HueSurname

Unreliable source

You have been adding this YouTube video to several pages in Wikipedia. Please don't do this. Teller is just informally discussing some of his ideas, this is not a WP:RS. Tercer (talk) 19:39, 8 January 2021 (UTC)

@Tercer: I'll split my reply into three points:

• Teller is most definitely an established expert in the field of quantum physics. His informal discussion of the Copenhagen interpretation should suffice. The source is definitely higher in quality compared to some other sources in the edited articles. The level of depth in the video matches the level of depth in the sections in the articles.
• Large swaths of the edited articles (measurement problem, interpretations of quantum mechanics, Copenhagen interpretation, wave function collapse, and Schrödinger's cat) don't have inline citations or they're cited to pop-sci publications. Citing a very well-regarded physicist who worked directly on these topics would definitely improve the article, especially the sections that I've edited that generally didn't have inline citations before, particularly the section in wave function collapse that makes sweeping determinations without citations.
• Academic papers and textbooks discussing the "irreversible process" Copenhagen interpretation of Bohr [and Heisenberg 13:12, 10 January 2021 (UTC)] are available:

Gunnar Sperber (1974), "On measurement and irreversible processes", Foundations of Physics, 4: 163–179

H. D. Zeh (1979), "Quantum theory and time asymmetry", Foundations of Physics, 9: 803–818

John Archibald Wheeler (1989), "Information, Physics, Quantum: The Search for Links", Proceedings III International Symposium on Foundations of Quantum Mechanics. Tokyo: 354–358 (this paper is cited by thousands of other papers)

This is what Teller is explaining in plain language for the lay person in the video.

(1) The video should not be regarded as an unreliable source because Teller is an established expert. (2) The quality of the video is higher than some of the pop-sci sources in the articles, and it is definitely better than not having sources at all. (3) The information can be cited further to the above peer-reviewed papers published in respected journals, as well as many others. HueSurname (talk) 12:26, 10 January 2021 (UTC)

Teller is an established expert on nuclear physics, many-body quantum physics, and some other fields, but as far as I know he has never worked on foundations of quantum mechanics. If you have some scholarly work from him on the subject, that's fine, but an informal discussion just doesn't cut it. Everybody and their dog have an opinion about interpretations of quantum mechanics, we should definitely not include those in Wikipedia. Talk is cheap, work isn't.

Yes, there is plenty of stuff in Wikipedia that shouldn't be there, and plenty of stuff that isn't in Wikipedia that should be there. This will always be true, and is not an argument for including any particular content.

If you have actual sources supporting your changes, well great, cite those instead, we don't need to argue about Teller. Note though that Heisenberg is explicitly about having wavefunction collapse in his interpretation, claiming otherwise is just bizarre. Tercer (talk) 13:03, 10 January 2021 (UTC)

If you have actual sources supporting your changes, well great, cite those instead, we don't need to argue about Teller. Note though that Heisenberg is explicitly about having wavefunction collapse in his interpretation, claiming otherwise is just bizarre.

@Tercer: If I attribute the "irreversible process" Copenhagen interpretation to Teller and Bohr using the references above, will you have any objections? HueSurname (talk) 13:09, 10 January 2021 (UTC)

Your first source seems rather obscure, but the other two are completely kosher. If they support your claim it's fine. I'm skeptical about the attribution to Teller, though. Tercer (talk) 13:27, 10 January 2021 (UTC)

Thanks, I'll attribute it to Bohr alone. HueSurname (talk) 13:31, 10 January 2021 (UTC)

Collecting a few more widely-cited sources:

• John Bell (1990), "Against 'measurement'", Physics World, 3 (8), doi:10.1088/2058-7058/3/8/26, . . . the 'classical object' is usually called apparatus and its interaction with the electron is spoken of as measurement. However, it must be emphasised that we are here not discussing a process . . . in which the physicist-observer takes part. By measurement, in quantum mechanics, we understand any process of interaction between classical and quantum objects, occurring apart from and independently of any observer. The importance of the concept of measurement in quantum mechanics was elucidated by N Bohr." (LL2) "According to LL (LL24), measurement (I think they mean the LL jump)'. . . brings about a new state . . . Thus the very nature of the process of measurement involves a far-reaching principle of irreversibility . . . causes the two directions of time to be physically non-equivalent, i.e. creates a difference between the future and the past.
• Niels Bohr (1985) [May 16, 1947], Jørgen Kalckar (ed.), Niels Bohr: Collected Works, vol. Vol. 6: Foundations of Quantum Physics I (1926-1932), p. 451-454, Here, I have in mind such considerations about the complementary relationships between thermodynamical and mechanical concepts as I tried to indicate in my old Faraday lecture. Just as such considerations offer a consistent attitude to the well-known paradoxes of irreversibility in thermal phenomena, so it appears to me that, notwithstanding the obvious qualitative relationship between such phenomena and the irreversibility of observations, we may more adequately regard thermodynamical considerations and the essence of the observational problem as different complementary aspects of the description. {{citation}}: |volume= has extra text (help)
• Stig Stenholm (1983), "To fathom space and time", in Pierre Meystre (ed.), Quantum Optics, Experimental Gravitation, and Measurement Theory, Plenum Press, p. 121, The role of irreversibility in the theory of measurement has been emphasized by many. Only this way can a permanent record be obtained. The fact that separate pointer positions must be of the asymptotic nature usually associated with irreversibility has been utilized in the measurement theory of Daneri, Loinger and Prosperi (1962). It has been accepted as a formal representation of Bohr's ideas by Rosenfeld (1966).
• Fritz Haake (April 1, 1993), "Classical motion of meter variables in the quantum theory of measurement", Physical Review A, 47 (4), doi:10.1103/PhysRevA.47.2506, We describe the measurement process for a model system whose Schrödinger equation yields to explicit solution. Any device for an effectively irreversible measurement must not just be a meter with a single degree of freedom; it must also contain a heat bath with many degrees of freedom. Such a bath may cause an effectively instantaneous decay of quantum coherences between macroscopically distinct meter readings, i.e., impart practically classical behavior to the meter. In turn, such a meter can be read without thereby suffering back reactions. We establish the limits in which a meter reading is uniquely related, with reasonable certainty, to a definite eigenvalue of the measured observable.

This will always be true, and is not an argument for including any particular content.

The argument I was making is that the reference improves the article relative to its current state, in case this ever comes up again. HueSurname (talk) 03:53, 11 January 2021 (UTC)

Bohr interpretation

I really don't understand how are you using Bell's paper to support the idea that "the Bohr interpretation" doesn't have a collapse. Bell is quoting Landau and Lifshitz, not Bohr, and Landau and Lifshitz do explicitly have a collapse. Tercer (talk) 22:35, 14 January 2021 (UTC)

We have no complete treatment by Bohr. We have Bell's Perhaps that of Landau and Lifshitz is the nearest to Bohr that we have. [...] The LL formulation, with vaguely defined wavefunction collapse [...] It remains that the theory is ambiguous in principle, about exactly when and exactly how the collapse occurs, about what is microscopic and what is macroscopic, what quantum and what classical and Once again we emphasise that, in speaking of 'performing a measurement', we refer to the interaction of an electron with a classical 'apparatus', which in no way presupposes the presence of an external observer and Stenholm's It has been accepted as a formal representation of Bohr's ideas by Rosenfeld (1966).

Bell says that LL is perhaps the nearest to Bohr, Stenholm says that Rosenfeld accepted irreversibility as a formal representation of Bohr's ideas.

Outside of that, we have Bohr in Essays 1958-1962 on Atomic Physics and Human Knowledge:

all unambiguous information concerning atomic objects is derived from the permanent marks such as a spot on a photographic plate, caused by the impact of an electron left on the bodies which define the experimental conditions. Far from involving any special intricacy, the irreversible amplification effects on which the recording of the presence of atomic objects rests rather remind us of the essential irreversibility inherent in the very concept of observation. The description of atomic phenomena has in these respects a perfectly objective character, in the sense that no explicit reference is made to any individual observer and that therefore, with proper regard to relativistic exigencies, no ambiguity is involved in the communication of information.

So we have Bohr "irreversibility inherent in the very concept of observation" [through a physical process of "observation"] and Bell saying LL's formal treatment is the closest to Bohr which is "ambiguous in principle" about the collapse, and Stenholm, presenting his "considerably simplified" version, pointing to Rosenfeld, pointing to Bohr, ending with "we have reached the point where "the quantum mechanical description of the process is effectively equivalent with the classical description", as the quote from Bohr at the end of the previous section states."

So there's the Bell account of the Landau-Lifshitz account of Bohr's interpretation, and Stenholm's account of Rosenfeld's account of Bohr's interpretation. If you want me to cut out the middlemen I'm sure I could do that. HueSurname (talk) 23:34, 14 January 2021 (UTC)

Rosenfeld (1966) describing Bohr's interpretation:

In particular, the measuring procedure by which the value of a physical quantity is ascertained has to be conceived in terms of some automatic recording device, subject only to the laws of physics and entirely analysable by means of them. The biological processes involved in human observation are perfectly irrelevant in this context; indeed, it is quite irrelevant whether or not any human observer is actually present, or even whether any reading is ever made of the recorded information.

It is the merit of the Italian physicists that they have provided precisely such a model, in complete harmony with Bohr's ideas. We have to visualize the measurement as an interaction between the observed atomic system and a registering device, ultimately leading to the formation of some permanent record, uniquely related to a definite quantity characterizing the state of the atomic system. How does such a permanent mark come about? Since it is of macroscopic character, it cannot be a direct result of the initial atomic interaction; the latter is rather of the nature of a triggering effect. It starts off within the measuring apparatus a macroscopic reaction, terminating when a state of stable equilibrium is reached, in which the desired characteristic mark has appeared. The triggering process only lasts for a time interval of the order of magnitude typical of individual atomic reactions; the ensuing macroscopic process necessitates a "relaxation time" which, although it may be very short on the macroscopic time scale, will in any case involve a large number of atomic reactions. This is the decisive point: the formation of the permanent mark is a process of ergodic character, entailing the wiping out of all structural details of the initial state of the total system, known as the 'reduction' of this state.

So according to Rosenfeld who is describing Bohr's ideas, "in complete harmony Bohr's ideas", there's no collapse, only a process that gradually leads to the reduction of the state. HueSurname (talk) 00:16, 15 January 2021 (UTC)

Guess who?

From this point we must take into consideration the interaction of the system with the measuring apparatus and use a statistical mixture in the mathematical representation of the larger system composed of the system and the measuring apparatus. It might appear that this could in principle be avoided if it were possible to separate the system and the measuring apparatus, as a compound system, entirely from the external world. However, BOHR has rightly pointed out on many occasions that the connection with the external world is one of the necessary conditions for the measuring apparatus to perform its function, since the behaviour of the measuring apparatus must be capable of being registered as something actual, and therefore of being described in terms of simple concepts, if the apparatus is to be used as a measuring instrument at all, and the connection with the external world is therefore necessary. The compound system of system and measuring apparatus is therefore now described mathematically by a mixture, and thus the description contains, besides its objective features also the previously discussed statements about the observer's knowledge. If the observer later registers a certain behaviour of the measuring apparatus as actual, he thereby alters the mathematical representation discontinuously, because a certain one among the various possibilities has proved to be the real one. The discontinuous "reduction of wave-packets," which cannot be derived from SCHRODINGER'S equation, is thus, exactly as in Gibbs' thermodynamics, a consequence of the transition from the possible to the actual. Of course it is entirely justified to imagine this transition, from the possible to the actual, moved to an earlier point of time, for the observer himself does not produce the transition; but it cannot be moved back to a time when the compound system was still separate from the external world, because such an assumption would not be compatible with the validity of quantum mechanics for the closed system. We see from this that a system cut off from the external world is potential but not actual in character, or, as BOHR has often expressed it, that the system cannot be described in terms of the classical concepts. We may say that the state of the closed system represented by a Hilbert vector is indeed objective, but not real, and that the classical idea of "objectively real things" must here, to this extent, be abandoned. The characterization of a system by its Hilbert vector is complementary to its description in terms of classical concepts, in a similar manner to the way in which the statement of the microscopic state is complementary in Gibbs' thermodynamics to the statement of the temperature. The description of a fact can be effected in terms of classical concepts in just the approximation in which classical physics can be used. The mathematics of quantum theory can be used for this description as well, i.e. the boundary between the object in quantum theory and the observer who describes or measures in time and space can be pushed further and further in the direction of the observer. In this case the measuring apparatus must be characterized as a statistical mixture, and account must be taken of the fact that the individual states in such a mixture are again altered by interaction with the observer. Knowledge of the "actual" is thus, from the point of view of the quantum theory, by its nature always an incomplete knowledge. For the same reason, the statistical nature of the laws of microscopic physics cannot be avoided.

W. Heisenberg (1955), "The Development of the Interpretation of the Quantum Theory", in W. Pauli (ed.), Essays dedicated to Niels Bohr on the occasion of his seventieth birthday, Pergamon Press

"for the observer himself does not produce the transition; but it cannot be moved back to a time when the compound system was still separate from the external world, because such an assumption would not be compatible with the validity of quantum mechanics for the closed system." Incredible. HueSurname (talk) 00:56, 15 January 2021 (UTC)

Your sources do not support at all your assertion. It is not acceptable to say that Bell's account of Landau and Lifshitz's interpretation amounts to Bohr's interpretation. If it were, then Bohr's interpretation would have a collapse. In Bohr's own writing there's nothing to indicate that the "irreversible amplification" doesn't happen through collapse. Rosenfeld's account describes vanilla collapse; "reduction of the state" is just a synonym. Tercer (talk) 09:33, 15 January 2021 (UTC)

I'll quote Zinkernagel 2016 which extensively quotes Bohr:

[Bohr's] collapse cannot therefore correspond to a physical process amendable to a causal space-time description (in conformity with the view that the wave function does not represent a physical wave). Calling the collapse a “detail of procedure” again suggests that Bohr took it to be a formal (as opposed to physical) notion in which a superposition is replaced by one of its components. As noted in the above subsection, this replacement is due to the change of context associated with an irreversible recording and not because an observer looks at the system. We can thus say that, for Bohr, the collapse is not physical in the sense of a physical wave (or something else) collapsing at a point. But it is a description – in fact the best, or most complete, description – of something happening, namely the formation of a measurement record (e.g. a dot on a photographic plate).

If the collapse is not (or not necessarily) a physical process then at least some Copenhagen interpretations (like Bohr's) do not (or do not necessarily) pose a collapse.

(As as aside I emphasized Heisenberg quote because the Wikipedia articles I edited had said that Heisenberg posed observer-induced collapse or some physical significance to to an anthropic observer. These articles I feel also mischaracterize Wheeler's anthropic principle, but that's another story...)

there's nothing to indicate that the "irreversible amplification" doesn't happen through collapse - that's a weird claim. Bohr in his writings never mentions collapse (Zinkernagel 2016, Howard 2004, Faye 2008) but because he doesn't indicate that there's not a collapse then there is a collapse? That's not sound reasoning.

Anyway I'm more or less satisfied with the state of my current additions to Wikipedia, and maybe later I'll get to fixing or removing all the unreferenced claims and the claims referenced to pop-sci sources in the articles I've added references to. HueSurname (talk) 12:43, 16 January 2021 (UTC)

ANI discussion with you

Wikipedia:Administrators' noticeboard/Incidents#playing with rules, ignoring any sources at StoreDot 2A02:2149:8BDB:B00:E9A0:470:B1A5:6F1E (talk) 12:35, 6 February 2024 (UTC)

Thank you for notifying me. Why not simply use the article's talk page to discuss this edit from more than a year ago? HueSurname (talk) 17:39, 6 February 2024 (UTC)

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