neumaier. It’s not peer reviewed, and it’ll never be.

Please take a visit to http://arnold-neumaier.at/" :

"I learned to see chance as the innovative potential of the Creator, both in small things (Prov. 16:33) that may be insignificant and in decisive situations (Ps. 139:13). I learned to see that (when one looks at the bottom line of arguments of chance, where they can be checked through calculations that can be compared with experiments) chance is simply the scientist's way to account for influences beyond one's control, that cannot be modeled by deterministic laws but appear to have a degree of surprise. (And indeed, one can find technical definitions of the concepts of `innovation' and `surprise' in some treatises of statistics. I recently wrote a formal paper about surprise.)"

On the same page Neumaier declares:
"The way protein molecules fold into their biologically active state is determined by the same mechanism: different possible conformers compete for survival, and the law of large numbers guarantees that most of the molecules will be in the shape corresponding to the smallest energy - forcing the shape to be in a well-defined form that allows the molecule to be used as a biological machine.
...
The possibilities of life are built in into the delicate mixture of deterministic and stochastic laws of nature; which possibilities are realized are determined by the creativity of God, combined with the properties of the environment that carries out the plans of God through self-organization processes governed by the second law of thermodynamics."

Besides the complete crackpot nonsense about "protein folding" and "the law of large numbers" (since it requires a time http://en.wikipedia.org/wiki/Levinthal%27s_paradox" to arrive at its correct native conformation), Neumaier has his own QM interpretation called the "Thermal Interpretation", and the rest you can figure out by yourself...

Some have http://www.askwhy.co.uk/truth/810NeumaierCoprolalia.php" about Arnold Neumaier, and personally it feels a little bit awkward he got the affirmation as a PF Science Advisor...? :bugeye:

Personally I don't care about his motivation, and I doubt that the rest of PF's "Inner Circle" cares much either. What I *do* care about is that he clearly separate his personal beliefs from his science, and in my experience he has never combined the two. He clearly delineates the interpretative aspects of the thermal interpretation from the hard math and science, which agrees with mainstream physics. Furthermore, his "Thermal Interpretation" is really only discussed on the thread in "Independent Research", which also happens to be a perfectly acceptable forum for such discussion.

This is the second time I have seen you post these statements about Arnold. It's fine if, in the interest of "full disclosure", you wish to make others aware about statements he has made publicly (i.e. in print) about his personal beliefs. I don't think the mocking tone you have asserted in the above post is appropriate however. If Arnold were proselytizing about his personal beliefs in these forums, then he would be sanctioned by the PF staff. The fact that he has instead been nominated and confirmed as a PF Science Advisor should be taken as a vote of confidence from the PF staff that Arnold understands how to appropriately maintain a separation between his personal beliefs and his scientific theories. I guess you should respect their judgment as well.
 
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  • #15
Well said SpectraCat. I don't always agree (and assume others don't always agree either) with all of the discoveries or claims or like certain approaches of Dr. Neumaier. But one thing is certain. His approach to QM is thorough, rigorous and adventurous. Rather than being someone who is content to regurgitate lessons learned by someone else (where usually something important gets lost) he is very actively and energetically attempting to build a cohesive new platform for understanding old and new problems. And he is providing all of the details of the building blocks. That should earn anyone's respect who appreciates how science advances.

By the way, if the last site you posted was supposed to represent criticism, in fairness you should warn readers of the bizarre and incoherent nature of its content.
 
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  • #16
I don't get it. I thought either the Maths is correct or it is wrong?! How can there be a dispute. I don't get how science can be a religious war, but then having done a PhD in condensed matter physics I might guess. When an there is an argument usually both sides are wrong and know nothing.

But thanks for pointing out some paragraphs. Such wording indeed makes a bad impression on me.

So anyone else with a suggestion for a book? :)
Ideally one which isn't too mathematical. I don't need theorems and rigor, but rather essentials.
 
  • #17
Gerenuk said:
So anyone else with a suggestion for a book? :)
Ideally one which isn't too mathematical. I don't need theorems and rigor, but rather essentials.
I still don't fully understand what you're asking for. It sounds like you just want a standard textbook that's written for people who have studied some QM before. How about Ballentine?

The books that really emphasize operators are much more mathematical than the standard textbooks. How about reading chapter 2 of Weinberg's QFT book? It's "mathematical", but not rigorous, and it's probably the best place to understand the concept of particles.
 
  • #18
SpectraCat said:
What I *do* care about is that he clearly separate his personal beliefs from his science, and in my experience he has never combined the two.

Check out his professional http://arnold-neumaier.at/" at the Fakultät für Mathematik, and you’ll get a slightly different experience. On 123 pages Neumaier refers to God, Jesus, Christianity or the Bible in an unambiguous mix of religion and science.

SpectraCat said:
He clearly delineates the interpretative aspects of the thermal interpretation from the hard math and science, which agrees with mainstream physics.

Mainstream physics?? 500 not peer reviewed pages is mainstream physics?? wow...

It looks like you are somewhat 'thunderstruck' by the "hard math"; however it doesn’t impress me that much. I listen more to what the man has to say, and he says (among a lot of strange things) that "conservation of energy" explains what goes on in the double-slit experiment. When 'explaining' Entanglement, he uses (only) the Stern–Gerlach Experiment as an example, but never mention that spin angular momentum is a purely quantum mechanical phenomenon. Instead, he talks about the "magnetic moment" and the fact that the silver atoms are heated, and concludes – "This explains why the two blobs in the Stern–Gerlach experiment are equally bright." ...

In the same chapter, in a footnote about 'coincidences' and 'acceptances', Neumaier also takes the opportunity to 'explain' that the acceptance of general relativity was a coincidence based on "noise" in agreement with the theoretical results...
"As more often in the history of physics, it was a coincidence that determined the acceptance of a theory. Another such example was the measurement of the deflection of rays of the stars that can be seen close to the sun during a solar eclipse done by Eddington in 1919, thereby verifying the general theory of relativity of Einstein. The actual deflections are too small to be measured and hence the deflections found by Eddington have to be ascribed to noise; luckily the noise gave a pattern in agreement with the theoretical results."

The actual 1919 "Noise":
300px-1919_eclipse_negative.jpg


(And I could go on and on about this paper, but that would be too tedious)

Maybe this is just me not understanding... or it’s just this paper... or just one little 'mistake'...

I don’t think so. Neumaier has been active in this 'regime' for years. In 2003 he published the paper http://arxiv.org/abs/quant-ph/0303047" in which he included a revised analysis of Heisenberg's HUP in terms of Bohr's Complementarity. I’m sure you’re familiar with the 'concept', which we discussed intensely in another thread (from abs):
"... The approach realizes a strong formal implementation of Bohr's correspondence principle. In all instances, classical and quantum concepts are fully parallel: the same general theory has a classical realization and a quantum realization."

(Almost identical 'thoughts'...?? :bugeye:)

Though Neumaier gets harsh critics at http://www.natscience.com/Uwe/Forum.aspx/physics/12383/Neumaier-s-Modification-of-Heisenberg-Uncertainty-Principle-HUP" :
Neumaier's Modification of Heisenberg Uncertainty Principle (HUP) 2: 2003 Paper

In his 2003 paper, "Ensembles and experiments in classical and quantum physics," J. Mod. Phys. B 17 (2003) 2937-2980, and quant-ph/0303047, Arnold Neumaier continues his somewhat refreshing march down the borderline between Nonconformity and Conformity in physics including a revised analysis of Heisenberg's HUP in terms of Bohr's Complementarity. Unfortunately, his section 3 (Complementarity) is largely a defense of the existence of complementary quantities.

In my world, this is not mainstream physics; this is "classical madness", most probably motivated by "personal beliefs".

SpectraCat said:
Furthermore, his "Thermal Interpretation" is really only discussed on the thread in "Independent Research", which also happens to be a perfectly acceptable forum for such discussion.

Sure, but in my browser he’s now in QM and promoting his own personal not peer reviewed stuff.

SpectraCat said:
This is the second time I have seen you post these statements about Arnold. It's fine if, in the interest of "full disclosure", you wish to make others aware about statements he has made publicly (i.e. in print) about his personal beliefs.

Thanks SpectraCat, for your support. I’m sure you agree that when one of Neumaier’s (now permanently banned) followers states that; "Neumaier who is equal to von Neumann in mathematical ability" and "He gets a Nobel" etc, someone has to react.

SpectraCat said:
I don't think the mocking tone you have asserted in the above post is appropriate however.

Since most of the content in my post is quotes from Neumaier’s homepage, I guess you are referring to my words "complete crackpot nonsense", right? I’m able and willing to get down on my knees and make a deep and sincere apology – if you can show me one trustworthy paper that solves protein folding solely by the law of large numbers (without any help from 'above').

SpectraCat said:
If Arnold were proselytizing about his personal beliefs in these forums, then he would be sanctioned by the PF staff.

True.

SpectraCat said:
The fact that he has instead been nominated and confirmed as a PF Science Advisor should be taken as a vote of confidence from the PF staff that Arnold understands how to appropriately maintain a separation between his personal beliefs and his scientific theories.

If the PF staff is truly aware of the 'science' that Arnold Neumaier is advocating, and they sanctions this as perfectly okay "mainstream physics" – the case is real easy – I’m out of here in a second.

However, I don’t think this case is as simple as that. Arnold Neumaier is a very brilliant man, as you may have noticed, and he has great skills when it comes to mathematics, and apparently he helps a lot of users, and he should of course have all the credit for this. And this is what he got from the PF staff.

In my view, the problem starts when he stops helping users and starts to delude them...

I would be really surprised if the PF Science Advisor status gives Neumaier carte blanche in posting anything he likes on PF, like recommending his own not peer reviewed papers to users, who only sees his advisor status.

But I could be wrong, maybe it’s me who will get an infraction or banning... we shall se...


(By the way, Neumaier and his delude followers are http://www.natscience.com/Uwe/Forum.aspx/physics/44445/Double-Slit-Experiment-Mystery-Solved" spreading the 'great news'...)
 
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  • #19
DevilsAvocado said:
(By the way, Neumaier and his delude followers are http://www.natscience.com/Uwe/Forum.aspx/physics/44445/Double-Slit-Experiment-Mystery-Solved" spreading the 'great news'...)

It's blindingly obvious such "followers" don't understand the maths of standard QM.
Just because someone yells "follow the sandal!" or "no, follow the gourd!" doesn't mean we should take notice of any of them without independently testing their assertions.

Arnold's only "mistake" was that he tried to dumb down some of the material in his book.
The venom responding against such dumbed down explanations is both astounding and unwarranted.

I sometimes wonder whether anyone but me and Meopemuk who participated in earlier photodetector/double-slit threads involving Arnold actually studied the detail in Mandel & Wolf (mentioned at length in threads here and in IR) on which Arnold's explanations are based. None of those who spit venom have bothered to contradict specific calculations in Mandel & Wolf, but such calculations are all that matter in the end -- for comparison with experiment.

For my part, I'm happy as long as the scientific material remains clearly delineated from other stuff.
 
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  • #20
Apparently, a lot of things are "dumb down" at the moment, including rhetoric.
 
  • #21
Gerenuk said:
I thought either the Maths is correct or it is wrong?! How can there be a dispute. I don't get how science can be a religious war, but then having done a PhD in condensed matter physics I might guess. When an there is an argument usually both sides are wrong and know nothing.

But thanks for pointing out some paragraphs. Such wording indeed makes a bad impression on me.
He didn't quote from my book, where you find only the math.
 
  • #22
I have been perfectly clear when quoting from Arnold Neumaier’s homepage. When talking about "the paper" (or 500 not peer reviewed pages), it is of course Neumaier’s own link that I’m referring to:
Classical and Quantum Mechanics via Lie algebras,
2008, 2011. http://lanl.arxiv.org/abs/0810.1019

To avoid any misunderstanding, everything below refers to the paper above:
DevilsAvocado said:
Mainstream physics?? 500 not peer reviewed pages is mainstream physics?? wow...

It looks like you are somewhat 'thunderstruck' by the "hard math"; however it doesn’t impress me that much. I listen more to what the man has to say, and he says (among a lot of strange things) that "conservation of energy" explains what goes on in the double-slit experiment. When 'explaining' Entanglement, he uses (only) the Stern–Gerlach Experiment as an example, but never mention that spin angular momentum is a purely quantum mechanical phenomenon. Instead, he talks about the "magnetic moment" and the fact that the silver atoms are heated, and concludes – "This explains why the two blobs in the Stern–Gerlach experiment are equally bright." ...

In the same chapter, in a footnote about 'coincidences' and 'acceptances', Neumaier also takes the opportunity to 'explain' that the acceptance of general relativity was a coincidence based on "noise" in agreement with the theoretical results...
"As more often in the history of physics, it was a coincidence that determined the acceptance of a theory. Another such example was the measurement of the deflection of rays of the stars that can be seen close to the sun during a solar eclipse done by Eddington in 1919, thereby verifying the general theory of relativity of Einstein. The actual deflections are too small to be measured and hence the deflections found by Eddington have to be ascribed to noise; luckily the noise gave a pattern in agreement with the theoretical results."

The actual 1919 "Noise":
300px-1919_eclipse_negative.jpg


(And I could go on and on about this paper, but that would be too tedious)
 
  • #23
DevilsAvocado said:
I have been perfectly clear when quoting from Arnold Neumaier’s homepage. When talking about "the paper" (or 500 not peer reviewed pages), it is of course Neumaier’s own link that I’m referring to:
Classical and Quantum Mechanics via Lie algebras,
2008, 2011. http://lanl.arxiv.org/abs/0810.1019

To avoid any misunderstanding, everything below refers to the paper above:
"As more often in the history of physics, it was a coincidence that determined the acceptance of a theory. Another such example was the measurement of the deflection of rays of the stars that can be seen close to the sun during a solar eclipse done by Eddington in 1919, thereby verifying the general theory of relativity of Einstein. The actual deflections are too small to be measured and hence the deflections found by Eddington have to be ascribed to noise; luckily the noise gave a pattern in agreement with the theoretical results."
The cited statement is fully correct. My book of course only gives an abbreviated account of the full story. The latter can be found in the paper

H. von Kluber,
The Determination of Einstein's Light-deflection in the Gravitational Field of the Sun,
Vistas in Astronomy 3 (1960), 47-77.

To check the accuracy of my account, it is enough to look at the figures on pp. 60-63 to see the amount of noise to be expected in the data. Eddington's scarce observations are given in the first of these plots and look (because of their sparsity) much less noisy compared to the observations of later eclipses.

von Kluber writes on p.64:
It is quite obvious that the actual deflection law cannot be determined by the observations available at present
and in the conclusions on p.73, he writes:
Without exception, all observations indicate clearly that a light-deflection effect of the kind expected quite obviously exists in the neighborhood of the sun. But the observations are not sufficient to show decisively whether the deflection really follows the hyperbolic law predicted by the General Theory of Relativity.''
This was the situation in 1960 ---- 40 years after Eddington!
 
  • #24
A. Neumaier said:
The cited statement is fully correct.

This is just amazing and completely new info, I had never heard of H. von Kluber before.

I’m trying real hard to understand this... you and von Kluber are saying that the measurement in the picture below is just noise, right?

300px-1919_eclipse_negative.jpg


Since you are highly skilled in mathematics, what is the probability for the photons to (completely at random) form this kind of trail (in an exposure of 28 seconds), to be in perfect agreement with the general theory of relativity? That must have been a major fluke, doesn’t it??

And If I understand this correct; the "next photo" would have shown a completely different trail, since we are talking noise, right??

Wow... just wow...

I tried to find out more about H. von Kluber, and I found discussions on http://forums.catholic.com/" .

Then I saw that Harry Collins and Trevor Pinch had made references to him in the book http://books.google.com/books/about/The_golem.html?id=ijtA0JLYlooC":
"Through a series of intriguing case studies including the study of relativity, cold fusion, the "memory" in worms, and the sex life of lizards, this book debunks the view that scientific knowledge is a straightforward outcome of competent theorization, observation, and experimentation."

Interesting indeed.

Finally I found a better source at the http://www.ast.cam.ac.uk/about/history/biographies.e.-.l", where one gets the quite stunning facts that Sir Arthur Eddington and Harald von Kluber worked in the same institute! Eddington as Plumian Professor/Director of the Cambridge Observatory (1914-1944) and von Kluber as Assistant Observer (1949-1960).

This is developing into a thriller...

If I have gotten this right – you are claiming that an Assistant Observer, in the same institute as Sir Arthur Eddington was active during the 1919 total solar eclipse, 41 years after the measurement finds out the astonishing fact that it was all "noise", but he doesn’t tell anyone at the University of Cambridge, but instead he publish his findings in an astronomy journal?? Hence, on the http://www.ast.cam.ac.uk/about/history/biographies.e.-.l" at the institute it still says (on the same page as Harald von Kluber):
Sir Arthur Eddington (1882-1944) Plumian Professor: 1913-1944, provided evidence for Relativity in 1919 eclipse expedition, popularizer of Relativity. Director of the Cambridge Observatory 1914-1944

I feel really really sorry for Harald von Kluber, someone needs to restore his good name...

Don’t take it wrong, I do not question your authority, but don’t you find this story a little bit 'peculiar'...?

And finally, what’s your view on the (probably faulty) information at Wikipedia?
http://en.wikipedia.org/wiki/Tests_of_general_relativity#Deflection_of_light_by_the_Sun

Tests of general relativity - Deflection of light by the Sun

The early accuracy, however, was poor. The results were argued by some[14] to have been plagued by systematic error and possibly confirmation bias, although modern reanalysis of the dataset[15] suggests that Eddington's analysis was accurate.[16][17] The measurement was repeated by a team from the Lick Observatory in the 1922 eclipse, with results that agreed with the 1919 results[17] and has been repeated several times since, most notably in 1973 by a team from the University of Texas. Considerable uncertainty remained in these measurements for almost fifty years, until observations started being made at radio frequencies. It was not until the late 1960s that it was definitively shown that the amount of deflection was the full value predicted by general relativity, and not half that number. The Einstein ring is an example of the deflection of light from distant galaxies by more nearby objects.

550px-Einstein_Rings.jpg
 
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  • #25
Neumaier's book is like the movie "A Bridge Too Far", an ambitious and bravely attempted project, but if only the real evidence was taken into account something less ambitious might have succeeded.

The "thermal interpretation" has no hope of explaining modern multi-entangled state experiments, let alone the incredible experiments of Zeilinger and co with single photons.

The Quantum world is so non-classical that Neumaier's ideas can clearly be seen to be in a long history of fruitless failed attempts to show otherwise.

The Lie Group/Algebra stuff looks good though. Should have stuck to that and maintained credibility.
 
  • #26
@DA

Please read the following article about the Eddington expedition.

http://arxiv.org/abs/0709.0685

I have not finished reading it in detail, but it seems to give an unbiased accounting of both sides of the story, replete with full details about the initial analysis, as well as the re-analysis (which showed that the famously discarded data actually *increased* the agreement with GR, when re-analyzed with modern techniques).

Anyway, it makes for fascinating reading for those of us with an interest in the history of science.
 
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  • #27
SpectraCat said:
@DA

Please read the following article about the Eddington expedition.

http://arxiv.org/abs/0709.0685

Thanks a lot SpectraCat! I have hastily scanned thru the paper and it looks very interesting, however "noise" is only mentioned once, and "von Kluber" not at all.

http://rsta.royalsocietypublishing.org/" (having the prestige of being the world’s first scientific journal) has the original paper by Sir Arthur Eddington available (including a picture of the plate on the last page):
http://rsta.royalsocietypublishing.org/content/220/571-581/291.full.pdf

A Determination of the Deflection of Light by the Sun's
Gravitational Field, from Observations Made at the Total Eclipse
of May 29, 1919

F. W. Dyson, A. S. Eddington and C. Davidson
Phil. Trans. R. Soc. Lond. A 1920 220, 291-333
doi: 10.1098/rsta.1920.0009


(Unfortunately von Kluber’s noise seems not to be available at Philosophical Transactions of the Royal Society.)
 
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  • #28
Would statistical deviation be a better term for describing that than "noise"? I believe Eddington described the problem of accounting for variable dispersion of light within the sun's atmosphere and how its effect on the observations is not predictable.
 
  • #29
SpectraCat said:
@DA

Please read the following article about the Eddington expedition.

http://arxiv.org/abs/0709.0685

I have not finished reading it in detail, but it seems to give an unbiased accounting of both sides of the story, replete with full details about the initial analysis, as well as the re-analysis (which showed that the famously discarded data actually *increased* the agreement with GR, when re-analyzed with modern techniques).

Anyway, it makes for fascinating reading for those of us with an interest in the history of science.

This paper is mostly about the selection of data in 1919/20 and whether Eddington intentionally fudged the data, and argues that the latter was not the case.

On the other hand, my statement, and that of von Kluber, does not claim anything negative about Eddington. Acting in good faith, his final data (a few points on a curve) supported general relativity.

The point of von Kluber is that the data themselves were subject to inaccuracies depending on observational conditions, whose magnitude is of the same size as the effect itself, as subsequent repetitions of measurements at other eclipses show. This is a very different point hardly considered in the paper you cited. From the point of view of subsequent data analysis, these inacccuracies are noise, though as von Kluber shows in the first plot quoted before, the few points used by Eddington accidently didn't show this noisyness, while the many more points in subsequent measurement clearly revealed it.

Indeed, the paper mentions on p.25 a quote from Stephen Hawking's ''A brief history of time'' that says essentially the same as von Kluber and my book; thus I am in good company:
It is ironic, therefore, that later examination of the photographs taken on
that expedition showed the errors were as great as the effect they were trying to measure.
Their measurement had been sheer luck, or a case of knowing the result they wanted to
get, not an uncommon occurrence in science.
The subsequent discussion in the cited paper only refultes the second alternative offered by Hawking, ''or a case of knowing the result they wanted to get, not an uncommon occurrence in science'', not the first one, ''Their measurement had been sheer luck''. Indeed, on p.26 they mention that even in 1969, the data from eclipses were inconclusive:
Looking over the results from all these eclipses (including that of 1919), Sciama
concludes
“One might suspect that if the observers did not know what value they were `supposed’
to obtain, their published results might vary over a greater range than they actually do;
there are several cases in astronomy where knowing the `right’ answer has led to
observed results later shown to be beyond the power of the apparatus to detect.” (Sciama
1969, p. 70)
and on p.23 that only data from radio astronomy are fully convincing:
This situation had barely improved even by
the time of the last such expeditions in the mid-1970s. It is only with radio telescopes
measuring quasars being occulted by the relatively radio-quiet Sun, thus with no need for
an eclipse, that the Einstein value has been precisely confirmed (Will 1993).
 
  • #30
unusualname said:
Neumaier's book is like the movie "A Bridge Too Far", an ambitious and bravely attempted project, but if only the real evidence was taken into account something less ambitious might have succeeded.

The "thermal interpretation" has no hope of explaining modern multi-entangled state experiments, let alone the incredible experiments of Zeilinger and co with single photons.

Could you please substantiate your claim? I am too curious how Zeilinger's experiments (with whcih I am familiar, being from Vienna) should contradict the thermal interpretation.

Please reply in the thread https://www.physicsforums.com/showthread.php?t=490492
which exists just for these discussions.
 
  • #31
A. Neumaier said:
This paper is mostly about the selection of data in 1919/20 and whether Eddington intentionally fudged the data, and argues that the latter was not the case.

On the other hand, my statement, and that of von Kluber, does not claim anything negative about Eddington. Acting in good faith, his final data (a few points on a curve) supported general relativity.

The point of von Kluber is that the data themselves were subject to inaccuracies depending on observational conditions, whose magnitude is of the same size as the effect itself, as subsequent repetitions of measurements at other eclipses show. This is a very different point hardly considered in the paper you cited. From the point of view of subsequent data analysis, these inacccuracies are noise, though as von Kluber shows in the first plot quoted before, the few points used by Eddington accidently didn't show this noisyness, while the many more points in subsequent measurement clearly revealed it.

Indeed, the paper mentions on p.25 a quote from Stephen Hawking's ''A brief history of time'' that says essentially the same as von Kluber and my book; thus I am in good company:

The subsequent discussion in the cited paper only refultes the second alternative offered by Hawking, ''or a case of knowing the result they wanted to get, not an uncommon occurrence in science'', not the first one, ''Their measurement had been sheer luck''. Indeed, on p.26 they mention that even in 1969, the data from eclipses were inconclusive:

and on p.23 that only data from radio astronomy are fully convincing:

Oh I know .. my suggestion was just that DA should familiarize himself with that paper before casting too many stones in your direction. I am quite familiar with the anecdotal representation of Eddington's experimental "confirmation" of general relativity being due to a fortuitous cancellation of errors in the analysis, since certain assumptions about the accuracies of the measurements were overly optimistic in the original analysis. However, I did not have a source for this information, but only the memory of the anecdote, which cropped up several times in different physics classes in college and grad school.
 
  • #32
DevilsAvocado said:
This is just amazing and completely new info, I had never heard of H. von Kluber before.

I’m trying real hard to understand this... you and von Kluber are saying that the measurement in the picture below is just noise, right?

300px-1919_eclipse_negative.jpg


Since you are highly skilled in mathematics, what is the probability for the photons to (completely at random) form this kind of trail (in an exposure of 28 seconds), to be in perfect agreement with the general theory of relativity? That must have been a major fluke, doesn’t it??

DA, I missed this in your original post, but upon re-reading I think you are making a serious error in your interpretation of Eddington's photo. I don't think the "trail" in the photo has anything to do with the experiment, but is most likely a flaw in the original plate which was intensified during digitization of the image.

The experiment was all about comparing the relative positions of the stars in photos taken "simultaneously" at two distant locations on the Earth's surface. The star positions are indicated by the fainter horizontal lines that can be seen at various positions in the photograph. These positions correspond to the relative positions indicated in diagram 1 in Eddington's original paper. The "trail" that you are so focused on is also not nearly so evident in the plate reproduction in that paper. Certainly the curvature of that "trail" is not indicative of any gravitational lensing due to the sun.
 
  • #33
A. Neumaier said:
Could you please substantiate your claim? I am too curious how Zeilinger's experiments (with whcih I am familiar, being from Vienna) should contradict the thermal interpretation.

Please reply in the thread https://www.physicsforums.com/showthread.php?t=490492
which exists just for these discussions.

Unable to reply there (it's locked), but a simple refutation of the 'thermal interpretation' is that your fields propagate at the speed of light so can't hope to explain experiments where detectors are placed outside future light cones of the other relevant apparatus, I posted a link to a particularly explicit experiment of this type in another thread Experimental realization of Wheeler's delayed-choice GedankenExperiment , but there are many others by people like Zeilinger etc

Standard QFT doesn't suffer since it doesn't naively associate the field with the particles 'ontologically' like you do.
 
  • #34
unusualname said:
Unable to reply there (it's locked),
Ah, yes, I had forgotten the precise date where they wanted to close down the forum on independent research...
unusualname said:
but a simple refutation of the 'thermal interpretation' is that your fields propagate at the speed of light so can't hope to explain experiments where detectors are placed outside future light cones of the other relevant apparatus, I posted a link to a particularly explicit experiment of this type in another thread Experimental realization of Wheeler's delayed-choice GedankenExperiment , but there are many others by people like Zeilinger etc
I think you misinterpret the implications of such experiemnts.

The arXiv paper you cite contains nothing about superluminal effects. Delayed choice does not contradict relativity. (Read papers by Peres on classical interventions in quantum systems.)

Moreover, every quantum aspect of _single_ photons (as opposed to entangled pairs of photons) can be modeled in full quantitative detail by classical stochastic Maxwell equations; see http://arnold-neumaier.at/ms/optslides.pdf

Finally, Zeilinger didn't do any experiment allowing superluminal information exchange. Thus detectors are placed outside the future light cone of a source will not respond to that source.
unusualname said:
Standard QFT doesn't suffer since it doesn't naively associate the field with the particles 'ontologically' like you do.
It doesn't suffer because, in agreement with experiment, it does not describe acausal dynamics.
 
  • #35
[quote="A. Neumaier]Moreover, every quantum aspect of _single_ photons (as opposed to entangled pairs of photons) can be modeled in full quantitative detail by classical stochastic Maxwell equations; see http://arnold-neumaier.at/ms/optslides.pdf[/quote]

No it can't. What you'll find is that your model ignores the non-classical aspect of the experiment but still claims to faithfully model the experiment.

You see, you'll model the experiment using maxwell's equations assuming no apparatus is outside the future light cone of any other apparatus. Then when I move my interferometer, polarizer, detector or whatever off to alpha centauri you'll just use the same analysis to still model the experiment. You'll claim something like sub-sampling explains it, ignoring the fact that the sub-samples are chosen by apparatus outside the future light-cone of the source.

I've been through this a dozen times, I'm pretty sure mainstream science agrees with me that maxwell's equations don't correctly model delayed choice experiments.

And in particular your ontological fields are ruled out by such experiments.

In any case, modern quantum physics is all about entanglement and even multi-particle entanglement, your interpretation is even more hopeless in explaining these experiments.
 
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FAQ: Exploring Quantum Mechanics without Representation: A Textbook Approach

What is quantum mechanics?

Quantum mechanics is a branch of physics that studies the behavior of particles at the subatomic level. It explains how particles such as electrons and photons behave and interact with each other, and it is essential for understanding many phenomena in the natural world.

What is the purpose of "Exploring Quantum Mechanics without Representation: A Textbook Approach"?

The purpose of this textbook is to provide a comprehensive and accessible introduction to the principles of quantum mechanics without relying on mathematical representations. It aims to help readers develop a conceptual understanding of the subject and apply it to real-world problems.

Who is the target audience for this textbook?

This textbook is suitable for undergraduate and graduate students studying physics or related fields, as well as anyone with a general interest in quantum mechanics. It assumes a basic knowledge of calculus and linear algebra, but does not require prior knowledge of quantum mechanics.

How is this textbook different from others on quantum mechanics?

Unlike traditional textbooks, "Exploring Quantum Mechanics without Representation" focuses on the conceptual understanding of quantum mechanics rather than mathematical formalism. It also includes real-world examples and applications, making the subject more accessible and relevant to readers.

What are the benefits of studying quantum mechanics?

Studying quantum mechanics can lead to a deeper understanding of the fundamental laws of nature and how the world works at a microscopic level. It also has many practical applications in fields such as technology, medicine, and materials science. Additionally, learning about quantum mechanics can improve critical thinking and problem-solving skills.

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