The Two-Slit Experiment

D

David George

The Force is Strong With This One
I was going to leave this for tomorrow, but I started writing and it went fairly quickly, so I will post this now.

Richard Feynman gives a version of the two-slit experiment using photons in "QED", p. 80-81, as follows. Photons/light waves are sent to a photomultiplier detector through a barrier in which are two holes. With one hole closed and the other open, the detector clicks are approximately equal for each hole: approximately 1% of the time, the detector clicks. Paraphrasing, 1 out of 100 photons is detected for each hole, with the other hole closed.
"When we open both holes, we get a complicated answer, because interference is present: If the holes are a certain distance apart, we get more clicks than the expected 2% (the maximum is about 4%); if the two holes are a slightly different distance apart, we get no clicks at all.
"One would normally think that opening a second hole would always increase the amount of light reaching the detector (D), but that's not what actually happens...."
With detectors A and B placed on both holes with varied spacing, "...the detectors at A and B never go off together - either A or B goes off. The photon does not divide in two; it goes one way or the other.
"Furthermore, under such conditions the detector at D goes off 2% of the time - the simple sum of the probabilities for A and B (1% + 1%). The 2% is not affected by the spacing between A and B; the interference disappears when detectors are put in at A and B!"

This passage illustrates what Feynman called the "central mystery" of modern physics, the seeming dual quality of light: that of a wave with the property of wave interference, and of a particle or wave packet, a photon. The light takes the form of a wave when it is not being observed (detected), but of a photon when it is being observed. Feynman uses the term photon throughout, but in classical physics it was shown by Fresnel (or Young, I don't remember which) in the 19th Century that a wave can act as a particle, i.e. it can "impact" at a specific point. In other words, a photomultiplier tube can detect a wave as a particle. So without the detail of the experiment, photon interference can be treated as wave interference. The mystery, then, is in why the photon/wave interferes when no detectors are present, but does not interfere when A and B are present. The answer lies in the assumption that "the photon does not divide in two; it goes one way or the other", and what that implies.

I question this assumption as follows. Imagine our two eyes are the two holes used in experiment. Viewing a scene - for example, a darkened room in which there is only a dim candle - we close each of our eyes in turn. We see a slightly different version of the scene through each eye. But we see the candle through both eyes. It is not reasonable that with one eye closed, we would deny that the candle we see with the open eye is not also available to the closed eye, if it were open. If we treat the candle light as a photon, we can say that if there is a photon at the open eye, there is also a photon at the closed eye. And if both our eyes are open, the photon interferes: this is seen in the experiment. So we understand the case when one or the other hole is open, and when both holes are open.

Now consider the case when there are detectors A and B at the two holes. What happens? A photon is detected 2 out of 100 times at A or B, and also a photon is detected 2 out of 100 times at D. But are these the same photons? I would say, no, a photon detected at A or B is not the same photon detected at D. They are different photons. I say this because it is not likely that a single photon would be detected at A or B, and also at D. The photon detected at A or B is absorbed (its momentum-energy is transferred), because it activates the photomultiplier. It cannot both transfer its energy to the photomultiplier and continue on to activate the detector at D. So there are four different photons detected: two at A and B, and two at D.

Does this mean that, out of 100 photons sent, two are detected by A and B, while two are undetected by A and B? How would two photons pass through A and B undetected and without interfering? Here, judging by the evidence of our eyes and the candle, we remember that if there is a photon at A, there must also be a photon at B. Would the photon at one hole pass through undetected, while the photon at the other hole does not pass through but is not detected either? That would have to be the case in order for a single photon to be detected. And if both photons pass through undetected, still they must interfere.

The only reasonable scenario, then, is that one photon is detected at A or B, while the other photon passes through the detectors at A and B and is detected as a single photon at D. There is no interference, and the statistics are accounted for. And since a photon can be treated as a wave, it is a wave that is detected at A, B and D. There is no photon in physical reality.

The question then becomes, why is the photon/wave detected at A (for example) but not at B? This is due to the form of the wave, which is an electromagnetic wave - a wave with two components, a magnetic component and an electric component, orthogonal to each other. The shape, or structure, of this wave, may not be well understood. A wave is a collective motion, but the electromagnetic field is a vacuum - so, as the physicists ask, what is waving? The electromagnetic wave is modelled on a pressure wave - that is, a wave consisting of slight changes in pressure, which moves in waves. However, the electromagnetic wave is also modelled as a plane wave, spreading orthogonal to the wave front, whereas a pressure wave is like a series of pulses over a wide area wave front (I think!). I believe it is more realistic to trreat the electromagnetic wave as a pressure wave with two components - that is, two separate pressure fronts. And these two components are not identical in different locations. Just as we see a slightly different scene through each of our eyes, any spatially distant locations will sense a slightly different pressure wave. The wave form at detector A is not, and cannot be, the same as the wave form at detector B. The question then is, what is the pressurized medium that can transmit pressure waves? That "mystery" replaces the wave-particle mystery, and must be explained, which I will do in a future post.

Now I am taking a break. In the next post I will describe the two-slit experiment with electrons.
 
I think the answer is that the photon we observe, traveling in one direction forward in time, also has a companion photon going the exact opposite direction and backwards in time. This companion photon might also be thought of as another (but invisible) aspect of the photon.

In the double slit experiment, the closed slit prevents the reverse-time photon from reaching the "origin" and therefore the photon "knows" that it can only pass through one slit. In other words, the photon can only travel (in forward time) along the path that is also available to its reverse-time aspect.

When there are two or more paths available IN BOTH DIRECTIONS, then the photon may behave as a wave, with the forward-time and reverse-time aspects producing the adding and subtracting features.

I think this hypothesis can also explain the "Fresnel zone" effect in radio communications.
 
Hello,
Just to make the remark that in the eyes analogy, we have a detector A in the right eye, and a detector B in the left eye.
 
Hi mkrnhr, yes that's right as I see it, I'm not sure how the analogy works with detector D as our stereoscopic vision!

Hi curious_richard, I will try to figure out how the scenario you describe works before responding.

Meanwhile, here is another instalment:

More mystifying than the particle-like behavior of light is the wavelike behavior of electrons. The distribution of electron impacts after they pass through a two-slit apparatus follows a pattern associated with interfering waves, provided we do not attempt to detect which of the slits an electron passes through. When we set up an apparatus to make that detection, the wave interference pattern disappears. This behavior is well described in "Six Easy Pieces" by Feynman, and there are many other descriptions.

So the question is, why do electrons "fired" through the slits one at a time, build up a wave interference pattern? And then, why does the pattern disappear when we examine it?

The second question is more easily answered than the first: by setting up an apparatus to detect which slit an electron goes through, we destroy the possibility of wave interference, in the same way that a detector at A or B in the photon experiment destroys the possibility of wave interference by absorbing an interfering photon. In other words, we deny the electron the possibility of interference.

The first question remains. An electron is demonstrably not a wave in that it can be manipulated as an individual entity, whereas a wave is a collective motion (an event rather than an entity). The wave function (as far as I understand it) deals not with a single electron but with a statistical ensemble (Einstein's words) of electrons. This is done in order to meet the experimental statistical requirements. When the electron is "measured" by prodding it with a certain amount of energy (in the form of light), its energy cannot be predicted with certainty (leading to the Heisenberg measurement uncertainty principle). The outcome of a measurement is a probability, within a range of probabilities given by the wave function. But in quantum mechanics the wave function comes to be more than a mathematical tool: it becomes an element of physical reality. So mathematical and physical reality are inextricably connected in quantum mechanics, and "theory" makes no further explanation of electron behavior. What then is a further explanaation, in the two-slit experiment? A probability distribution for electron impacts is derived from the wave function, and the impacts follow a wave interference pattern (so long as we do not look and so interfere with the interference). But what causes the wavelike interference pattern?

It is useful first to study the experimental setup. For example, Feynman tells us that the electrons are "fired" from an electron "gun" (p. 122). "We make an electron gun which consists of a tungssten wire heated by an electric current and surrounded by a metal box with a hole in it. If the wire is at a negative voltage with respect to the box, electrons emitted by the wire will be accelerated toward the walls and some will pass through the hole. All the electrons which come out of the gun will have (nearly)
the same energy. In front of the gun is again a wall (just a thin metal plate) with two holes in it. Beyond the wall is another plate which will serve as a 'backstop'. In front of the backstop we place a movable detector."

So this is one experimental setup. The key (here) is the heated tungsten wire which emits electrons. The electrons are accelerated toward the walls. Accelerated electrons emit light. So apart from electrons, light also passes through the hole in the box: the box is a light source as well as an electron source. And it is reasonable that when the light passes (ahead of the electron) through the metal plate with the two holes in it, a wave interference pattern will be produced behind it. What does this interference pattern represent, in physical reality? I believe it represents the instantaneous shape of the electromagnetic field in the vicinity. And the shape of the field is due not only to the waves passing through the holes but to the entire physical surrounding with which the light interacts.

As an electron moves toward one of the two holes, the shape of the electromagnetic field both in its vicinity and on the other side of the holes will change. But an interference pattern of some kind will be produced (depending on the spacing of the holes) up to the moment when the electron enters one hole.

What happens when the moving electron (as the source of a moving electromagnetic field) arrives in the immediate vicinity of the hole? It must interact in some way with the metal in the plate. While the metal sees the electromagnetic field of the electron, the electron sees the electromagnetic field of the metal (which is moving relative to the electron). And this electromagnetic field is not restricted to the metal in the vicinity of the electron. It encompasses the entire metal plate, including the other hole, and the entire physical surrounding. So the electron's path is influenced by an electromagnetic field whose instantaneous shape includes an interference pattern of the same kind as that produced by the light. The electron then follows a path to the detector which is determined by the wave interference of its light (i.e., its electromagnetic field disturbance). And so, one at a time, the successive electron impacts build up a statistical ensemble identical to the prediction of the electron wave function. As far as I understand it, identical experimental setups, placed at distant locations, each producing only a few electrons, when the results are collated will display a wave interference pattern. So the wave interference pattern is not dependent on space or time. It is a statistical pattern, built up as successive electrons "ride the wave" created by their light.

And it is natural that detectors placed to see which hole an electron passes through will absorb or otherwise interact with the light from the electron, destroying the interference pattern "shape" of the electromagnetic field behind the metal plate. In Feynman's example, a strong light source behind the metal plate takes the part of the detectors A and B in the photon experiment. When an electron passes near the light source, it interacts with it, absorbing and re-emitting a photon so that a flash of light is seen. Only one flash is ever seen, and the location tells us which hole the electron went through: the electron indeed goes through only one hole. However, the interference pattern at the backstop detector disappears. It only reappears if the light is so weak that it is impossible to tell which hole the electron went through: in other words, if the accelerated electron-induced electromagnetic field is more influential than the light source-induced field.

As quantum mechanics was applied to the electromagnetic field, it was convenient (or necessary) for the purpose of calculation to treat photons and electrons as mathematical point particles, so that there is no physical distinction between a photon and an electron. However, there is manifestly a difference, if we recognize that a photon is nothing more than the particle-like behavior of interacting light (i.e., the wave front is treated as following a path), while an electron is a spatially extended form of matter having its own gravitational field (not simply being influenced by a gravitational field as is light).

This latter property of an electron, that of spatial extension, is not strictly recognized in modern field theory (which I do not understand), where an electron is a point-like "excitation" of an electron-matter field, and a photon is a point-like excitation of the electromagnetic field. This "equal" treatment of light and matter does not in my opinion promote understanding of the physical reality with regard to light and matter. But due to the success of the statistical ensemble approach, ever more esoteric particle-field theories have been developed, to the point that the physical reality of particles and fields (mathematical constructs) is informally accepted as "true", and is everywhere promoted as the "politically correct" view of physical reality.

I do not agree with this view. Here I follow Einstein, who said that physics will not abandon quantum mechanics since it provides a way to make predictions which agree with experiment; however, it is not a complete description of physical reality. And in that regard, in the next post I will attempt to describe the experiments by which a 100% certain prediction is made of electron behaviors while at the same time this 100% certain prediction is treated as no more than a statistical probability in an inherently uncertain natural system. (That is, quantum mechanics transfers measurement uncertainty into natural -physically real - uncertainty, perhaps in order to bolster its claim to be a complete description of physical reality.) And in future posts I will attempt to describe the extended space occupied by an electron (and proton, and neutron), and how it comes about.
 
curious_richard, I have a hard time understanding "backwards in time" (emphasis on the "in"). It appears you are saying that there is a physically real, backwards-flowing time continuum "within which" events occur, so that our future (however we perceive that, which I have been thinking about recently) is its past. This would have to be a universally applicable continuum, so that there is a universe opposed to ours in which events occur in a reverse order. But I have trouble figuring out how causal relations would operate in such a universe. Would the two-slit experiment then "begin" with a result and "end" with the emission of photons? That does not make sense to me. I recall that mathematical equations dealing with antimatter can be construed so that a positron is like an electron moving backward "in" time. But whether that reflects physical reality I do not know. It may be that a positron is an electron "walking backward" (but in the same time direction). I will have more to say about that in a later post.

You say that when there are two or more paths available in both directions, then the photon may behave as a wave. But I do not see a wave interference explanation for the "adding and subtracting features". And I cannot imagine what happens when the reverse-time photon comes across a detector as it moves "forward" in its time (backward in ours).

(More broadly, on the subject of "time", I believe that the "sequential time" of cause-and-effect is the physically real time, not the "parallel continuum" or time-stage upon which events take place. I think that, psychologically and historically (judging by our language) we have hit upon a concept of time in which "future" exists "in front" of us, just as what we see with our forward-pointing eyes lies "in front" of us. And as we move "into the future" and leave the past "behind" us, we create a scenario in which time moves forward with us into the future: so the "arrow of time" is from past to future. But then we are faced with this question: does the light arrive in our eyes from the future, or from the past? That is a subject which has the ability to keep me occupied for hours. And it links intimately to the sequential-time causal relation of events, and hence to our perception and understanding of universal evolution. There is much more to be said on that subject.)

I am not sure what the "Fresnel zone" effect is in radio communications. I am aware that there is some kind of resistance in the field near an antenna, over and above the resistance of the wire, but I don't know how it works. It is difficult even to say what is going on at the scale of the electrons in the metal plate of the electron two-slit experiment. I only assert in general terms that the field (or current) created by the electron influences in turn the path of the electron. If I say that the effect you refer to is due to the interaction between the field (or current) around the electrons in the wire, and the current of the incoming or outgoing radiation, I am only repeating (in ignorance) what is probably already understood. The "resistance" could well be due to wave interference. (There is no doubt something in Wikipedia about all this, but it will take some time to go through it, if it is even understandable non-mathematically.)
 
David George said:
curious_richard, I have a hard time understanding "backwards in time" (emphasis on the "in"). It appears you are saying that there is a physically real, backwards-flowing time continuum "within which" events occur, so that our future (however we perceive that, which I have been thinking about recently) is its past.
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That seems close enough. I did write about a "companion" photon, but I think my idea would be clearer if I wrote that the backwards-time photon is the same photon, but a different aspect of it -- the one that travels backwards in time.

Would the two-slit experiment then "begin" with a result and "end" with the emission of photons?
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No, there would be no "beginning" and no "ending" in time, as the past, present, and future are simultaneous. Since we (the observers) do experience time, we can only look at four dimensions of the photon, and to us it has the appearance of traveling through space and time.

I do not wish to force you to believe anything against your wishes, so I will not spend much effort trying to argue or prove anything. Take it or leave it as you wish.

I am not sure what the "Fresnel zone" effect is in radio communications.
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If you have two radios with their antennas pointed at each other, you would probably think that the photons emitted from the antennas would travel in straight lines. Some of those photons that are aimed "just right" would arrive at the other radio's antenna and you would have communication. The other photons would miss the target. In effect, you could draw a "cone of photons" coming out of each antenna to describe the paths of the photons.

With this mental picture, you would probably expect that you only need line of sight for the photons in the exact center of the cones, the exact line between the two radios' antennas. It should be no problem if a tree or house or other obstruction got in the way of the photons that were not going to the receiver anyway.

Well, it seems that you DO need clearance for some of those "unused" photons, almost as if they were going at the wrong angle but somewhere midway between the antennas, they bend back to magically go to the receiver. This circle may be dozens of feet in diameter, or maybe much larger depending on the frequency and the distance between the antennas. Even though the Fresnel zone may seem rather modest, it does raise the question of whether the photons really do travel in straight lines, or if there is bending. And if there IS bending, how do the waves know which way to bend in order to go to the receiver?

It is easy for me to visualize this by looking at the photon and its path as happening simultaneously in the past and future, so it does not need to "know" anything because it already IS there. We see only a piece of it at a time, and in only one time direction.

Again, I do not feel the need to "prove" anything. If you find the idea useful, great. If not, that is fine too.
 
curious_richard,

Thank you for a very interesting post. I will read it thoroughly and try to understand it - your earlier post got me started on the time phenomenon, and I have been writing on it today (learning process). Off the top of my head I sense some limitation in simultaneous future, past and present due to causal sequence but I will say no more for now.
 
curious_richard, quoting you with my responses:

". . . I think my idea would be clearer if I wrote that the backwards-time photon is the same photon, but a different aspect of it -- the one that travels backwards in time."

Sorry, this doesn't make your idea any clearer to me. To keep it simple, start with a cause, and end with an effect, and say which takes place "first", "in" "time".

". . . there would be no "beginning" and no "ending" in time, as the past, present, and future are simultaneous. Since we (the observers) do experience time, we can only look at four dimensions of the photon, and to us it has the appearance of traveling through space and time."

I don't believe that we can look at any "dimensions" of the photon, or assign any "appearance" to the photon, since it is by the photon (or light wave) that we see. In order to see a photon, we would need a second photon. How would the second photon, travelling at the same speed as the first, overtake the first, and run back to us. . . And to see that one, a third . . . . Sorry, makes no sense to me. Neither do I believe the past, present and future are simultaneous! However, how we designate past, present and future in a causal sequence is something else again, potentially crucial to understanding nature.

With regard to the Fresnel zone, as far as I understand what you are saying: (1) Photons (which to my mind are pressure waves) ought to travel in straight lines but don't. An off-center obstruction can affect them. This indicates that they bend. (2) If they bend, how do they know which way to bend? (3) They don't need to know because they are already at where they are going to (or not, depending on the environment).

But: (1) Waves can be treated as if they follow a path, but I believe they are a wide area pressure disturbance. I am not sure intrinsic bending is involved in the wide area pressure disturbance - it depends on the environment. (2) Pinpointing a location where a wave "should" be, then questioning why it takes a roundabout route to get there, seems to ignore the environment which affects the shape of the disturbance (and consequent wave interference effects). If the "Fresnel zone" effect is the "near field" effect which forces me to stand in a specific location near the radio antenna to get a signal, it is evident that the environment (i.e., nearby electrons and electromagnetic radiation) influences the signal. (3) Again, I don't believe in simultaneous past, present and future. Perhaps I ought to post what I have written on "time" today, in a new topic.
 
David George said:
Sorry, this doesn't make your idea any clearer to me. To keep it simple, start with a cause, and end with an effect, and say which takes place "first", "in" "time".
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If you look at a flag of the US, which color comes first? Is it blue, white, or red? I guess it depends on where you start looking as your reference point, doesn't it? It is my current belief that time is an illusion to us humans, albeit a very useful one. If you like to read science fiction, I think you may really enjoy Isaac Asimov's novel, "The End of Eternity" which gives a fun look at time and manipulation.

Neither do I believe the past, present and future are simultaneous!
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Okay. Most people would agree with that and I do not ask that you accept my words as anything other than the ramblings of a madman.

But: (1) Waves can be treated as if they follow a path, but I believe they are a wide area pressure disturbance. I am not sure intrinsic bending is involved in the wide area pressure disturbance - it depends on the environment. (2) Pinpointing a location where a wave "should" be, then questioning why it takes a roundabout route to get there, seems to ignore the environment which affects the shape of the disturbance (and consequent wave interference effects). If the "Fresnel zone" effect is the "near field" effect which forces me to stand in a specific location near the radio antenna to get a signal, it is evident that the environment (i.e., nearby electrons and electromagnetic radiation) influences the signal.
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Those are very interesting points. I will think about them. Thanks for sharing your thoughts.
 
David George said:
[...]
It is useful first to study the experimental setup. For example, Feynman tells us that the electrons are "fired" from an electron "gun" (p. 122). "We make an electron gun which consists of a tungssten wire heated by an electric current and surrounded by a metal box with a hole in it. If the wire is at a negative voltage with respect to the box, electrons emitted by the wire will be accelerated toward the walls and some will pass through the hole. All the electrons which come out of the gun will have (nearly)
the same energy. In front of the gun is again a wall (just a thin metal plate) with two holes in it. Beyond the wall is another plate which will serve as a 'backstop'. In front of the backstop we place a movable detector."

So this is one experimental setup. The key (here) is the heated tungsten wire which emits electrons. The electrons are accelerated toward the walls. Accelerated electrons emit light. So apart from electrons, light also passes through the hole in the box: the box is a light source as well as an electron source. And it is reasonable that when the light passes (ahead of the electron) through the metal plate with the two holes in it, a wave interference pattern will be produced behind it. What does this interference pattern represent, in physical reality? I believe it represents the instantaneous shape of the electromagnetic field in the vicinity. And the shape of the field is due not only to the waves passing through the holes but to the entire physical surrounding with which the light interacts.

As an electron moves toward one of the two holes, the shape of the electromagnetic field both in its vicinity and on the other side of the holes will change. But an interference pattern of some kind will be produced (depending on the spacing of the holes) up to the moment when the electron enters one hole.

What happens when the moving electron (as the source of a moving electromagnetic field) arrives in the immediate vicinity of the hole? It must interact in some way with the metal in the plate. While the metal sees the electromagnetic field of the electron, the electron sees the electromagnetic field of the metal (which is moving relative to the electron). And this electromagnetic field is not restricted to the metal in the vicinity of the electron. It encompasses the entire metal plate, including the other hole, and the entire physical surrounding. So the electron's path is influenced by an electromagnetic field whose instantaneous shape includes an interference pattern of the same kind as that produced by the light. The electron then follows a path to the detector which is determined by the wave interference of its light (i.e., its electromagnetic field disturbance). And so, one at a time, the successive electron impacts build up a statistical ensemble identical to the prediction of the electron wave function. As far as I understand it, identical experimental setups, placed at distant locations, each producing only a few electrons, when the results are collated will display a wave interference pattern. So the wave interference pattern is not dependent on space or time. It is a statistical pattern, built up as successive electrons "ride the wave" created by their light.

[...]
As quantum mechanics was applied to the electromagnetic field, it was convenient (or necessary) for the purpose of calculation to treat photons and electrons as mathematical point particles, so that there is no physical distinction between a photon and an electron. However, there is manifestly a difference, if we recognize that a photon is nothing more than the particle-like behavior of interacting light (i.e., the wave front is treated as following a path), while an electron is a spatially extended form of matter having its own gravitational field (not simply being influenced by a gravitational field as is light).

This latter property of an electron, that of spatial extension, is not strictly recognized in modern field theory (which I do not understand), where an electron is a point-like "excitation" of an electron-matter field, and a photon is a point-like excitation of the electromagnetic field. This "equal" treatment of light and matter does not in my opinion promote understanding of the physical reality with regard to light and matter. But due to the success of the statistical ensemble approach, ever more esoteric particle-field theories have been developed, to the point that the physical reality of particles and fields (mathematical constructs) is informally accepted as "true", and is everywhere promoted as the "politically correct" view of physical reality.

I do not agree with this view. Here I follow Einstein, who said that physics will not abandon quantum mechanics since it provides a way to make predictions which agree with experiment; however, it is not a complete description of physical reality. And in that regard, in the next post I will attempt to describe the experiments by which a 100% certain prediction is made of electron behaviors while at the same time this 100% certain prediction is treated as no more than a statistical probability in an inherently uncertain natural system. (That is, quantum mechanics transfers measurement uncertainty into natural -physically real - uncertainty, perhaps in order to bolster its claim to be a complete description of physical reality.) And in future posts I will attempt to describe the extended space occupied by an electron (and proton, and neutron), and how it comes about.
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I hope you will forgive me if I have not understood you fully. I find descriptions of this sort rather difficult to follow, (which is to be expected given the complexity of the subject and is not intended to be a reflection your communication skills). So just let me re-cap what I think you are saying in order to make sure we are on the same page before I add any comments of my own. . .

Are you suggesting: The physical properties of the device used in detecting the passage of electrons and photons in the double-slit experiment are the direct cause of the observed effects upon which Quantum Mechanics are based and NOT whether or not they are measured by an observer?

And. . ,

Are you suggesting that electrons are being affected by the wave behavior of photons and that this is (possibly) the reason they are behaving like waves rather than particles?

That's what I've managed to pick up from your essays. Am I totally missing something or am I correct in my reading?

Thank-you!
 
curious_richard, in the example you give of the flag, there is no cause-effect relation of the stripes. I believe it is the causal relation that produces a "physically real" sense of time.

Woodsman, quoting you and my response:

"Are you suggesting: The physical properties of the device used in detecting the passage of electrons and photons in the double-slit experiment are the direct cause of the observed effects upon which Quantum Mechanics are based and NOT whether or not they are measured by an observer?"

This may need some subtlety which I may not have. The physical properties of the device are macroscopic atomic properties, including some "emergent properties" I am not aware of, and also small-scale properties that are not understood (or known). However, I believe they all boil down to the interactions of electrons (at this level); the electromagnetic field; and disturbances which change the instantaneous "shape" of the electromagnetic field - to which both the electrons and the disturbances respond in turn. So a "wave disturbance" moving through the field interacts with another wave disturbance just as waves on the ocean interact with each other, producing interference effects; and the waves also interact with the shoreline (the electron - which may constitute a moving shoreline). So there is a lot of disturbance going on. So much so that it is practically impossible to follow, and we must rely on statistics to try to figure out what is going on. (However, the statistics gives us some clues.) The physical devices are one set of "actors" (the shoreline), and the waves are another, and the source is another, etc. And we find certain results - wave interference if we don't look, "particles" if we look. In the case of the photon, I am suggesting that the statistical results will be obtained if the detected photon at A is accompanied by an undetected photon at B, and the B photon is later detected at D. And there is indeed an interaction of the photons (pressure waves) with the equipment, but the "direct cause" of the detection is the light source! In the case of the electron, I am suggesting that the electron's path (and subsequent statistical results) is influenced by the electromagnetic field it creates as it moves (and this field is disrupted by interaction with the detector). However, fundamental to both these cases is the possibility of structure of an electron. It is that structure which may "determine" what happens everywhere, all the time.

In both cases, the addition of detectors to the experimental setup does affect the experiment: it adds another actor - even an actor with an independent power source (I think), such as a photomultiplier tube. There is a situation possibly more pertinent to what you may be thinking, involving the decision of the experimenter which measurement to make. It will be a later post.

"Are you suggesting that electrons are being affected by the wave behavior of photons and that this is (possibly) the reason they are behaving like waves rather than particles?"

Yes indeed, I am saying that the path of the electron, being influenced by its own electromagnetic field, creates the wave interference pattern (one electron at a time) at the backstop detector - so long as the interference is not disrupted by a detector at the metal plate, or a light source behind it.

Now here is more:

In his book "Six Easy Pieces", describing the two-slit experiment with electrons, Feynman says, "In our experiment we find that it is impossible to arrange the light in such a way that one can tell which hole the electron went through, and at the same time not disturb the pattern. It was suggested by Heisenberg that the then new laws of nature could only be consistent if there were some basic limitation on our experimental capabilities not previously recognized. He proposed, as a general principle, his uncertainty principle, which we can state in terms of our experiment as follows: "It is impossible to design an apparatus to determine which hole the electron passes through, that will not at the same time disturb the electron enough to destroy the interference pattern.... No one has ever found (or even thought of) a way around the uncertainty principle. So we must assume that it describes a basic characteristic of nature....
"One might still like to ask: 'How does it work? What is the machinery behind the law?' No one has found any machinery behind the law. No one can 'explain' any more than we have just 'explained'. No one will give you any deeper representation of the situation. We have no ideas about a more basic mechanism from which these results can be deduced."

As far as I am aware, Feynman's clear and simple statements can describe the evolution of physics since the 1920's, when quantum mechanics was developed out of the Bohr model of an atom. No model of an electron has been developed to explain the interaction of the electron and the electromagnetic field (radiation field, or "light field"). Orthodox physics is far from finding any "machinery" that gives rise to the uncertainty principle. But the uncertainty principle, while it recognizes a definite limit on our ability to make a measurement on a very small scale, does not prohibit a model at the small scale. The uncertainty principle is a measurement principle. It appears to be absolutely true (i.e., a "law of nature") that two properties of an electron, namely its position and its momentum, cannot be accurately measured in the same experiment. If we allow the two-slit experiment to take place "unmeasured", we will find an interference pattern; if we measure it, we destroy the interference pattern. It is as if "nature" is determined not to let us know the "secret" of wave interference. However, I do not believe nature is keeping any secret. Physics has simply stopped looking for the "machinery". Perhaps this is because knowing the machinery would not enable physicists to make any better prediction than can be made by the system of quantum mechanics, which at its root is a system of probabilities, embodied in the wave function.

The use of probability distinguishes quantum mechanics from classical physics, in that according to classical physics the evolution of a system ought to be exactly or precisely determinable if enough information is known. Quantum physics appears to recognize that enough information to make a precise determination at a small scale can never be known: the energy used to measure an electron bumps the electron, making the measurement imprecise.

This difference between the "classical" and "quantum" approaches to nature is due to the small scale of measurement in quantum mechanics. As scale increases, the "classical" approach is sufficient for the purpose of measurement. If small-scale measurement of energy produces uncertainty, so be it a law of nature. However, a more philosophical debate arose as quantum mechanics developed, due perhaps to politics in the school of physics, in which "defenders" of quantum mechanics appear to insist that quantum mechanics is a complete description of nature; then nature, at its smallest scales, is inherently uncertain or indeterminate. I believe this view misinterprets the Heisenberg uncertainty principle, which while it governs measurement at small scales, does not necessarily govern nature at small scales. It is rather like saying that in viewing a distant country, we do not know what is going on in that distant country, and therefore neither do the natives living in that distant country know what is going on in their own country.

Einstein (ironically a "founding father" of quantum mechanics) did not agree with this view. He believed that quantum mechanics is not a complete description of nature (physical reality). He recognized that physics will not give up quantum mechanics because experimental results agree very well with its probabilistic predictions. However, he did not find a model that describes the machinery "behind" the phenomena revealed by the two-slit experiment. And theoretical physics has taken quantum mechanics, the study of atomic systems, into the realm of the fields within which atomic systems operate (i.e. the "empty space" around the "particles" of atomic systems). The mathematics of probability being successful (to an obscure point) using the machinery of mathematical points (no spatial extension) and fields, there appears to be no need to seek any other kind of machinery. But the school of physics appears to take this approach a step further, and treats the mathematical system of point particles and fields as a physical system: those outside the school are given to believe that physical reality does indeed consist of mathematical points and fields. As a result of this, the "model" of modern physics cannot be visualized. A modern model maker does not attempt to make what we might think of as a "physical" model - even though, at a certain scale, such a "physical" model is not only necessary (since we come to the scale of visibility) but actually seen (for example using microscopes).

You may say, "Well, if nature prevents us from seeing (measuring) what is going on at a small scale, and we do well enough without a visualizable model, why do we need such a model of an electron, for example?" The answer is that the school of physics is operating in regions where its own "discoveries" are of little value to society - other than as philosophical "insights"! I am speaking here of the schools of high energy particle physics and Big Bang cosmology, which have developed a closeness such that it is self-justifying. While it may be that some "useful" technology flows from discoveries in the course of high energy collisions, the "pure science" of high energy collisions aims to produce (or disprove) a natural system of such complexity that it is unlikely ever to be applied to technology. Outside the school of high energy physics, the main "customer" for high energy collision results appears to be the school of Big Bang cosmology. And what is the purpose of Big Bang cosmology? It is to understand the evolution of the universal system - in effect, to show us that the universe as we know it is doomed, and the method of its destruction. We should not mistake ourselves that its inquiry is into the "origin" of the universe (i.e. T=0). Big Bang cosmology does not touch T=0 (and it does not intend to touch it). It is a "metatheory" of universal evolution to oblivion from a hot dense state a short time after T=0. And this hot dense state is the field of study of high energy physics. So the "value" of quantum physics is to tell us there is no point to anything! This does not strike me as high value, especially since quantum physics does not necessarily give a complete description of physical reality. But if we believe in the completeness of quantum physics, it appears we must believe the universe is doomed. So the lack of a model for an electron may be quite important in our perception of the purpose of our lives, for example.

The "debate" about the completeness of quantum mechanics (the "Bohr-Einstein debate") eventually produced a problem (the "EPR Paradox") directed at Bohr by Einstein and his associates. The original problem stated that if two "entangled" electrons emitted by a single system are measured, one for its momentum and the other for its position, the state of the entangled electron system can be completely known (in this way evading the uncertainty principle). It has evolved in a slightly different direction, involving those two entangled electrons and also entangled photons. It is a phenomenon of quantum mechanics that some experimental outcomes can be predicted with 100% probability - i.e., with certainty. This was a sign to Einstein that an "element of reality" is connected with the system in question. But this element of reality is not recognized by quantum mechanics - it is simply a 100% probability - in a "naturally" uncertain system!

As far as I understand it, a pair of entangled electrons is a system in which two electrons have interacted with each other within an atomic system. Following this interaction, a measurement made on one electron can - depending on the measurement - give the experimenter information about the other electron. The information about the system that can be found this way is the strength of the magnetic field produced by each electron, called its "spin state". According to the Heisenberg uncertainty principle, the "root mean square" deviation of electron momentum from its mean, multiplied by the r.m.s. deviation of the electron position from its mean, can never be less than h/4pi. In this formula, "h" is Planck's constant, a quantity which can be used to represent energy multiplied by time or momentum multiplied by distance. It is a foundational constant found in the equation for the energy of a photon or "wave packet", E = hf, where E is the energy (in joules) of the photon, f is its frequency, and h is Planck's constant. Two electrons (measured by having a light, i.e. photons, shined on them) which have shared the same atomic orbital cannot both have the same energy. If the two electrons are measured (in exactly opposite directions) it will be found that one will have an "added" energy of h/2pi (called "spin up", while the other will have a subtracted energy of h/2pi ("spin down"). And the measured "energy" in this case is the energy of the electron's magnetic field. (I must clearly state here that I am a layman, self-taught without a single physics class to my credit. If this incomplete - and incompletely understood - description is wrong or misleading, I welcome correction.)

There is a problem to be addressed before the experimental outcomes are studied, and this is the problem of the electron's magnetic field. In order to create a magnetic field, some electric field must be in motion - in this case, the electron must be spinning. In the Bohr model of an atomic system, an electron is visualized as a small planet orbiting a nucleus (as the Earth orbits the Sun). However, in order to have a magnetic field as strong as it is, the electron would have to be spinning impossibly fast - faster than the speed of light. The Bohr model was abandoned, and the point particle took its place. This means there is no "visible" physical model that explains the "intrinsic angular momentum" or spin of the electron. The "planetary" model is abandoned, and a mathematical point takes its place. A conventional statement of this situation is that "there is no classical analogue of quantum spin". And I believe that is all the explanation you will see in the books.

With that in mind, experiments dealing with electron spin (and a related phenomenon, photon polarization) give interesting results, which I will attempt to describe in the next post. Stipulating that two electrons can be entangled, I will then attempt to describe an electron structure which will give the experimental outcome.
 
David George said:
Woodsman, quoting you and my response:

"Are you suggesting: The physical properties of the device used in detecting the passage of electrons and photons in the double-slit experiment are the direct cause of the observed effects upon which Quantum Mechanics are based and NOT whether or not they are measured by an observer?"

This may need some subtlety which I may not have. The physical properties of the device are macroscopic atomic properties, including some "emergent properties" I am not aware of, and also small-scale properties that are not understood (or known). However, I believe they all boil down to the interactions of electrons (at this level); the electromagnetic field; and disturbances which change the instantaneous "shape" of the electromagnetic field - to which both the electrons and the disturbances respond in turn. So a "wave disturbance" moving through the field interacts with another wave disturbance just as waves on the ocean interact with each other, producing interference effects; and the waves also interact with the shoreline (the electron - which may constitute a moving shoreline). So there is a lot of disturbance going on. So much so that it is practically impossible to follow, and we must rely on statistics to try to figure out what is going on. (However, the statistics gives us some clues.) The physical devices are one set of "actors" (the shoreline), and the waves are another, and the source is another, etc. And we find certain results - wave interference if we don't look, "particles" if we look. In the case of the photon, I am suggesting that the statistical results will be obtained if the detected photon at A is accompanied by an undetected photon at B, and the B photon is later detected at D. And there is indeed an interaction of the photons (pressure waves) with the equipment, but the "direct cause" of the detection is the light source! In the case of the electron, I am suggesting that the electron's path (and subsequent statistical results) is influenced by the electromagnetic field it creates as it moves (and this field is disrupted by interaction with the detector). However, fundamental to both these cases is the possibility of structure of an electron. It is that structure which may "determine" what happens everywhere, all the time.

In both cases, the addition of detectors to the experimental setup does affect the experiment: it adds another actor - even an actor with an independent power source (I think), such as a photomultiplier tube. There is a situation possibly more pertinent to what you may be thinking, involving the decision of the experimenter which measurement to make. It will be a later post.
Click to expand...

I agree that detectors add another element to the double slit experiment, and your assessment of just how much complexity is added is persuasive. However, explaining this in detail, as you have supposed, doesn't answer my question.

I hope you will forgive me for being blunt. . .

I'm trying to figure out what your basic understandings are with regard to quantum mechanics and what your goal is in posting here. You appear to have numerous opinions and you have offered that you disagree with some of the established schools of thought on the subject. You seem to want to illustrate your opinions, and you have offered lots of complex information and historical notes, and at times, your posts appear to have morphed into a lecture series on the fundamentals of the experiment itself.

The problem is. . , your posts are long, complicated and they meander without seeming to have a clear objective. Perhaps I am alone in this, but I am finding three things:

1. You are talking about a subject I am fascinated by.
2. You have clearly done a lot of research and have invested a lot of thought in the subject.
3. I would very much enjoy and appreciate learning from your discoveries.
4. However, I am finding this very difficult to do. This may be entirely due to my own limitations in understanding, but it may also be due to limitations in your communications.

In either case, I would certainly appreciate it if you would consider making the following changes to your posting format: (I found that these helped me when I was full of ideas and was having trouble explaining myself to others. Perhaps they can be of use to you also.) Try to establish briefly and without getting side-tracked through the sharing of vast quantities of complex data, what you:

A: Understand the Double Slit Experiment to be.

B: What you understand the generally established wisdom tells us the experiment demonstrates.

C: What parts of that conventional wisdom you are at odds with or which you feel can be expanded upon.

Try to achieve each step with one or two very clear paragraphs. Sometimes it helps to pretend that you are trying to explain these principles to a class of average high school students. Those of us who need the help will appreciate it, (I know I would!) and those who are well-informed on the subject will appreciate knowing what page you are on so a lot of time needn't be spent trying to suss out what sort of animal you are.

Then, by breaking down your thoughts into pieces which can be easily communicated and built upon, using focused and relevant bits of your research, explain why you think your stated opinions are valid and/or why you think the established opinions are invalid.

Do that, and I'll try my earnest best to understand what you are talking about. If you can't, I'll have to admit defeat and move on to other pastures, which would be a shame because it really does seem like you've got some cool ideas to share.

Cheers, and Thank-You! :)


(EDIT: I changed some wordings to hopefully increase clarity.)
 
Thank you Woodsman, I will try to respond briefly as you advise on the three points. Then I will make a final post on this topic, which may clear (or muddy even further) the water.

"Try to establish briefly and without getting side-tracked through the sharing of vast quantities of complex data, what you:

"A: Understand the Double Slit Experiment to be."

An experiment where light (or electrons) is sent through two slits to a detector, either with one slit blocked or with both slits open, then with both slits open but with detectors at the slits.

"B: What you understand the generally established wisdom tells us the experiment demonstrates."

An interference pattern appears when both slits are open and no detectors are at the slits, but disappears when only one slit is open or when there are detectors at the slits.

"C: What parts of that conventional wisdom you are at odds with or which you feel can be expanded upon."

The assumption that this is a case where "nature just is that way", and it is useless to attempt to explain what is going on.

Now, a final post (in this topic), only for the reason that it follows from the last post:

The phenomenon of electron spin was first recognized when electrons (in the form of cathode rays, emitted from the cathode of a vacuum tube) passed through a strong magnetic field and impacted on a screen. The pattern of electron impacts indicated that each electron chose one of two specific paths (rather than taking a random path) through the tube, due to their interaction with the magnetic field. A magnetic current flowing in a certain direction would cause half the electrons to "bend" one way, while the other half would "bend" the opposite way. This phenomenon gave rise to the concept of electron spin, as I noted in the post above. The two sets of electrons must be spinning in opposite directions to each other (with a corresponding slight difference in the strength of their magnetic field according to the uncertainty relation, "spin up" being slightly stronger than "spin down").

As quantum mechanics developed, the Pauli principle was formulated, prohibiting two electrons from sharing the same orbital from having the same spin. So if one electron is "spin up", the other must be "spin down". The same phenomenon arises between an electron and a positron as described in Wikipedia, "EPR Paradox". The electron bends one way ("spin up") and the positron bends the opposite way ("spin down"). The particles are sent in opposite directions through a magnetic field. Their motion through the field (their motion "about the measurement axis") shows their "spin state". When they are measured, there is a 50% probability for each particle that it will "spin up", and a 50% probability that it will be "spin down".

Experiments find with 100% certainty that if particle A is "spin up" on the measurement axis, particle B is "spin down" on that same measurement axis (say, the "x" axis). However, if the measurement axis for one of the particles is rotated by 90 degrees (the "y" axis), there is only a 50% probability that the two particles will be in opposite spin states. If both measurement axes are rotated by 90 degrees (both "y" axes), there is then a 100% certainty that they will be in opposite spin states - but these spin states will not necessarily correspond to the spin states measured on the "x" axis. Since the decision as to the measurement axis is up to the observer, it seems the observer determines what the spin state of the electrons is. However, this is not so, since the particles are not known to have any particular spin state until they are measured. And, according to quantum mechanics, observations made on the "x" and "y" axes constitute "incompatible observables". In other words, according to q.m. there is no relation between an observable on the "x" axis and an observable on the "y" axis.

Nevertheless, there appears to be a mystery, which is not solved by quantum mechanics. The question is, how can a particle be "spin down" on one axis and "spin up" on the orthogonal axis? This appears to be the case, since if particle A is "spin up" on the "x" axis, we can be 100% certain that, if the measurement on particle B is done on the same axis, it will be "spin down". But on the "y" axis, there is a 50% probability that it will be "spin up". So its spin state appears to change depending on the direction of the magnetic current it passes through. Not only does quantum mechanics not answer this question - it does not ask it. The theory is silent on the subject of the spin state of a single electron, and essentially silent on the spin state of an "entangled" pair. There is no "predetermined" spin state - it is only revealed by a measurement.

But when a measurement is made on one particle, then (as if by magic) the states of both particles are known - on that axis. Although the choice of measurement axis cannot tell us anything about the particle on that axis until the measurement is made, once it is made it tells us about both particles - on that axis. So when a measurement is made, both the observer and the particle suddenly acquire magical powers reaching over long distances. How does a distant particle know which way to point on a particular axis once a nearby measurement is made on that axis, and moreover made according to the subjective judgement of the observer? The answer is that the universe is "nonlocal", which is a kind of "nonanswer", since it cannot be explained by quantum mechanics. Commentators on quantum mechanics find a kind of mystical attachment to the phenomenon of "nonlocality". But in reality it points to the question we asked earlier: how can a particle - keeping it simple, an electron - be "spin down" on one axis and "spin up" on the orthogonal axis? As I said, this question is neither asked nor answered by quantum mechanics.

When Einstein presented the "EPR Paradox" problem, his point was as follows: "... if, without disturbing a system in any way, it is possible to predict with certainty the result of the measurement of an observable of the system, then there exists an element of reality associated with the observable in question: the system 'objectively possesses' the relative property." Otherwise, he said, quantum mechanics is not a complete theory.

Defenders of quantum mechanics would refute both these points: they would say, there does not exist an element of reality associated with the observable (say, electron spin); and yet quantum mechanics is a complete theory. The universe is nonlocal! And, at its root, nature is indeterminate, even "random". And further, they would say, no classical theory can replicate the results found by experiment according to quantum mechanics. (I ought to add that it appears most practitioners of quantum mechanics do not care whether it is complete, or whether the universe is local, etc. -- they are interested in how to use what nature reveals.)

Here I must digress a little. The technique for dealing with a statistical ensemble of electrons is known as "superposition". So (simplifying greatly according to my limited understanding) in the case of electron spin states, a pair of entangled electrons exists in a superposition of spin states. And I imagine a single electron also exists in a superposition of two states, "spin up" and "spin down". Then in an entangled pair, in one system state, electron A is spin up and electron B is spin down; in the second state, electron A is spin down and electron B is spin up. The superposition of states, expressed in the wave function, is then manipulated to arrive at probabilities for experimental outcomes in measurements made on respective axes where the source of the magnetic current is rotated by small degrees, varying the measurement angle (cosine theta - don't ask me, I don't know) between the two electrons.

(Similarly, in the case of photons passed through a polarizing filter which splits a beam of light into two entangled beams with polarization orthogonal to each other. For example, the superposition is of "horizontal" and "vertical" polarization. And in that case, each polarized state is a further superposition - for example, a V photon (90 degrees) is a superposition of a 45 degree photon and a 135 degree photon.)

The predictions made by quantum mechanics, according to the variations of measurement axis between partners of an entangled pair, follow a specific pattern. On a graph this pattern will show a 100% probability, or a "perfect correlation", between spin states meaured on the same axis, a 50% probability, or "no relation", between spin states measured on orthogonal axes, and a 100% probability, or a "perfect anti-correlation", between spin states measured on axes at 180 degrees to each other. Between these three points (0 degrees, 90 degrees, 180 degrees) the pattern is that of a curve representing the probabilities associated with various degrees of measurement difference (cosine theta) between the two particles. And the wave function technique of quantum mechanics, predicting these probabilities, agrees very well with experimental outcomes. Classical mechanics, on the other hand, has no way of predicting experimental outcomes, not least because there is no classical (or quantum) understanding of electron spin! The planetary model has been abandoned, and quantum mechanics is essentially probabilistic.

Einstein's position, that (in this case) there is an element of reality associated with electron spin (and necessarily with photon polarization, since they appear to be related, and a photon is emitted by an electron), is described as a "local realist" position. Local realism requires a "hidden variable" property of an electron that is not recognized by quantum mechanics. But no such "hidden variable" (i.e., the unknown "machinery" described by Feynman) has been found. And moreover, according to the quantum theorists, no such hidden variable of a form required by classical mechanics can ever replicate the predictions of quantum mechanics! This is despite the fact that no such hidden variable has been proposed. How can quantum theorists make such a claim? It is based on work done by J.S. Bell in the 1960's and further developed since that time. The assumption is that any such "hidden variable" must be a random variable. And, when a random variable is applied to the problem of spin state relations according to mathematical probability theory, the curve of quantum mechanics is not replicated; instead, a straight line appears, intersecting the quantum mechanics curve at 90 degrees. The differences are called the "Bell inequalities".

I will give an example of the reasoning of the defenders of quantum mechanics when they apply the random variable to a measurement problem, and attempt to show where it fails. According to the Wikipedia section on "Bell's Theorem", this is an intuitive illustration of a test of the "Bell inequalities":

"If the result of three different statistical coin-flips A, B, and C have the property that:

1. A and B are the same (both heads or both tails) 99% of the time
2. B and C are the same 99% of the time

then A and C are the same at least 98% of the time. . . .

"In quantum mechanics . . . . A and B are 99% correlated, B and C are 99% correlated, and A and C are only 96% correlated.

"Imagine that two entangled particles in a spin singlet are shot out to two distant locations, and the spins of both are measured in the direction A. The spins are 100% correlated (actually, anti-correlated but for this argument that is equivalent). The same is true if both spins are measured in directions B and C. It is safe to conclude that any hidden variables which determine the A, B and C measurements in the two particles are 100% correlated and can be used interchangeably.

"If A is measured on one particle and B on the other, the correlation between them is 99%. If B is measured on one and C on the other, the correlation is 99%. This allows us to conclude that the hidden variables determining A and B are 99% correlated and B and C are 99% correlated. But if A is measured in one particle and C in the other, the results are only 96% correlated, which is a contradiction."

In summary, a coin toss (random variable) produces a result different from the q.m. result. The first thing to note is that the "hidden variable" must obey the statistics of a coin toss! Without knowing anything about the electron spin (or any electron structure), the q.m. "test" of a hidden variable assumes that it must be random. What is the justification for that assumption?

Now we must examine the statement, "It is safe to conclude that any hidden variables which determine the A, B and C measurements in the two particles are 100% correlated and can be used interchangeably." It may appear safe to conclude that, but it is not necessarily true. Here we are talking about different measurements, taken on different axes, at different times. And we must remember that neither quantum mechanics nor classical mechanics has answered the question raised earlier: How can a particle be "spin down" on one axis and "spin up" on the orthogonal axis? A more fundamental question is, how can a particle be "spin down" half the time and "spin up" half the time on the same axis? It must be due to some property of an electron sharing an atomic orbital with another electron. (As far as I am aware, a single electron can be manipulated experimentally so that it moves or "flips" between the "spin up" and "spin down" state.) Now putting the two questions together, what would be the possible property of a particle that would cause it to (1) move in one of two different directions in the same magnetic field and (2) move in a different direction from its first direction (whichever that direction was) in an orthogonal magnetic field - but only half the time? Because these are the experimental facts. We must accept that the electron produces a magnetic field, because its magnetic field interacts with the applied magnetic field, causing its path to bend. It is reasonable that the electron's intrinsic magnetic field is due to rotation. But what is the form of this rotation? Is it, like a small planet, on a single axis? No one knows, but the Bohr model does not work: such a planet, orbiting a nucleus and rotating as it orbits (like Earth), would be rotating impossibly fast.

And it appears unlikely that such a "mono-axial" rotation will produce the necessary response to a magnetic current: no matter how any such electron is initially oriented toward an applied magnetic current, all electrons will end up oriented identically with all other electrons. They will not "naturally" choose one of two paths.

Does the electron then rotate on two axes, orthogonal to each other? This is an enticing possibility (and requires us to suspend our initial disbelief in such a phenomenon - we are not necessarily dealing with a massive planet "ball"). But there is a problem with "bi-axial" rotation, which is that it can be resolved into "mono-axial" rotation. In other words, just as a photon's polarization can be "decomposed" and treated as two superimposed polarizations (separated by 90 degrees), so "mono-axial" rotation can be decomposed into two superimposed rotations - and by the same reasoning, "bi-axial" rotation may be composed into "mono-axial" rotation. In other words, bi-axial spin still appears to leave two apparently identical electrons.

This leads to a third possibility - a third rotation axis. Superposition in that case does not result in two identical electrons. And it is possible to locate three rotation axes, orthogonal to each other, on a sphere. When it faces a disturbance in the electromagnetic field around it (for that is what it will sense in the magnetic current - a pressure wave with two components orthogonal to each other), one electron may move according to the orientation of two axes (superimposed as one); and the other electron may also move according to the orientation of two axes (superimposed as one); but the two axes need not be the same axes. Only one of the two axes is necessarily the same; the other may be different for each electron. In other words, tri-axial rotation allows for two electrons rotating orthogonally to each other. And, to complicate matters further, it may never be known by which two of the three axes the electron is responding to the magnetic current.

Expanding this description (or complicating matters even further), I noted above that from the perspective (according to special relativity) of an electron moving through a magnetic field, it is at rest and a changing magnetic field is moving through it. A changing magnetic field gives rise to a changing electric field. So, from the perspective of the electron, it faces an electromagnetic field ("light field") with two orthogonal components. One component would then be the electric component, and the other the magnetic component. If we give the electron the property of two "magnetically responding" axes and one "electrically responding" axis, then it has two choices how to respond to the field it faces. And (producing an eternally hidden variable) which of the axes are magnetic, and which electric, may never be known (or knowable). And the electron may not "know" or care which of three axes are electric or magnetic. It simply responds to what is, from its position, a pressure wave with two orthogonal components.

This appears to be an extremely complicated imaginary model, and tri-axial rotation is very difficult to visualize or even to plot; but it may become simpler as it develops. For the present time, the point is that it is not necessarily safe to assume that any hidden variables (in this case, the properties of tri-axial rotation), which determine the A, B and C measurements in the two particles dealt with in the "Bell's test" above, are "100% correlated and can be used interchangeably". The absence of a model does not require that such an absent model be dealt with as if its "hidden variable" property is random. There may be an element of reality that is not dreamt of by quantum theorists.

The problem with the "planetary" model of an electron has not been addressed here. That model assumes that the electron is a small solid body. In future posts (perhaps in a new topic) I will attempt to describe what form an electron (and a proton, and a neutron) may actually take, in a more extensive model of a powered universe whose creation moment lies forever in the future.
 
David George said:
Thank you Woodsman, I will try to respond briefly as you advise on the three points. Then I will make a final post on this topic, which may clear (or muddy even further) the water.

"Try to establish briefly and without getting side-tracked through the sharing of vast quantities of complex data, what you:

"A: Understand the Double Slit Experiment to be."

An experiment where light (or electrons) is sent through two slits to a detector, either with one slit blocked or with both slits open, then with both slits open but with detectors at the slits.

"B: What you understand the generally established wisdom tells us the experiment demonstrates."

An interference pattern appears when both slits are open and no detectors are at the slits, but disappears when only one slit is open or when there are detectors at the slits.
Click to expand...

I think there is a very important part being left out in the above point 'B'.

As I understand it, the detector itself is not the issue, but rather whether a consciousness chooses to look at the information collected by the detector. I am referring to the "Delayed Choice Experiment". Yet, from reading your extensive posting on the subject of QT, I am having a hard time determining if you are aware of this experiment or not. It seems altogether unlikely that you should not be aware of it, as your research clearly goes quite deep and the delayed choice experiment is such an integral part of the whole reason QT fascinates the world, but it seems to be quite conspicuous in its absence from all your thinking. I am curious about this, but my questions don't seem to engage you in a manner which would reveal what is going on here.

I cannot tell if I am just missing something, and that you have taken this aspect of QT into account, or if you are deliberately avoiding it for some reason. In either case, I am curious to get to the bottom of it.

(For anybody interested, the delayed choice experiment is explained in part 6 of this series. . . http://www.youtube.com/watch?v=W5bZ3JWCh_0&feature=related though, I would recommend watching through from part 4 for a more robust explanation from this presenter.)


"C: What parts of that conventional wisdom you are at odds with or which you feel can be expanded upon."

The assumption that this is a case where "nature just is that way", and it is useless to attempt to explain what is going on.
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I think there may be a larger issue at hand here; that conscious awareness is an integral part of QT, and indeed, the universe we experience. It seems to me that you might be limiting yourself by trying to find an explanation which ignores consciousness, and forces the experiment to be entirely "on the lab bench" as it were, and not involve the viewer. But again, I might be mis-reading your postings, so please forgive me if I am not following you correctly.

As for your continuing essay on the subject of QT. . .

It is important to remember that in such a public forum as this, one objective is to communicate with each other rather than talk to ourselves. It seems that you do indeed have much to share, and I am finding excerpts of your essays very informative, but a greater degree of awareness of the other minds here, I think, would make your knowledge far more accessible and thus useful.

There's nothing wrong with posting long thoughts and research. There are lots of great essays to be found on this site. And I know how exciting it is to have discovered something and to want to get it recorded in a place where it can be seen. But all it takes is a little conscious awareness of one's community, and the process of essay writing can give a great deal rather than sit on its own and be ignored because it is too self-referential and confusing to follow for somebody who hasn't gone through your own personal and specific exploration process.

I am not trying to dampen your enthusiasm. I just think with a little adjustment, you could share that enthusiasm much more effectively. :)
 
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