Ken. You were the only one who can see through the weak measurement haze in the latest trajectory paper. So let me ask you something about Neumaier Thermal Interpretation. What is it all about. Simple. He took the field in QFT as real ontology. And he believes particles don't really exist. And with it he can explain the double slit experiment using purely the language of QFT and fields. And so far it has survived the scrutiny of many physicists. I'd like to you see if you can detect some subtle problem or conflict that can falsify or refute it. In the thread
https://www.physicsforums.com/showthread.php?t=490492&page=6
I have asked him many questions. The following is collection of my questions to him and his answers in the form of a FAQ that focus particularly on the double slit experiment and how it can work with pure field and no particles.
Let us go to the beginning (this is related to this thread because it is seeing Copenhagen in the eyes of QFT):
Varon: Let us focus on the double slit experiment as Feymann said it's the main mystery. If it's solved, the entire quantum mystery solved.
I can't understand what you meant by "passing the screen turns the electron into a delocalized object". You said the electron is a particle before it passes the screen. Since it is already a particle, how can it turned into a delocalized particle at the screen?
Neumaier: The electron is always a quantum field. The quantum field can be regarded to describe a particle if and only if the field has a nonzero expectation only in a region small compared to the whole system considered. Thus we may say that the field is a particle as long as this condition is satisfied. Because of the dispersion of the field caused by the slits, this condition stops to be satisfied almost immediately after the field (with support large enough to cover both slits) passed the double slit. Thus it is no longer justified to talk about a particle.
The situation is similar as with a sphere of glass. If you throw it, you may regard it as a particle. But if it hits an obstacle and fragmentizes, it is no longer localized enogh to deserve the name of a particle.
Varon: Let's go from the beginner in the emission. So the electron is emitted. You believed it travels as particle? But where does it pass, the left or right slit? And what caused the interferences in the screen. Standard explanation says it interferes with itself because it is a wave after it is emitted.. and only become a particle at the detection screen. Pls. elaborate what happened to your electron after emission.. before it reaches the slits.. after it exits the slits and after detection in the screen.
Neumaier: The field passes the doulbe slit in a fashion similar as a water wave would do, except with quantum corrections."
Varon: Interesting. But how come the detector detects one electron and not the fragmentized parts (after passing thru the slits)?
Neumaier: The quantum field does not fragmentize like a broken glass sphere. It just expands into a superposition of two spherical waves. The outer electrons of the detector respond to the incident quantum field by an approximate Poisson process with rate proportional to the incident density. This accounts correctly for the simple statistics obtained for an ordinary electron beam. See post #4 of this thread, and the longer discussion of the case of photons in
https://www.physicsforums.com/showthr...39#post3187039
and in the thread
https://www.physicsforums.com/showthread.php?t=480072
Varon: What "outer electrons"?
Neumaier: The detector wouldn't be able to respond if it hadn't loosely bound electrons that could be freed when responding to the impinging quantum field formed by your single electron. The response of the detector to the field is a multibody problem, and solving it in the semiclassical approximation gives the desired effect."
Varon: Are you saying your interpretation only work for an ensemble of electrons?
Neumaier: No. I am considering your situation: precisely one elctron moving theough the double slit. But once this electron reaches the detector is meets a host of electrons in the detector. The latter are responsible for the measurable response (since ultimately a current is measured, not the single electron)."
Varon: I want only one electron at a time. What do you mean "The detector wouldn't be able to respond if it hadn't loosely bound electrons that could be freed when responding to the impinging quantum field formed by your single electron." Please rephase it in clearer words. As I understand it. The emitter emits one electron. After it pass thru the slits, it became smeared. Now how does the smeared field converge back into a single electron detected at the screen?
Neumaier: It doesn't. It remains smeared. But one of the electrons in the detector fires and (after magnification) gives rise to a measurable current.. This will happen at exactly one place. Thus it _seems_ that the electron has arrived there, while in fact it has arrived everywhere within its extent.
If a water wave reaches a dam with a hole in it, the water will come out solely through this hole although the wave reached the dam everywhere. A detector is (in a vague way) similar to such a dam with a large number of holes, of which only one per electron can respond because of conservation of energy
Varon: But your theory doesn't explain one electron at a day double slit experiment or in instance where only one buckyball is sent out in a year. It still interferes with itself. Because after 20 years. The 20 buckyball would still form interference patterns added up one year at a time.
Hence your model may not tally with reality.
Neumaier: Each electron capable of responding has a response rate proportional to the intensity of the incident field. This is enough to correctly account for the interference pattern. No memory is necessary to achieve that.
If you send one buckyball a year in a coherent fashion (I doubt that one can prepare this, but suppose one could) then at positions of destructive interference the response rate would be zero while at positions of constructive interference, the resonse rate would be zero except once a year where it would be maximal. Thus it is most likely that the yearly recorded event comes from an electron sitting at a point of constructive interference. After 20 years, one would see the pattern emerging.
Varon: Something that puzzles me greatly. First of all. How many electrons do typical detectors have? Let's say there are a thousand.
Neumaier: Its more like 10^20.
Varon: How can the uniform quantum wave after the slits trigger just one of the electrons in the detectors and not others. How can the principle of energy conservation cause it? Pls. elaborate. Thanks.
Neumaier: Each electron feels just the piece of the quantum wave reaching it. The electron responds by random ionization, with a rate proportional to the intensity. It takes the energy from its surrounding.
The detector as a whole receives the energy everywhere, also with a rate proportional to the intensity. This energy is redistributed (fast, but with a speed slower than that of light) through the whole detector, roughly according to hydrodynamic laws.
Thus there is no violation of conservation of energy.
Varon: But in one-electron (or photon or buckyball) at a time double slit experiment, how does the wave after the slits select only one electron among the 10^20 in the detector?
Neumaier: The wave selects nothing. It arrives at the various places of detector with different intensities, and these intensities stimulate all the electrons. But because of conservation of energy, only one can fire since the first one that fires uses up all the energy available for ionization (resp. jumping to the conduction band), and none is left for the others.
Varon: In other words. There are really no particles?
Neumaier: Particles are semiclassical approximations for field phenomena concentrated along narrow beams. It is not very different from water - which is in particle form if a tab is dripping but not if the water flows in a river.
The particle concept loses its meaning when applied outside its domain of applicability. Trying to keep the concept then leads to all sorts of weird things.
Varon: So in the photoelectric experiment, what makes each electron eject from the material?
Neumaier: Its the same principle as in the double slit experiment. This is explained in the entry ''The photoelectric effect'' in Chapter A4 of my theoretical physics FAQ at http://arnold-neumaier.at/ph...photodetection ,
and discussed in the thread
https://www.physicsforums.com/showthread.php?t=480072
Varon: Come on PF members. If Neumaier was right. Others would have figured this out already for more than a century.
Neumaier: How could this have been figured out before 1911, at a time where not even the Schroedinger equation was discovered? The reason why it hasn't been discovered is that those working on the foundations rarely also work on quantum fields, and those who work on the latter usually have more pressing things to do than to indulge in foundational issues. So the interface between foundations and quantum fields has been very little explored.
Varon: I'll start with Camboy criticism (A. Neumaier, pls. comment on it):
"I'm sorry - this sounds like nonsense to me. He says only 1 electron in the detector responds because of conservation of energy. What happens when the screen is the inner surface of a hollow sphere a light-year across, and the emitter is a point source dead in the middle emitting a spherical moving quantum field? How is the energy transported across space via the quantum field? Across the whole wave front? In which case, what kind of process involving conservation of energy takes place around the whole surface of the sphere instantaneously when the wave hits the screen? How does this work? if you wish to provide an 'interpretation' one must do more than simply state something happens."
Well?
Neumaier: A quantum field transports the energy in the same way as a classical field, namely by evolution according to the field equations. The energy of a radially expanding field is distributed uniformly.
So an extremely tiny amount of energy arrives at any place of the hollow sphere, integrating over the sphere to the energy of one electron. Thus energy is conserved. The probability of response anywhere is extremely tiny, too, so that uncertainties in the sphere by far dominate the effect, and nothing can be concluded.
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Ken. Can you see any flaw or experimental facts that can falsify it or put it into question? Thanks.