Continued from above...
I argue that my description is close enough for the non-technical to grasp the underlying idea; should I have felt that more detail was needed to get to Afshar, then I would have provided it. To state that this is "wrong" merely because I avoided a concept that a) is not necessary to understand what is happening, and b) is highly abstruse, is not a correction for accuracy's sake, but simple harassment.
This is just silly. The uncertainty principle is essential to even the most cursory understanding of Afshar. And there is no way you can even begin to touch on uncertainty without mentioning the quantum of action (which is distinct from the action principle by the way).
You have implied that I said that measurement of one such quantity
could not disturb the measurement of another; that is not what I said. What I said is, that is not what the uncertainty principle means. Nor is it what Heisenberg thought it meant; the gamma-ray microscope is a pedagogical tool, and Heisenberg himself said so. The following site contradicts you, in Heisenberg's own words, and it is the official historical site of the American Institute of Physics for the history of Heisenberg's uncertainty principle. See
this page at the bottom: "So far the experiments all confirm
Heisenberg's conviction that there is no 'real' microscopic classical collision at the bottom."
I did not. I took issue with your claim that Heisenberg originally thought in terms of disturbances and then changed his mind to the idea that measurable quantities didn't exist. He didn't exclusively rely on the gamma ray microscope either. And as for the claim about what it says at the link (the correct link is:
http://www.aip.org/history/exhibits/heisenberg/p08b.htm) that is quite deliberately misleading out of context. The emphasis is on the word "classical". In other words it says that it's too simplistic to think of a
classical collision as being the true nature of the disturbance. But this only relates to the microscope example, not to everything else that Heisenberg had to say about it. Not to mention the quote contradicts precisely what you say above if it is taken as you present it.
Your replies are straw men. You do not answer the criticisms I made, you simply fudge around and try to claim I said something completely different which you can then hopefully refute. I am calling you on your claim that Heisenberg changed his mind about disturbances being an issue in the uncertainty principle and the claim that "the mathematics showed" that measurable quantities didn't exist. You won't answer
that because you know it's something you just made up. If you claim you
didn't make it up then let's see those mathematics.
Furthermore, Heisenberg developed matrix mechanics; Schroedinger later showed that the wave equation was equivalent, but Heisenberg's view of things didn't originally include the wave equation, but matrices and the concept of the "quantum jump;" to state that Heisenberg believed that measurement of one quantity would disturb the value of another in the face of quantum jumps and matrices is patently ludicrous.
Well that's precisely what he
said about it in his book on the subject (which I've already quoted bits of elsewhere)! And it's also what Bohr said in his argument against EPR. I guess that Heisenberg and Bohr simply didn't know as much about QM as you do...
Now, I have brought matrices into the conversation; let me explain for the non-technical what is involved. Heisenberg deliberately avoided discussing any sort of description of the "orbit" of an electron around an atom. Max Born read his paper, and realized immediately that Heisenberg's formulation could be expressed mathematically using a technique called "matrices." He wrote a paper showing how, and Heisenberg and he (and Pascual Jordan, a student of Born's who had assisted Born on his paper and shared credit) then released another paper jointly on it the next year.
Matrix mechanics was not immediately accepted; matrices were not well-known in physics, and had not been widely studied. The technique was seen as very abstruse mathematics, whereas Schroedinger's wave equations were seen as much more concrete representations. Furthermore, matrix mechanics went far beyond stating that the position and momentum of a particle were conjugate under uncertainty; its most obvious feature, the quantum jump, implied that the position of an electron could vary discontinuously; that is, that an electron could be found at point A at one time, and point B at a later time, without having traversed the space between. It was not until Schroedinger showed that matrix mechanics and his wave equation were equivalent mathematically that matrices were widely accepted.
Sigh! WHEN IN A HOLE STOP DIGGING!!!!! Matrix mechanics did not imply that an electron did not traverse "the space in between" etc. Heisenberg made his position quite clear - he did not consider anything he couldn't actually measure. It was irrelevant whether any space was traversed or not, it was unmeasurable so Heisenberg made the philosophical choice to disregard it. To claim that it's some ontological reality is simply extrapolating well beyond the known facts.
Whether his idea "went beyond that" or not, you have both imputed something false about what I said, and made a false statement about what Heisenberg believed according not merely to his own words, but to the very technical basis of his (and Born's) theory. Again, this is harassment, not valid criticism.
On this page, Heisenberg is quoted as follows: "In the sharp formulation of the law of causality-- 'if we know the present exactly, we can calculate the future'-it is not the conclusion that is wrong but the premise." The implication is that we cannot know the present exactly- that at least some of the values of parameters
literally do not exist. Further, the clear implication of the quantum jump is that intermediate positions between the starting and finishing positions
do not exist. And that is precisely what I said. You do not know the difference between matrix mechanics and wave mechanics.
Firstly here is the correct link for that quote:
http://www.aip.org/history/exhibits/heisenberg/p08c.htm
It does not say what you claim otherwise. Heisenberg certainly considered the idea that unmeasured quantities didn't exist. But that view was widely challenged and in any event was a philosophical speculation, not a demonstrable physical fact. The math didn't tell him that - its obvious that discrete math says nothing about what comes in between discrete sampling points. But saying nothing about something certainly does not imply that it doesn't exist.
I preceded this with, "here is a generalized and simplified explanation." If you don't like it, I suggest you start your own thread. I chose photons; you chose harassment. It is more important that your opponent be "wrong" than that you bother to write something informative to those who may have less understanding than you. It is this that I find "wrong" with you.
Nonsense. How is complete misinformation "generalised and simplified"? If I claim that World War II started because Hitler invaded China and the Chinese got pissed off and bombed Pearl Harbour - there is no way that it could be described as "generalised and simplified". It is simply
wrong. There is a vast difference between simplification and outright misinformation. Einstein, Podolsky and Rosen didn't mention one word about photons or spins. They described position and momentum of generalised particles. Given that one of the objections that is
still made about alleged EPR tests is that nobody has actually tried to test the actual situation described by EP&R, and that photons and spins are a different kettle of fish, it is highly relevant.
The argument you described is
not Einstein, Podolsky and Rosen's. So why try to pass it off as such? You could easily have said, "EP&R proposed measuring the position and momentum of generalised particles. A more recent form of the proposal which many (but not all) consider to be equivalent is to measure photon spin states." That is simplified and generalised and vastly more accurate. You are making specific claims about specific people, it's not too much to ask that you at least give them the dignity of not grossly misrepresenting their arguments.
The reason this is easier to explain with spin is because spin is discrete. The arguments also apply to continuous variables, but are much more difficult to understand. Note that understanding it there requires the action principle and the quantization of action; I have already covered why I did not believe that that level of detail was needed. This is a consistent pedagogical approach that avoids matters that are unnecessary to understand Aspect, Afshar, and the DCQE. I or someone else may later choose to add the action principle in another discussion; you may do so yourself, if you choose. But again, this is not a correction; it is harassment, plain and simple. Your intent is not to inform; if it were, you would have explained the action principle, and its quantization. That you did not do so proves conclusively that your intent was only to be able to write "wrong" twelve times, not to inform others. And that is harassment plain and simple, no question about it.
I agree, It is much easier to explain with spin. And the EPR argument is complex and subtle. And that is precisely
why it shouldn't be misrepresented because there are still some physicists who believe that the argument hasn't been fully addressed. And I repeat what I said before, you can't understand uncertainty without understanding the quantization of action. If you don't understand the latter then you will never understand the rest. Any attempt to try to circumvent the facts is not a simplification, it's fiction. It's ridiculous to imply that lay people will understand your spiel about "conjugate variables" and "complementary under uncertainty" without explaining any of the basics of what uncertainty is about. And, quite simply if I had to go around giving corrected explanations for all of your stuff I wouldn't have any time for anything else. You are certainly prolific with misinformation. Why on earth should it be
my job to re-write everything you do to make it correct? The responsibility lies with
you to either make an effort to give correct information or simply shut up and stop pretending that you know things that you obviously don't. And for the record, I have explained bits of the quantization of action and the action principle many times.
I also point once again to your hypocrisy with others as in the quotes at the beginning above.
Again, simplified and generalized. "Wrong" here is again harassment, which is your entire goal.
No, again,
completely wrong not "simplified and generalised".
To go into Bohr's argument here is another waste of time, another side-track that will do nothing but confuse the reader. That argument is based on an interpretation of quantum mechanics that most physicists no longer believe is consistent with the facts; specifically, the original unvarnished Copenhagen Interpretation. Even proponents of CI say that it doesn't make sense without decoherence; and decoherence was not to be developed for decades at the time of this argument. I have presented a version of the modern argument; it is easier to understand, does not involve either matrices or bra-ket Dirac notation, and gets to the heart of the matter.
If it's a waste of time to go into Bohr's argument then you shouldn't have brought it up. There is no excuse to blatantly misrepresent it. And the rest is nonsense - what on earth has bra-ket notation got to do with anything? I don't believe that you even understand what bra-ket notation is. You may fool the odd lay person by throwing in random buzz words, but it doesn't make you look any more credible to those who actually
do understand something about it.
While true, it is (again) a simplified and generalized description. Every point you have made while technically true cannot help the layman understand the situation; in fact, all you have done is succeeded in derailing the thread and making it one (to judge from the comments that follow) that is incomprehensible to the individual who asked the question in the first place. You have not only harassed me, you have rendered the discussion of the subject useless to the person who it was intended for. This behavior is unjustifiable; it is harassment, and personal attack, nothing else but. You have no place here if your only motivation is attack; it is against the rules of this site. By engaging in it, you have not only broken the rules, but rendered a discussion that you did not understand the need for incomprehensible to the person for whom it was intended, as that individual has clearly indicated in as many words:
So after all your ranting about how much of a woo I was, how I was completely wrong in everything and how it was obvious I didn't understand anything, you now say every point I have made is technically true. Way to go!
And if you believe my post was against the rules then report it. This is just rhetoric. In what way is your incredible rudeness to other posters (not just me - and not just in this thread) justified and in accordance with the rules of this site? Please explain. This is hypocrisy, nothing less. And, if kjkent has to rely totally on your explanations to have any understanding of the subject then he is sorely misled. Firstly, I don't make any assumptions about his knowledge. I don't condescendingly dismiss him as ignorant as you do. He asked for an opinion on Afshar's experiment, not a fictional account of the basics of QM. I didn't see kjkent saying that he found the subject incomprehensible - I saw him saying that he was still waiting for an opinion on Afshar which, at the time you wrote all this
you still hadn't given. I haven't offered an opinion because there are issues involved that I still am not clear about and so reserve judgement, I would rather say nothing than misinform.
As an aside to kjkent - I'm sorry if I have derailed the thread. I am genuinely concerned that people are being misinformed by someone who is pretending to have knowledge that he doesn't really possess and I thought it was more important to make sure that the information was correct.
Good job, Pragmatist. I'm sure that an exhaustive discussion of the details of the action principle is precisely what kjkent wanted. S/he seems to have found it very useful and have full understanding. If you were pursuing an agenda of sharing knowledge, this would not have happened; but your agenda can be judged by your actions, and it has nothing to do with sharing, nor with politeness, nor even with correct understanding on the part of the layman. Your agenda is to harass.
I'm amazed at your psychic powers that allow you to divine everybody's intent!
And your argument is a ridiculous straw man. Show precisely where I have demanded "an exhaustive discussion of the details of the action principle". I won't hold my breath...
And here we have yet another side-track, to go with the action principle and the quantization of action: superposition. It is unnecessary to a layman's understanding of Afshar and the DCQE.
Superposition is a concept that I have explained elsewhere; its applicability to wave mechanics is that it is a mathematical method of describing waves by decomposition into simpler waves. The Schroedinger wave equation that describes a propagating (i.e., moving) particle can be decomposed into simpler components that are called "states."
The implication of wave mechanics is that particles ordinarily exist as a combination, that is, a superposition, of these states, when it is propagating in free space; but when the particle is detected, the superposition collapses into a single state, and that state interacts with the state of the detecting particle. This is the collapse of the wave function, which is also the quantum jump of matrix mechanics. The notation, invented by Paul Dirac, used to describe this is also called "bra-ket" notation.
Well, if anyone with any knowledge of physics was in any doubt about the extent of your knowledge this nicely demonstrates it. This is just nonsense. What on earth has bra-ket notation got to do with superposition or wave form collapse? You obviously don't know what you're talking about and once again engage in vague handwaving and buzzwords designed to appear impressive to lay people.
Superposition, in the context of the measurement problem is the idea that the wavefunction of the system under observation can become superposed with the measuring apparatus and the observer. Wavefunctions are linear equations, and superposition is simply a condition where multiple wavefunctions are linearly added together to make a composite function. Bra-ket notation is simply a way of writing vectors and their transposes - the state of a system can be considered to be a special kind of vector called a state vector in a multidimensional abstract space called a Hilbert space. Adding the wavefunctions is mathematically equivalent to adding the state vectors. Bra-ket notation is commonly used to represent state vectors but is not essential to the concepts.
Decoherence proposes that after this interaction, the descriptions of the two particles decohere back into their separate (or combined, if they happen to stick together and form a system) wave equations, which are again superpositions of states, and remain so until the next detection/interaction.
This is harassment, plain and simple, nothing else but. You prove it every time you say "wrong." Feel free to explain it so that people who don't want to have to understand every last detail can comprehend it. That is the intent of this thread. You have failed miserably; kjkent has no description that s/he can take away as to what is going on. All you have succeeded at is harassment.
Huh? This is more nonsense. Decoherence is the idea that spontaneous interactions between the environment and a system lead to collapse of the wavefunction of a system into a definite state.
OK, then feel free to explain it in terms that the original inquirer can understand. I have already done so; all you have done is confuse with a bunch of unnecessary detail and technical quibbles in pursuit of a personal attack agenda. I'll show precisely why in my next response.
I have no idea what the original inquirer can or cannot understand and I don't presume to pontificate about it. Also, if indeed he understands absolutely nothing as you constantly presume, it's not my place to provide a basic education. If that is indeed the case then I would suggest he gets some textbooks and makes an effort to try to learn the basics first.
He did; however, to explain and describe his conclusion, which is based upon pure mathematics, to a layman is a daunting task. It is considerably eased by folding CHSH and the use of spin singlet states as CHSH, and then Aspect, did to physically show the inequality's underlying idea by a comprehensible (not to mention unambiguously experimentally testable) example.
I could, I suppose, have plagiarized Greene's Mulder and Scully magic box idea; but I am guessing anyone interested enough to ask in the first place will eventually wind up reading that, or may have already done so, so I prefer to provide another way to think about it so that Greene's explanation will hopefully prove more revealing when it is encountered. Of course, this explanation must also stand on its own; and it must be brief enough to fit in a post, yet descriptive enough for the idea to be relatively clear.
What you have succeeded in here is not to illuminate; it is to obfuscate. And harass, your original intent. You have basically made the conversation incomprehensible to all but an elite few. You have illuminated nothing, but you have succeeded in harassing.
Since you admit he did, then why did you claim he
didn't? That is simply a lie. If you thought it was too complex, then why didn't you simply say, "Bell's original argument is complex, and I prefer to refer to a more recent and simpler reformulation called CHSH". That involves less verbiage than your original, and is accurate. There is absolutely no excuse for a complete fictional claim that Bell, "had said that he knew how to do this, but had not shown the way before he passed away". There is not one word of truth in that, and no matter how much rhetoric and handwaving you engage in, it doesn't alter the fact that it is complete and utter fiction. There is not one legitimate way in which this fiction could possibly enhance
anybody's understanding of the real issues and your constant attempts to divert attention from it are completely transparent. The fact of the matter is that
you are making things up as you go along. It's obvious and undeniable. Only you know
why you do it - but my personal suspicion is that you simply make things up to fill gaps in your own knowledge and that
you do not really want to inform, but rather you want to create the impression that you are knowledgable in areas in which you are actually ignorant. It's called BS'ing (I can't use the full word because of the autocensor). And it doesn't reflect well upon you.
Current repetitions of Aspect or more accurately of experiments based on Aspect's idea give beyond six sigma certainty; this is technically speaking the equivalent of "beyond a reasonable doubt." See Charles Weiss' arguments
here. I am surprised that you would maintain this position when I have every reason to believe that you have already been exposed to this information when we were discussing "framing" and science in skeptigirl's
recent thread.
Aspect is pretty much a done deal. There are a few people still arguing against it, but by and large the majority of the physics community accepts those results as definitively disproving either local realism or locality (and there are, I believe, still a majority who reject locality violations on the same grounds Hawking make the Chronology Protection Conjecture on; this is my position on the matter as well). Six sigma, for those not familiar with statistics, is a level of certainty of 99.9964%. I have seen it stated that recent instantiations have put this beyond nine sigma, but I cannot provide a reference; on the other hand, originally in January of 2003, and most recently updated May 24 2006, Richard Gill provides data in his second appendix to his paper, "Time, Finite Statistics, and Bell's Fifth Position" that show six-sigma results,
here, and Weihs' results are available
here, and finally you can look
here where 242-sigma (no, that is not a typo- two hundred and forty-two standard deviations) results are presented. I have chosen preprints so that the arguments are available for inspection by those who do not have access to
Physics,
Nature, and other expensive literature of the physics profession.
So much for "Aspect proved nothing beyond a reasonable doubt." I have shown a rigorous definition of the level of scientific experimental certainty consistent with "beyond a reasonable doubt," and shown that Aspect experiments have raised the certainty beyond that level. If you are merely saying that Aspect's
original experiment didn't put it at that level, I'm not sure
that's even true; but even if it is, the long explanation involved in explaining it is not worthwhile in a post of reasonable length on a non-physics board.
And finally, if that's the only quibble you have, it certainly isn't worth a "wrong," unless you're looking to harass someone.
So I should accept that any doubt of the validity of Aspect's experiment is
unreasonable because of one man's opinion about the risks of genetically modified crops? Talk about surreal! It makes absolutely no difference how many "sigmas" you want to quote - it all sounds very impressive to the uninformed. It doesn't mean one thing to all the scientists who challenge the actual validity of
Bell's logic in the first instance. Let alone those still think there are serious loopholes, including
loopholes in principle that can never be plugged no matter how precise the experiment. Sure you can quote statistics and handwave away all objections - but all this "reasonable doubt" stuff is just your own personal opinion, it is not scientific fact, and to pretend it is, is fundamentally dishonest. And of course, what is hilarious is that you refer to Gill - who maintains that Aspect's experiments may not actually show what many people think they do because Bell missed a fundamental fifth logical option in his original argument!
There is a great deal of proof in the three papers above; there is also a refutation of several loopholes in Gill's paper.
Now, I will not state that the majority of qualified physicists still questioning this are woos; in fact, very much the opposite. It is their task to attempt to find defects in the theory. If they succeed, they will make an inestimable contribution to the progress of physics. They will also be famous, and will likely win money, neither of which is to be sneezed at, but in most cases neither of which is a primary motivation. Still, it does add some spice to the pie. Furthermore, collectively, they will make that inestimable contribution even if they fail, because the more folks try and fail to disprove it, the more sure we can be that it is a useful theory.
On the other hand, anyone who is not a qualified physicist, who expresses an opinion in contradiction of the mainstream, and who engages in pre-emptive harassment of perceived opponents, IS a woo. No question about it, we can all go look at an Evilution thread on this very site to see numerous examples.
So I have to ask you straight out, Pragmatist, what is your position on proof by Aspect of counter-factual local realism as opposed to counter-factual locality? And do you know the difference between local realism and locality? Can you state it? Because this, you see, is absolutely the core of the discussion of Aspect, EPR, the DCQE, and Afshar. And if you don't know the difference, then you do not have sufficient knowledge to discuss this subject technically.
You may well be looking to prove locality violations; and whereas Aspect can be interpreted as either a breakdown of locality or a breakdown of local realism, the DCQE has no such alternative explanation that does not involve explicit violation of the Chronology Protection Conjecture. Where Aspect only violates locality (if it does; i.e., if you interpret it that way) in that it shows "spooky action at a distance," and this merely implies a causality violation, if the DCQE is violating locality, it is a directly perceivable causality violation, i.e. a violation of the time ordering of cause and effect. Of course, either can be explained by a breakdown of local realism, and this requires neither the implicit nor the explicit causality violation, but woos generally like locality violations rather than the more prosaic explanation that there are no local hidden variables. And that's why I ask. I want to know where you stand, and whether this is all just an exercise prompted by defense of belief in "nonlocal phenomena." This last has unfortunately become a faux justification for all sorts of mummery including psychic phenomena, ghosts, and other tripe.
This is another ridiculous straw man argument. It all sounds wonderful, emotionally charged, obligatory references to woos and creationism - I mean it's obvious that no sane person could or would ever challenge THE TRUTH as you see it. You know perfectly well what my position is given that I've discussed it with you in the past - I don't have a fixed position on the matter, but I have reservations about Bell's logic. The simple fact that you are trying to force me to declare a belief in nonlocal phenomena so you can handwave away my objections to your claims by saying that I believe in "the same thing that woos do" says everything about the quality of your arguments. It's so ridiculous it defies description. I have no idea whether locality or realism are violated (or anything else)
and neither do you. I accept that there are valid arguments for many different interpretations and I reserve judgement as to which is better until I have seen more evidence. I argue whichever case appeals most to me at the time.
I don't ever argue on the basis of qualifications, either an argument stands on its merits or not. I don't need to rely on qualifications to make a point. You have no idea of my qualifications and I wouldn't presume too much if I were you.
I think this merely adds grist to the mill of speculation; the fact that you went on and tried (and, by the way, completely failed) to anticipate my counter-arguments shows a pattern of behavior: the pre-emptive strike. The post where you did this is
here.
Why is it necessary to attempt to pre-emptively discredit an opponent, Pragmatist? What is the point? Do you even care that what you have done has not helped anyone understand anything? Is it of any importance to you? If it is, why have you done this? What is your motivation? I will not even ask whether you have a justification, since it has to be obvious to any observer that nothing can justify rendering this subject incomprehensible to the person the thread was started for, and that that person is in fact not helped is beyond question. I'll leave judgement of the ethical implications of this to the reader.
Well, you can rely on speculation - I don't. It's really quite amusing how presenting
evidence in support of my claims suddenly becomes "a pre-emptive attack" - it's also amazing how I tried to anticipate your counter arguments after you had already claimed you weren't going to present any counter-arguments!
All this is just silly. I have challenged the factual accuracy of your claims. I have shown the evidence that supports that challenge. Your only responses have consisted of personal attacks, straw men and diversionary tactics and vague references to alleged evidence that doesn't actually exist or support your claims.
I couldn't care less what you think of me. What I
do care about is how you mislead others. I care that you make up complete fiction and pretend that you are knowledgeable in areas you clearly are not. I care that you try to bully and shout down anyone who disagrees with you.
As far as I am concerned the matter is closed, I have no intention of wasting more time on your nonsense.
To anyone else who is reading this, once again I apologise for any derail. I sincerely hope that if you are genuinely interested in these matters and you want to learn more, that you take the time to try to study information from reputable sources (i.e. not Wikipedia!). I also strongly recommend learning more about the real history because that will give you a much better grounding as to what is going on and how particular beliefs and arguments developed. But above all, please understand that if you know nothing about the subject you're not going to learn all about it from some posts on a bulletin board. Any information on here should be treated as suspect and verified independently (regardless of who provides it).
LOL.