Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Insights Tools to enrich our quantum mechanics interpretations discourse - Comments

  1. Feb 22, 2016 #1

    aleazk

    User Avatar
    Gold Member

    Last edited by a moderator: Feb 24, 2016
  2. jcsd
  3. Feb 22, 2016 #2

    A. Neumaier

    User Avatar
    Science Advisor
    2016 Award

    ''It’s not the theoretician’s task to give methods to test concepts, only to give physically well defined concepts.''
    Well said!
     
  4. Feb 22, 2016 #3
    I'm more motivated by "we need to attack it systematically" part. I always imagined it would be so much easier to learn quantum mechanics in a more visualised course.Many things that seems weird in textbook descriptions actually are things that most of our generation can comprehend, due to been exposed to virtual reality from a very young age. I'm constantly strugling to find more visual represantations to bypass some parts of my course, becouse the more I read it, the more I became convinced that I'm not understanding it, only after the very end when I find out that it was what I thought it was...Now saying this sounds even more arrogant especially when I first thought of this, the next sentence in my textbook was a quote from Richard Feynman, " if you think you understand quantum mechanics, then you don't". I couldn't even think of oposing to Richard Feynman, as but he was also very famous with his analogies and representations of complex problems. It just seems like with all the technological innovations now being considered to use in education of hard sciences, and even more delicate medical education, it would greatly reduce the continuous notation and accurate description burden.a more object oriented quantum physics if you will :D Don't get me wrong, our textbooks are written beautifully but a new generation of physicists educated entirely in this visual way, could allow them to take into account of many subjects that everyone should be talking about.Not that everyone should have a say just because now they can understand but , it'll be like using all the resources, who knows maybe it 'll work.. superdeterminism, bohmian mechanics, more collapse theories involving the neuroscience of observers, nmda receptors, effects of lateral movement on interpreting numerical calculations, matter evolution ad life as a manifestation of the second law of thermodynamics, non equilibrium thermodynamics, I don't know whatever now seems to be the crazy idea (or the "conspiracy theory"), at least then would be easily filtered by physicist at younger age so that they can progress further.
     
  5. Feb 23, 2016 #4

    Ken G

    User Avatar
    Gold Member

    I agree that it is important to use our terms very clearly, and people who say it is "just semantics" are missing that semantics is about what we mean by what we say, so there's no "just" to it-- it's a lot of the hardest work of science to explore what our own words are intended to mean. But where I differ is, I would say that in the process of this exploration, we must above all avoid imposing assumptions onto our meanings that are not necessarily helpful. We must not lose sight of the fact that whenever we choose a meaning, we have in some sense limited our own horizons, which is a double-edged sword: we can say something more specific, but we allow the possibility that we are saying something wrong.

    In particular, I feel this double-edged sword appears clearly in statements like "So, to the standard formalism of QM, A and its eigenvalues are real, objective and independent properties of the quantum system." This is actually not a statement from the "standard formulation" of QM, it is actually a philosophical choice applied to standard QM. Indeed, Bohr would have rejected as false the assumptions that go into that statement, and he would have done it without ever leaving the standard formulation. It is simply not true that a physicist must assume a system has "properties" in order to apply physics to its analysis. Instead, the physicist only needs to manipulate the concept of properties.

    The distinction there relates to the question of whether or not there really is a clear separation between a semantic interpretation, and a pragmatic one, and in particular, whether or not a physicist really needs both. I would argue that those two concepts are easily unified in the following way. Above it was argued that if we have five different experiments that all relate to what we regard as a single "property of the system", say "spin", then the pragmatic interpretation must see those as five different things, while the semantic interpretation is allowed to see them as all referring to the same thing. But it would not be pragmatic to regard five experiments that can be unified by the concept of spin as five separate things, because much of the pragmatism of science involves treating things that are actually different as though they were similar in some crucial way. We do this all the time in science, it is absolutely essential to the practical value of science to be able to make connections like that. So it is the connection that is crucial-- but never the idea that what we are connecting is a "property of the system." Rather, it is quite the other way around: the only thing we need to mean by the words "property of a system" is the ability to make these kinds of mental connections that we call "spin" and so forth. It is not spin that gives these connections meaning, spin is the name of the meaning we give to those connections. So what is referred to as "semantic interpretations" can always be viewed as pragmatic interpretations-- it is pragmatic to notice the value of grouping together a set of experiments than can all relate constructively to our concept of spin, and that is all we need to mean by "spin." We are free to imagine we mean something more if that is our philosophy, but it is not necessary for anything that is done in the act of doing physics.
     
  6. Feb 23, 2016 #5

    Ken G

    User Avatar
    Gold Member

    By the way, I meant that as a reply to the article, not necessarily the post by Berg.
     
  7. Feb 24, 2016 #6

    bhobba

    User Avatar
    Science Advisor
    Gold Member

    Man that's one deep article:rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes:

    I am bit anti philosophy personally so I don't get into that philosophical depth.

    I am however not a big fan of the usual way QM is taught ie in a semi-historical way where you need to unlearn stuff as you go just like the original pioneers did.

    I like much better an approach that gets to the heart of the matter from the start:
    http://www.scottaaronson.com/democritus/lec9.html

    It wont resolve the very deep issues raised, but it will form a common basis to discuss them. I find many that post are very caught up in things like the wave particle-duality etc from the early days of QM that were overthrown early on. In solving problems it's not an issue and may even help in promoting intuition. But for foundational issues it causes a lot of problems in my experience.

    The other thing I have noticed is a tendency to ask deep questions independent of an interpretation when they are easy to answer when you specify one. Examples is superluminal signalling - BM has it - Consistent Histories doesn't, and other such as my ignorance enseble dont really care. But we have these long threads trying to promote one view or the other in a vacuum. Its rather counter productive IMHO.

    Thanks
    Bill
     
  8. Feb 24, 2016 #7

    Ken G

    User Avatar
    Gold Member

    Sorry about that, my browser wasn't working properly and I can't see how to delete the excess!
    I think it's safe to say this article is trying to focus on the question of what is productive, which is expected to be a more productive area of discussion than the interpretations themselves. So that is indeed the key question-- how to make philosophy discussions productive. What I was commenting on is that I actually don't think it is productive to try and separate semantic interpretations from pragmatic ones, because semantics in science is all based on pragmatism. So my comment is simply, the best way to keep philosophy productive in science is to separate the philosophy we need from the philosophy we just add on because it's part of our interest.
     
  9. Feb 24, 2016 #8
    "I am bit anti philosophy personally" my thoughts as well but I didn't want to put it in that way, because I was already leading to a seemingly -leave the details, they are not important- type of argument. I cannot emphasize strongly enough how important it is to define an event correctly(or a natural phenomenon, but i dont know how to write it correctly, I never care to learn because once I associated its meaning, i really don't need to remember its spelling correctly while thinking, it only becomes important when you are writing the argument you arrived at when you were thinking). Defining an argument with the least amount of best words is excatly what any science,linguistics,programmers, (other than lawyers)is trying to achieve and the reason is so that we can take the argument from there and shove it in out brain, where we'll write it in memory by our own means, so that we can use it in an upcoming process. If we leave loose ends in arguments, intentionally or unintentionally we are also leaving a door open to (I'm sorry if this offend anyone but) Deepak Chopra style thining....but only in the verbal argument area, which we already cleared from those kind of people. I never underestimated the value of formalism, definition, semantics, but, as a physics student, I always thought there must be a way to reduce this unnecesary self repeating part. This might sound yet another self claiming genuis(<-look i cant even write it :D ) is speaking kind of argument but, it seems to me most of the weird stuff in QM is really not that difficult to understand for new generation. Non-locality? no problem, we've been playing online games where your character is suspended in a jail cell, while you can still control you bank account in a nother city-ultima online)

    Might sound like an ultra stupid place to start my argument but, most of that generation went in to programming to understand how to create these kind of realities, which actuall nothing more than mimicing real world, half of that half (obviously I'm making up the fractions) also got interested in physics and mathematics, and now, on top of our overall understanding is increasing exponentially, the age at which you start to be exposed and get adapted to this new environment also decreasing. And they're improving their branches, in my opinion, thanks to their early understanding of their environment. The world of brokarage, that thing that was "soo complicated that normal people need some abnormally clever guy who understands it to understand it) is almost gone now, thanks to the open source programming of automated market buy-sell bots.Most of these programmers are using things that they learned in thermodynamics classes.Interestingly its working.

    All this is thanks to the daily language being a rudimentary version of programming languages and programming languages being a rudimentary version of mathematics, which we understand and describe the world. A generation that is growing with the aid of the technology, no matter how much we say that internet, phones, tv this and that making us stupid, wheter they are physicists or not, will be more capable of solving these problems. I mean yes some of us getting more stupid but lets face it, this was going to happen with or without the phones or the tv.

    What I'm trying to say is, I really am motivated by that "we need to attack it systematically" part. We can create a better platform for QM education. (yes, i have a dreaaaammm :D)

    We almost have all we need, Medical students are almost about to use VR, AR sets to get educated in human anatomy, and who knows for surgeries in the future, engineers are uging all sorts of 3d rendering, modelling and animation programs, I even saw a student(i cant remember her branch it was something to do with selling real estate) using 3d simulations for vilages. Yes we have many beautiful online resources (youtube]myxx2uaqPLM, csi.chemie.tu-darmstadt.de/ak/immel/misc/oc-scripts/orbitals.html?id=1?lang=EN geart3, space engine, atom theabox, etc) but scattered all around the internet and you never know if one simple video about entanglement will end up with ancient egyptian gods watching us kind of conclusion...yes it happens a lot...i mean the video, no one is really watchin u)

    Its probably not my place to suggest anything among experienced scientists, but for someone who's dying to get into game(if graduates without any shame), it looks like, most of these "are we interpreting it right?,yea but we missed this part, that info" problems is due to our lack of not yet established common platform to understand QM. English is not my native language but I'm taking my classes in English. Although I talk and walk like Borat in real life, when it comes to reading an English paragraph its really not that difficult.You're not commuting with every letter. But when it comes to playing with more word requiring concepts, English fails for me (Perhaps I should move to Germany, they got a word for everything :D). I'm not having dificulity with the English part, I'm having dificulity the way someone ese explains it from hispoin of view with the details that he finds necessary to remind listener, which I can find irrelevant or distracting. But when I see a 3d representation of it, all the subject, all that long paragraph turns into piece of cake :D I actually wasn't trying to promote BM or anything (although I'm voting for it internally) but merely suggesting that, as the article says, we can do something about this, which approach is correct? problem. And, as a professional programmer and a physics undergradute, I believe we can create tools for the next physicists, so that they can distinguish which approach is better earlier and faster. It kind of worked with that scientists wrote an online game for online gamers to solve a protein folding of some...protein (i guess :D) and it turned out it really was useful to use some resources of (almost mathematically thinking) humans, at least in terms of timing.


    [Late edit] instead of more beautifully cgi'ed and really cool narated documanteries that will leave your mouth open, create accurate simulations for primarily students, then to public. We don't need a new Carl Sagan, we already have a perfect Carl Sagan.. I'm sorry I love NDT but just like Michau Kaku, it seems like instead of promoting science he started to promote himself, especially after I saw NDT in Zoolander 2. Its not 1980's anymore, showing those awe inspiring documentaries on tv or internet, is not going to make people a U turn and jump into science and commit themself into contribute even a single tiny bit of useful info. Im not saying they are useless, but they are more efficient way to really promote science...I just had to add this part :D
     
    Last edited: Feb 24, 2016
  10. Mar 1, 2016 #9
    Hi aleazk:

    I confess I do not understand your philosophical argument. How does the argument relate to the following "interpretation"?

    In QM the math is interpreted as calculating the relative probability of a range of possible specific observations.

    I guess that this would be a pragmatic kind of interpretation. Why is that not philosophically sufficient? It may well be that the nature of reality imposes a constraint on the kind of interpretations that are pragmatically acceptable.

    Regards,
    Buzz
     
  11. Mar 1, 2016 #10

    Demystifier

    User Avatar
    Science Advisor

    I like both approaches. They are complementary to each other so the most complete understanding is achieved by knowing both. The problem with the direct non-historical approach is that it often makes difficult to figure out how, on earth, can one arrive at such an original idea in the first place? This is especially important if you are a scientist who wants to discover something fundamentally new by himself.
     
  12. Mar 1, 2016 #11

    vanhees71

    User Avatar
    Science Advisor
    2016 Award

    I'm also against the historical approach, but you cannot teach quantum theory to beginners by just throwing the rigged-Hilbert space postulates on them and then calculate fancy things. That's math but not physics. Particularly for QT it's important to stay down to earth in the physical foundations, i.e., phenomenology. So you should have in the first one or two lectures a review about the failure of classical physics but emphasizing experiments. I'd start with Rutherford's famous gold-foil experiment and discuss why a classical picture of electrons running around a nucleus must be wrong (including that the Bohr-Sommerfeld atom must be wrong too; it's more an example for a bad theory than a good one, and Bohr was the first who know that; that's why he was very enthusiastic about the discovery of the modern theory by Heisenberg, Born, and Jordan in 1925). Then I'd discuss de Broglie and Schrödinger ("wave mechanics") but point right in the beginning to the failure of their "classical-field theory interpretation". After that you've formulated QM in terms of wave mechanics, including the Schrödinger equation and then you can formalize it to the Hilbert-space formalism a la Dirac (with some hints to caveats concerning the math of unbound self-adjoint operators). From then on you can build up the theory in a systematic way from symmetry principles, which are at the heart of all physics, quantum as well as classical.

    One must avoid in any case a detailed treatment of the Bohr-Sommerfeld model and a naive photon picture (I think photons and the relativistic theory in general must not be discussed before you can teach QFT). Completely obsolete and useless in being rather confusing than helping are remnants of the "old quantum theory" like the wave-particle dualism or vague ideas like complementarity. The right interpretation to teach in the physics course is the minimal interperation (aka "shut up and calculate"). One can and should mention quantum correlations and long-ranged correlations aka entanglement and the empirical refutation of local deterministic hidden-variable theories to give a glance on these issues that some people consider a metaphysical problem.

    Philosophy may be interesting for scholars that are familiar with this physical core of the theory. It's not as interesting for physics itself as one might think on the first glance.
     
  13. Mar 3, 2016 #12
    It is clearly important for theorists working on the foundations of physics to know and understand the philosophical model with its assumptions that allows the formulation of physical theories. However, I don't think the model you have specifically presented as a tool for framing quantum theory can be used as such.

    There are good reasons to believe, that the most fundamental theories we can formulate do not allow for the direct identification of objects or quantities from our experience of reality. The reason is, that these properties, as well as the entirety of reality as perceived by us, appear to be emergent from more fundamental structures and their behaviour. This asks for a completely different philosophical approach and even a different understanding of the statements that can be made by a fundamental physical theory.

    The question, if the physics described by quantum theory is of that kind does not seem too difficult to answer. The failure of ordinary "interpretations", which are based on the philosophical model described in the article, to resolve the most prominent issues in a universally agreeable way strongly suggests, that a different approach needs to be considered.

    To me, this is the best argument to take a closer look at quantum realism* and stripping any postulated relation to reality from the theory. Replacing such relations by emergent behavioural patterns, that can be brought into congruence with our physical description of reality, only requires a much less restrictive philosophical model.

    (*)It is often said that quantum realism necessarily leads to a relative state interpretation of quantum theory. I strongly disagree with this and would argue that quantum realism has not yet found its complete toolset to fully understand emergence and come to a conclusion about the nature of emergent reality. I also do not consider relative states/MWI or related interpretations as true quantum realism, because they end up postulating vital parts of what should be emergent to solve the measurement problem.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Tools to enrich our quantum mechanics interpretations discourse - Comments
Loading...