• Art48
    459
    Is this accurate? Comments?

    The collapse of the wave function in quantum mechanics is sometimes loosely described as caused by “observation,” which implies consciousness can physically affect the universe by causing the collapse. However, “measurement” is more accurate that “observation” because measurement apparatus itself rather than consciousness causes wave function collapse.
  • universeness
    6.3k
    No, the measurement problem causes wave function collapse in the sense that a result will be gained from the act of measuring. No human or electronic observer makes any difference so human consciousness has no impact or role to play in wave function collapse.
    Carlo Rovelli and others, propose that the collapse is localised. The wave function does not collapse universally.
  • jgill
    3.6k
    It's unfortunate this kind of language is used for this purpose. Heisenberg and Bohr cautioned against thinking of this as a physical process or having a "picture" view of what was going on. But then there are several interpretations of what's going on. Its so easy to let one's imagination follow a kind of mental animation.
  • alan1000
    182
    What a jewel in the mud this thread is. Only three posts; an intelligent question, which attracts two intelligent answers, and no further comment really needed. If only the rest of the forum could be like this.
  • javi2541997
    5k
    . If only the rest of the forum could be like this.alan1000

    Waiting for your answer about the OP then.
  • sime
    1k
    A generally problematic consequence of making a hard distinction between conscious observation and measurement, is that it throws the empirical significance of measurement into doubt; science is supposed to validate theory against observation through measurements, but how is that validation possible if measurements aren't at least partially identified with the conscious observations themselves?

    The general reason why science resists taking measurements for conscious observations, is because measurements are taken as referring to the obtaining of observable values, whereby the set of measurements is taken to include both potential observations and actual observations. This is because science is by design not a private language, but a public language for facilitating inter-subjective communication among individuals whose actual experiences are in contradiction with one another.

    The conundrum for the realist is, if 'potential observations' are to be of necessary importance to empirically accountable theories, as opposed to being unverifiable dogma for facilitating 'ornamental coping' among the communicating public, then what could potential observations amount to other than actual observations of some sort or other?

    Roger Penrose once criticised the many universe interpretation, saying it fails to address the central mystery of Quantum Mechanics which is why can't we directly observe the quantum superposition of live cat and dead cat"?. On the other hand, if potential observations are taken to be semantically equivalent to actual observations of some sort, then one does indeed observe "Live cat + dead cat" - for example by interpreting "live cat + dead cat" to refer to the conditions of state preparation of the respective quantum superposition. This aspect of semantics is of course not what Penrose had in mind.

    Until another big theory change comes along, QM is most naturally interpreted as irrealist theory that describes a process of interaction between a particular individual and his world, as opposed to being a realist theory defining a set of propositions that are held true by all observers simultaneously. For verification minded logical positivists, this isn't a defect of the theory since they interpret all theories in this way.

    When interpreted in irrealist or idealist fashion, it is logical to associate consciousness with wave-functions in the same way as with any other proposition whether classical or quantum - but it isn't logical to[ think of consciousness in terms of wave-function collapse- for this move prohibits the deflation of "conscious observation " to "observation", since according to verificationism quantum superpositions are consciously observable. It also goes without saying that consciousness cannot be considered a causal event.
  • universeness
    6.3k
    At the risk of demonstrating the folly of employing imagery of the type that jgill is correctly pointing out with:
    It's so easy to let one's imagination follow a kind of mental animation.jgill
    I 'imagine' measuring at the sub-atomic level as trying to measure the amplitude of a small water wave during a hurricane using a ruler. You might take lots of snapshot pictures and then try to identify and measure a small wave amplitude. To me, this is probably a poor conceptualisation of wave collapse but it kind of explains that the water wave system did not universally collapse and taking the snapshots did not physically collapse the wave but your measuring technique was able to achieve a valid measurement of the amplitude of a small water wave, during a hurricane. I used the hurricane image to invoke (again probably quite poorly) the random chaos proposed in underlying quantum fluctuations.
    This is only my own musings based on what I have watched and read from those who know much more than I on the topic but the measurements taken at the subatomic level are very accurate as they match equation predictions.
  • apokrisis
    6.8k
    However, “measurement” is more accurate that “observation” because measurement apparatus itself rather than consciousness causes wave function collapse.Art48

    A thing to think about is that the “collapse” happens when reality is forced to answer a counterfactual question as some kind of suitable mechanism is imposed upon it. So the experimenter demands a clear yes or no as a logical demand. Some instrument physically implements that logic in its design. Nature delivers an answer in the tick or flash of a detector circuit.

    So we can at least see that it is not “consciousness” interacting with nature as some kind of substance. It is us humans imposing our logical conception on the situation to discover how closely nature might conform to our mechanistic vision of causality.

    That is not to say that nature doesn’t thermally decohere in a manner that we would describe as counterfactual. But it is to draw attention to the semiotic nature of the interaction between experimenter, instrument and world.

    The experimenter is looking for a sign. A machinery is created to produce one. It only has to be “the truth” in a pragmatic sense. A number on a dial.
  • Gnomon
    3.5k
    The collapse of the wave function in quantum mechanics is sometimes loosely described as caused by “observation,” which implies consciousness can physically affect the universe by causing the collapse. However, “measurement” is more accurate that “observation” because measurement apparatus itself rather than consciousness causes wave function collapse.Art48
    I agree that "measurement" is more appropriate as a causal force, than mere "observation". The latter term can be construed as Passive, while the former is Active. But the causal "apparatus" here is not necessarily the dumb machines focused on the event. For example, a video camera aimed at a physical incident does not cause anything to happen (e.g. video of Rodney King being beaten by police). Yet human minds, not just docilely observing, but actively extracting meaning from the video, can eventually cause a rioting mob scene.

    In a similar manner, a scientist setting-up a quantum experiment is guided by the conscious intention of extracting information from the observed "collapse"*1 of wave-like behavior into particular activity. The key word here is "information", traditionally known as "meaning in a mind". 21st century physics is now equating Information with Energy. So, it's not surprising that extracting bits of information from a physical process could have measurable physical consequences. In the 20th century that suggestion sounded like magical mind over matter. Now, it's no more magical than a physical particle passing through a solid barrier (as in Flash Memory). Remarkable yes, but magical no. A number on a dial has no meaning until interpreted by a mind in the observer. :smile:

    *1. More like an instantaneous Phase Transition (e.g. water to ice)

    The mass-energy-information equivalence principle :
    Here we formulate a new principle of mass-energy-information equivalence proposing that a bit of information is not just physical, as already demonstrated, but it has a finite and quantifiable mass while it stores information.
    https://aip.scitation.org/doi/10.1063/1.5123794

    ENERGY AND INFORMATION :
    https://www.jstor.org/stable/24923125

    Mental Measurement -- Physical Effect :
    The author notes that “everything strange about quantum mechanics comes down to measurement”. But, what’s so odd about taking the measure of things? In this case it’s the active intrusive role of the mind of the measurer. The Latin root is “mensura”, from the word for “mind”. Which may be why Protagoras claimed that “man is the measure of all things”. So the “measurement problem” of quantum physics is concerned with what causes the superposed (all over the place) continuous wavefunction to “collapse” into a single discrete particle in one location. How does an inquiring mind cause an invisible potential object to suddenly appear, as-if from nowhere?
    One clue may be found in the notion that a scientific measurement can be construed as extracting essential Information (like pulling a Linchpin⁹) from the oceanic waveform. Thus disentangling the whole system into its components, one of which is a quantum of energy that we perceive as a specific particle of matter. That’s a metaphorical¹⁰ explanation for an otherwise inexplicable physical event, barring magic of course. . . . . Bohr explained that the difference-that-made-a-difference¹² in information received by an experiment is not just looking, but in “the way we look”. And the “way” (the question) is determined by what we want to know.
    Note --- quotes from Phillip Ball's, Quantum Weirdness
    http://bothandblog7.enformationism.info/page45.html
  • boethius
    2.2k
    The collapse of the wave function in quantum mechanics is sometimes loosely described as caused by “observation,” which implies consciousness can physically affect the universe by causing the collapse. However, “measurement” is more accurate that “observation” because measurement apparatus itself rather than consciousness causes wave function collapse.Art48

    It's now in vogue to say "measurement" than "observation", but that seems more to do with new age spiritualists wildly speculating in a word salad of quantum and consciousness and universe and so on.

    However, it is not accurate.

    The whole point of Schroedinger's cat in the box, is that we don't know the state of the cat until we look. If we put some measuring device inside the box, to measure the cat's breathing for example, then we don't know the state of the measuring device until we look.

    Indeed, the whole point of the cat in the thought experiment, is to measure the state of the poison, which measures the state of a geiger counter, which measures the state of radioactive decay.

    "What's actually in the box when we don't look" is not answerable, and our state of knowledge will be a probability distribution of the possible states ... until we look.

    If you say "no, no, no, the box has a definite state because of this measuring device; look, we can open the box and read out the measurements" the whole point is that doesn't prove what the state of the measuring device was before looking.

    There's many interpretations available, including fully deterministic formulations of quantum mechanics, but wave collapse isn't excluded either.

    However, the "local collapse" proponents just don't seem to get the whole point of Schroedinger's cat thought experiment, which is that we don't know until we look. If we don't look at a measuring device, we don't know what it's measured and we don't know if it's in a superimposition of having measured different things. The only way to verify it's in a definite state is to go look ... which of course doesn't prove what state it was in before looking.

    Although it seems incredibly bizarre that consciousness is the only real "measurement" standard (the only one we can consciously verify anyways), and the implications would be even more bizarre, naive realism has always failed in quantum mechanics.

    Not to say that local collapse isn't a candidate for how the "world really works", but my feeling is that it's mostly used as a naive realist crutch, whereas the history of quantum mechanics is the systematic removal of all such crutches; so, mostly obstructs people's understanding of quantum mechanics by providing something easier to visualise (that there is a "definitely real" measuring apparatus and all the weirdness of quantum mechanics is confined to small systems being measured).

    For all these reasons, one of the most popular interpretations of quantum mechanics among working physicists is "shut up and calculate".
  • Agent Smith
    9.5k
    An observation is sometimes a measurement itself (quasi-mathematical) and at other times, it's becoming aware of a measurement (by an instrument).

    While it seems hard to determine whether measurement (the first sense, vide supra) alone causes the so-called collapse of the wave function, it doesn't seem impossible to do so. Oui?
  • boethius
    2.2k
    While it seems hard to determine whether measurement (the first sense, vide supra) alone causes the so-called collapse of the wave function, it doesn't seem impossible to do so. Oui?Agent Smith

    There may not even be a wave function to collapse. Pilot wave theory, for example, is fully deterministic formulation of Quantum mechanics.

    Deterministic theories have hidden variables we can't see ... so how do we know they are there? We don't.

    Likewise, maybe a measuring device causes collapse even when we're not looking ... but how would we know without looking? We can't.

    If one simply takes the basic equations of quantum physics, one can simulate them forward indefinitely, there's zero reason to assume measurements have to happen at any time or anywhere.

    Indeed, there's no reason to assume the variables that evolve in super positions and entanglements are in some way strange at all. If we ignore our experience: it's just math and numbers that go from one state to another. Nothing more strange than solving any equations whatsoever.

    The only reason we assume there's some "definite" reality is because we are only aware of one definite reality, and therefore the other possibilities determined by the equations and some initial conditions, have to "go away".

    However, if for some reason we weren't aware of reality, just pure intellects considering the mathematics of quantum physics, we would not likely postulate measurements needs to happen at all.

    The whole troubling thing to the discoverers / inventors of quantum mechanics is that the state of knowledge of the system and absurd logical consequences of assuming our state of knowledge was how reality worked ... was how reality worked.

    For these purposes of understanding how strange this is, it's good to visit the first and simplest examples, such as quantum tunnelling. Our state of knowledge could be that the electron could be in region A or region B, but zero probability of being in region C that connects A and B. Naive realism would conclude that our theory is obviously wrong, and there must be some chance, even small, of finding the electron in region C as it quickly passes from A to B. This was the expectation, and people spent a lot of effort expecting to prove that "yes, yes, electron can be found in the space in between", but this test and all tests pitting naive realism against quantum mechanics failed.

    For, the first interpretation of the electron being in a probability distribution of locations was simply that it's somewhere flying around ... just we don't know until we look, is fundamentally disturbed if the electron can be in separate regions, since it cannot fly (at least in a continuous sense) between disconnected regions.

    In short, there's been a long series of unintuitive conclusions ... that even the discoverers thought must be wrong! Starting with Plank, who believed his quantising black body radiation was just a clever hack to be able to solve the equations in a way that matched up with reality. Which is not an unreasonable expectation as we use mathematical hacks all the time that clearly have nothing physical about them.

    To discover energy states really are quantised was truly shocking.

    Point is, whenever naive realism is "versus" quantum state of knowledge arguments, the latter has always won in the past. So, the measurement in the detector, in the wires, in the ram and on the screen is not determined until we look ... who knows, but the history of quantum physics does not support the habit of any fast and easy conclusions that are simple to "see".
  • boethius
    2.2k
    Additionally, if we were pure intellects discussing the equations of quantum physics, it would be unlikely that we'd posit the existence of a macro world that can be experienced in a pleasant way at all.

    We do not assume experience because our physical theories predict it, but because we experience.
  • Agent Smith
    9.5k
    I, for better or worse, lack the qualifications necessary to grasp the full import of your post.

    I can tell you this though, quantum physics to my reckoning is in dire need of philosophical nuance; something like that. Warning; pure speculation on my part.
  • boethius
    2.2k
    I can tell you this though, quantum physics to my reckoning is in dire need of philosophical nuance; something like that. Warning; pure speculation on my part.Agent Smith

    I think it's more how quantum mechanics is usually presented to a general audience, there is usually a "philosophical agenda", such as multi-world's theory, or new age-spiritualism, or proving or disproving God and so on.

    The problem is more that quantum physics has essentially zero philosophical content: as much compatible with free will as determinism, miracles "can happen" as much as they are extremely unlikely to happen, could be all a simulation and a way to simply compress the data of the simulation and so on and so on.

    Since quantum physics does not "reveal" real reality, just keeps tabs on observations, one can project anything one likes to imagine onto what is "really happening", which quantum physics does not actually comment on.

    Probably the most knowledgeable and the best lecturer (that we can observe on film), trying to connect with a general audience today on modern physics is Professor Suskind.

  • Agent Smith
    9.5k
    That's a fresh perspective - I don't recall coming across it till date. Awesome!

    Truth tends to be, fortunately/not, very mundane. Oh well, c'est la vie, mon ami.
  • boethius
    2.2k
    That's a fresh perspective - I don't recall coming across it till date. Awesome!Agent Smith

    To be clear, it's not my perspective but the pretty standard view among professional physicists (that I have talked to or have heard lecture).

    The Feynman lectures are the total classic:

    This 5 minutes excerpt explains incredibly well how the different interpretations of a theory on one level don't matter, but to find new ideas for a new theory matter very much:



    And if you really want to understand straight from the great genius (that we really don't understand what's really going on), the following lecture is "the classic":



    Throughout the lecture, he returns to the analogy of Mayan priests who know how to calculate and predict a lot of celestial phenomena, by just continuing the numerical pattern they've inferred from observational logs. They could do it, make predictions that came true, but (presumably) at that time would have zero idea what's really happening in the sky, and one speculation is as good as another, as much from the expert priest as from the laymen.
  • Gnomon
    3.5k
    The problem is more that quantum physics has essentially zero philosophical content: as much compatible with free will as determinism, miracles "can happen" as much as they are extremely unlikely to happen, could be all a simulation and a way to simply compress the data of the simulation and so on and so on.boethius
    That's a provocative assertion for a philosophy forum. Of course, Quantum Physics has no philosophical content for those who prefer to "shut up and calculate". Likewise, the self-moving rocks in the desert have no inherent philosophical implications, for those who are content just to dispassionately observe a strange phenomenon.

    But some of us are inclined to ask "how" (scientific) or "why" (philosophical) questions about mysterious events, such as invisible mathematical quantum fields suddenly manifesting detectable physical particles, only when actively measured. We can either explain one mystery by another, as in Miracles, or we can try to find a direct mechanical cause & effect connection (how).

    Or, we can propose an answer that is somewhere in between Magic & Mechanics (why). For example, the relationship between Information & Energy suggests a possible relationship between Quantum Queerness and Consciousness. Why? Because the physicist wants to know "how". :nerd:

    Does Consciousness Cause Quantum Collapse? :
    In conclusion, the ‘consciousness causes quantum collapse’ hypothesis – at least when combined with modern neuroscience – is a viable theory of physical and mental reality, which offers a clear research program and distinctive experimental predictions. It proposes a solution to the measurement problem by defining when and where collapse occurs. And it provides a place for consciousness in nature by giving consciousness a causal role. Developing this theory may well enable us to answer even deeper questions; questions such as why consciousness causes collapse and why consciousness exists at all.
    https://philosophynow.org/issues/121/Does_Consciousness_Cause_Quantum_Collapse

    Quantum Weirdness :
    Phillip Ball introduces his topic by clarifying the murkiness of Quantum Physics : “what has emerged most strongly from this work on the fundamental aspects of quantum theory is that it is not a theory about particles and waves, discreteness or uncertainty or fuzziness. It is a theory about information.” [My emphasis] He then admits that “quantum information brings its own problems, because it raises questions about what this information is . . . because information is not a thing that you can point to . . .” Consequently, his book is more about Philosophy than Science. Ironically, the exotic mathematics of Quantum Theory has become the foundation of 21st century science, even though its implications cannot be understood intuitively, or in terms of 19th century Classical Physics. Hence the so-called “weirdness” of QT has remained as queer as ever over the last century.
    http://bothandblog7.enformationism.info/page43.html


    Mystery of Death Valley's 'Sailing Stones' Solved :
    The rocks' apparent movement has been blamed on everything from space aliens and magnetic fields to pranksters. But no one has actually seen the rocks move, which only adds to the mystery.
    https://www.livescience.com/37492-sailing-stones-death-valley-moving-rocks.html

    QKLgMUWMSEGT35L7y5aZsM-970-80.jpg.webp

  • Agent Smith
    9.5k
    You hit the bullseye! That's why...

    Shut up and calculate. — N. David Mermin

    Why do you think it's the way it is? What's so incomprehensible about QM? Is it because when we translate the math (equations) into English we end up with gibberish (read contradictions)? As far as I can tell, there's a translation issue at the heart of so-called quantum weirdness. In short the problem is linguistic (mistranslations).

    Great post! I second the motion that philosophy has a stake in QM; at a bare minimum the philosophy of language wise.

    ---

    Zeno's paradox was "solved" using mathematics (of the summation of infinite series). :chin:

    Mayhaps we should mathematize the liar sentence and other paradoxes as well, oui mes amies?
  • Babbeus
    60


    I think measurement is the really relevant thing and not conscious observation because you can do multiple sequential measurements without observing any of them and check the results later. You will observe that the first measurement actually produced the collapse and all the subsequent measurements resulted in the same collapsed state, even though nobody observed it.
  • Agent Smith
    9.5k
    even though nobody observed it.Babbeus

    How do we know nobody observed? Wigner's friend? :chin:
  • Agent Smith
    9.5k
    Heisenberg and Bohr cautioned against thinking of this as a physical process or having a "picture" view of what was going on.jgill

    On point! Like the famous chiliagon (1000-sided polygon) .
  • Babbeus
    60

    How do we know nobody observed? Wigner's friend? :chin:

    It's a mental experiment where nobody observes.
  • Agent Smith
    9.5k
    It's a mental experiment where nobody observesBabbeus

    :chin:
  • noAxioms
    1.3k
    The whole point of Schroedinger's cat in the box, is that we don't know the state of the cat until we look.boethius
    That’s true of the cards the other poker player holds. The cat goes beyond just not knowing what’s in the box.

    Indeed, the whole point of the cat in the thought experiment, is to measure the state of the poison, which measures the state of a geiger counter, which measures the state of radioactive decay.
    All that can be done without the box. The point is what the box (something that hypothetically lets zero information escape from within) adds to the same situation without it. It can be done in a practical manner only by distance (putting the cat outside one’s past light cone). It isn’t a true superposition since there no way one is going to measure interference between the two cat states, so it actually does boil down to just plain not knowing, I admit. You seem to be taking an epistemological take on all this, but most of the interpretations are ontological, not just epistemological. Ontologically, the guy across the table holds three jacks, but you don’t know it is all.

    If you say "no, no, no, the box has a definite state because of this measuring device
    There can be no (external) device. The whole point of the box is to prevent decoherence, which leaves nothing to measure.

    If we don't look at a measuring device, we don't know what it's measured and we don't know
    Ah, but the superposition is gone if any decoherence occurs. One doesn’t have to actually know the result for the collapse to occur, as shown by say double slit experiments with polarized light: No interference pattern so no superposition even though the lab guy has no way of knowing which slit the thing passed through. This is pretty hard evidence that conscious knowledge has nothing to do with the collapse.

    Suppose you take away the hammer that breaks the poison bottle. The Geiger counter detects the decay or doesn’t, but the cat lives either way. Now you open the box and collapse the wave function, but learn nothing since both outcomes appear the same, and the cat isn’t going to tell you if the device clicked or not when detecting the decay.

    I know of only one interpretation that suggests consciousness is involved, and it’s author abandoned it since it can be driven to solipsism. Nobody but the woo forum crown is still on that wagon.

    For all these reasons, one of the most popular interpretations of quantum mechanics among working physicists is "shut up and calculate".
    Shuting up means just work with the theory, and kindly ignore all the interpretations, none of which have any scientific value. It isn’t an interpretation itself.

    There may not even be a wave function to collapse. Pilot wave theory, for example, is fully deterministic formulation of Quantum mechanics.boethius
    MWI also shares these traits. Collapse is phenomenological, but not physical in either case.

    Deterministic theories have hidden variables we can't see
    MWI is deterministic, and does not have hidden variables. Just saying.

    Likewise, maybe a measuring device causes collapse even when we're not looking ... but how would we know without looking? We can't.
    Again, that goes for the queen of clubs face down in front of me. Don’t confuse knowledge with something like the fact that the card in front of me is in fact the queen of clubs. This isn’t necessarily the case with quantum things.

    If one simply takes the basic equations of quantum physics, one can simulate them forward indefinitely, there's zero reason to assume measurements have to happen at any time or anywhere.
    That’s what MWI does, except for something ‘simulating’ it. I defy you to do such a simulation of say a radioactive sample for 10 seconds.

    Indeed, there's no reason to assume the variables that evolve in super positions and entanglements are in some way strange at all. If we ignore our experience: it's just math and numbers that go from one state to another. Nothing more strange than solving any equations whatsoever.

    The only reason we assume there's some "definite" reality is because we are only aware of one definite reality, and therefore the other possibilities determined by the equations and some initial conditions, have to "go away".
    Agree here. The going away part is mostly a matter of different definitions of what is and isn’t. Some interpretations are quite identical except for definitions like that.

    For, the first interpretation of the electron being in a probability distribution of locations was simply that it's somewhere flying around ... just we don't know until we look, is fundamentally disturbed if the electron can be in separate regions, since it cannot fly (at least in a continuous sense) between disconnected regions.
    Ouch for pilot wave theory then, which doesn’t use the term ‘flying around’, but definitely has it traversing some continuous path between A and B. Not sure how that (or any other counterfactual) interpretation deals with tunneling.

    Point is, whenever naive realism is "versus" quantum state of knowledge arguments, the latter has always won in the past.
    I’m not sure what model you’re calling ‘naive realism’. It gets mentioned a lot. Also not sure which interpretation is ‘knowledge argument’ since knowledge is only about what one might know about a system, not about what is actually going on.
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