Wulf Rehder: "When Alice makes a measurement on her qubit, say ↑↓, then for Bob, making a subsequent measurement, the outcome ↓↑ is determined by what Alice had measured"

Alice measures a single particle, she cannot get ↑↓. A single particle responds by either ↑, or ↓. If Alice and Bob measure along the same direction in space, then, if she got ↑ Bob gets ↓, and vice-versa.

Standard quantum physics predicts that, when a superposed quantum system S is measured by an apparatus A that can distinguish between the superposed states, S entangles with A in a state having the form (for 2-state "qubit" systems) (|S1>|A1>+|S2>|A2>)/√2. Such entangled states have non-local properties, as verified by many experiments. As shown in my paper "Review and suggested resolution of the problem of Schrodinger's cat," this state is not paradoxical. The entanglement is the collapse, i.e. collapse occurs instantaneously and nonlocally upon entanglement. Nature randomly "chooses" one of the two correlations, either S1/A1 or S2/A2, and initiates a macroscopic process that records the "chosen" outcome irreversibly.

Cheers - Art Hobson  Emeritus Professor of Physics, U Arkansas.   See my book Tales of the Quantum,  Oxford UP. Art’s homepage https://sites.uark.edu/ahobson/

Email [email protected]

Dear Art Hobson and Wulf Rehder

Art Hobson: "Nature randomly "chooses" one of the two correlations, either S1/A1 or S2/A2, and initiates a macroscopic process that records the "chosen" outcome irreversibly."

This statement is as good as the postulate of the collapse. It contains no explanation. It's difficult to insert a whole rationale into a short comment but, when having to do with entanglements and also with the relativity, this "random choice" of the Nature, poses very, very, difficult question.

Wulf Rehder: "The GRW version introduces an ad hoc (as many non-convinced critics call it) random collapse mechanism . . ."

Excellent remark! You said things straightly from my heart. I fully subscribe. Yes, GRW introduce an ad hoc mechanism just for obtaining the effect of the collapse. I don't feel that the mechanism is supported by some natural justification. Please be so kind and tell me where did you see this criticism. Can you give me references? I would be happy to contact people who think as you and I think.

With best regards,

Sofia

Dear Wulf,

You are very nice. Thanks a lot about the references. There are also a few references in quant-ph, but they don't address the problem that we both saw. I will look in the references you indicated. Please, in each ones of them did you see this criticism that GRW introduced an ad hoc mechanism? This is a very profound criticism - I wonder why Bell himself didn't do it. Unfortunately, the GRW theory appeared after Einstein's death. I suppose that Einstein would have done this criticism.

Now, in my modest opinion, the only good thing in the GRW theory, is the conclusion that the collapse may occur only in the detectors, i.e. when a macroscopic process is triggered. This is also what our current experience seems to show. (To the difference, Bohm's interpretation postulate a substructure of particles and trajectories for the QM. By the way, are you acquainted with Ghose's experiment, and the SSW experiment? Both show that the Bohmian mechanics is contradicted by experiment.)

As I said, I have many objections on the GRW theory. I just finished a section in my article, criticizing a paper that Ghirardi recommended me:

D. J. Bedingham, D. Dürr, G-C. Ghirardi, S. Goldstein, R. Tumulka and N. Zanghì, “Matter Density and Relativistic Models of Wave Function Collapse”, Journal of Statistical Physics 154, page 623 (2014), arXiv:quant-ph/1111.1425v4.

You can see who are the people signed on this paper.

I tell you frankly, I saw black before my eyes when I read it. It predicts that the mass of particles, for example of an electron, is spread over the universe in portions proportional with the absolute square of the wave-function. It's unbelievable how such wise people can write such a thing; did somebody see an electron split into crumbs, and spread over the universe?

Maybe you can afford to take a look.

With thanks and kind regards,

Sofia

Dear Wulf,

a lot of thanks. I am going to introduce these objections in my article. First of all, please be so kind and give me the exact reference of the book Philosophie der Quantenphysik, i.e. authors, editors, year, I want to insert it in the reference list.

There is one more issue. I seem to remember that I saw somewhere that those constants were though estimated in base of physical data and the result wasn't good - but it's years since then, and I don't remember where I saw this.

To my understanding you are also a phylosopher. I would like to share with you a very hard issue about the collapse. Put in simple words, we know that in the fermion singlet, the result obtained by Alice depends not only on the settings of Alice's apparatus, but also on those of Bob's apparatus and on the result obtained by Bob. The situation is symmetrical, the result obtained by Bob depends also on the type of test and result got by Alice. There would be nothing to warry as long as the two people do the measurements simultaneously. But if the two labs are in relative movement, it appears that the result obtained by one experimenter, depends on the type of test chosen LATER by the other experimenter.

Did you ever encounter this problem? I told Ghirardi, and to my astonishment, he told me that he is not aware of it. It surprized me a lot, because Ghirardi's co-worker, Roderich Tumulka - a very knowleadgeable scientist, wrote about that in some article. I had a talk with Tumulka years ago. It's a problem that nobody solved.

You see, in my understanding, our universe is not built so that outcomes of present events depend on future. If the present would depend on future, I believe that present and future would loose meaning. If you encountered this problem I think it would be interesting to discuss it.

Again with thanks and kind regards,

Sofia

Dear Wulf,

You are very, very kind. A lot of thanks for the help,

Sofia

Dear Sofia, I recently read your question, which always follow with interest. But I completely can not understand what the problem is?

You write:

"If the quantum superposition is broken at this step, how does it happen that the quantum correlations are not broken? For instance in the spin singlet ( |↑>|↓> - |↓>|↑>) one gets in a Stern-Gerlach measurement with the two magnetic fields identically oriented, either |↑>|↓>, or |↓>|↑>. The quantum superposition is broken. But the quantum correlation is preserved. On never obtains, if the magnetic fields have the same orientation, |↑>|↑>, or |↓>|↓>."

In my view when Alice makes a measurement on (|↑>|↓> - |↓>|↑>) she collapses it to |↑>|↓> or |↓>|↑>). This act precludes also the corelation conection with Bob. (of course only the results stay correlated, but the pair they used is no more correlated so there is no more corelation).

Or did you mean something different?

Dear Sofia,

Actually, in establishing his "uncertainty" principle, Heisenberg disregarded the fact that the localized electron is an electrically "charged" particle.

When this is taken into consideration, even with the theoretical localization related to the just as theoretical collapse of the wave function, it can be observed that both the "position" and the "energy" of the electron can both be known simultaneously, because said position in any orbital can only be calculated axially with respect to the positively charged nucleus, which sets its momentary distance from the positive charge of the nucleus, which in turn immediately reveals its Coulomb force induced momentum energy, which then allows calculating either the velocity that the electron would have if free moving, or alternately the pressure that this energy vectorially applies towards the nucleus even if its motion is inhibited.

So it is not completely true that position and velocity cannot be determined simmultaneously even in QM.

Best Regards

André

The question “At which stage of the measurement the collapse occurs?” has the unambiguous answer in quantum mechanics: When the observer finds out the measurement result. But most physicists were doing not want to admit this obvious answer since it indicates the absurdity of quantum mechanics. Therefore numerous interpretations of quantum mechanics, including the Bohmian mechanics and Ghirardi-Rimini-Weber (GRW) theory were proposed. Although no scientific theory must have interpretation. We must understand quantum mechanics unambiguously since it as well as any theory about the outer world is created by our (human) mind, see the article “What is wrong in quantum mechanics?” at ResearchQate https://www.researchgate.net/profile/Alexey_Nikulov/contributions . It is wrong to think that By the Bohmian mechanics there is no collapse. The Bohmian mechanics cannot describe, for example the double-slit interference experiment, without the collapse of Bohm’s quantum potential when the trajectories of particles are observed with the help of the Wilson chamber or the bubble chamber, see section 4.6. Single-particle interference and multiverse of the article “Impartial History and Philosophy of Quantum Mechanics ” by Alexey Nikulov at ResearchQate.

Einstein wrote to Schrodinger as far back as 1928: ”The soothing philosophy-or religion?-of HeisenbergBohr is so cleverly concocted that it offers the believers a soft resting pillow from which they are not easily chased away”. Impartial history witnesses that Einstein’s words turned out prophetic. Quantum mechanics is a religion rather than merely a scientific theory for most physicists. Any religion has different interpretations and is the object of the controversy between the believers of different confessions. Quantum mechanics has many interpretations and is the object of the controversy of many years. I must say that this uncritical attitude to the scientific theory is evidence of the crisis of physics, see the articles “Absurdity of quantum mechanics and the crisis of physics ” and “ Challenging local realism and the crisis of physics ” by Alexey Nikulov at ResearchQate.

Dear Alexey,

The GRW theory proposes, essentially, that the localization occurs when the quantum system meets a macroscopic object, and becomes part of it.

"no scientific theory must have interpretation. We must understand quantum mechanics unambiguously since it as well as any theory about the outer world is created by our (human) mind, . . . "

But the Nature is not created by our mind. A theory created by our mind, but disconfirmed by experiment, falls.

"The Bohmian mechanics cannot describe, for example the double-slit interference experiment, without the collapse of Bohm’s quantum potential"

What you need quantum potential, use the Bohmian velocity and calculate the trajectories. Why do you want to work with 2nd order differential equations when you can work with 1st order? Because so worked Hiley?

"Quantum mechanics has many interpretations and is the object of the controversy of many years."

Did you notice that each interpretation of QM, adds something to the QM formalism? Unfortunately, QM behaves as a living body with tough immunity system. It rejects whatever added thing. The experiment does not exactly confirm GRW, Bohm's mechanics quarrels with the relativity, and - I am examining this now - seems to have troubles with the electromagnetic field.

We have to understand QM without falsifying its formalism.

"Crisis"? "Absurdity of quantum mechanics"?

Crisis is when the theory is disconfirmed by experiment. We have no experiment that disproves QM. The Nature agrees with QM. The Nature is not absurd, WE are not wise enough to understand. And some people raise our lack of wisdom to the rank of method of work: "shut up and calculate!". We have to ask and invent experiments, not to shut up. We are endowed with minds.

Dear Sofia,

I draw attention on the crisis of physics which was predicted by Jose Ortega y Gasset (the great philosopher according to Schrodinger’s opinion). Ortega y Gasset clearly indicated the cause of this crisis. He was writing in his famous book ”The Revolt of the Masses” published 1930: ”The most immediate result of this unbalanced specialisation has been that today, when there are more scientists than ever, there are much less ’cultured’ men than, for example, about 1750.··· Newton was able to found his system of physics without knowing much philosophy, but Einstein needed to saturate himself with Kant and Mach before he could reach his own keen synthesis. Kant and Mach - the names are mere symbols of the enormous mass of philosophic and psychological thought which has influenced Einstein – have served to liberate the mind of the latter and leave the way open for his innovation. But Einstein is not sufficient. Physics is entering on the gravest crisis of its history, and can only be saved by a new Encyclopaedia more systematic than the first”. The ’cultured’ men about 1750, including Kant, were solicitous about the consistency of the reason with itself whereas most modern scientists are solicitous only about agreement between theory and experiment. To avoid the contradiction of reason with itself Kant concluded that we can know our notions about the Nature but not the Nature as ’thing-in-itself’. Thus, according to Kant our mind create the Nature which we know (since we create our notions), although we cannot created the Nature as ’thing-in-itself’. The ’thing-in-itself’ is the cause of the phenomena which we observe. Our notions about the Nature should satisfy the phenomena which we observe and should not be disconfirmed by experiment. But our notions are formed based not only on the phenomena but also our a priori knowledge. For example we have a priori knowledge about three-dimensional isotropic space. I demonstrate in my articles “Absurdity of quantum mechanics and the crisis of physics ” and “ Challenging local realism and the crisis of physics” that we cannot think because of this a priori knowledge that quantum states of particles of the EPR pair exist before an observation. The mind of the observer creates the states of the both particles at observation according to quantum mechanics. The notion of quantum mechanics about the omnipotence of the mind of the observer contradicts to our reason. Two observers, Alice and Bob, as human beings have free will to observe different dynamical variables. For example, they can choose different orientations of their Stern-Gerlach analyzers and create different spin states of the same particles. This logical absurdity is deduced from quantum mechanics at two assumptions: 1) more than one observer exist and 2) the observers have free will. In order to annihilate this absurdity and to save the belief in quantum mechanics Gerard ’t Hooft cast doubt on free will of the mathematician Conway (and thus all human beings). I demonstrate in my articles that the Nobel prize winner said nonsense in his talk ”The Free-Will Postulate in Quantum Mechanics” presented at the General meeting of the Russian Academy of Sciences. Everyone can understand what Gerard 't Hooft said is absurd. This absurdity most clearly demonstrates the validity of the warning of the crisis of physics made by Ortega y Gasset. Our free will is something mysterious, unspecified for Gerard 't Hooft. The ’cultured’ men about 1750 also perceived our free will as something mysterious, something that is impossible to understand. But they did not deny the existence of our free will on that basis. They understood the existence of the contradiction between our free will and determinism in Nature. In order to eliminate this contradiction Kant decided that the determinism exists in our notion on Nature but not in Nature as 'thing-in-itself’. Kant’s 'thing-in-itself', as well as our free will, is something mysterious, unidentified. But according to the foundation of the natural science (the Cartesian polarity between ’res cogitans’ and ’res extensa’) created by Descartes, Kant and other ’cultured’ men, phenomena of Nature are determined by 'thing-in-itself' but not our free will.

You are sure “We have no experiment that disproves QM”. Even such critic of QM as John Bell was agreeing that ordinary quantum mechanics is just fine ‘for all practical purposes'. I draw the reader’s attention in the paper “Could ordinary quantum mechanics be just fine for all practical purposes?» (published in the journal Quantum Studies: Mathematics and Foundations. 3, 41-55 (2016) and available at ResearchGate) to experimental results and contradictions of quantum description testifying against this belief of almost all physicists. Quantum mechanics cannot describe even the Zeeman effect without a mathematical mistake. Rather, believers believe that there are no experiments to refute quantum mechanics than that these experiments are indeed absent.

Dear Alexey,

When people begin to place in my threads texts not related to the question, that is harm for my question. My question is not about crises, about philosophy, about history of physics, about free will, etc., etc. So, if you are interested to participate, please stay with the question. My question is VERY difficult - see below - and I need my thread focused.

So, returning to the question, it's not obvious to me that the "collapse" of the wave-function, i.e. the selection of one result out of a set of possible results, is done as you say, when the observer finds it. In the 21th century the result may be at all passed to a completely automatic process. But not this is the issue, whether the observer is human or a machine. The question is whether the picking of one particular result may occur before the quantum system meets a macroscopic body or apparatus. THIS is the question.

I mean, could it be that in a given trial of the experiment, one component of the wave-function is present and the others are false (empty waves), or, not present (as says the many worlds theory), or, removed in some way? Is there some evidence, some experiment, which gives us a reason to think that the result of the measurement is decided before the encounter with the macroscopic detector? THIS is the question.

I will tell you MY reason: assume that the wave-function is a superposition of the form a|x> + b|y> + c|z> + . . . , where |x>, |y>, |z>, etc. are wave-packets traveling, each, to another station. The collapse says that in a trial in which the result is, say, y, the wave-packets |x>, |z>, . . . , have to disappear. But nobody can say when do they disappear. Imagine that each station is in movement with respect to the others. So, each station has its own time-axis, s.t. it may be that no agreement can be possible about when disappear the other wave-packets.

Dear Sofia,

I have written about crises, about philosophy, about history of physics, about free will since these issues are directly relevant to your question. It is impossible to answer correctly on your question without an understanding of the Kant philosophy. Your question is VERY difficult without understanding of the Kant philosophy and the answer on this question will be simple and unambiguous if you, as Einstein, will saturate himself with the Kant philosophy. You write: “In the 21th century the result may be at all passed to a completely automatic process. But not this is the issue, whether the observer is human or a machine”. This opinion is typical for most modern scientists who sure that we can know the Nature as ’thing-in-itself’ and who don't make the distinction between ’res cogitans’ (thinking entities) and ’res extensa’ (extended entities). I draw your attention on the problem of free will in quantum mechanics since this problem is actual only if the observer is human since no machine can have free will. If the observer is a machine and the act of the observation in quantum mechanics is a real interaction of quantum system with a macroscopic body or apparatus, as you think, then the Nobel prize winner Gerard 't Hooft tries to solve a nonexistent problem of free will and numerous publications refuting realism (for example The BIG Bell Test Collaboration, Challenging local realism with human choices. Nature 557, 212216 (2018)) make no sense. I tried to draw the attention in my letter to an Associate Editor of Nature (see attached file) that the believers in quantum mechanics belong to different confessions: the believers of one confession refute realism whereas the believers of other confession don’t want to hear that quantum mechanics contradict realism. Your questions and remarks witness that you belong to the latter confession as well as most physicists of Soviet school. You are sure that quantum mechanics describes real processes. Therefore it's not obvious for you that the "collapse" of the wave-function occurs under influence of the mind of the observer. It was not obvious for most physicists but was obvious for Einstein, Schrodinger, Bell and other critics of quantum mechanics. It is obvious according to the Born interpretation of the wave-function. In order to understand the collapse of the wave-function occurs under influence of the mind of the observer it is needed to put the question: ”Why the realistic understanding of the wave function proposed by Schrodinger was rejected and Born’s interpretation was accepted?” The answer is obvious: ”We cannot think that a real density can change due to an observation whereas we know from our everyday experience that a probability of observation changes at first

observation”. For example, your friend takes away a one dice without looking from a box with one white dice and one black dice. You know before observation of the remaining dice that your friend will see the white dice with the probability 0.5. The probability will become 1 when you will see the black dice and 0 when you will see the white dice, regardless of distance between you and your friend. Thus, the wave function describes first of all the state of the mind of the observer, according to Born’s interpretation. We can think that only observer’s knowledge changes because of observation in the case of the dices. But the wave-particle duality observed for example in the doubleslit interference experiment cannot be described if only observer’s knowledge changes. Therefore Dirac postulated in 1930 ”that a measurement always causes the system to jump into an eigenstate of the dynamical variable that is being measured”. The wave function describes the states of both the mind of the observer and quantum system according to the Dirac jump or the collapse of the wave-function. This renouncement of the distinction between reality and our knowledge of reality creates the illusion that quantum mechanics can describe the wave-particle duality and other paradoxical quantum phenomena. But it is very strange that only few scientists understood that this renouncement of realism leads to the logical absurdity.

Dear Alexey,

You say interesting things, but my question is not there where you transport the problem to.

I do belong to the materialist school, indeed. However, you inferred about me some things that I deny. You say

(Alexey) ". . . the believers of one confession refute realism whereas the believers of other confession don’t want to hear that quantum mechanics contradict realism. Your questions and remarks witness that you belong to the latter confession as well as most physicists of Soviet school."

First of all, let's make clear what means realism in QM. It means that a result of a measurement is predetermined. Example: if a quantum particle is detected at a certain position IT WAS THERE before the measurement. We have NO IDEA if it is correct, this issue is under examination, theoretically and experimentally.

(Alexey) "If the observer is a machine and the act of the observation in quantum mechanics is a real interaction of quantum system with a macroscopic body or apparatus, as you think, then the Nobel prize winner Gerard 't Hooft tries to solve a nonexistent problem of free will and numerous publications refuting realism (for example The BIG Bell Test Collaboration, Challenging local realism with human choices. Nature 557, 212216 (2018)) make no sense."

This is not the issue at all. I am not concerned at all with "who is the observer?" The experience seems to prove that the so-called "collapse of the wave-function" occurs when the quantum particle becomes part of a macroscopic body. The first macroscopic body the quantum particle encounters, is the macroscopic detector. Well, I am not convinced that the collapse of the wave-function occurs at the encounter with the macroscopic body. I have strong arguments that it occurs before.

You see, what has my question to do with the free will?

(Alexey) "Therefore it's not obvious for you that the "collapse" of the wave-function occurs under influence of the mind of the observer. It was not obvious for most physicists but was obvious for Einstein, Schrodinger, Bell and other critics of quantum mechanics. . . . . . . . . . . "

If the collapse occurs under the influence of our mind, why our mind cannot dictate the result of the measurement? Why does the result remain stochastic?

(Alexey) "The wave function describes the states of both the mind of the observer and quantum system according to the Dirac jump or the collapse of the wave-function."

No, Alexey, the mind has no wave-function. A macroscopic body has no wave-function, read the classical limit of the path integral - Feynman. It's physics here, it goes with rigorous proofs, not with wording.

BOTTOM LINE: my question is an invitation for rigorous mathematical proofs and for experiments. Not for speculations in wording (please don't feel offended in any way whatsoever.)

With kind regards,

Sofia

My answer, as soon as the measurement is made.

No explanation? Yet there is a reason, the union of subjective(or predictive) and objective,

or empirical probability.

The best, juan

Juan !!!

It's a long, long time that I saw no word from you. Why? Is everything O.K. with you?

Now, "subjective", "objective", don't have much meaning to me. However, please be kind, see my question

https://www.researchgate.net/post/A_5_events_relativistic_problem_Can_somebody_solve

You say the collapse occurs "as soon as the measurement is made." It may be that there is no such time. We can have 5 events for which no frame of coordinates exits so as the 5 events be simultaneous. Imagine for instance that the wave-function is

|ψ>=a|x> + b|y> + c|z> + d|u> + e|w>,

where |a|2 + |b|2 + |c|2 + |d|2 + |e|2 =1, and |x>, |y>, . . . , |w>, being wave-packets travelling to the detectors X, Y, Z, U, and W, distant from one another, and in relative movement with respect to one nother. The movement of the detectors may be such that in no frame of coordinates the impingement of the wave-packets on the detectors is simultaneous.

Glad to have seen you on my screen,

Sofia

Dear Sofia,

“What is realism?” is main question for the understanding of quantum mechanics. Einstein answered enough clear on this question when he was saying “I like to think that the moon is there even if I don't look at it” and was writing that realism is ”the presupposition of every kind of physical thinking”. But most physicists did not understand what is realism because they, in contrast to Einstein, did not saturate himself with the Kant philosophy. They, in contrast to Einstein, don't make a distinction between the Nature as our notions and the Nature as ’thing-in-itself’. Most modern scientists have illusion that they can know the Nature as ’thing-in-itself’. We have NO IDEA about position of a particle before the measurement if we consider the particle as ’thing-in-itself’, because we can know nothing about ’thing-in-itself’. On the other hand we must understand unambiguously our notions about the Nature since we create these notions. I draw reader's attention in my articles “Absurdity of quantum mechanics and the crisis of physics” and “Challenging local realism and the crisis of physics” that local realism is refuted by naive realists. Einstein was realist but he was not naive. Einstein defended realism in our notions. Quantum mechanics contradicts realism in our notions because of the collapse of the wave-function. Therefore it is impossible to answer correctly on your question without an understanding what is realism in our notions and remaining naive realist who is sure that we can know ’thing-in-itself’. I will try to explain you what is realism in our notions. We can think that the Moon exists before our observation. But we cannot think that states of particles of the EPR pair exist before observation because of our a priori knowledge about three-dimensional isotropic space. A rigorous mathematical proof of this impossibility to think realistically is in my articles. The impossibility to think realistically means the renouncement realism in our notions.

I'm very surprised by your statement “The experience seems to prove that the so-called "collapse of the wave-function" occurs when the quantum particle becomes part of a macroscopic body”. What experience? Numerous experimental evidences of violation of Bell's inequalities prove the opposite. Do you ignore these experimental evidences?

Your question is connected with problem of the free will since this problem appeared in quantum mechanics because of the collapse of the wave-function.

I should say that Feynman did not understand quantum mechanics.

I don't feel offended in any way whatsoever. I have written in my article: “The time about 1750 of Ortega y Gasset represents a relatively short period of critical thinking when David Hume had awoke Immanuel Kant from dogmatic slumber. The dogmatic belief in the omnipotence of God, in the natural philosophy of Aristotle and in philosophical speculations predominated before this period. And now most scientists believe in the omnipotence of experimental science and disdain philosophical speculations”.

With best wishes,

Alexey

Dear Alexey,

What people mean by realism is that the result of the measurement of a quantum particle doesn't appear, at random, during the measurement, but is caused by some reality, existing prior to the measurement. For instance the reality may be hidden variables, or some events that happened before the experiment, or some facctors in the environment that took some values prior to the experiment, etc. Realism means that a certain result of the measurement is determined by a real factor that appears before the experiment, not as a value picked purely at random, from the set of eigenvalues of the tested operator.

More than this I'll tell you, with God's help, tomorrow. Now it's very late in my country.

Best regards,

Sofia

1) You skip mani-world interpretation, which does not refer "collapse" at all.

2) The stage at which collapse supposed does not matter. See the link below

Article On uniqueness of quantum measurement theory

Dear Sofia,

I know how most people understand realism. The false understanding by the most people of the meaning of realism is one of the evidence of the crisis of physics which Jose Ortega y Gasset warned. But you have written rather about determinism than realism. German mathematician and philosopher Greta Hermann tried to convince Werner Heisenberg and Carl von Weizsacker that quantum mechanics, abandoning the determinism in nature, cannot be considered a scientific theory: "In Kant's philosophy, the causal law is not an empirical assertion which can be proved or disproved by experience, but the very basis of all experience-it is part of the categories of the understanding Kant calls 'a priori.' … The causal law is a mental tool with which we try to incorporate the raw material of our sense impressions into our experience, and only inasmuch as we manage to do so do we grasp the objects of natural science. That being the case, how can quantum mechanics possibly try to relax the causal law and yet hope to remain a branch of science?" see Heisenberg's memory. Most physicists, following Heisenberg and von Weizsecker, don’t understand the validity of Greta Hermann's objections against quantum mechanics. Heisenberg attempted to refute a priori nature of the principle of causality with the help of empirical data. But such attempt does not make a sense, since it contradicts the notion of a priori knowledge, which is a prerequisite for any experience, cannot be refuted by experience. We cannot think of causeless phenomena. And if we deny the cause of the phenomenon outside our mind, as did the creators of quantum mechanics, the cause is our mind. Schrodinger demonstrated clearly this logic by his celebrated paradox with cat. Abandoning causality, as well as realism, leads to absurdity and no experimental results can save quantum mechanics from this absurdity.

With best wishes,

Alexey

Dear Alexey,

" . . . if we deny the cause of the phenomenon outside our mind, as did the creators of quantum mechanics, the cause is our mind."

You do too much high phylosophy for me. What I know is that the world and its laws were created before the humankind, and will continue after the humankind. QM just describes the microscopic world, which also does not need the humankind for existing.

It is true that for testing a quantum object we need macroscopic apparatuses, because the quantum systems are small, while we are big. However, if the quantum system meets a macroscopic detector, or, it meets a macroscopic object which is not a detector, the joint evolution of the two is the same. The exception is only that in the former case the final state of the joint evolution is recorded.

I won't do philosphy on this.

But there was something else that I promissed to tell you. I hoped to be able to tell you today, but I happened to be very busy, so it remains, with God's help, for tomorrow.

Also, you didn't tell if Ruth Kastner is she on RG. I would like to have a talk with her.

With kind regards,

Sofia

Dear Sofia,

You, as well as most modern scientists, are naive realist. The crisis of physics and its manifestation - delusion of most physicists about quantum mechanics - have become possible precisely because most scientists are naive realists. Most physicists, including such distinguished physicist as Feynman, Landau and other could not understand during a long time that quantum mechanics contradicts realism since they were naive realists and believed in quantum mechanics as naive realists. Only few ’cultured’ men, first of all the critics of quantum mechanics Einstein, Schrodinger, Greta Hermann and some others, understood that quantum mechanics is not scientific theory because of its contradiction with realism and determinism. Most physicists could not understand the arguments of the critics because they did not want to do philosophy of quantum mechanics. The problem of the contradiction of quantum mechanics with realism has become popular among many physicists only when the believers in quantum mechanics misinterpreted violation of Bell's inequalities as the need to renounce local realism. Alain Aspect states in his Viewpoint ”Closing the Door on Einstein and Bohr's Quantum Debate” Physics 8, 123 (2015): “By closing two loopholes at once, three experimental tests of Bell's inequalities remove the last doubts that we should renounce local realism”. I draw reader's attention in my article “Absurdity of quantum mechanics and the crisis of physics” that John Bell, the author of Bell’s inequalities, had opposite opinion. He said in his talk ”Speakable and unspeakable in quantum mechanics” at Naples-Amalfi meeting 1984 about experimental evidence of violation of Bell’s inequalities obtained by Alain Aspect with coauthors in 1982: ”For me then this is the real problem with quantum theory: the apparently essential conflict between any sharp formulation and fundamental relativity. That is to say, we have an apparent incompatibility, at the deepest level, between the two fundamental pillars of contemporary theory... and of our meeting”. Bell was right whereas Alain Aspect and other authors of numerous publication refuting realism are wrong. They remain naive realists even renouncing realism.

I should say that you cannot know that the world and its laws were created before the humankind, and will continue after the humankind. You can only believe that the world as ’thing-in-itself’ was created before the humankind and will continue after the humankind. We cannot know the laws of the world as ’thing-in-itself’. We know only the laws of the world of our notions. We (humans) create these laws. I draw your attention that the laws and notions, which we know, change. Your belief that the world was created before the humankind is not based on any experience. Whereas the belief of most people before Copernicus that the Sun revolves around the Earth was based on the direct experience. According to our modern notions about the world the Earth revolves around the Sun rather than the Sun revolves around the Earth. The conviction of naive realists that we can know the world as ’thing-in-itself’ means that before Copernicus the Sun revolves around the Earth and now the Earth revolves around the Sun.

With best wishes,

Alexey

Alexey,

"Most physicists, including such distinguished physicist as Feynman, Landau and other could not understand during a long time that quantum mechanics contradicts realism since they were naive realists and believed in quantum mechanics as naive realists."

QM is rigorous science. I can accept rigorous proofs, not wording.

"quantum mechanics is not scientific theory because of its contradiction with realism and determinism."

I am not sure that QM contradicts realism. And if indeed does, i.e measurement results are picked at the measurement time, not before, we have to accept that the Nature behaves this way at microscopic scale. But we are far from having said the last word. As to Einstein, he never said that QM is not scientific - it's you who says. Einstein posed the problem whether QM admits a substructure.

"John Bell, . . . . said in his talk ”Speakable and unspeakable in quantum mechanics” at Naples-Amalfi meeting 1984 ”For me then this is the real problem . . . . "

We are now in 2018. Since 1984 until now, many things were clarified. We understand how work the entanglements. Bel and his contemporaries did not. We still do not understand the superposition principle, phenomenologically.

"We (humans) create these laws."

I would like to create a law that permits me to know in advance what will happen tomorrow. If we the humans can create laws for the Nature, can you tell me how to create the law I mentioned?

"Your belief that the world was created before the humankind is not based on any experience."

How do we get light from the most distant galaxies? The light travels so long time that the Earth may not have been existed when it was emitted by those galaxies.

". . . the Sun revolves around the Earth . . . the Earth revolves around the Sun"

Both views are true. But it's easier to do calculi taking the planets as rotating around the Sun, and not the other way.

Dear Sofia,

I would like to draw your attention once again that you and the authors of numerous publications (for example H. Wiseman, ”Quantum physics: Death by experiment for local realism,” Nature 526, 649 (2015); B. Hensen et al., ”Loophole-free Bell Inequality Violation Using Electron Spins Separated by 1.3 Kilometres, Nature 526, 682 (2015); The BIG Bell Test Collaboration (106 authors!), Challenging local realism with human choices. Nature 557, 212216 (2018) and many others) are the believers of the same religion – quantum mechanics, but belong to different, even opposite confessions. You are not sure that QM contradicts realism whereas these authors refute realism. Only religion can have different confessions whereas any scientific theory must be understood unambiguously.

You, like most believers in quantum mechanics, haven't read Einstein enough carefully. Einstein was first who said that quantum mechanics is religion. He was writing to Schrodinger as far back as 1928: "The soothing philosophy—or religion?—of Heisenberg-Bohr is so cleverly concocted that for the present it offers the believers a soft resting pillow from which they are not easily chased away. Let us therefore let them rest….This religion does damned little for me". Einstein’s words turned out prophetic. I see that it is very difficult to chase away the believers from soft resting pillow proposed by Heisenberg, Bohr and other creators of quantum mechanics. John Bell was agree with Einstein. He was saying in his Introductory remarks ”Speakable and unspeakable in quantum mechanics” at Naples-Amalfi meeting 1984 that “This progress is made in spite of the fundamental obscurity in quantum mechanics. Our theorists stride through that obscurity unimpeded…sleepwalking?” The sleepwalkers have perverted the meaning of Bell's inequalities and the entanglement. Only the sleepwalkers can think that they understand the meaning of Bell's inequalities is better than Bell and the meaning of the entanglement is better than Schrodinger who coined as far back 1935 the term entanglement as ”entanglement of our knowledge” in order to to describe the EPR paradox. You write: “We understand how work the entanglements. Bell and his contemporaries did not”. Who are “we”? The well-known experts on the foundation of quantum mechanics Caslav Brukner, Marek Zukowski, Anton Zeilinger interpret the entanglement in the article arXiv:quant-ph/0106119 “The essence of entanglement” as ”entanglement of our knowledge”, as well as Schrodinger. Could your “we” be agree with this interpretation?

You as a naive realist don't want to understand the differences between the Nature as ’thing-in-itself’ and the Nature of our notions. We the humans create laws for the Nature of our notions which we know but not for the Nature as ’thing-in-itself’, which we cannot even know.

The light from the most distant galaxies it is only phenomenon on base of which we create our notions about the Nature. Our notions may not match the Nature as ’thing-in-itself’. Your worldview is eclectic. Your point of view “Both views are true. But it's easier to do calculi taking the planets as rotating around the Sun, and not the other way” is the one of the instrumentalism rather than naive realism.

You are sure that QM is rigorous science. Therefore I draw your attention on section 4 “No theory can describe two opposite cases using the same Hamiltonian” of my paper “Could ordinary quantum mechanics be just fine for all practical purposes?» published in the journal Quantum Studies: Mathematics and Foundations. 3, 41-55 (2016) and available at ResearchGate. I show in this section that quantum mechanics cannot describe different quantum phenomena without a mathematical mistake.

With best wishes,

Alexey

Alexey,

"You are not sure that QM contradicts realism whereas these authors refute realism. Only religion can have different confessions whereas any scientific theory must be understood unambiguously."

Nobody is sure. Absolutely nobody. People have reasons for believing this or that. That's all we have. Indeed, there are arguments for one direction, and reasons for the opposite. But not all the people are aware of all the arguments.

"You, like most believers . . . . . . . . Could your “we” be agree with this interpretation?"

I understood nothing from this long phrase. And if Einstein indeed said that QM is religion, I have no obligation to that. We live in the 21th century and know things that Eistein didn't know. Who chooses to live in Einstein's time and ignore whatever was understood since then, it's his right, and his bussiness, not mine.

"You as a naive realist don't want to understand . . ."

I think that you are naive, and don't possess enough knowledge in the domain.

"The knowledge of the observer about the object changes at the observation . . . ."

Which knowledge? The quantum object is distorted when submitted to macroscopic test. We gain no knowledge about how the object was before the test, unless we repeat the test many times, or, if we know how it was prepared. You put wrongly the problem.

Consider the following experiment:

A single particle wave-packet, describing a proton, lands on a beam-splitter and exits as a superposition (1/√2) ( |a> + i|b>). Then, each one of the wave-packets |a> and |b> pass through an identical electrostatic field - see the figure.

There is only one proton in each trial of the experiment, a which-way test confirms that. So, one would expect that in a given trial of the experiment, only the wave-packet containing the proton be deflected by the respective field.

Though the things go differently: bringing |a> and |b> to cross one another, after many trials an interference pattern appears. The pattern indicates that in each trial and trial both |a> and |b> were deflected by the fields, as if each wave-packet comprised a proton. So we should have two protons in each trial. But, how, what impinged on the beam-splitter was a wave-packet with a single proton. So, we have one single proton in each trial, not two. Or, alternatively, could the beam-splitter produce protons?

See more discussions on this experiment at the question

https://www.researchgate.net/post/Is_something_wrong_with_the_superposition_principle_Do_there_apear_phantom_particles

I have an idea: maybe the proton doesn't travel only inside the wave-packet |a>, or only in the wave-packet |b>. Maybe it appears in one wave-packet, then disappears there and appears in the other wave-packet, and so, all the time. Thus, both wave-packets would be deflected by the fields.

This idea can explain both the whichway experiment, and the interference experiment, with NO NEED OF THE COLLAPSE postulate.

Unfortunately, this idea is not free of problems. If |a> and |b> travel in regions greatly separated in space, it is hard to imagine jumps from one to another, all the time. Also, thinking relativistically, a frame of coordinates can be found by which, after the proton disappeared from the wave-packet |a>, only after a long time it appears in |b>. Meanwhile, the proton disappeared from the universe.

Does somebody have some solution, or a better idea?

Dear Sofia,

As you know, I claim that the reality of the motion is the disappearance and appearance actions across time and space:

https://www.researchgate.net/publication/322437488_The_theory_of_disappearance_and_appearance

, and to understand the mechanism of this movement we have to pay attention to the following points:

1- In the classical concept, particles are influenced by the forces that are placed on them, but in quantum mechanics, the particle is affected by the forces that are scattered in all space.

2- The particle takes into account the distribution of forces in space during its transition from position to other through disappearance and appearance actions.

3- So the particle doesn't pass itself through the wave-packet A or wave-packet B, but moves through the disappearance and appearance actions from the original position to the interference device

4 - Moving from its original source to the interference device gets at an average speed less than the speed of light.

5- We need too, to suppose that all particles in the universe have also a special appearance and disappearance motion in the particle's unique related reference, in this case, we can describe the movement in all references similarly (to be compatible with the relativity restraint)

6- If you are wondering how the particle knows about the distribution of forces in space, we can say:

since the particle's motion is a sequence of appearances and disappearances events, the law of conservation of energy can states that the total energy of the Universe remains constant over time, so I assume that when the particle disappears, it back to the universe as an energy distributed randomly throughout it, then after some time it returns as a normal particle etc., according to the point 5, the particle is always in trembling motion between disappearance and appearance modes so it always spends half its time h/(4mc^2) in disappearance mode, so during this time the particle collects the information about the forces that are scattered in all space.

With kind regards,

Mazen

Sofia

Yes, I had other matters and interests, but well. Thank you

The subjective and obyective probability is often explained in books of probability theory.

Subjective refers to the a priority probability that you predict ahead of time.

Schrodinger makes this prediction.

Objective means the probability that emerges statistically after measurement...ie from the pattern formed when electrons multiply hit

a screen, say.

Both better be the same, or something is wrong.

As long as experimental conditions remain the same, time should

not be an issue.

I will just say a few things that have helped me conceptually, over a period of over 30 yrs.

a) Distinguish the particle from the wave function. One is a real particle,

a little ball say, the wave function merely related to the probability of finding it. Two different things.

b) Rarely or never can you tell exactly where the particle is. That is why you use probability.

c) My belief is the reality of the particle, taking precedence.

d) within this scheme there is no problem thinking in terms of amplitudes

for finding a particle in chanel a> or chanel b> after a beam is split. The particle is real and therefore can be influenced by electrical fields and such.

It is the calculation of its probability amplitude that causes the most surprise, I guess. After many repeats on the single particle level you get coincidence with experiment. The statistics must be in accord with the wave function. A single measurement is not that significant.

Maybe this means that that nothing really collapses?

(because to draw out the wave function you need many measurements)

Juan,

If you believe that at a given moment the particle is either in the wave-packet |a>, or in the wave-packet |b>, then there is no collapse. The measurement catches the particle there where it is.

However, there are problems with this view:

1. Suppose that the discussed particle is an ion. Passing the two wave-packets, |a> and |b>, through an electric field - see picture - both are deflected, as if each wave-packet contains an ion.

2. One might be tempted to suggest that the ion jumps extremely frequently from one wave-packet to the other, and such, it is practically present in both. But, for accomplishing such an activity, the ion has to jump with infinite velocity between regions that may be very distant from one another. Infinite velocity does not exist, velocities are limited to the light velocity.

3. If in one frame of coordinates the ion may appear as jumping instantly from one wave-packet to the other and doing this all the time, in another frame, in relative movement with respect to the other, the effect is that the ion may appear as present at once in both wave-packets. The most natural moving frames are those moving with the group-velocity of the wave-packets. In the regions enclosed in light-gray rectangles, the horizontal velocity components of the wave-packets are opposite.

So, there are too many problems with the hypothesis of a jumping ion. What remains is to suppose that each wave-packet possesses its own ion. But this is also problematic because the wave-function has no component |a>|b>.

Finally, there is a problem with both above options: if one can estimate the time when the wave-packets touch the detectors, by recording the detection time one can see that sometimes the particle is detected at the beginning of the wave-packet, sometimes is detected at the end of the wave-packet, sometimes in different parts in-between. However, if the particle is present, by one option or the other, all the time in both wave-packets, it is not clear why it is not detected always in the beginning of one wave-packet or the other. Maybe, even within the wave-packet, the particle jumps all the time from place to place, and only when it happens to land on the detector window, it is detected.

The electric field implies the presence of an electrostatic potential difference. According to Schrodinger a potential influences the nature

of the wave function, in this case the direction of the beams. So I do not see any real problem.

regards, juan