CATEGORY:
What's Ultimately Possible in Physics? Essay Contest (2009)
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Ordinary Analogues for Quantum Mechanics by Arjen Dijksman
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Author Arjen Dijksman wrote on Sep. 30, 2009 @ 14:28 GMT
Essay AbstractMatching quantum behaviour with our ordinary macroscopic experience is commonly regarded to be impossible. The difficulty to relate the quantum world to common sense experience stems partly from the fact that classical physics was not sufficiently advanced to deal with macroscopic particle-wave systems at the birth of quantum mechanics. Physicists therefore lacked references to compare quantum with analogous macroscopic behaviour. After consideration of some recent experiments with droplets steered by waves, we examine possibilities to give some intuitive meaning to the rules governing the quantum world.
Author BioI graduated in 1991 as Applied Physics Engineer at Delft University of Technology (Holland) after research work on radiation defects in fusion reactor materials. I subsequently worked as IT Project Manager in the Paris, France, area until February 2009. Meanwhile, I kept an active interest in epistemological and foundational questions, developing pedagogical approaches to quantum physics that favour intuition and common sense. As for the 2009-2010 academic year, I return to school, following the Optics and Photonics Master of Science programme at Institut d'Optique Graduate School, Palaiseau.
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Uncle Al wrote on Sep. 30, 2009 @ 21:39 GMT
Given: a monochromatic laser with a Brewster window that outputs TEM_00 100% linearly polarized light with a long coherence length. Run said beam throught a 50:50 beamsplitter. One arm has a quarter wave plate converting output to 100% left-circularly polarized light (LCP). The other arm has a quarter wave plate converting output to 100% right-circularly polarized light (RCP). A double slit is placed in each beam. Are the separate diffraction patterns unremarkable?
Remove the two double slits. Mirrors reconstruct a still-coherent bifilar beam that impacts a double slit. RCP goes in one slit, LCP goes in the other. What diffraction pattern results?
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Author Arjen Dijksman wrote on Oct. 1, 2009 @ 08:42 GMT
Dear Uncle Al,
Because your question relates to basic quantum interference effects, I assume your question is: how would ordinary analogues handle these two experiments?
If we want to simulate the quantum results, you need:
1. polarized macroscopic particles
2. and a pilot wave composed of polarized macroscopic particles.
If we take the rotating needle analogue...
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Dear Uncle Al,
Because your question relates to basic quantum interference effects, I assume your question is: how would ordinary analogues handle these two experiments?
If we want to simulate the quantum results, you need:
1. polarized macroscopic particles
2. and a pilot wave composed of polarized macroscopic particles.
If we take the rotating needle analogue and these 2 setups (assuming the beamsplitter is at 45° with the incoming beam), we may simulate :
1. TEM_00 linearly polarized light with the help of a beam of traveling needles which individually rotate at a constant frequency in a random plane containing the direction of propagation,
2. the beamsplitter with the help of a grid that lets 50% through without changing the rotational plane of each individual needle and reflects 50% by changing the rotational plane of each individual needle by 90°,
3. the quarter wave plate with the help of a grid combination with only two perpendicular rotational planes for the output needles, say x-z and y-z, and that dephases the y-z needles by a 90° phase relative to the x-z needles (advancing the phase for RCP and retarding the phase for LCP).
The surrounding needles will evolve in phase with the needles of the beam and thus act as a pilot-wave. This gives characteristic interference patterns in your first setup. The LCP and RCP patterns are identical in intensity. You could eventually distinguish them with the help of a grid that selects only RCP or LCP.
For your second setup, I assume that you direct RCP towards one slit and LCP towards the other slit with both slits open at the same time. It is important to keep track of the polarization of the needles of both pilot-waves. LCP and RCP pilot-waves will be 90° out of phase. The RCP interference pattern therefore will be exactly complementary to the LCP interference pattern, which erases the interference pattern into a smooth curve. By the way, if both beams are directed towards the same slit (or somewhere between both slits), it will also give a smooth curve.
Regards,
Arjen
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Uncle Al wrote on Oct. 1, 2009 @ 17:24 GMT
Circularly polarized photons and electrons are both trivially obtainable. Fly them through vacuum. Use solid state polarized electrons, e.g., spintronics. "The surrounding needles will evolve in phase with the needles of the beam" No waffling! We know how to arbitrarily close to 100% polarize a beam. Shave away the dross. "Pilot waves" as a richer description of what is observed compared with mundane QM would not survive the first benchtop reduction to practice.
Linear polarization suffers from transmissive anisotropy of the slits vs. orientation of the plane of polarization. The linearly polarized beam is 50:50 split, then one half rotated +45 degrees and the other -45 degrees. Recombine into the coherent bifilar single beam and simultaneously hit the open double slit, one rotation through one slit and the other through the other. Photons or electrons. QM is wholly sufficient. As you have illustrated, "pilot waves" require excess baggage but do not evince excess testable prediction. Can they? How? What new observable is predicted?
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Author Arjen Dijksman wrote on Oct. 1, 2009 @ 19:49 GMT
Uncle Al,
"Pilot waves as a richer description of what is observed compared with mundane QM would not survive the first benchtop reduction to practice": the point I argue in my essay is that pilot waves with ordinary particles give a richer description than the bullet and wave approach, that misleads into quantum weirdness. This is confirmed by the benchtop experiments with bouncing droplets on liquid surfaces.
I don't exactly see how I illustrated that pilot waves require excess baggage. They are just a means to have an intuition of quantum behaviour, not an end. If we want to see what they predict, the best way is to get acquainted with their experimental behaviour. And that has only just begun.
Regards,
Arjen
J.C.N. Smith wrote on Oct. 2, 2009 @ 19:22 GMT
Mr. Dijksman,
Thank you for an interesting and clearly written essay. You wrote, "Lee Smolin identified five problems in contemporary physics. The second problem deals with the foundations of quantum mechanics and might be resolved 'by making sense of the theory as it stands'."
As I'm sure you probably know by rote, Smolin wrote in a subsequent paragraph that, "There are unfortunately not many physicists who work on this problem. This is sometimes taken as an indication that the problem is either solved or unimportant. Neither is true. This is probably the most serious problem facing modern science. It is just so hard that progress is very slow. I deeply admire the physicists who work on it, both for the purity of their intentions and for their courage to ignore fashion and attack the hardest and most fundamental of problems." (pp. 8-9, 'The Trouble With Physics')
Judging from the clarity of your essay, I've concluded that you must be one of the "handful of smart people" who are working on the problem. Good luck! We certainly can use all the clarity that you and others can muster in this area.
Cheers
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Phil Warnell wrote on Oct. 3, 2009 @ 13:11 GMT
Hi Arjen.
I must say I truly like how you are approaching all of this and I wish more would try to gather what stands as being uniquely relevant from all the models, rather than focusing on simply one. I thus have always founnd it somewhat ironic that the more a physicist takes QM seriously, often the less seriously what they say is considered by their peers. I’m also intrigued by the recent particle/wave macro experiments you draw note of in your essay, as I’ve always imagined the actions of nature being in many respects the same regardless of scale. Perhaps one day such invariance may in itself be considered as a postulate of physics, as it being also a conserved quality.
Best,
Phil
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Author Arjen Dijksman wrote on Oct. 4, 2009 @ 09:28 GMT
@ Mr Smith:
Thanks for your encouraging words. At the time I was reading Smolin's The Trouble Of Physics, I asked myself how I could contribute to the solution of the five great problems. Regarding my situation, I concluded that the only way I could help was (I quote from page 8):
"by making sense of the theory as it stands"
"provide a sensible language for the theory"
"find a new interpretation of the theory – a new way of reading the equations".
I am not inventing a new theory. I just take all of conventional quantum mechanics and rephrase it in words that I can use with non-specialists, with my friends or with my children. I started some pedagogical projects (at wikiversity or on youtube). The more I advance, the more quantum mechanics seems to me so much more intuitive than classical physics. This feeling is corroborated by the impression I get with the many lectures I follow currently in optics and photonics where both classical and quantum approaches are explained. The classical way often confuses me with rules of thumb that I learned some 20 years ago, but are relegated to the background of my memory, while I can follow the quantum approach intuitively with real spinning arrows. I have not found a single experimental fact that is weird with this approach.
@ Phil:
You're right in saying that we may gather relevant things from different models.
A little word for all those who read my essay: I may give the impression that I am a pilot-wave advocate. I want the things to be clear: I am not. I merely put pilot waves at the forefront because there are hard experimental facts that show that pilot waves are part of nature. But all of the current pilot-wave and hidden variable theories should be adjusted with the knowledge gained from these experiments. Many other features from other interpretations (multi-verse, Copenhagen, Dirac ket, Feynman particles...) are compatible with pilot waves.
Steve Dufourny wrote on Oct. 5, 2009 @ 15:57 GMT
Hello Mr Arjen Dijksman,
I read your essay ,very interesting your extrapolations and aims .
Congratulations for this whole point of vue.
I didn't know these 5 problems and the pilot wave ,very relevant all that .
I am going to learn more about that .It's interesting .
The light becomes mass ...
good luck for the contest .
Best Regards
Steve
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Steven Oostdijk wrote on Oct. 9, 2009 @ 15:29 GMT
Dear Arjen and Uncle Al,
Beam splitter experiments or more general "superposition" experiments do not require quantum mechanical explanations at all. You just need a wavelength for a photon.
I could try to describe it in a long post, but it can all be found here:
Superposition again.
Best regards,
Steven Oostdijk
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Steven Oostdijk wrote on Oct. 9, 2009 @ 15:54 GMT
Dear Arjen,
My congratulations on well written and well comprehensible article. It is slightly out of focus wrt. to the contest challenge, but no less relevant.
Have you ever considered that the spins described by QM could be real stacked spins? A spherical particle would normally spin over an axis, but on top of that one could add three levels of "head to tail" spin, one for each dimension. One could even consider a fifth spin level relative to the linear motion of the particle.
Good luck with the contest,
Steven Oostdijk
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Author Arjen Dijksman wrote on Oct. 9, 2009 @ 22:51 GMT
Hello Steve (Dufourny) and Steven (Oostdijk);
@Steve
Thanks for your feedback. Yes, mass may be viewed as more energetic light.
By the way, I've seen that you've read quite a lot of essays. Don't hesitate to draw my attention to other ones that handle quantum theory.
@ Steven
Thanks for your comments and link to Miles Mathis' explanation for superposition. As I've read it, it seems to me that he needs a bit more than just "a wavelength for a photon". He invokes also a "spinning circle" model for his photon which introduces polarization. In that sense, it is similar to other photon models, like the needle model which I mention in my essay. You may imagine other ones (rotating coins, crosses, etc) that would give the same prediction. Miles Mathis' explanation makes sense in case of polarizing beam-splitters, but not for non-polarizing beam-splitters (at least I don't see how). In case of non-polarizing beam-splitters, interfering waves will do, because each reflecting surface shifts the phase by 180° (I'm not aware of the 90° phase shift invoked by the youtube "magicians", except if it incorporates a quarter-wave mask).
Yes, I've considered supplementary degrees of self-rotation. I detailed it only for spinning needles for which 2 degrees of independent self-rotating motion are sufficient: one fixed axis and a precession axis (Poinsot motion).
I've printed your essay. I'll read it extensively soon.
Cheers,
Arjen
Eckard Blumschein wrote on Oct. 10, 2009 @ 14:33 GMT
Dear Arjen Dijksman,
Arje Oostdijk's link "superprosition again" claims a lot.
While I do not claim dealing with quantum theory, I collected what I consider
evidence for implications of a very basic arbitrariness, affecting quantum theory too.
I would in particular appreciate an explanation concerning Gompf et al.
Please find attached a manuscript "A still valid argument by Ritz" the major part of which hopefully makes more understandable what might be wrong in QM before questionable guesses of mine are added.
Regards,
Eckard Blumschein
attachments:
Ritz09.pdf
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Ben Baten wrote on Oct. 10, 2009 @ 23:39 GMT
Dear Arjen (Beste Arjen),
Thank you for your interesting essay. It is different from many others in the pack in the sense that it is 'creative' and mostly avoids speculation.
Louis de Broglie suspected the co-existence of two phenomena in a single particle: the 'pilot' wave and a highly non-linear pulse-like corpuscular behavior, which is currently designated as wave-particle duality...
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Dear Arjen (Beste Arjen),
Thank you for your interesting essay. It is different from many others in the pack in the sense that it is 'creative' and mostly avoids speculation.
Louis de Broglie suspected the co-existence of two phenomena in a single particle: the 'pilot' wave and a highly non-linear pulse-like corpuscular behavior, which is currently designated as wave-particle duality [1]. He became discouraged by the disapproval of mathematical physicist like Heisenberg (as I recall) and, as a consequence, discontinued his research for many years. Unfortunately, he was not able to complete his research.
More recently, Andrei P. Kirilyuk originated a theory, called Quantum Field Mechanics (QFM), which shows the co-existence of the two mentioned alternating phenomena caused by interaction between two entities. This interaction results in a highly non-linear internally random pulsation. The existence of such behavior has never been recognised, since a mathematical analysis of state equations is normally simplified and, therefore, cuts out this phenomenon. In Kirilyuk's approach, the state equation is linear such that the superposition principle applies for solutions. However, oddly enough, each solution is highly non-linear and has 'hidden variables'. I.e. dynamically created eigenvalues which drive the non-linear state transitions, but which are inaccessible to measurements.
The dynamically created interaction object is identified with a massive particle, which exhibits internal randomness due to random state transitions (reduction states, see my essay). The corpuscular aspect is present in case of a stationary particle and when a particle is in motion. Wave behavior is only present when a particle is in motion and is caused by 'coherence' of the internal states of the particle (intermediate states).
In QFM, a photon can be viewed as a massive particle lacking internal random motion. Interestingly, for high speeds, the behavior of a massive particle resembles a photon. Quantitatively, this can be understood by considering the relativistic expressions for energy E and momentum p of a massive particle. They relate as Ev = pc^2, where c is the speed of light and v is the particle's speed. For v -> c, this gives the well-known photon relation E = pc. Thus, a massive particle can also be viewed as a 'wrapped up' photon, which gets 'unwrapped' as its speed in creases.
These results can never be obtained in current 'linear' physics, which seems more interested in discovering abstract symmetry principles and uses equations that could be viewed as best guesses.
In QFM, the 'needles' that you are talking about on page 4 are repeatedly dynamically created and subsequently destroyed resulting in an unceasing pulsation, and do not need a 'computational tool'. Rotation of the 'needles' results from the fact that two media with different mobilities are attracted to one another, such that any perturbation in the media caused by the attraction must 'rotate'. You also say "we could apply the whole quantum mechanical machinery to this system.'" In consider this explanation after the fact, but for now suffices to get the point across. In truly universal approach, theory should obey reality (well said Eckard Blumschein!), i.e. fit like a glove on a hand. It should explain Planck's constant, and the character of space, time, energy, momentum, charge, spin, the wave function etc. and avoid introduction of non-observed entities. Kirilyuk maintains that QFM is extensible to compositions of particles and could be used as a Universal Science of Complexity which may also be applicable to the experiments you describe.
More details on QFM can be found in my essay (which took a number of artificial postulating shortcuts to limit content), extra notes on the page where you can find my essay, and in a slide deck on
my website.
1. L. de Broglie. Non-linear wave-mechanics - A causal interpretation.
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N Nath wrote on Oct. 11, 2009 @ 06:41 GMT
Author's emphasis on intution and commonsense in working out Physics is commendable. His earch to find simple examples to illustrate quantum aspects is welcome too. But the difficulties Quantum mechanics faces in combining with other approaches still presents difficulties. An alternate search can materialise if one has some phenomenon to investigate which is neither ideal for classical nor for the Quantum mechanics. For example, let us look for cases where putting h to zero is not practical but at the same time the quantum picture too is not entirely valid. Large mass structures open to experimental basic studies may be searched. One possibility may lie with large ensemble of nanostructured material crystals where we can study diffraction and compare the results with same sample composed of ordinary atomic configuration or lighter nanostructured configuration. The problem of coherence effects as sample gets affected by environment may be tackled by preparing such samples in a parallel chamber in UHV and then tranfering to a coupled but another chamber where the samples may be studied experimentally. Author's response in this regard will be highly useful!
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Steve D. wrote on Oct. 12, 2009 @ 09:58 GMT
Dear Arjen Dijksman ,
You are welcome .
To all
very interesting thread ,relevant .
Best Regards
Steve
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Don Limuti (www.zenophysics.com) wrote on Oct. 13, 2009 @ 00:08 GMT
Dear Arjen,
This is such an important, clear and well written essay. I am jealous.
I would like you to take a glance at "Gravity from the ground up" in this contest. I also feel that deBroglie has the best key for unlocking QM. I found the pilot wave awkward and went with a digital wave instead. Perhaps another view of similar territory may give you some insights. And you may be interested in how I got gravity into Broglie's equation?
I believe we are uncannily close in outlook and interests and approach.
Best of luck,
Don L.
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NN wrote on Oct. 13, 2009 @ 02:22 GMT
i eagerly await the response of the author to my post of Oct 11 where i suggest possible experiments , in view of the ideas he has expressed in the essay.
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Gerhard Groessing wrote on Oct. 13, 2009 @ 18:21 GMT
Dear Arjen Dijksman,
congratulations for a lucidly written Essay! I particularly like your pointing out of the work of Couder's group, i.e., about the existence of classical pilot waves, and your statement that the latter are a means to get better intuitions about quantum systems. Actually, I have tried throughout the last 25 years or so to model quantum systems by exactly that mutually causal relationship between "particles" ("drops") and waves. (See my monograph, "Quantum Cybernetics", Springer, New York, 2000, on that.) In recent years, however, I believe I have come even closer to an adequate modelling, and the works by Couder et al. could not illustrate this approach better. In this regard, I recommend two recent papers of mine (Foundations of Physics Letters 17, 4 (2004) 343-362, and Phys. Lett. A 372 (2008) 4556-4563), where I derive the Schroedinger equation from slightly different perspectives, but still very similar in spirit to what you say. The said papers are available at arXiv:quant-ph/0311109 and arXiv:0711.4954 .
Best wishes,
GG
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Author Arjen Dijksman wrote on Oct. 13, 2009 @ 21:22 GMT
Thanks all, for your interest in my essay and for your voting. I'll try to answer the best I can, with some delay regrettably, because I'm quite busy these days.
@Eckard. I read your essay and will leave a comment on your forum page.
"Beste Ben", I already knew about Kirilyuk's approach but am not versed in it. I also read your essay and will have a look at the tutorial. Anyhow, I would like my focus to remain on translating conventional quantum mechanics into ordinary language. That's already a huge piece of work ;-) If Kirilyuk's QFM helps me in that task, I'll spend time on it.
@Narendra Nath,
You're right, investigating the limit between quantum particles and macroscopic systems is important. I don't know whether it is possible to maintain coherence with the preparation method you mention. It seems to me technically very complicated. It is important that the molecules you use "possess some statistical similarity, which is the essence of coherence" (quote from Emil Wolf).
@Darryl Jay,
In order to help in reading your essay, could you point me towards shared insights? Thanks.
@Don,
Thanks for your encouraging words. I selected your essay as a must read. I'll comment on your page later on.
Author Arjen Dijksman wrote on Oct. 13, 2009 @ 22:10 GMT
Dear Gerhard Groessing,
Thank you for pointing to your two papers on the Schroedinger equation derivation. I like Schroedinger's quote about longitudinal and cross-wise action. You only mention your derivation sideways in your essay, isn't it?
I really think that we should take the results of Couder's group seriously in our understanding of wave-particle phenomena. Einstein said about de Broglie that he lifted a corner of the great veil. During 80 years, physicists studied extensively the little corner that was unveiled. Why not lift the veil a little more?
Sincerely,
Arjen
Terry Padden wrote on Oct. 14, 2009 @ 12:00 GMT
Arjen
A very good essay with real physical content. One comment:
You write in your conclusion "We then noticed that there are actually classical experiments which give results analogous to the quantum world and ended up with an ordinary system with everyday objects that may be described with the help of quantum mechanical computational tools. The declared impossibility to give a deeper representation of single particle interference may therefore be seen, not as a scientifically proven impossibility, but rather as a cultural one, emerging probably from our physics education that prescribes that macroscopic objects be described with classical physics tools."
Whether we use classical tools or quantum tools to describe classical and/or quantum phenomena (assuming that distinction in phenomena makes sense & your essay gives reason to doubt that) we can only use the tools we have available. They are provided by our Logical / Mathematical methodologies that I refer to as formalisms.
Perhaps to paraphrase a well known Shakespearean saying (from Julius Caesar) - "the fault, dear Arjen, lies not in our culture but in our tools !" That in fact is the conclusion of my essay. The problem is in the tools, both classical and quantum. We need better ones. To get them we need to re-invent Logic & Maths. Once that is done, ultimately, everything will be easy.
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Member Matthew Saul Leifer wrote on Oct. 14, 2009 @ 12:46 GMT
Arjen,
Thanks for a very interesting essay. It is always good to learn about new analogs of quantum phenomena. I noticed that you were careful in your essay not to suggest that the needle analogy is what is "really going on" in quantum theory. In particular, I am doubtful that you could obtain a Bell inequality violation, since real waves cannot make their influence felt at a distance unlike quantum pilot waves. On a similar note, you did not have a guidance equation, such as the one that features in de Broglie-Bohm theory, and I imagine that if you did formulate one then it would have to be different from the quantum one.
As a final critique, I think that your discussion of de Broglie-Bohm theory and Bell violation around footnote 1 was a bit too vague. It makes it sound like de Broglie-Bohm is ruled out by Bell violation, which is untrue since the former is nonlocal. It is a common misconception, so care needs to be taken in discussing it accurately.
Overall though, a very thought provoking essay.
Matt Leifer
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Anonymous wrote on Oct. 14, 2009 @ 13:58 GMT
Hi dear all ,
I begin to encircle these ideas about Broglie-Bohm theory and Bell's inequ.
It's very interesting .
That said I have doubts about these hidden variables .If the ineq of Bell don't permit these local variables thus the interpretations are bizares .
If a pilot wave acts like a electric field and if we take these local variables and intrications more these inequalities ,thus some laws disappear and the imaginaies appears .In conclusion ,Everett and Bell are falses .
We can't pass the speed of light,the locality don't change never .The intrication furthermore is coorect for light .
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Steve Dufourny wrote on Oct. 14, 2009 @ 14:43 GMT
Error of posting sorry ,I am continuing.
In fact ,these hidden variables don't exist ,simply I think.
About the intrications and the EPR paradox ,it's just a perception of things .
In all case it's far of us .
The synchronization is like a code ....and the rotations always are an important piece of the puzzle.
The topology and the locality more the waves...
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Error of posting sorry ,I am continuing.
In fact ,these hidden variables don't exist ,simply I think.
About the intrications and the EPR paradox ,it's just a perception of things .
In all case it's far of us .
The synchronization is like a code ....and the rotations always are an important piece of the puzzle.
The topology and the locality more the waves and rotating spheres can improve the extrapolations .
An important point I think is to relativate our localities in fact ,in accepting our fundamental laws.
The relativity and the causality in the global locality and its local parameters ,separated but linked .How interpret our fundamentals ,perhaps only with pragmatism and rationality .
It's essential, it seems to me, to accept our limits .We are so far of our walls .Of course the variables are there but not hidden ,just different parameters under the same laws .
Sincerely
Best Regards
Steve
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Florin Moldoveanu wrote on Oct. 14, 2009 @ 17:21 GMT
Dear Arjen,
I do not understand your conclusion:
“The declared impossibility to give a deeper representation of single particle interference may therefore be seen, not as a scientifically proven impossibility, but rather as a cultural one, emerging probably from our physics education that prescribes that macroscopic objects be described with classical physics tools.”
It is well known that Bohm’s quantum potential is non-relativistic. This shows itself for example when one tries to determine the “which path“ information. In any water droplets experiments, the “pilot wave” does not instantaneously change when one slit is obstructed like in Bohm’s theory, resulting in obvious different transitory behaviors compared with quantum mechanics. Because of this the macroscopic model is not exact. A partial model may be helpful for visualization, but it cannot be used to gain intuition where the model is not accurate.
So here is what I do not understand from your statement. You imply that the lack of intuition of QM is a cultural phenomenon because there are macroscopic models available. But the models are not exact and they do not stand up to closer inspection precisely where QM lacks macroscopic intuition. I hope you do not get offended, but to me it looks like those models (water droplets, needles) are like fool’s gold which only look like the real thing from 10,000 feet, but in fact they do not produce genuine intuition about quantum mechanics. A genuine intuition would require (as a pre-requisite) a sharp crisp difference between classical and quantum mechanics, and not obfuscating their differences with partial models.
Florin
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Author Arjen Dijksman wrote on Oct. 14, 2009 @ 21:00 GMT
Terry,
Thanks for your comments. Maybe it are the tools that mislead us. But tools are products of a culture. So I may agree with you, although I would hesitate to say that the tools are the problem. Tools whether classical or quantum are OK. We just have to improve the way we handle and interpret them. I'll have to read your essay in order to say something sensible about your argument that physicists need better tools.
Author Arjen Dijksman wrote on Oct. 14, 2009 @ 21:07 GMT
Matt,
Thanks for your remarks. I tried indeed my best to distinguish analogs, models, theories and even the numerical measurement results from the ontology of deeper reality. What's "really going on" must remain questionable for the sake of science. One thing that's important is to change regularly our perspective and not to stick too long with the same paradigms. I emphasized the relevance of pilot waves for our intuitive representation of quantum mechanics, because there are new experimental facts from which we could learn. But once we have learned all there was to learn, it is of interest to change our viewpoint, formulating a new interpretation or even returning to many-worlds or Copenhagen. And that is often a personal quest (at least in my case).
With respect to Bell inequalities, to my knowledge, all current interpretations assume that what we measure is the eigenvalue of the state in which the system is collapsed. Because measurements of quantum particles imply detection dots, this is a reasonable assumption for point-like particles. However, if we use a model where the particle has some spatial extension (needles, strings...), the detection dot represents the location where the quantum particle and the detector particle have intersected, which is not necessarily the location corresponding to the eigenvalue of the state. This yields detection joint probabilities that have the same profile as correlations between entangled photons. I give a derivation of this result in a paper I wrote a couple of years ago:
Quantum mechanics and observation on macroscopic arrows.
But I hid the entanglement problem in the vague footnote you dug up, because I had no experimental result which could underpin my argument. I should indeed have been more precise that Bohmian interpretation is not ruled out by Bell violation, contrarily to the locally causal hidden-variable theories which I mentioned. By the way, clarifying my ideas on entanglement is also one of the reasons why I'm back at school (Alain Aspect's school). I'll have labworks on coincidence counting of entangled photons, so I'll go through the whole process by my own. I'm sure my opinion will be adjusted with that experience.
Regards,
Arjen
Author Arjen Dijksman wrote on Oct. 14, 2009 @ 22:04 GMT
Dear Florin,
Thanks for your remarks. I think we should compare experimental electron interference results with experimental bouncing droplets results, leaving aside Bohmian theory. My concern for the essay was to take Feynman's description of electron double slit interference and show that you could reproduce the same features with bouncing droplet interference. The experimental results of Couder's group show that you get the same behavior with respect to single particle interference. Electrons arriving in lumps, droplets arriving in lumps. Interference with two slits open. Decoherence when the electron or the droplet is disturbed by a which way detection. So Feynman's impossibility statement is a very relative one, which is limited only by our creativity to find intuitive models. Of course, you're right, those macroscopic models will never reproduce the full "glory" of quantum mechanics, because they are only models, like pictures are only pictures of the real world. But what I wanted to show is that we can get farther than we currently think is possible and that it is of interest to explore that field. With respect to the sharp crisp difference you require for a genuine intuition, I think we should be given some time to let it emerge progressively from the study of particle pilot-wave systems.
Sincerely,
Arjen
Terry Padden wrote on Oct. 14, 2009 @ 22:53 GMT
Arjen
I appreciate you being open minded enough to consider an alternative conclusion.
I agree tools are the products of culture; but I recognise two distinct cultures in science.
1 The empirical / experimental culture that by appllying scientific method to the real world produces undeniable - but sometimes inexplicable - truths about our universe. I call this the REASONABLE culture.
2. The Theoretical / Maths-Logic culture that by abstract Platoist thinking produces the tools (formalisms) we use to formulate the general laws of explanation. I call this the RATIONAL culture.
Some sciences are dominated by (1) experimental discovery, e.g Biology. Some are (now) dominated by (2) Advance Maths e.g. Physics.
In practice the two are intertwined to provide explanations. Your paper is an example of this. The experimentally determined facts of your experiments and QM cannot be denied. They are true. If we have problems explaining them I suspect we should take a closer look at the tools.
I hope you get time to read my stuff.
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Florin Moldoveanu wrote on Oct. 15, 2009 @ 00:36 GMT
Dear Arjen,
Like Terry, I too appreciate you being open minded and not getting offended by my criticism. For me it was a very long and hard road to develop an intuition about QM and the trick was to learn in what way classical and QM are identical and in what way they are different. Unification of classical and QM in the same mathematical structure was first achieved by Segal, and second by Grgin and Petersen. Even now, FQXi is sponsoring someone to find yet another solution. The differences are much better known and many authors discovered them over time. The biggest peculiarity of QM is probably that the pure state space is continuous, while in classical mechanics it is discrete. Because of this the Born rule does not apply in classical physics and any classical model falls short on this point. So if your equations 4-7 may look similar with QM’s equations, they are not enough without Born’s rule.
Developing an intuition about QM is a very hard process. I can give examples of well known and widely respected physicists with hundreds of publications which do not really understand QM. I’ll say that today no more than 100 people truly understand QM, with the real number being much lower. My contention is that superficial similarities between QM and classical mechanics give you a false sense of confidence about understanding QM.
Regards,
Florin
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Steve Dufourny wrote on Oct. 15, 2009 @ 12:30 GMT
Hi all ,
It's the eternal problem between the reals and the imaginaries ,between our left and right brains ,between the Copenhagen Interpretation and the EPR ....
My only conclusion is that a balance is necessary to harmonise the extrapolations towards truths .
Pragamatism or imaginaries ...how can wehave a real physical system without real tools,it's impossible .
The...
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Hi all ,
It's the eternal problem between the reals and the imaginaries ,between our left and right brains ,between the Copenhagen Interpretation and the EPR ....
My only conclusion is that a balance is necessary to harmonise the extrapolations towards truths .
Pragamatism or imaginaries ...how can wehave a real physical system without real tools,it's impossible .
The hidden variables are few probables ,why our big equation should have different hidden laws .....the system is simple and complex thus it's not necessary .Our only hidden things are our walls of perception .
The empirism of Copernic and its friend Newton under discussions about realities .....and Borh and its sighs ,....even Heisenberg .....the conclusions aren't a play but are reals .....Feynman d have liked a lot .....the axioms don't change ,the formalisation must be fundamentals .
Thus like say some people ,I shut up and I calculate the rotating spheres ,it's a personal choice of course .
Your essay is relevant in its direction ,specific .
Good luck for the contest ,
Best Regards
Steve
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Member Matthew Saul Leifer wrote on Oct. 15, 2009 @ 14:06 GMT
Arjen,
I'm intrigued by your response, but I don't really see how you can realistically model Bell correlations in this way. According to QM, the form of the Bell correlations need not depend on the distance between the detectors, and indeed Bell experiments have been performed with photons over distances of many kilometers. To account for these correlations in the way you suggest, it would seem that we would need very long needles. Such needles could not be treated as rigid bodies, since if we were doing our Bell experiments well enough to evade the locality loophole then the timescale involved means that they would have to be treated relativistically, i.e. we would have to take into account the amount of time that a change to one end of the needle takes to propogate to the other end. I imagine that would break the Bell correlations.
On the other hand, if we do treat it as a rigid body then we have nonlocal influences, in which case it is not clear to me why this model is preferable to the standard Bohmian ontology.
Matt
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Andreas Martin Lisewski wrote on Oct. 15, 2009 @ 14:11 GMT
Nice writing--but I am afraid this essay entirely misses the point. There have been many papers in the last 80 years which try to "explain" quantum behavior with classical phenomena.
However, the true success story of quantum mechanics is relativistic quantum field theory (QFT) and attempts, like this one, to classically "explain" quantum theory with double slit experiments and the like are, in my opinion, not more than irrelevant curiosities or side notes at high school or undergrad physics level.
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Anonymous wrote on Oct. 15, 2009 @ 15:29 GMT
I enjoyed reading your essay and I would like to direct your attention to my essay
contribution to the FXQi contest listed below. You will find that it has a connection
to your area of interest.
Your further comments would be appreciated.
Darryl Leiter Ph.D
--------------------------------------------------------
-----------------------------------
What Is Ultimately Possible in Physics Will Be Found Within An Observer-Participant Universe Where The Photon Carries The
Arrow of Time
by Darryl Jay Leiter, Ph.D
ABSTRACT
In confronting the challenge about what is ultimately possible in physics one must resolve three fundamental issues which occur at the interface between the microscopic and macroscopic levels of the universe: (1) the origin of the arrow of time in the universe; (2) the nature of macroscopic objective reality in the context quantum theory, and (3) an explanation for the emergence of macroscopic conscious minds in the universe. In response to this challenge we argue that the resolution of these three fundamental issues may be found within the paradigm of an observer-participant universe where the photon carries the arrow of time
attachments:
LeiterFQXi_ESSAY.pdf
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Author Arjen Dijksman wrote on Oct. 16, 2009 @ 21:46 GMT
@Terry,
I printed your essay out in order to read it. I completely agree with you about the necessity of physics to be reasonable.
@Florin,
I certainly am confident that you and Emile Grgin are doing a good work in optimal axiomatization for the whole of physics. That's very important and a good path to scientific discovery. In an alternative way, I do the same. While you're focusing on the mathematical organization of theory, I'm privileging plain language formulation. I like it when physicists explain physical truths in ordinary words and I've made it my hobby to follow that path. It's not an easy path. I'm on it since before my graduation, so that's nearly 20 years of (almost) continuous questioning, pondering, reading, exploring different insights, with the necessary amount of sleepless nights. So we have a different story, different intuitions but we may come at the same conclusions. As you said it and as I wrote it in the paragraph following my equation (7), Born's probability rule is necessary to reproduce quantum behavior. The evolution equations are not enough. For ordinary rotating needles, Born's rule follows from phase matching of the interacting needles with the pilot-wave.
@Matt,
In fact, in my entanglement analogy, two needles are first tangled up in their spinning motion and then separate in opposite directions with perpendicular rotational planes (see my aforementioned paper). The detections are at opposite wire-grids, so there is no nonlocal interaction in that way. I only show that there is no "classical" kink in the joint probability function at polarizer angle differences of 0° and 180° (could be tested experimentally with real needles), but Bell's inequality isn't violated.
@Andreas,
To have quantum behavior introduced with ordinary analogues at high school is one of my goals. So if my essay may contribute to that, I hit my target. But yes, the true success of quantum theory is relativistic quantum field theory (especially QED). That's stuff for another essay. I would start with Feynman's "All we do is draw little arrows" and show how interactions in the field of spinning arrows / needles resemble the interactions of quantum particles.
Kind regards,
Arjen
Don Limuti (www.zenophysics.com) wrote on Oct. 18, 2009 @ 01:20 GMT
Arjen,
I do believe it is a fact that "Developing an intuition about QM is a very hard process". And your attempt to remedy this is to be commended and is in the spirit of Galileo.
Developing an intuition about how to use "epicycles" to calculate the motion of the planets is a very hard process. But how can anyone deny that the earth is the center of the solar system. It is just so intuitive!
Your work is helping to get a better viewpoint on QM so that it will be understandable, and I do believe it will succeed.
Thanks,
Don L.
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Ian Durham wrote on Oct. 18, 2009 @ 13:51 GMT
Arjen,
I finally found a free moment to read your essay. I enjoyed it. I have a couple of thoughts that came up while reading it.
1. For a really good pedagogical and heuristic derivation of the time-independent Schödinger equation that anyone with a knowledge of basic calculus can understand, see Tom Moore's Six Ideas That Shaped Physics: Unit Q. In my classes, I extend his derivation to the time-dependent version. Bohm's Quantum Theory (written before he got into pilot waves and such) also has some great discussions of waves in general, both classical and quantum. In short, the fact that your equation (4) looks like Schrödinger's equation doesn't surprise me because they both ultimately describe wave-like behavior which takes the same basic mathematical form whether or not it's quantum.
2. Regarding 'grandmothers, children, and barmaids' you haven't sold me on whether your approach is any easier to understand than any other. Just because it's got some classical features doesn't necessarily make it easier to understand. See those books I mentioned above. That being said, I do find your approach intriguing. The idea of finding classical analogues is something probably subconsciously done by a lot of people who teach introductory physics. Trying to teach quantum mechanics to freshman requires a good deal of creativity (I speak from experience).
3. Regarding quantum interference, it only seems strange to me in the particle context. In other words, in the wave/field context it seems perfectly natural and normal. It's when you start playing around with individual particles that it starts to deviate from something analogous to classical behavior. But, at least in regard to light, attempts to understand it in some kind of dual manner actually has origins much older than the quantum revolution. One could argue Huygens attempted something like it with his wavelet theory and one might even argue that there are hints of a pilot wave concept there.
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Frank Martin DiMeglio wrote on Oct. 18, 2009 @ 16:29 GMT
Greetings Arjen.
This discussion is inseparable from the question of how space manifests as energy. How can you consider/understand/apply the following in keeping with your ideas/essay? For example, how could the below be applied to describing gravity in relation to the strong force?
To unify gravity and electromagnetism/light fundamentally and comprehensively, balancing/unifying scale by making gravity repulsive and attractive as electromagnetic energy/light is required. In demonstrating electromagnetic energy/light as gravitational space, the unification/balancing/inclusion of both invisible and visible space is central to balancing/unifying scale and attraction/repulsion in conjunction with space manifesting both gravititationally and electromagnetically. We can thus understand the wave-like properties of matter better as well.
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Andreas Martin Lisewski wrote on Oct. 18, 2009 @ 21:17 GMT
Arjen, thanks for the reply. I agree that it is important to look for alternatives to the conventional interpretation of quantum theory. But I get the impression that, after all these years, those attempts essentially never went beyond the stage of the quantum theory of, say, 1926. Is this perhaps a sign that those attempts may be in vain?
In other words, if quantum theory had remained at a preliminary level before relativistic quantum field theory (QFT), it probably had never become more than a footnote in science history. Thus alternative theories have actually to be measured against the shining beauty and tremendous success of QFT.
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Author Arjen Dijksman wrote on Oct. 19, 2009 @ 11:25 GMT
@Don
I'm glad we have a common interest in making QM understandable. QM deals about elementary physical systems. So there are no simpler systems than quantum systems. Unhappily, this simplicity is often veiled by our classical physics spectacles. By the way, I quoted from your essay on my twitter page. I anticipated you were OK about that.
@Ian
1. Thanks for recommending Moore's Quantum volume "Six ideas that shaped physics". If I manage to get a copy under my eyes, I will jump right away to Schrödinger's equation.
2. I'm aware that I don't wipe away all the difficulties in teaching QM, but I believe that with my approach quantum physics may be taught at the same level as classical physics. Classical physics with billiard balls or bullets, quantum physics with rotating arrows. Feynman initiated this approach with his "All we do is draw little arrows on a piece of paper". It is of interest to extend this approach to "All we do is imagining little arrows in 3D space", because QM is fundamentally about objects that are described by vectors, i.e. arrows.
3. Indeed, there have always been attempts to describe reality in terms of waves (periodical behaviour) and particles. Huygens, but also Newton with his corpuscles that are pulsed by his vibrating aether. 17th century physicists already had the feeling for pilot-waves. Funny that, for more than three centuries, we didn't try to put this idea to the test with ordinary systems.
@Frank
In quantum field theories, forces are mediated by particles. The same for ordinary analogues of quantum field theories. I've not worked out any of these analogues to full extent, so I have only some guiding principles, like: the influence of an object decreases as the inverse of the square distance, two needles are weakly coupled if they glide on each other but are strongly coupled when three of them are aggregated, etc.
@Andreas
I totally agree with you that alternative theories have to be measured against the success of QFT. As you may have noticed in my essay, I don't propose an alternative theory. I try to explain QM (and consequently QFT) "as it stands". I don't think we need another theory. There is need for making sense of the theory "as it stands" (Smolin's Problem n°2 in "The Trouble with Physics").
Andreas Martin Lisewski wrote on Oct. 20, 2009 @ 04:12 GMT
Arjen, of course I agree that you do not present a new theory but perhaps a new opinion. If I understand it correctly, your opinion would mean that, if we only pursue further in the future, in maybe five years from now we would have a classical mechanics equivalent of pair creation, and--if we try really hard--in ten years we may discover an "ordinary system" made perhaps of balls, sticks, or needles fully equivalent to non-commutative quantum gauge theory.
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Eckard Blumschein wrote on Oct. 20, 2009 @ 07:55 GMT
Dear Arjen you promised:
@Eckard. I read your essay and will leave a comment on your forum page.
Do not hurry. For your
convenience .
Yours sincerely,
Eckard
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Author Arjen Dijksman wrote on Oct. 20, 2009 @ 14:39 GMT
Andreas,
What you say is indeed close to my opinion, with the following 'important' reserve that there will be only analogues, never 'equivalents', because an ordinary object will never be equivalent to microscopic objects.
I am reticent also in using the qualifier 'classical mechanics' analogues. I prefer to say 'ordinary physics' analogues. Classical mechanics is not well suited to give approaching representations of quantum mechanics. In classical mechanics, one often pictures particles as points. Classical particles than interact with each other through 'mysterious' or 'weird' forces at distance (I say that intentionally to enforce my argument). I would call that classical mumbo jumbo. Quantum particles have a simpler way to interact . An electron goes from place A to B, couples at B with a photon, than travels from B to C, etc. Quantum interactions are better suited to be explained with the help of ordinary contact interactions.
Eckard Blumschein wrote on Oct. 20, 2009 @ 16:40 GMT
Dear Arjen Dijksman,
Do not confuse forces at distance with indeed spooky action at distance.
Eckard
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Author Arjen Dijksman wrote on Oct. 20, 2009 @ 19:16 GMT
Dear Eckard,
Well, I used the words 'mysterious' and 'weird' for classical forces on purpose. One should not forget the 18th century controversy about the cause of gravity, which forced Newton to write in the General Scholium of his Principia: 'I frame no hypotheses'. An 'intuitive' explanation for the cause of classical forces at distance has come with Quantum Field Theories, where forces are mediated by quantum particles. In a certain way, quantum physics has thus removed weirdness from ordinary physics.
For a discussion about the 'weird' entanglement effect brought by quantum physics, a.k.a. 'spooky action at a distance', please consider the above discussion with Matt Leifer.
Regards,
Arjen
Florin Moldoveanu wrote on Oct. 20, 2009 @ 20:25 GMT
Arjen,
In your last reply to me you said: “As you said it and as I wrote it in the paragraph following my equation (7), Born's probability rule is necessary to reproduce quantum behavior. The evolution equations are not enough. For ordinary rotating needles, Born's rule follows from phase matching of the interacting needles with the pilot-wave.”
And the corresponding essay text is the following:
“The projection of a needle on a given axis will evolve sinusoidally. This will affect scattering probabilities. Two needles will therefore collide with a probability proportional to the projection of the first needle times the projection of the second needle on the axis perpendicular to the line joining the centres of both needles.”
This is factually incorrect. Suppose needle 1 rotates in a plane perpendicular on the axis between the two needles and suppose needle 2 rotates in a plane including the axis. Then the needles will collide with probability 1 if the distance between the center of the needles is smaller than the needle half length, and not zero as you state. The whole analysis of the probability of needle collision is much more complex than your statement seems to imply.
Obtaining Born’s rule is critical of providing a genuine classical mechanics and this can be mathematically shown to be impossible. Here at FQXi, Enrico Prati shows that classical and quantum mechanics cannot be combined based on the GNS construction. Indirectly this means that quantum mechanics cannot be modeled from classical mechanics. Therefore any “modeling” of QM from classical mechanics is misleading.
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Author Arjen Dijksman wrote on Oct. 21, 2009 @ 08:31 GMT
Florin,
I thank you for your remark which has the advantage of considering the experimental facts and noticing an imprecision in my formulation. My statement "The projection of a needle on a given (fixed) axis will evolve sinusoidally" is correct but afterwards I switch to an undefined (and variable) axis perpendicular to another axis. I should have mentioned that we must consider averages. I beg your pardon for that imprecision. As you wrote, "the whole analysis of the probability of needle collision is much more complex than (my) statement seems to imply". I have not yet found a general statement in terms of scattering cross sections and projection axes. I've worked out some simple analogues where you may retrieve Born's probability rule (see for example my video
Quantum probabilities with ordinary objects).
I don't see how the scattering probability of your counterexample gives "1", except for the special cases where the 2 needles' relative translational velocity is extremely slow with respect to their rotational velocity or where the line joining the needles' centres is collinear with both translational velocities.
I completely agree that quantum mechanics cannot be modeled using classical mechanics. In classical mechanics, there is a one to one mapping between the state of the object and the detection result (i.e. location). As you may have verified with your needles counterexample, this classical one-to-one mapping doesn't pertain to spatially extended objects analogies using contact interactions. For one state of the needle, there is a whole set of statistically distributed possible measurement results spreading over the spinning volume of the needle. Commutative algebra doesn't apply to such analogies.
Anton W.M. Biermans wrote on Oct. 21, 2009 @ 09:08 GMT
Dear Arjen,
Your quote '.. impossible, to explain in any classical way (..) quantum mechanics' is exactly to the point. Quantummechanics indeed is impossible for classical physics to explain as it is a causal, religious kind of physics, the kind which creates artificial problems which never can be solved as they are brewed out of unfounded assumptions and an outdated notion of reality. As...
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Dear Arjen,
Your quote '.. impossible, to explain in any classical way (..) quantum mechanics' is exactly to the point. Quantummechanics indeed is impossible for classical physics to explain as it is a causal, religious kind of physics, the kind which creates artificial problems which never can be solved as they are brewed out of unfounded assumptions and an outdated notion of reality. As long as we cling to the idea of a particle as some tiny pellet acting as the source, the cause of its wavelike behaviour, we will never comprehend quantummechanics. If particles create and preserve each other by alternately borrowing and lending each other the energy to exist and by this continuous exchange at the same time express their properties, then they are as much the product as the source of their interactions, so there is no need for a pebble at the mass center of the particle to act as a source of gravity. (For the mechanism how particles keep existing even outside the particle cluster they forged each other in, see my reply dd 17 oct to your comment on my essay). To me there is no pebble at its center which can act as a source, no interaction-independent something. Though the De Broglie waves then must refer to the energy exchange between particles and their environment and can guide them, these waves have no pellet-like source at their center. If what we call a particle is an oscillating piece of spacetime, a pure wave phenomenon, it can, of course, behave like a tangible, pellet-like thing: as time passes slower where the field is stronger, nearer its mass center, it offers an increasing opposition to a probe trying to penetrate the field. So if with very tiny fingers we would try to pinch the particle/field, we would feel spacetime become more viscous, more frozen in time, offering a stronger opposition as we increase the pressure, so it would feel like a tiny pea. The harder we pinch, the nearer to its mass center we get, the more violent its energy exchange is expressed as a counterforce to our pinching.
As there's nothing special to find at its mass center and these pilot waves are involved in the continuous energy exchange with its environment to keep existing, and even are part of what we call a particle, this two-way traffic is subject to manipulation. As the setup of the screen with the two slits and the machine gun in the experiment affects the directions of the energy exchange of the bullets (electrons) with their environment, interference effects are to be expected as this exchange is instantaneous, so in this view there's nothing in quantummechanics to get excited about. If the indefiniteness in the position of an electron depends on the distance it is observed from, by an observing particle exchanging energy with the electron, then to a distant observer the indefiniteness in the position of the electron is so large that it contains the experimental setup, so the electron is already partly behind the screen with the slits, the position of the particles of the screen and the slit edges being similarly indefinite. Hence Schrodingers cat, hence the entanglement of particles.
What is surprising is that so long after the discovery of the quantum nature of our world we still cannot let go of the antique particle idea which implicitly refers to objects having an absolute kind of reality, an existence outside interactions, as if they are created by some creator outside the universe and thus exist even without interacting to their creator. By clinging to classical, causal physics, by thinking about particles as pellets, we require something of them which they simply don't posess: an autonomous, interaction-independent existence, an individual nature of their own. This is why particles of the same kind are identical, so they the nature they have they owe to, maintain by mutually exchanging energy, their exchange with other kinds of particles proceeding in a different way -the how being the main question in particle physics. The pellet idea is related to the similarly naïve idea of spacetime as something which comes for free, as if, though deformable, it doesn't have properties of its own and doesn't need any work to keep existing. Though we're aware that spacetime is filled with virtual particles, spacetime to us is still too obvious a quantity to be able to concede that it is the product as well as the source of all particles that inhabit it, so we still tend think about spacetime as something which exists only to accommodate particles.
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Eckard Blumschein wrote on Oct. 21, 2009 @ 17:36 GMT
Dear Arjen, dear Anton,
I hope, Anton is able to explain why the measurement by Gompf et al. with single photon counting is obviously wrong. You will find some further details in a corrected reply to Arjen at my thread 527.
Curious,
Eckard
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Don Limuti (www.zenophysics.com) wrote on Oct. 22, 2009 @ 05:52 GMT
Hello Arjen,
1. Please quote me all you like.
2. When I said you were like Galileo, I wanted to indicate that the viewpoint taken on QM will determine if the model is understandable. The solar system is easily understood looking from the sun, it is difficult looking from the earth.
3. Your "Principles of Quantum Mechanics" wiki site and the animation of the vectors increased my knowledge of standard QM quite a bit. And it helped me understand how my work "Digital Wave Theory" differs from QM as it stands.
My concept of observables (for lambda-hopping particles) may be of interest to you. I mention it here because your reference caused me to notice it.
a. A particle can have both a position and time (from a local clock) as observables. However, velocity (translational and rotational) along with momentum and energy can never be observables because they can never be observed they can only be calculated by invoking measurements made in the past [Velocity = (X2-X1)/(T2-T1)]. Where X2 and T2 are the current position and time, and X1 and T1 are the previous position and time. Thus for me those Feynman spinning vectors may need to contain a little microprocessor and some memory:)
b. I am also thinking that this may explain the arrow of time? To get a velocity we have to reference the past from memory and thus time only moves forward.
I am always interested in what you think.
Thanks,
Don L.
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Narendra nath wrote on Oct. 27, 2009 @ 04:30 GMT
It is daring for me to budge in a discussion between theoreticians of high order. Being an experimentalist and a low level empirical physicist, i find that it is we who make nature complex by the way we deal with it in bit and pieces. To me a particle's fuzziness in quantum physics and the wave packet analogy are not two different pictures. Classical analogs for quantum pictures need not describe...
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It is daring for me to budge in a discussion between theoreticians of high order. Being an experimentalist and a low level empirical physicist, i find that it is we who make nature complex by the way we deal with it in bit and pieces. To me a particle's fuzziness in quantum physics and the wave packet analogy are not two different pictures. Classical analogs for quantum pictures need not describe reality, as Physics just deals with relative reality and not the absoluteness of truth. Uncertainity is the way of life as we live and it should be taken normally in Physics too. Once we understand the physics phenomena much more comprehensively, the theory will get simplified and unitarity will result out of duality/multiplicity. In fact the creation and evolution of the universe contains all the facets of Physics. Present day Physics was evolved without any study of the early universe and that is why we have ended with so many mysteries there by way of dark matter/energy, black holes and what not. Physics as evolved is literally not valid for the early universe of about first billion year starting with birth, which too is anamolous as per the Big bang approach. We are unable to say anything about what existed prior to it!
Thus, issues of classical and quantum Physics and their correspondence and reconcialiation are beyond us till we evolve an intermediate physics, such as has been proposed by Tejinder in this very forum as mesomorphic region where the planck constant can not be treated either as zero or its full estimated value. To put emphasis to this view, i refer to some isolated measurements done on the light signals coming from distant galaxies/stars , estimated to be 12 billion years away. The velocity of light has been measured to be distinctively higher than the accepted value of c. Similarly, the rato e/m has also been observed to be different. Thus, as we approach still closer to the birth of the universe, one may find further escalation in the magnitude values of such ' constants'. In fact, i conjecture that the value of Planck's constant itself may come out to be lower in the early universe. In short the physics of the early universe holds the keys to solving the riddles of present day physics as well in resolving the mysteries of the early universe. May i humbly indicate my essay in this forum as well as last year forum that indicate such possibilities and perspectives!
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Eckard Blumschein wrote on Oct. 27, 2009 @ 17:51 GMT
Dear Arjen,
I feel a bit dense because you are claiming to make your, as I understood, dipole-like alias doublet-like needles understandable to a six year old child or a bar maid and I am not even in position to imagine what you meant by a dense field of other needles.
You certainly know: A doublet is the formal derivative of the Dirac impulse.
Since you used j instead of i, I guess you are familiar with the decrease of an electric field with increasing distance. Why do you favor the coexistence of both a local needle and a guiding wave standing or propagating (?) in 3D? What is wrong with the layman's guess outlined in my essay and M291 that wave and particle are the same merely seen from different perspectives as are for instance function of time and corresponding function of frequency? The latter would presumably be understandably to my grandmother when she was still alive.
Regars,
Eckard
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nn wrote on Oct. 28, 2009 @ 06:11 GMT
Author may consider the comments of Eckard and myself above and indicate his own response to the same. truth of physics is still beyond us all and only a widely open mind can provide us greater insights!
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Eckard Blumschein wrote on Oct. 28, 2009 @ 19:05 GMT
I guess nn means Narendra Nath. I slightly disagree. I mentioned Galilei, Gold, and Ren. The latter is unfortunately not yet known to average physicists.
Eckard
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Author Arjen Dijksman wrote on Oct. 30, 2009 @ 17:51 GMT
In order to illustrate the fact that ordinary analogues are not necessarily classical, I've written the attached addendum about non-commutative operators applied to the needle analogy. This follows up the discussion with Andreas and Florin.
attachments:
Addendum_Commutator_X_P__Ordinary_analogues_for_Quantum_Mechanics.pdf
Don Limuti (www.zenophysics.com) wrote on Nov. 4, 2009 @ 08:12 GMT
Arjin,
1. The updated arrow animations on the wiki site are much improved.
2. It struck me that that Huygens wavefront propagation diagrams are very similar to the spinning arrows diagram of Feynman. It has a benefit? in that it actually shows the wave spread out in space. The arrow diagrams make it look like the arrows are in a straight line which are easier to sketch but hide some action.
Do you have any thoughts on Huygens vs. Feynman.
3. Your Blog is great promotion for FQXi and this contest.
Thanks,
Don L.
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Peter Jackson wrote on Nov. 4, 2009 @ 09:26 GMT
Arjen
I greatly appreciate your excellent work and approach, but have you yet visually transposed the mechanism to compound longitudinal pressure waves. I believe that will be the key.
Consider; The 'lateral wave' is just a mathematical construct, and representation on an oscilloscope, but not a 'real thing' in nature. It was forced upon us when the ether had to be removed. Now we know there IS a quantum field, and another possible answer NOT needing it to have no properties, we don't need to be tied by it any more and can look to reality.
Have you properly checked out the Discrete Field Model yet?
Best wishes
Peter
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Florin Moldoveanu wrote on Nov. 5, 2009 @ 06:27 GMT
Arjen,
I just saw your new document. Thank you for it. But here, I have a challenge for you. Reading this essay: http://www.fqxi.org/community/forum/topic/555 and their additional papers, I came in contact with a QM experiment, the so-called Hardy’s paradox: http://en.wikipedia.org/wiki/Hardy's_paradox
Here is how it goes:
1. take an electron source, pass the beam through a 50/50 beam splitter, and recombine the beams with another 50/50 beam splitter with 2 outputs C and D.
2. adjust the arms of the interferometer in such a way that the intensity of C is 100 and at D 0% (C=constructive interference, D=destructive interference)
3. repeat steps 1 and 2 with a positron source
4. put the two interferometers close to each other in such a way that the right arm from the electron interferometer (R_e) touches the left arm from the positron interferometer (L_p).
Now here is the problem.
Consider the case where an electron and a positron are launched at the same time.
If the electron tales L_e branch and the positron the L_p branch, the positron will destroy with the interference pattern of the electron causing its detection at D_e. Similarly if the electron travels on branch R_e, and the positron on the R_p branch, the positron will be detected at D_p because the electron blocked the L_p and R_p interference causing a D_p click. Moreover, if the electron is traveling on R_e and the positron on L_p, the two particles will collide and generate gamma radiation with no clicks at any C or D detectors.
Finally, here is the paradox. Is it possible to have simultaneous detections of the electron at D_e and positron at D_p? QM says yes, classical mechanics says no. Any classical mechanics modeling would require for the D clicks that the opposite particle travels inside the inner arms of the interferometers. But when both particles travel on the inner arms, the particles annihilate each other and therefore simultaneous D clicks are impossible in CM.
Just like GHZ, this is also impossible to be modeled by classical mechanics. Ergo, QM cannot be modeled by CM.
Florin
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Florin Moldoveanu wrote on Nov. 5, 2009 @ 06:48 GMT
Arjen,
Sorry, I want to clarify something wrong in my earlier posting. If a blocking particle is in the inner arm, the other particle has 50/50% chances to be detected at C or D, not always 100% at D. But if the electron is detected at D_e and we introduce which path detection for the positron, then every single time we find the positron to be located in its inner branch. Same for the other way around.
Florin
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Florin Moldoveanu wrote on Nov. 5, 2009 @ 07:06 GMT
Arjen,
Sorry to bother you again, here is a nice QM talk by the (sadly late) legendary Sidney Coleman: “QM in your face” explaining why GHZ is cannot be modeled by CM.
http://media.physics.harvard.edu/video/index.php?id=Sidne
yColeman_QMIYF.flv
Florin
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Author Arjen Dijksman wrote on Nov. 5, 2009 @ 10:38 GMT
Hello all,
Thanks for all your comments. Due to some work overload, I'll answer later in detail to them.
Just a short answer related to Florin's comments. There seems to be some misunderstanding about my purpose to explain quantum mechanics intuitively. I use ordinary physical analogies. These are neither classical nor quantum-mechanical from the outset. They just are *physical*. You may choose to describe them classically (assigning definite measurement results to definite physical states). Up to now, all 'realistic' attempts are trying to model quantum mechanics in this way. That's a dead end and leads to all those famous paradoxes: EPR, Hardy... And Aspect, GHZ, Sydney Coleman and many others explain it much better than I'll do. They are right!
Another way is to describe these ordinary physical systems *non-classically* using state vectors with an intrinsic indeterminacy: when something is measured, you don't know for sure that the result reflects the state. This is the way I understand quantum mechanics and IMO it better describes nature than classical mechanics. So my essay is about *ordinary* analogues for QM, not about *classical* analogues.
Peter Jackson wrote on Nov. 28, 2009 @ 14:10 GMT
Hi Arjen
I hope you're not being worked too hard.
Demonstrating to someone how a key area of 'logic' proving SR and QM are not compatible is flawed has shown how a very important door is opened. Your simple physically based solution is entirely consistent.
If you're interested see my posts, and please comment.
Peter
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Author Arjen Dijksman wrote on Dec. 4, 2009 @ 22:59 GMT
Hello,
I'm sorry I waited so long to comment on this forum. I enjoy all your reactions. However, I had to keep up with my study. As some may have noticed, I went back to school since September. And that yields its load of exams, homework and labworks, which are hard to catch up when you've been out of that system for 20 years.
@Florin. Concerning Hardy's paradox, it seems to me that it's paradoxical if one tries to explain it with a classical "bullet-particles". But with pilot-waves and particles, I don't see the paradox. If the electron and the positron travel at the same time through the set-up, this will always modify the overall interferences at the output beam-splitters. The pilot waves of both the positron and the electron will act on both output beam splitters. Simultaneous D-clicks could be allowed depending on the temporal coherences of positron and electron.
@Anton. I cannot let go the antique particle idea, because our ordinary world is populated with particles. My understanding of the quantum world is eased if I can relate it with ordinary behaviour.
@Eckard. I've had no time to ponder over the sonoluminescence pulse width. Maybe one day, I'll encounter it again;-) I'm sorry I was unable to communicate clearly about a dense field of needles. Does the bunch of nails story of the
wikiversity Principles of Quantum Mechanics page illustrate it better?
@Don. I aim to write another blogpost on the FQXi contest, with quotes;-) I don't forget you. I'm glad the wikiversity Principles of Quantum Mechanics page helped in some way. If it needs to be adjusted, don't hesitate to contribute at it. I think indeed that we need to combine the Huygens and Feynman picture to have a fuller insight of the wave-particle duality.
@Narendra. You're right when you write "it is we who make nature complex by the way we deal with it in bit and pieces." As for myself, I first need to clarify the most elementary, i.e. photons, electrons, positrons, quarks... before I can have some non-speculative understanding of cosmological issues. Although cosmology is extremely interesting.
@Peter. I've not yet properly checked your Discrete Field Theory. Can you indicate a practical case for which it can be used (for example, refraction or reflection of light at the water/air interface).
Anonymous wrote on Dec. 6, 2009 @ 16:46 GMT
Hi Arjen.
It's 'model' rather than 'theory' (DFM), as it's highly testable.
Yes, in fact it'll be a good test to 'think on my feet' here, so here's some thinking aloud on refraction:
We're considering signal waves. A couple of 'warm up' points; Although the earth is spinning, light entering the sea on each side of the planet, dawn and dusk, is measured at exactly the same...
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Hi Arjen.
It's 'model' rather than 'theory' (DFM), as it's highly testable.
Yes, in fact it'll be a good test to 'think on my feet' here, so here's some thinking aloud on refraction:
We're considering signal waves. A couple of 'warm up' points; Although the earth is spinning, light entering the sea on each side of the planet, dawn and dusk, is measured at exactly the same speed. This is a paradox of SR, but not when adjusted by DFM; Whatever local field the waves travel through they do it at the constant for that material ('c' or less), whatever speed that 'chunk' of material is doing in relation to any other.
Let's first consider light coming OUT of water. Say an aquarium with glass sides. It instantly speeds back up to 300,000km/sec! What amazing energy the zero mass photons must have to do that! Of course that's nonsense 19th century science. The model tests if the energy keeping light at exactly the same speed (for over 10bn years!) comes from the dark energy/matter field itself, which only allows it to travel AT 'c' and modulates it's frequency accordingly (FM is done by 'particle' oscillation) to Christian Dopplers fomulae.
Lena Hau has also demonstrated this at Harvard, stopping & restarting wave signals.
REFRACTION Stop thinking about the surface 'bending' the light. That's just our naive description of the 'effect'. Think about the wave front, at particle level, being slowed due the material change. Take 2 oscillating particles (of the 1/137th fine structure constant of the surface of the water), side by side. A light wave, part of a sphere representing an 'event', hits them at 'c' at a 45 degree angle, so it hits one particle before the other. They both slow the signal down the same amount.
Now you must remember simple causality. Our only definition of the 'angle' of the light is that the identical signal, from the part of the sphere representing that 'event', is in line with another part. if we 'draw a line' connecting the 'identical moment' signal from that sphere the line will be at an angle to the original sphere tangent. The angle is proportional to the speed change, as Snells equation.
You may need to read that twice and draw diagrams, but I assure you it works, and once you understand it you'll see how dead simple it is! Of course it does have many implications. In this case I've demonstrated the 'implications' first and just thrown your question at it as a test to see what comes out. This has been very interesting for me! and looks like a pass with Hons!! (hope you get the same), but typically easy once the basic architecture of the model's been discovered.
The real beauty is that the 1/137th increases with velocity of the mass, because the Doppler shift required is greater (also explaining the photoelectric effect). It also means the cloud of crazy free action 'photoelectrons' round a proton in an accellerator IS, or is closely related to, Dark Matter, and is the same phenomina as the dark matter halo's and shocks of larger groupings of mass. All in the viXra paper. But perhaps we're getting out of your area?
Are you starting to understand the model better now? How well could it fit with your own mental model of QM.
Best of luck with your exams.
Peter
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Peter Jackson wrote on Dec. 6, 2009 @ 17:05 GMT
Ooops, sorry Arjen, didn't log in for the above on refraction.
But it should certainlly be clear it was me!
Relflection is of course just essential conservation of the energy when the new material can't absorb it, and evidences the resiliant 180 degree nature of the relevant quantum spin.
Now if you could just pick which 'spin' was involved!!!
Best wishes
Peter
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Anton Biermans wrote on Dec. 12, 2009 @ 11:11 GMT
Dear Arjen,
If you agree that 'an electron cannot express its charge if there is no other charge in the universe, then it couldn't be charged itself, so a property is something which is shared by particles', then this must mean that it cannot have a charge outside of this 'sharing'.
In clinging to the antique particle idea, you assume that it is charged even as seen from outside the universe, outside of interactions, as if it has a kind of 'surplus' charge ready to show to anyone looking from the outside in. The antique particle idea is a religious idea as it ascribes the thing an absolute kind of reality it cannot have in a self-creating universe.
Similarly, in speaking about 'the universe', we claim it to be an entity which in principle, though not in practice, can be observed from the outside, as if it has an absolutely objective existence, meaning that there is some Observer to which it exists. In doing so, we imagine it as seen standing in god's shoes, so we automatically and without even being aware of it, agree that our universe is created by some outside influence, that it is a caused, a causal universe. This way of looking at things is a form of self-deception, the product of an age-long collective self-hypnosis that our universe has been created by some god, with disastrous consequences for science.
Though our way of reasoning to us may seem too self-evidently logical to even be able to entertain doubts about, it actually is the product of a long trial-and-error kind of evolution, so what to us seems logical sometimes may very well be the result of the way our blinders are directed. If problems cannot be solved by clinging to old ways of reasoning, then we should try to dream up new ones, a new logic which obviously cannot be appreciated from the old point of view, understood by the old logic, but which, planed and sanded, may be designed to fit experimental evidence.
Speaking of evidence, I wonder if you happen to know of papers specifying the experimental conditions of experiments as described by Feynman in his Lectures, Vol III, 1-4, the setup with the electron gun ? I'd be obliged if you would mail this to anton@quantumgravity.nl
Regards, Anton
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Jamie wrote on Jan. 6, 2010 @ 00:13 GMT
Hi Arjen
Major bombshell from NASA - conflicting completely with SR but exactly following the predictions of Peter Jackson DFM model, see my message in his Perfect Symmetry posts.
Jamie
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Author Arjen Dijksman wrote on Jan. 10, 2010 @ 20:25 GMT
@Anton
You'll find references for the electron double-slit experiments at
double slit experiment page of wikipedia.
I don't think I cling to the "antique" particle idea. I'm welcoming any idea that helps to get grip of the behaviour of nature and the particle concept is only one of the means to that. By the way, I don't think of the particle having charge by itself. Charge emerges when two types of particles interact: for instance photons and electrons. Charge is then a constant that gives a measure of their coupling. By themselves, particles "possess" no charge.
@Jamie
I'll have a look.
Regards,
Arjen
Don Limuti (www.zenophysics.com) wrote on Jan. 15, 2010 @ 00:25 GMT
Arjin,
I did respond to your post on my forum concerning:
a. A minimum velocity for particles
b. Photons as having mass in the same sense as particles have mass
In the investigation into a new interpretation of deBroglies work (Digital Wave Theory) neither the concept of charge or electro-magnetism appeared. I am not sure if this is a benefit or disadvantage. I do not believe Feynman in QED goes into charge or electromagnetism?
Alway interested in your thoughts.
Thanks,
Don Limuti
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Author Arjen Dijksman wrote on Jan. 18, 2010 @ 19:59 GMT
Hello Don,
If you want to develop your Digital Wave Theory into a more complete account of Nature, charge and electromagnetism must appear in some way or the other. In Feynman's book QED, have a look at Figure 58, where he explains charge as being the amplitude for an electron to emit or absorb a photon. This is a very powerful insight. Electromagnetic fields are wave fields of photons (the quanta of the electromagnetic field).
Greetings,
Arjen
Don Limuti (www.zenophysics.com) wrote on Jan. 18, 2010 @ 23:10 GMT
Arjen,
Thanks for the info. I did miss that in QED. I will look into it a bit because it is puzzling: How to convert probability into Coulombs?
The stuff of my essay did not hit against any need to go into concepts of charge or electromagnetism. I had enough to handle so I let these sleeping dogs lie.
I have this intuition that there is a fundamental connection between gravity-inertia and electro-magnetism but nothing more than that.
So it is true, I do not have a complete theory of nature. I just have an interesting tidbit.
Don Limuti
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Don Limuti (www.zenophysics.com) wrote on Jan. 20, 2010 @ 15:34 GMT
Arjen,
Just wanted you to know that I was disappointed in your not taking a prize.
From another admirer of Louis deBroglie.
Don L.
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Author Arjen Dijksman wrote on Jan. 20, 2010 @ 16:07 GMT
Don,
Thanks for your sympathy. If FQXi is going to launch a contest every year, there will be a lot of other occasions to compete again:-) I guess we'll both join in. Till then, keep in touch!
Arjen
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