• Andrew M
    598
    Those two version of Alice, being in different worlds, cannot communicate or otherwise be aware of each other. But they behave exactly identically because they're keeping that knowledge a secret.noAxioms

    But note that they're not actually identical since they each have a different memory of what they measured. What Bob can do is reverse Alice's polarity measurement while retaining the record that the measurement occurred, which is identical for both Alices. This means that the two Alices will merge without memory of the polarity result and with all records of the polarity result having been erased. That is, there will be only one world branch again, with multiple histories, and with the record that a definite polarity result was measured by Alice.

    This is analogous to the double-slit experiment where the single particle detected on the back screen had two distinct path histories (one for each each slit).

    Anyway, point is, Alice learning of the measurement results splits Alice, but does not split the universe, as is commonly assumed.noAxioms

    Yes.

    So yes to the three worlds if you count them that way: One for each Alice, and one for Bob. But there is obviously communication between the Bob world and both Alice worlds, but Bob cannot pass a message from one Alice to the other. With the communication, Bob's world is clearly not isolated from Alice's world, and hence doesn't really count as a separate world.noAxioms

    Agreed. Alice's worlds are separate from each other, but they are in superposition in Bob's world.
  • Andrew M
    598
    The funny stuff aside; how can you "measure" a superposition or how can a measurement be in a superposition? I thought any observation causes the wave function to collapse in a single eigenstate and a measurement, I would think, involves an observation.Benkei

    It's illustrated in the article's image of the experiment (Figure 2 in the paper). Bob's friend's measurement occurs in the gray box (with a record that a definite result occurred). There are detectors on the far right after the beam splitter that Bob observes (and similarly for Alice on the far left). The statistics collected from the detectors over multiple runs indicate quantum interference which means that Bob's friend's measurement in the isolated box was in superposition. It's analogous to the interference pattern in the double-slit experiment which indicates that the emitted particle was in superposition when it passed through the slits.

    What this experiment challenges is the idea of objective collapse. Instead collapse is observer-dependent - there is collapse for Bob's friend but not collapse for Bob.
  • Terrapin Station
    7.8k
    Now I am not a physicist, but I would remind us all of a conceptual issue that might cause misunderstandings here.

    We seem to have a situation where one observer sees a certain situation, and another sees a contradictory situation. A sees p, B sees ~p.

    It's worth reminding ourselves that this is not new. The same thing can happen in relativistic physics where one observer will see events in a different sequence to another.

    But of course what happens in relativistic is that a set of equations are used to translate between the observations. SO although A sees p and B sees ~p, A will also see that B sees ~p, and B will also see that A will see p.

    That is, A and B agree that: A sees p, yet that B sees ~p.

    Now it seems to me that objective reality has here not so much been undermined as redefined.

    A corollary: this fits in with a view of language, logic and mathematics such that we choose a grammar for our descriptions that suits our purposes.
    Banno

    It's actually even "less" than that in these experiments. The two observers are not observing the same thing and reaching different conclusions about it. They're observing two different things. X in state m and y in state n. The issues arise merely due to theory about what the relationship between x and y should be, what the values of m and n should be per the theory.
  • boundless
    112


    Thank you for giving this excellent counter-argument! :wink:

    I am too reticent to accept completely what people like Bitbol, d'Espagnat etc are positing (and in some sense even Rovelli). In fact, I share your concerns. But IMO correlationism says something really 'deep' about our knowledge, so to speak. Meilassaux's argument is very strong but IMO it does not really refute the 'correlationist' argument. I am not trying to be difficult (I am sorry if I am giving this impression) but IMO Meilassaux's argument refutes the strongest form of 'correlationism', that is: there is no mind-independent reality.

    IMO, a weaker form of 'correlationism' is, in fact, right. Let me explain this briefly. First, let's define 'direct knowledge' as a form of knowledge that is not based on inference but it is immediate. I believe that for this form of knowledge the 'correlationist' is right. We cannot 'neglect' its 'perspectival nature'. On the other hand, there is another type of knowledge, based on inference that is necessary for science. For instance, if we accept the reasonable assumption that we can know by inference, it seems hard to deny. We can say that we cannot be 'absolutely certain' about it, but it is difficult to think that all our inferences about something independent from our own perspective cannot give us knowledge.

    Now, let me give a longer answer (I hope that isn't too unclear)...

    Let me begin again from Rovelli's Relational interpretation (it is a somewhat long answer, sorry!). According to Rovelli, there is no truly 'absolute' perspective. But here whatever physical system has its own 'perspective'. So there are no 'observer-dependent' states. A 'perspective from no-where' or 'God's eye view' is impossible. Rovelli writes in his pre-print 'Relational Quantum Mechanics' (p. 1 and p.15):

    The notion rejected here is the notion of absolute, or observer-independent, state of a system; equivalently, the notion of observer-independent values of physical quantities. The thesis of the present work is that by abandoning such a notion (in favor of the weaker notion of state –and values of physical quantities– relative to something), quantum mechanics makes much more sense.
    ...
    Let me summarize the path covered. I started from the distinction between observer and observed-system. I assumed (hypothesis 1) that all systems are equivalent, so that any observer can be described by the same physics as any other system. In particular, I assumed that an observer that measures a system can be described by quantum mechanics. I have analyzed a fixed physical sequence of events E, from two different points of observations, the one of the observer and the one of a third system, external to the measurement. I have concluded that two observers give different accounts of the same physical set of events (main observation).
    Rather than backtracking in front of this observation, and giving up the commitment to the belief that all systems are equivalent, I have decided to take this experimental fact at its face value, and consider it as a starting point for understanding the world. If different observers give different descriptions of the state of the same system, this means that the notion of state is observer dependent. I have taken this deduction seriously, and have considered a conceptual scheme in which the notion of absolute observer-independent state of a system is replaced by the notion of information about a system that a physical system may possess.

    If the above is true then we simply cannot have a 'perspective'-independent knowledge. Rather all knowledge is 'perspectival' by necessity. Does this mean that there are only 'perspective' and nothing else? That is: can we still speak about 'absolute' properties of things? For instance, can we speak of an intrinsic property of an object O? Or all properties of O are relational, i.e. defined only in relation to other objects?
    I believe that if Rovelli is right, then we simply cannot know intrinsic properties of objects (or maybe even that there are no intrinsic properties...). I honestly do not know if this 'makes sense', so to speak. But in my opinion this is quite interesting*.

    Given the above, how can we make sense of the sentence: 'the universe is 13.8 billions years old'? If we accept Rovelli's interpretation, IMO we cannot even speak of 'the universe as a whole'. Why? Because, there is nothing outside that can be used to define a relation (this is very reminiscent of Kant's antinomies about the universe). So, fine! But as you say cosmology is very effective so it is hard to think that even such statement is perspectival. On the other hand, we should not forget that even that statement is made according to a 'perspective', the reference frame where the Cosmic Wave Background is isotropic, that is the 'co-moving reference frame' (check: https://en.wikipedia.org/wiki/Age_of_the_universehttps://en.wikipedia.org/wiki/Cosmic_time ). So, strictly speaking it is still 'perspectival'.

    Even Relativity itself seems to suggest this, if we want to avoid the 'block world'. In the 'insight' article 'Block universe, refuting a common argument' on physicsforums, the 'block world hypothesis' is criticized because the assumption that the 'present' of each 'observers' is 'fixed' (in fact, the 'block universe' would follow if you accept relativity of simultaneity and this assumption). The reason why such an assumption is rejected is because of the velocity of light speed limit: no information is available outside the light cone, so only events in the past light cone are really 'fixed'.

    So, ok, let us now accept all of this reasoning. Does all of this suggest an absurd form of relativism? The point is that although there are perspectives, one can still speak of 'shared truths'. 'The universe is 13.8 billions of years old in the 'co-moving' reference frame' is true for everyone, because it specifies the appropriate context. Also, from the reference frame of the Earth we can know the age of the universe in that reference frame. So, we actually can know other 'perspectives'. Hence, despite the fact that we cannot have a 'view from no-where' we still are able to make statements valid in the various 'perspectives'.

    OK. Now let us bring our consciousness inside all of this. We have accepted that we cannot speak of 'perspective-independent' states. Our consciousness arguably gives us another perspective. So, we actually see everything from this 'perspective'. If the above is right, we can know by inference what is true according to other 'perspectives'.

    But Kant reasoned that 'the world that appears to us' is (in part) conditioned by our a-priori forms, categories etc and, therefore, we cannot neglect the contribution of these a-priori forms. Hence, So, even if the 'correlationist' position seems absurd it cannot be really rejected. Statements about other perspectives become 'hypotheses'. How all of this escapes the charge of being 'epistemic solipsism' is unclear to me - it is IMO an 'aporia'. (It is epistemic because Kant accepts that we do not create the world but at the same time we cannot know it independently by our own a-priori forms, categories and so on)

    We might try to say that our perspective is itself conditioned by the 'external world'. I'd agree. But still IMO does not actually overcome all of these difficulties. Rather, we have a changing perspective rather than an unchanging one. But still I cannot see a real refutation of the 'correlationist' view.

    It might be said, however, that taking very seriously 'correlationism' is due to a sort of 'excessive skepticism'. That is, while it is true that we cannot completely neglect our 'situatedness' we can still say that statements about the world independently by our minds are reasonably true (after all, your concerns are well-justified IMO). But again, I do not see a true 'refutation' here so to speak.

    What is fascinating however is that it seems that all this reasoning is suggesting that we should take into account a perspectival thinking. That is, it seems to suggest that all 'true statements' we make are context-dependent, so to speak even if we do not accept the 'correlationist' position. We are always 'forced' to specify the context in which a statement is true. (And also we should not neglect too easily our own perspective!)

    As I said, maybe, however, we can accept a weaker form of the correlationist position by distinguishing something like 'direct knowledge' and 'knowledge based on inference'. The correlationist position is applicable to 'direct knowledge'. But he is wrong if he is too skeptical about 'knowledge based on inference' (which enables us to say, for instance, what happened during the evolution of the universe...).

    [*As an aside, I find fascinating that David Bohm already by 1957 - only five years after the publication of his 'deterministic' interpretation of QM - arrived at a similar conclusion with the concept of 'qualitative infinity of nature'. According to him, all our knowledge is valid only in a specific context. For instance, classical mechanics is not 'wrong'. Rather, it has a limited validity. And according to Bohm [i]all[/i] physical theories must be of limited validity. The difference with Rovelli's view might be that Bohm assumes that there is a perspective-independent reality but it is unknowable. Rovelli does not. But I am not an expert on both. So, I won't digress any longer...]
  • boundless
    112


    In summary, I agree with the 'correlationist' is right in believing that all our knowledge being with our 'situated' lived experience (which is changing and conditioned by the 'external world'). I agree also with him that we cannot neglect completely the 'contribution' of our mind. So, 'direct knowledge', i.e. immediate non-inferential knowledge, occurs within this aforementioned perspective.
    But I disagree with him if he denies that we absolutely cannot know anything except the world as it appears to us. In fact, I believe that we can be reasonably sure that we can have a (partial) indirect, inferential knowledge of what is 'outside' our situated experience.

    But, interestingly, it seems that a 'perspectival' reasoning (somewhat analogous) to the one of the correlationist can be applied to science. And one wonders if there is a link :chin:
  • Joshs
    438
    I'm wanting to add an intermediate between your strong and weak examples. It seems that thinkers following Hegel, such as Quine, Putnam and Kuhn, argue that the universe(or universes) is a process of self-development that we contribute to via our theorizations. The difference between their approaches and those of radical relativists like Nietzsche, Heidegger and Derrida is that they believe it makes sense to talk about one account being more adaptive than another beyond the historical contingency of conventional norms. Piaget, for instance, likened human cognition to a dynamical system whose eqiulibrations , disequlibrations and reequillibrations at a higher level produces a spiral-shaped evolution of knowledge, a movement from a weaker to a progressively stronger and stabler structure of anticipatory understanding.

    Obviously this would not be possible if it did not assume a real world whose functioning produced specific constraints on thinking. So this intermediate claim considers post-Nietzscheans to have gone too far in their relativism. On the other hand ,it rejects the rationalism of Lakatos and Popper, who assume fixed norms as underlying scientific practice.
    I suspect such an intermediate position is more appealing to scientists like Lee Smolen and Ilya Prigogine than the Popperian-Lakatos Kantian one.
  • Andrew M
    598
    "I have analyzed a fixed physical sequence of events E, from two different points of observations, the one of the observer and the one of a third system, external to the measurement. I have concluded that two observers give different accounts of the same physical set of events (main observation)." [Rovelli]boundless

    As I'm guessing you're well aware, Rovelli's main observation exactly describes the Wigner's friend scenario that this thread is about. But it's worth shining a light on. Also of interest, Rovelli commented on the OP experiment in a recent New Scientist article:

    I do take it as a great piece of evidence directly supporting the relational interpretation. I agree in full with the way they interpret it,” he says. “It is fantastic that ‘ideal experiments’ of the past become real experiments of today.Rovelli in New Scientist (Quantum experiment suggests there really are ‘alternative facts’)
  • fdrake
    1.9k
    IMO, a weaker form of 'correlationism' is, in fact, right. Let me explain this briefly. First, let's define 'direct knowledge' as a form of knowledge that is not based on inference but it is immediate. I believe that for this form of knowledge the 'correlationist' is right. We cannot 'neglect' its 'perspectival nature'. On the other hand, there is another type of knowledge, based on inference that is necessary for science. For instance, if we accept the reasonable assumption that we can know by inference, it seems hard to deny. We can say that we cannot be 'absolutely certain' about it, but it is difficult to think that all our inferences about something independent from our own perspective cannot give us knowledge.boundless

    The relevant question about our networks of inferential knowledge is whether they are vindicated solely by virtue of being intersubjectively validated or whether a knowledge claim's intersubjective validation tracks how nature behaves. Scientists don't produce theory or experiment, usually, for the purpose[ of intersubjective validation, they validate claims about the world using shared methodologies. Even repeating an experiment is done to assess whether a claim is true, consistent with the available evidence, or neither of these things.

    If the above is true then we simply cannot have a 'perspective'-independent knowledge. Rather all knowledge is 'perspectival' by necessity. Does this mean that there are only 'perspective' and nothing else? That is: can we still speak about 'absolute' properties of things? For instance, can we speak of an intrinsic property of an object O? Or all properties of O are relational, i.e. defined only in relation to other objects?boundless

    It's worthwhile to remember here that our discussion about intersubjective validation relates to the phenomena of quantum mechanics only analogically. Is a scientific theory a quantum observer? Is a research practice a quantum observer? No to both of these things, scientists don't fire scientific theories at particles to determine their state. Can a chlorine atom serve as an observer for a sodium atom when forming an ionic bond? I think, absolutely, and the latter is the run of the mill kind of quantum interaction that's been going on since things have been going on.

    Even when all properties are relational, we can still be in the state where Alice agrees that Bob sees X, Bob agrees that Alice sees not-X, or that one was in a superposition or whatever. The general logic here is about as banal as @Banno portrayed it outside of the QM context and @Andrew M portrayed it within the context of the paper in the OP. Collapse is observer dependent, great, we have established something about nature.

    What is fascinating however is that it seems that all this reasoning is suggesting that we should take into account a perspectival thinking. That is, it seems to suggest that all 'true statements' we make are context-dependent, so to speak even if we do not accept the 'correlationist' position. We are always 'forced' to specify the context in which a statement is true. (And also we should not neglect too easily our own perspective!)boundless

    I would remind any reader that a view from somewhere is a view of something. The context dependence of the production of a theory; through whatever intersubjective validation mechanisms you like; does nothing to diminish the truth of well established claims using methods consistent with the theory (or theoretical context).

    Given the above, how can we make sense of the sentence: 'the universe is 13.8 billions years old'? If we accept Rovelli's interpretation, IMO we cannot even speak of 'the universe as a whole'. Why? Because, there is nothing outside that can be used to define a relation (this is very reminiscent of Kant's antinomies about the universe). So, fine! But as you say cosmology is very effective so it is hard to think that even such statement is perspectival. On the other hand, we should not forget that even that statement is made according to a 'perspective', the reference frame where the Cosmic Wave Background is isotropic, that is the 'co-moving reference frame' (check: https://en.wikipedia.org/wiki/Age_of_the_universehttps://en.wikipedia.org/wiki/Cosmic_time ). So, strictly speaking it is still 'perspectival'.boundless

    Yes, the calculation of the age of the universe is done with respect to a reference frame in which its expansion is isotropic. But:

    You can still make ancestral statements within the frame; its history goes back well before the advent of humans; before the advent of the distinction between unconditioned datum ('raw experience' or 'direct knowledge') and conditioned factum ('processed experience' or influence from a category of the understanding). The more relevant point here is that we can make sense of statements which describe events anterior to the the genesis of the a-priori; of conditioning sensibility.

    Meillassoux discusses this point in terms a distinction between 'the lacunary nature of the given' (say that we only see one side of an object when looking at it) and 'occurrences which are not contemporaneous with any given':

    The objection against idealism based on the distal occurrence is in fact identical with the one based on the ancient occurrence, and both are equivalent versions (temporal or spatial) of what could be called ‘the objection from the un-witnessed’, or from the ‘un-perceived’. And the correlationist is certainly right about one thing – that the argument from the un-perceived is in fact trivial and poses no threat to correlationism. But the argument from the arche-fossil is in no way equivalent to such an objection, because the ancestral does not designate an ancient event – it designates an event anterior to terrestrial life and hence anterior to givenness itself. Though ancestrality is a temporal notion, its definition does not invoke distance in time, but rather anteriority in time. This is why the arche-fossil does not merely refer to an un-witnessed occurrence, but to a non-given occurrence – ancestral reality does not refer to occurrences which a lacunary givenness cannot apprehend, but to occurrences which are not contemporaneous with any givenness, whether lacunary or not. Therein lies its singularity and its critical potency with regard to correlationism.

    The strategy here is to locate the conditioning sensibility within a time concept or becoming concept; whereby the conditioning sensibility passes from a state of nonbeing to a state of being. (I'm quoting out of order from the book because I think it fits the flow of our discussion better) It is tempting to say that the existence of such an ancestral state of affairs is a merely empirical matter, which does nothing to change the relationship between the forms of sensibility and their conditioned facts - as I believe @Wayfarer likes to emphasise. However, the interpretation of the ancestral statement; and the required condition for it to make sense; is that we imagine a time before there was a conditioning transcendental subject, a time in which the sensibility's conditioning becomes an event. We need to be able to say that a transcendental subject occurs for the occurrence of the conditioning relationship the sensibility has upon our interpretations. As he puts it: (quoting out of order since it fits our discussion better)

    We are told that the transcendental does not exist because it does not exist in the way in which objects exist. Granted, but even if we concede that the transcendental subject does not exist in the way in which objects exist, one still has to say that there is a transcendental subject, rather than no subject. Moreover, nothing prevents us from reflecting in turn on the conditions under which there is a transcendental subject. And among these conditions we find that there can only be a transcendental subject on condition that such a subject takes place... In other words, at issue here is not the time of consciousness but the time of science – the time which, in order to be apprehended, must be understood as harbouring the capacity to engender not only physical things, but also correlations between given things and the giving of those things. Is this not precisely what science thinks? A time that is not only anterior to givenness, but essentially indifferent to the latter because givenness could just as well never have emerged if life had not arisen? Science reveals a time that not only does not need conscious time but that allows the latter to arise at a determinate point in its own flux.

    What this argument reveals is that the conditions of possibility for the sense of ancestral statements require us to be able to think of a world indifferent to any given; any conditioning sensibility or emergent system of intersubjective validation. The meaningfulness of ancestral statements requires us to adjust our sophisticated intuitions about the a-priori nature of the correlation between thought and being to include the ability to interpret, since we inhabit, a world radically indifferent to any conceptual distinction. Nature becomes a curmudgeonly gainsayer who can refuse to yield to any determination of theory or sensibility; it will shout "NO!" whenever it bloody well likes and may not speak our language.
  • Joshs
    438
    "Nature becomes a curmudgeonly gainsayer who can refuse to yield to any determination of theory or sensibility; it will shout "NO!" whenever it bloody well likes and may not speak our language."

    If nature does not speak our language then it will not exist for us except as it is translated into our language. Then we will hear nature's 'no' as we interpret any affirmation or negative, as relative to a particular account. That is, its refusal to yield to a determination of theory or sensibility will nonetheless by a refusal that is recognized, that makes sense, and this can only take place through an authorizing scheme. This language-dependency is not unique to human sense-making. A form of it inheres in the sense-making of all living, self-organizing systems. What disturbs a living system only appears as a disturbance, a 'no', in relation to the norms that system sets up via its produced environment.
  • boundless
    112
    The relevant question about our networks of inferential knowledge is whether they are vindicated solely by virtue of being intersubjectively validated or whether a knowledge claim's intersubjective validation tracks how nature behaves. Scientists don't produce theory or experiment, usually, for the purpose[ of intersubjective validation, they validate claims about the world using shared methodologies. Even repeating an experiment is done to assess whether a claim is true, consistent with the available evidence, or neither of these things.fdrake

    I agree with you here. And IMO the 'weak correlationist' does not have a problem with it.

    Even when all properties are relational, we can still be in the state where Alice agrees that Bob sees X, Bob agrees that Alice sees not-X, or that one was in a superposition or whatever. The general logic here is about as banal as Banno portrayed it outside of the QM context and @Andrew M portrayed it within the context of the paper in the OP. Collapse is observer dependent, great, we have established something about nature.fdrake

    Well, I agree again :wink: I mean, 'perspectival knowledge' about something is still knowledge about that. BTW, I agree that objective reality is redefined...when you specify the 'perspective', that is when you give the appropriate context then the statement becomes true for all.

    [On the other hand, there might be the problem of how can we talk about objects that do not have any intrinsic property. It seems that a defining (i.e. 'essential') property of an object (i.e. the property that makes an object that object) is intrinsic, not relational...but maybe this is off-topic...]

    I would remind any reader that a view from somewhere is a view of something. The context dependence of the production of a theory; through whatever intersubjective validation mechanisms you like; does nothing to diminish the truth of well established claims using methods consistent with the theory (or theoretical context).fdrake

    Agreed!

    Yes, the calculation of the age of the universe is done with respect to a reference frame in which its expansion is isotropic. But:

    You can still make ancestral statements within the frame
    fdrake

    Yeah! And I agree with you that such a knowledge does tell you something about the object of knowledge. Still, however, you cannot completely remove the fact that it is 'perspectival'. In fact, I cannot think that it is really possible to deny it.

    BTW, cosmology is also not the study about 'the universe' in the sense of 'everything'. In fact, in cosmology you neglect small-scale perturbations.

    What this argument reveals is that the conditions of possibility for the sense of ancestral statements require us to be able to think of a world indifferent to any given; any conditioning sensibility or emergent system of intersubjective validation. The meaningfulness of ancestral statements requires us to adjust our sophisticated intuitions about the a-priori nature of the correlation between thought and being to include the ability to interpret, since we inhabit, a world radically indifferent to any conceptual distinction. Nature becomes a curmudgeonly gainsayer who can refuse to yield to any determination of theory or sensibility; it will shout "NO!" whenever it bloody well likes and may not speak our language.fdrake

    Again, I think I, in fact, agree with you. And I believe that the 'weak correlationist' does not deny the validity of ancestral statements. Rather, as you said before he only says that ancestral statements are made within a frame. Of course, this does not make them invalid!
    I really do not think that 'weak correlationism' is more (or much more) than this.

    [Also, I believe that the distinction between 'direct' and 'indirect' that I made in my previous post knowledge is apt. This should not be taken to mean that knowledge of e.g. what is observed in other perspective is devalued (unless one wants to become an epistemic solipsist of sorts) but only that it is indirect...]
  • boundless
    112


    Thank you for emphasizing that!
  • boundless
    112


    Regarding the fact that cosmology is not a 'theory of everything', I suggest this nice talk about Carlo Rovelli: https://www.youtube.com/watch?v=TzmykSv6OBY (especially around minute 7 - it is a hour-long talk).

    Also the response to the first question in the Q&A section of that talk is interesting since it gives the idea of how much 'perspectival' is RQM, see: https://www.youtube.com/watch?v=TiXzq4G10mk (the first question ends around 2:30). Anyway, the whole video is very good.

    Maybe also @Andrew M and @noAxioms might find the above linked videos interesting.
  • Wayfarer
    7k
    Nature becomes a curmudgeonly gainsayer who can refuse to yield to any determination of theory or sensibility; it will shout "NO!" whenever it bloody well likes and may not speak our language.fdrake

    How is this not simply Popper's 'falsification' at work? In saying that, I'm not implying any belittlement of that principle, I think it is profoundly important. But the point of the principle is explicitly to differentiate empiricism from metaphysics, and here I think we're dealing with the latter.

    we inhabit a world radically indifferent to any conceptual distinction.fdrake

    But that can't be true, or else mathematical physics would not have been as brilliantly successful as it has been (not to mention all of the other successes of mathematical science). As to why this is the case, Einstein himself said that 'the most incomprehensible thing about the universe is that it is comprehensible', and Eugene Wigner wrote his well-known essay, 'the unreasonable efficiency of mathematics in the natural sciences' on the same topic.

    I think the basic issue with Meillassoux' analysis, is that it doesn't properly grasp the meaning of 'a priori'. The priority of the categories of the understanding (and so on) is not a temporal priority. It's that in order to understand anything, in order to exercise reason, then the axioms of reason, the laws of thought must hold true. So they're prior to empirical science, in the sense that empirical science has to assume them in order to begin to theorise about anything.

    Because we now naturally view everything through an evolutionary perspective, then it's also natural to assume that logic, reason and language are an evolved capacity - which in the temporal sense they obviously are. Then we further think, well the Universe is vast and 13.8 billion years old, whereas us tiny specks ('chemical scum' in Hawking's charming phrase) are like insignificant blips in a vast and largely incomprehensible Universe. Hence 'Science reveals a time that not only does not need conscious time but that allows the latter to arise at a determinate point in its own flux.'

    Whereas the classical understanding was that because we're able to reason and discern causal laws and principles, then the mind's capacity to reason must correspond to a kind of sovereign reason that governs the Cosmos. (Of course that sounds far too close to natural theology to be PC in today's world.)

    But in my view, Meillassoux' attitude is precisely that which is subject to Bohr's criticism when he said that 'the objective world of nineteenth-century science [is] not the whole reality.' Meillassoux is insisting that this 'wholly objective view' is ultimately authoritative, but again it doesn't acknowledge the role which the human mind, or rather, the rational intellect, plays in the construction of that scientific world-view, because it continues to insist that it must be based on something that exists independently of the mind. That is the basic error that crept into Western cultural discourse through Galileo and Descartes, and which quantum mechanics is now showing to be incorrect - but no matter how many times it does so, what Heisenberg termed 'dogmatic realism' will always find a way to deny it.
  • Andrew M
    598
    Maybe also Andrew M and @noAxioms might find the above linked videos interesting.boundless

    Thanks boundless - they're excellent videos and well worth watching for anyone with an interest in the philosophical aspects of QM. Fun quote from Rovelli at 36 mins: "When I told Max (Tegmark) that he was a relationist, he told me that he is going to convince me that I'm, without knowing, a Many World believer." Anyway, Rovelli has a slide at 40:15 that says:

    The price to pay for RQM:
    We need to get rid of the notion of:
    - absolute (observer-independent) state of a system
    - absolute (observer-independent) value of a physical quantity
    - absolute (observer-independent) fact

    The claim of RQM is that if you take this step, everything becomes simpler (cfr: special relativity, and the need of getting rid of absolute simultaneity.)
    RQM - Rovelli

    My questions are:
    1. Is this just a semantic difference with Many Worlds? (That is, there are nonetheless many physical branches, but there are only deemed to be facts relative to an observer's branch.)
    2. If not, then what is the substantial physical difference and what explains physical interference effects? (Many Worlds would explain it as physical interference between branches.)
  • fdrake
    1.9k


    I was wondering if you would answer a few questions for me before I respond in more detail:

    (1) Do you believe that ionic bonds happen without human intervention?
    (2) Do you believe they happened before the advent of humans?
    (3) Do you believe that human ratiocination can find order in nature because the human mind and the regularity in nature jointly participate in some eternal cosmic logos? If so, how do you think that works?
    (4) Do you believe in anything like the distinction between primary and secondary qualities? Primary qualities being like mass, tensile strength, temperature and so on. Secondary qualities being heaviness, sturdiness, warmth and so on.
  • fdrake
    1.9k
    What troubles me about this is that, on my understanding of QM, wave function collapse is non-measurable. It is a matter of interpretation, of ontology, not something that can be measured - so strictly speaking it isn't even part of QM. So either this experiment implies less than the MIT pop summary says it does, or I am going to have to radically revise my understanding of QM.andrewk

    Collapse mathematically is a mapping from an operator's spectrum to a one of its eigenstates right (a projection map)? Whether this collapse has a physical interpretation, and what that physical interpretation is, are where all the knots are AFAIK.
  • Wayfarer
    7k
    (1) Do you believe that ionic bonds happen without human intervention?
    (2) Do you believe they happened before the advent of humans?
    fdrake

    In principle, it doesn't matter whether it's an 'ionic bond' or any other chemical or physical relationship. The ionic bond is just an illustrative example.

    In response, it is perfectly possible to have a realist view of the empirical domain - the age of the earth, the universe, the solar system and so on. I take a realist view of all such facts. But it doesn't obviate the point, which is that the human mind - your mind and mine - is an essential pole in any such statement, even statements of empirical fact - which is the basic claim of transcendental idealism. So empirical knowledge, even knowledge of the early cosmos, is still the analysis of phenomena, of what appears.

    There's a passage in Magee's book on Schopenhauer that I've quoted previously. It's a bit lengthy but it does articulate the exact point, from a passage discussing some of the objections to Kant, and Schopenhauer's response.

    'Everyone knows that the earth, and a fortiori the universe, existed for a long time before there were any living beings, and therefore any perceiving subjects. But according to Kant ... that is impossible.'

    Schopenhauer's defence of Kant on this score was [that] the objector has not understood to the very bottom the Kantian demonstration that time is one of the forms of our sensibility. The earth, say, as it was before there was life, is a field of empirical enquiry in which we have come to know a great deal; its reality is no more being denied than is the reality of perceived objects in the same room.

    The point is, the whole of the empirical world in space and time is the creation of our understanding, which apprehends all the objects of empirical knowledge within it as being in some part of that space and at some part of that time: and this is as true of the earth before there was life as it is of the pen I am now holding a few inches in front of my face and seeing slightly out of focus as it moves across the paper.

    This, incidentally, illustrates a difficulty in the way of understanding which transcendental idealism has permanently to contend with: the assumptions of 'the inborn realism which arises from the original disposition of the intellect' enter unawares into the way in which the statements of transcendental idealism are understood.

    Such realistic assumptions so pervade our normal use of concepts that the claims of transcendental idealism disclose their own non-absurdity only after difficult consideration, whereas criticisms of them at first appear cogent which on examination are seen to rest on confusion. We have to raise almost impossibly deep levels of presupposition in our own thinking and imagination to the level of self-consciousness before we are able to achieve a critical awareness of all our realistic assumptions, and thus achieve an understanding of transcendental idealism which is untainted by them.

    Bryan Magee Schopenhauer's Philosophy, Pp 106-107

    Notice that whether we speaking of the ancient universe, an ionic bond, or a pencil on your desk, the same general observation applies.

    (3) Do you believe that human ratiocination can find order in nature because the human mind and the regularity in nature jointly participate in some eternal cosmic logos? If so, how do you think that works?fdrake

    Have a glance at the two paragraphs below this heading in the SEP entry on Schopenhauer.

    As the article states, this is a 'perennial philosophical reflection'. I mean - how is it that maths is predictive? What is the nature of number, and why, by being able to understand mathematical ratios, have so many profound discoveries been made by science? I'm not asking that to elicit an answer, and I don't claim to have an answer, other than to say that reason or the rational faculty obviously discloses facts about reality which can't be discovered by any other means. And furthermore that I don't believe it is meaningful to depict the consilience between mathematical logic and the properties of nature in terms of either mere chance, or biological necessity.

    (4) Do you believe in anything like the distinction between primary and secondary qualities? Primary qualities being like mass, tensile strength, temperature and so on. Secondary qualities being heaviness, sturdiness, warmth and so on.fdrake

    That distinction was essential to Galileo and subsequent science and philosophy. But even though it has been extraordinarily fruitful, it's also deceptive, because of the ramifications that it has for philosophy. Chiefly, this is because it results in what has been called 'the reign of quantity', the notion that only what is mathematically quantifiable is real, because then the mind and judgement and intellect and much else besides is covertly assigned to the domain of 'secondary qualities' (and then we wonder why there's a "hard problem"!) You will notice that this emphasis on the reality of the quantitative is a very widespread assumption in modern culture. But, as Robert M. Pirsig said, what is really wanting is a true 'metaphysics of quality' - and this is just what such an attitude excludes.

    I think we habitually adopt the outlook of scientific realism, without acknowledging the sense in which that too is a construct - vorstellung, in Schopenhauer's terminology. That doesn't mean it's all in the mind in an obvious sense, but that the subjective or mental pole is fundamental to it, and that pole is never objectively disclosed.

    (Michel Bitbol has written a lot about this, as I have recently discovered, courtesy of some links provided by boundless.)
  • fdrake
    1.9k
    I honestly don't understand your position and the relationship it has to my questions. I appreciate that you are probably trying to argue that the answer to the questions is immaterial because what is at stake is you educating me out of my unsophisticated pre-critical realism. In contrast, what I am trying to do is to show that the conditions for the possibility of sense of ancestral statements is a problem for correlationism. IE, the direct truth or falsity of these statements is not relevant, only the ability for it to make sense to suppose the truth or falsity of any statement.

    Ideally I want to know whether you think 'Ionic bonds happened before there were humans' makes sense when interpreted literally, even if that interpretation is misguided or shows an insufficient deference to the role the transcendental subject plays in apperception.

    In principle, it doesn't matter whether it's an 'ionic bond' or any other chemical or physical relationship. The ionic bond is just an illustrative example.Wayfarer

    In response, it is perfectly possible to have a realist view of the empirical domain - the age of the earth, the universe, the solar system and so on. I take a realist view of all such facts. But it doesn't obviate the point, which is that the human mind - your mind and mine - is an essential pole in any such statement, even statements of empirical fact - which is the basic claim of transcendental idealism. So empirical knowledge, even knowledge of the early cosmos, is still the analysis of phenomena, of what appears.Wayfarer

    Does taking a realist view mean you believe "Ionic bonds happened before the advent of humans"? I have a realist view and find this largely unproblematic to believe, even with the caveats related to 'ionic bonds' as a concept being the product of our understanding. They also just happened to happen long before they were theorised.

    Ionic bonds happened before the advent of humans, yes or no? Ionic bonding would have occurred even if humans never existed, yes or no?
  • noAxioms
    698
    In MWI, there is only a quantum system, the universe itself. Its quantum state is a vector in a Hilbert space.

    Now, consider a complex quantum system, that is a quantum system like, say, a pair of particles. Let us call them P1 and P2. To each particle is associated a Hilbert space, say, respectively, H1 and H2. To the total system we associate the Hilbert space, H, which is the tensor product of H1 and H2. So, the quantum state of the total system is a ray in the Hilbert space H, which is 'factorizable' into H1 and H2, the Hilbert spaces related to each particle. Here, the factorization is well-defined by the two particles themselves.
    boundless
    Sounds like if H is also factorizable into H3 and H4 instead of just H1 and H2, H3 and H4 'exist' as much as the other two, and yet cannot exist in different worlds from H1 and H2, only in different worlds from each other. I think I got the gist of your explanation in your post, but it seems that RQM might suffer from some similar issues.

    Well, I think that probably different 'Copenaghists' would give different responses (after all, there is no agreement among them about the right interpretation of the wave-function). But, I suspect that this problem might be avoided using the same argument that (IMO) is used by RQM, that is, reasoning with 'perspectives'. After I make a measurement, I am sure about the outcome of the other measurement. But until I actually receive the confirmation of it, such an event (the measurement) is outside my perspective.
    I do not know however if this argument is really enough to avoid non-locality.
    (Note that, more or less, this is the reasoning that is employed to avoid the 'block universe' interpretation of Relativity. In that case, the point is that each 'observer' can define 'its' own plane of simultaneity, i.e. its own present. But if we believe that all these events are 'actually real', then it is not too hard to show that it would imply that we are in 'block world': https://en.wikipedia.org/wiki/Rietdijk–Putnam_argument).
    boundless
    Don't know what simultaneity has to do with it. Relativity seems to work fine with a defined preferred present, even if there is no way to determine it in SR. I suppose that with spooky action at a distance, a preferred foliation would unambiguously label one event as the cause and the other as an effect, but as the experiment that Wayfarer linked shows, there is no spooky action. The distant person (Alice) can make the measurement and Bob (local) know it because it was a scheduled thing. And yet Bod can measure his half of the pair and verify it is still in superposition. QM demands this, so it is not an interpretation.thing . The OP sort of disproves and spooky action at a distance. Alice knows that Bob will take a measurement in one second, and knows the result she will learn tomorrow when Bob reports it, and yet Bob verifies continued superposition, and then an hour later he actually measures the polarity. The superposition doesn't go away due to Alice's action. Therefore there is no spooky action at a distance. No?

    As an aside, a note in that table says that the de Broglie-Bohm interpretation is compatible with relativity. This is IMO wrong. The point is maybe that we cannot observe any violation of relativity via the transmission of faster than light signals.
    The table says it denies locality. OK, I see the note [15] which seems to claim a sort of loophole in Bell inequality. I do suppose that relativity has an implication of locality since without it, events with cause/effect relationship are ambiguously ordered. Not sure if relativity theory forbids that explicitly. A nice unified theory would be nice. The sort of 'weak' non-locality required by dBB interpretation claims to be Lorentz invariant, so that means causes and effects are unambiguously ordered, no? Not an expert, but if Alice and Bob both measure their entangled polarities fairly 'simultaneously', it seems the order of events is hardly Lorentz invariant. So maybe I just don't understand that note.
  • noAxioms
    698
    Those two version of Alice, being in different worlds, cannot communicate or otherwise be aware of each other. But they behave exactly identically because they're keeping that knowledge a secret.
    — noAxioms

    But note that they're not actually identical since they each have a different memory of what they measured. What Bob can do is reverse Alice's polarity measurement while retaining the record that the measurement occurred, which is identical for both Alices. This means that the two Alices will merge without memory of the polarity result and with all records of the polarity result having been erased.
    Andrew M
    Don't know what you mean by 'reverse polarity', but yes, Alice can take her knowledge of the result and put in on paper and mail it to somebody, and then forget about it, allowing Alice to merge with herself. That's how they do it in the lab. The device that takes the measurement sends the result down the pipe and is afterwards totally unaltered by the result of that measurement. It un-splits, and only the thing 'in the mail' is still in superposition.

    That is, there will be only one world branch again, with multiple histories, and with the record that a definite polarity result was measured by Alice.
    If Alice discards the result like that, then it wasn't done. Memory of having done it doesn't change that. A mirror doesn't reflect a photon. It measures it and sends a new photon out at the new angle and same polarity, and is afterwards unaffected by having done that. It doesn't count as a measurement since the photon is still in superposition.

    This is analogous to the double-slit experiment where the single particle detected on the back screen had two distinct path histories (one for each each slit).
    Yes.
  • boundless
    112
    Thanks boundless - they're excellent videos and well worth watching for anyone with an interest in the philosophical aspects of QM. Fun quote from Rovelli at 36 mins: "When I told Max (Tegmark) that he was a relationist, he told me that he is going to convince me that I'm, without knowing, a Many World believer.Andrew M

    Yeah they are very good and the quote is very funny :wink:

    1. Is this just a semantic difference with Many Worlds? (That is, there are nonetheless many physical branches, but there are only deemed to be facts relative to an observer's branch.)Andrew M

    I believe that Rovelli himself treats the wave-function as not descriptive. So, he would not say that there are 'many physical branches'. I am inclined to agree with this but I understand that it is somewhat problematic. As I said elsewhere, honestly I am a bit averse to the idea behind 'Many Worlds' (i.e. that "whatever can happen, does happen"). But that's subjective.

    Anyway, even if one accepts the 'existence' of 'many physical branches' there is still a crucial difference IMO between MWI and RQM - and this is a more 'technical' objection if you will. In MWI, the 'only real thing' is the quantum state of the universe. This leads to some problems as I mentioned to NoAxioms. Check for instance this paper by JM Schwindt: https://arxiv.org/abs/1210.8447.

    Here Schwindt says that even if one accepts that decoherence solves the 'preferred basis problem' once a factorization of the Hilbert space is done that allows for instance to 'decompose' the universe into the measured physical system and its environment (BTW, as I understand it, decoherence solves this 'for all practical purposes' in fact but let's assume we are content with it). But as you might have noticed, decoherence is based on the assumption that a factorization is already made. The point is that Hilbert space by itself is structureless and this raises a lot of problems. Firstly, why we would make a factorization in the first place? This is a need that, of course, we have but it is an a-posteriori requirement based on our experience that a propri is not needed in the theory. Secondly, assuming that we do not regard that a problem, we need to factorize. What happens, however, is that factorization is arbitrary and in some factorizations 'nothing happens' (no interaction etc). Hence, even if we do the factorization the theory itself does not justify that we experience change and so on. So, to avoid this, it seems that we need to accept all possible factorizations: MWI becomes a Many-Many World Interpretation where all histories of all factorizations 'exist' (like the one we are 'experiencing').

    Now, I do not know if a version of this problem might appear in RQM (which AFAIK does not even use decoherence). The reason is that in MWI you regard the entire universe as the single 'real system' and you need to add an 'additional structure' in order to decompose the universe into subsystems. In RQM, the subsystems are the 'primary' because they are given by experience (in MWI, instead you try to derive experience from the universal wavefunction).
    In other words, factorization is something that you do not need to justify simply because it is so to speak given by experience. (Also the comparison between RQM and Everett's theory in the SEP article about RQM might be interesting here...)

    Check also this discussion on physicsforums: https://www.physicsforums.com/threads/why-does-nothing-happen-in-mwi.822848/

    Honestly, I do not know if MWI-supporters have found a solution to this problem.

    2. If not, then what is the substantial physical difference and what explains physical interference effects? (Many Worlds would explain it as physical interference between branches.)Andrew M

    Well, yeah I honestly do not know how you can explain that if you assume that the wave-function is not 'real'. So, I unfortunately cannot give you a response.

    If the wave-function is taken as 'real', then the situation is still different from MWI IMO (as I explained above, hoping that it made some sense LOL...). Mauro Dorato apparently tried to explain RQM in terms of dispositions, check: https://arxiv.org/pdf/1309.0132.pdf
  • boundless
    112
    Sounds like if H is also factorizable into H3 and H4 instead of just H1 and H2, H3 and H4 'exist' as much as the other two, and yet cannot exist in different worlds from H1 and H2, only in different worlds from each other. I think I got the gist of your explanation in your post, but it seems that RQM might suffer from some similar issues.noAxioms

    I'll answer to this now. I try to answer to the rest of your post ASAP.

    Anyway, as I said also to AndrewM I think that the problem is even deeper. Consider now that you want to identify H1 as the Hilbert space of physical system that is measured and H2 as the Hilbert space of the 'environment' (that is 'the Universe minus the system').

    In MWI, you just have H. The theory itself does not tell give you any way to decompose H a-priori. Of course, we observe that something happens and, therefore, we need a factorization/decomposition (but note that the basic ontology of MWI is simply H, which is a-priori without any structure). But here we have two problems:

    1) if we factorize, we note that the factorization is completely arbitrary. And in some factorizations you get into a 'situation' where nothing happens. No measurement, no interactions etc. So it just appears that the measurement is due to a sort of illusion due to a bad choice of 'decomposing' the universe.
    2) even if you accept the above, then you have to accept that all factorizations/decompositions are actual. So you end up in the situation you mentioned: a Many-Many world situation where all decompositions and all histories related to each of them 'exist' like the one you are living.

    As I (tentatively) said to AndrewM:

    Now, I do not know if a version of this problem might appear in RQM (which AFAIK does not even use decoherence). The reason is that in MWI you regard the entire universe as the single 'real system' and you need to add an 'additional structure' in order to decompose the universe into subsystems. In RQM, the subsystems are the 'primary' because they are given by experience (in MWI, instead you try to derive experience from the universal wavefunction).
    In other words, factorization is something that you do not need to justify simply because it is so to speak given by experience. (Also the comparison between RQM and Everett's theory in the SEP article about RQM might be interesting here...)
    boundless

    Check also this discussion on physicsforums: https://www.physicsforums.com/threads/why-does-nothing-happen-in-mwi.822848/
  • boundless
    112
    Ionic bonds happened before the advent of humans, yes or no? Ionic bonding would have occurred even if humans never existed, yes or no?fdrake

    I am not Wayfarer, but I try to give an answer from a 'Kantian' or 'quasi-Kantian' viewpoint.

    A 'moderate correlationist' (i.e. neither 'weak' nor 'strong') might say 'a la Kant' that while humans (or more generally sentient beings) do not 'create' reality, the 'world as it appears' to us is just our representation. In other words, it is given by the sum of the 'noumenon' (which is unkowable) and our mind. So, to your questions he might answer: for the first 'yes' in the sense that 'things in themselves'* exist independently and 'no' for the second in the sense that 'Ionic bondings' are 'empirical things in themselves' (and hence part of the 'representation'): see the fifth note here https://plato.stanford.edu/entries/kant-transcendental-idealism/notes.html (these are the notes to the SEP article on Kant's transcendental idealism).

    *Note that Kant used the plural and hence he allowed the possibility that the 'noumenon' could be made of a plurality of things (and hence, this would put him quite close to the 'transcendental realist' camp). Schopenhauer denied that plurality could be a feature of the 'thing in itself' (hence, he used the singular), claiming that it is a category of our intellect.

    A 'strong correlationist' might say that it appears that ionic bonding would exist before the advent of sentient beings. I believe that Schopenhauer is a 'stronger correlationist' than Kant, because he says explicitly that you cannot even think about the universe where no sentient being exist and the previous story of the universe is actually related to the opening of the 'first eye' (i.e. the appearance of the first conscious being) and he also believed that the 'thing in itself' was singular.

    BTW, similar remarks have been made by e.g. John Wheeler with his idea of 'Participatory Anthropic Principle' (check the 'Variants' section in the article on Wiki about the anthropic principle, which also mention Schopenhauer) and this interview with Andrei Linde (especially after minute 6). So, it seems that some physicist do embrace this sort of idea (there is also the 'Many-minds interpretation', a version of the MWI where minds have a special role).

    In any case, what is common in Kantian-like philosophies is a sort of paradoxical situation of 'external objects'. Since they are regarded the cause of our sensorial experience, they must exist independently by us as the 'empirical things in themselves' (hence 'empirical realism'). At the same time, however, they are still 'inside' the representation. Check also how Kelley L. Ross deals with this issue of 'empirical realism': http://www.friesian.com/kant.htm#idealism.
  • fdrake
    1.9k
    In any case, what is common in Kantian-like philosophies is a sort of paradoxical situation of 'external objects'. Since they are regarded the cause of our sensorial experience, they must exist independently by us as the 'empirical things in themselves' (hence 'empirical realism'). At the same time, however, they are still 'inside' the representation. Check also how Kelley L. Ross deals with this issue of 'empirical realism': http://www.friesian.com/kant.htm#idealism.boundless

    Yes, the relationship between empirical exteriority and transcendental interiority is exactly what this kind of argument challenges.

    What is remarkable about this description of the modern philosophical conception of consciousness and language is the way in which it exhibits the paradoxical nature of correlational exteriority: on “the one hand, correlationism readily insists upon the fact that consciousness, like language, enjoys an originary connection to a radical exteriority (exemplified by phenomenological consciousness transcending or as Sartre puts it ‘exploding’ towards the world); yet on the other hand this insistence seems to dissimulate a strange feeling of imprisonment or enclosure within this very exteriority (the ‘transparent cage’). For we are well and truly imprisoned within this outside proper to language and consciousness given that we are always-already in it (the ‘always already’ accompanying the ‘co-’ of correlationism as its other essential locution), and given that we have no access to any vantage point from whence we could observe these ‘object-worlds’, which are the unsurpassable providers of all exteriority, from the outside. But if this outside seems to us to be a cloistered outside, an outside in which one may legitimately feel incarcerated, this is because in actuality such an outside is entirely relative, since it is – and this is precisely the point – relative to us.
  • Wayfarer
    7k
    Ideally I want to know whether you think 'Ionic bonds happened before there were humans' makes sense when interpreted literally, even if that interpretation is misguided or shows an insufficient deference to the role the transcendental subject plays in apperception.fdrake

    Why is the question being asked? What lead to the asking of the question? What is the issue? Isn’t it because physics itself has challenged the idea of ‘observer-independence?’

    Ionic bonds happened before the advent of humans, yes or no? Ionic bonding would have occurred even if humans never existed, yes or no?fdrake

    You can’t get a y/n answer to that question. Yes, there is evidence of the history of the cosmos prior to the evolution of h.sapiens . But all of that evidence exists in an interpretive framework which presumes a perspective. Thatt perspective is generally implicit, bracketed out. But physics has made that ‘bracketing out’ explicit - hence the interpretive issue.
  • boundless
    112
    Yes, the relationship between empirical exteriority and transcendental interiority is exactly what this kind of argument challenges.fdrake

    Yeah, I should have specify that :smile:
  • andrewk
    2k
    Whether this collapse has a physical interpretation, and what that physical interpretation is, are where all the knots are AFAIK.fdrake
    With decoherence, which is key to my preferred interpretation, collapse does not happen, unless we want to call a rapid but continuous evolution from one state to another a collapse.
  • fdrake
    1.9k
    Why is the question being asked? What lead to the asking of the question? What is the issue? Isn’t it because physics itself has challenged the idea of ‘observer-independence?’Wayfarer

    The claim that something exists mind-independently does not commit one to the claim that it is conceptually inaccessible. We conceptualise the world and thereby come to know it. You're continually confusing the ability to conceptualise X with X's existence. The reason for me continuing to pursue the question is because I hope that we agree that the ability to conceptualise X is different from X existing; and I want to bring that to a point by inviting you to consider a scenario in which one of our concepts continues to operate; ionic bonding; its reference class continues to have exemplars; the formation of sodium chloride; but we are not around to see it.

    You can’t get a y/n answer to that question. Yes, there is evidence of the history of the cosmos prior to the evolution of h.sapiens . But all of that evidence exists in an interpretive framework which presumes a perspective. Thatt perspective is generally implicit, bracketed out. But physics has made that ‘bracketing out’ explicit - hence the interpretive issue.Wayfarer

    The interpretive issue is not whether the term 'ionic bonding' in 'ionic bonding occurred prior to humans existing' is a result of human conceptualisation; we do have a theory of ionic bonding; the interpretive issue is that a condition for the possibility of the meaning of the statement 'ionic bonding occurred prior to humans existing' requires there to exist a reality prior to the existence of humans. Of course our theories about ionic bonding are a theoretical construct, but ionic bonding itself is not.

    The substitution of 'the conception of X' for 'X' is completely illegitimate in all cases for any empirical realist; you already know that X's existence is not dependent upon the conception of X.

    This is why I have been harping on about nature shouting 'no', and perhaps in a language we don't understand. We inhabit a reality which is not intrinsically concept ladened; it is independent of our conceptions of it; just like an uninhabited landscape exists and we do not populate it simply by thinking about it.

    It frustrates me somewhat that in order to defend the mind dependence of quantum observers you defend a Kantian position of transcendental idealism which grants the real an autonomy in excess of the phenomena constitutive of our interaction with it. If you are operating under the presumption of empirical realism, the literal interpretation of 'ionic bonding occurred prior to the advent of humans' is something which must make sense for you even if you think the claim is false.
  • fdrake
    1.9k
    decoherenceandrewk

    Thanks, I am a noob in this kind of discussion.
  • Wayfarer
    7k
    You're continually confusing the ability to conceptualise X with X's existence.fdrake

    I am not confusing anything. Why do you think Neils. Bohr found it necessary to say that ‘if you haven’t been shocked by quantum physics, then you don’t understand it?’ It’s precisely because it calls into question our innate realism. You have a commitment to the reality of the domain of sense-experience, but you don’t see the way in which the mind itself imbues that domain with reality.

    Notice that snippet from Magee which refers to the ‘inborn realism that arises from the natural disposition of the intellect’. That’s what you’re arguing on the basis of. And it’s not stupid or deficient to see it in those terms. It’s simply that it’s been called into question by science itself. That is what, I say, Bohr says is ‘shocking’.

    If you are operating under the presumption of empirical realism, the literal interpretation of 'ionic bonding occurred prior to the advent of humans' is something which must make sense for you even if you think the claim is false.fdrake

    I don’t think the claim is false, but that it’s ‘a claim’!
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