• noAxioms
    1.5k
    Notice the quotes around 'bigger'. What I think you actually mean is, 'many'. They're very different things.Wayfarer
    They are very different things, and I meant ‘bigger’. Still one universe, but more of it than the story you found comfortable as a child. There were other universe theories (the only reasonable alternative to the intelligent design argument) long before Everett came along, so having other worlds is hardly a painful step.
    Einstein didn't like the uncertainty principle or the 'quantum leap' because he was a determinist.
    He also held to locality, so I think he would have liked an interpretation that was both local and deterministic.

    The observer problem is a problem because there’s nothing in the maths to indicate where the observer must come into the picture.Wayfarer
    I suspect that decoherence calculations do just that.
    This undermines the principle of objectivity
    That it does. I’ve discarded that principle, as do most of the interpretations. The science doesn’t care. Quantum theory is not concerned with what goes on in the absence of interaction between systems.

    Per your comment, "one also has to deal with how some of them are more probable than others", the basic idea (from Zurek - see the above post) is that paths that are not equally probable can be mathematically reduced to paths that are. For example, a beam splitter with a 2:1 transmission/reflection ratio is equivalent to a beam splitter with a 1:1:1 ratio once a 1:1 beam splitter is added to the transmission path.Andrew M
    What if the ratio isn’t rational?

    There's an 'observer effect' in Einsteinian relativity which nobody objects to. That's not the problem. — Andrew M
    There is? There are dependencies on frames (what velocity has object X?, a completely frame dependent question since Galileo), but I've not heard that observers have any effect at all. — noAxioms
    Yes, I'm referring to frame dependency.Andrew M
    That is a dependency on a choice of coordinate system. No actual observer need be present, or be stationary, in an arbitrary choice of coordinate system. The people on the platform and the train may (or may not) just happen to make different choices. You make different choices for yourself, such as using one frame to describe where your house is, and a completely different one to describe what Neptune is doing (which is moving faster than c in the frame you probably chose for your house).
    While the laws of physics are the same for all observers, they may describe things differently from their respective reference frames.
    That’s quite different than the interaction (measurement) actually changing the system being measured, which is what this topic is about.

    What Einstein does with "special relativity" is to give 'special' status to light, freeing it from the principles of relativityMetaphysician Undercover
    On the contrary, he brought light to be included in the principle of relativity, that it moving at c was such a law of physics that was unchanging, part of the principle of relativity. He freed light speed from being relative to a medium, or possible relative to that which emitted it, in both cases being different from one frame to the next. We each see the same things differently. I see it as bringing light into PoR, and you see it as being taken out.
    to allow that its motion is not relative to the motions of material bodies.
    But it’s motion IS relative to material bodies, or rather relative to any inertial frame including the one in which the material body is stationary. The second premise says that directly.

    This amplifies the 'observer effect' by greatly increasing the possibilities for subtle differences. Now there is a need for principles like time dilation, length contraction, relativistic mass, and things like that.
    But those are all frame effects, not observer effect. For instance, a clock coming at you fast will tick slow in your inertial frame, but it will be observed to run fast. Observer effects and frame effects are not the same.
    There are objective demonstrations of say length contraction, contraction that is real regardless of observer or choice of frame. That makes length contraction part of ‘a true perspective’, if that phrase is to have any meaning.

    Schrödinger's cat (call PETA asap) is both dead and alive (this is impossible in one world)Agent Smith
    Shouldn’t the cat simply be dead or alive then? What’s the difference when the box hasn’t yet been opened, other than the epistemological one where the lab guy doesn’t know the state of the cat. That would be a classic state like a coin tossed and caught, but not yet revealed. What makes the cat different if the world has already split?
  • Metaphysician Undercover
    13.2k
    I understand your point, however the specific contrast being made was between an observer qua reference frame and an observer qua rational agent. Only the latter can be understood as a user of quantum theory, and thus active in that sense.

    Unfortunately, I was not able to easily follow the rest of your post. Perhaps you could concisely state your claim and quote specifically from SEP what you're arguing for (or against).
    Andrew M

    I figured you wouldn't easily follow the post. It's an unconventional perspective, therefore adjustments to fundamental assumptions are required for understanding. So I'll give you the gist in a more straight forward way.

    The first point is that I do not accept the proposed contrast between "observer qua reference frame and an observer qua rational agent". All observations are human (rational agent) based activities. We can however, make a separation between the types of tools used by human beings in observation. We can distinguish the use of theories as tools, from the use of material objects as tools. It's easy to see that these two types of tools are fundamentally different, so this provides good grounds for a separation of distinct types of observational tools.

    So we can start with the "frame of reference", and understand this as a theoretical tool intended to aid in the interpretation of information received in observation. It is a feature of basic relativity theory which allows for choice in observational interpretation. All that is required is a valid "rest frame", or in the terms of the referred article, "inertial frame". The rest frame provides a grounding for the application of temporal measurement through the assumption of uniformity or constancy in the existence of mass relative to the passing of time. This is what is required for Newton's first law to be applicable. This law being a description of the existence of material bodies relative to the passage of time. So whenever the motion of an object is constant relative to that of another, we have the means for representing those objects relative to an independent measurement of time, and therefore a choice of inertial frames. Each is a valid inertial frame as constant relative to an independent measurement of time.

    The point I made in the last post is that special relativity effectively robs us of that choice of inertial frames by denying the validity of the independent measurement of time. Instead, it assigns an absolute value to the speed of light. There is still the illusion of a choice of inertial frames, but any such choice must be rectified in relation to light, so the absolute value assigned to light actually nullifies any truth to such a choice.

    Under special relativity the passage of time is not represented as relative to the inertial frame (as Newton's first law describes it with the constant, or uniform existence of mass), it is relative to the electromagnetic activity. In other words, the passage of time is not understood as, and measured as a constant relative to moving bodies, it is understood as a constant relative to the activity of light. The important point is that this means that there is no true inertial frame. Mass was defined as the temporal constant, now light gives the temporal constant. The concept of "inertial frame" is rendered invalid because no frame of reference can be constant. Each frame is moving relative to light, and time is understood as relative to light, so there can be no valid rest frame. The result is that uniform or constant motion, the property of an inertial frame, which is how Newton relates the passage of time to the existence of mass, is not a valid concept. Therefore there is no valid concept whereby the passage of time is related to the existence of mass.

    That, as I understand it, describes the theoretical aspect of observational physics. There are two distinct theoretical frameworks for interpreting information received in observation, the Newtonian perspective of "inertial frame", of the temporal continuity of mass, and the Einsteinian perspective which I'll call "energy". One bases the passage of time, therefore the standards for understanding time, in the constant uniform existence of mass, the other bases the passage of time in electromagnetic activity, "energy". There is an inconsistency between these two theoretical tools, which is displayed by the concept of "relativistic mass".

    From here, we can move toward understanding the other type of observational tool, the material objects which are employed as aids in receiving information. Consider an observational glass like a magnifying glass. Interpreting information received through the use of such a tool requires an extra layer of theory. We need theory as to how the light is affected by the glass prior to being observed by the human eye. This is the theory which goes into the production of the glass. Understanding the theory by which the glass affects the light, and by which the glass was produced, is an important feature required for a proper interpretation of the information received through the glass.

    Now consider the equipment used in typical wave-particle experiments, detectors and things like that. Within the equipment itself, there is built-in interpretive theory. So the information received by the observational equipment is interpreted according to the applied theory, and presented to the human being as already interpreted, an interpretation based in that theory. And, as explained above, we have two inconsistent theories with respect to temporal information, the inertial frame perspective (Newtonian), and the Einsteinian perspective, "energy". Therefore it is very important that we know exactly how (by which theories) the equipment interprets temporal information.

    On the contrary, he brought light to be included in the principle of relativity, that it moving at c was such a law of physics that was unchanging, part of the principle of relativity.noAxioms

    I believe this is an improper interpretation noAxioms. The principle of relativity makes all motions equally relative to each other. To stipulate that one movement, "c", is exempt from that principle, is to remove it from the application of that principle, "relativity", and give it special status, and we are left with "special relativity".

    I see it as bringing light into PoR, and you see it as being taken out.noAxioms

    I think you are "seeing" it incorrectly then. Prior to Einstein there appeared to be no way to make the motion of light compatible with the principle of relativity. It was a practical problem involving the difficulty in measuring the speed of light. If light was included within the application of the relativity principle, then the person on the embankment, and the person in the train car, would have to measure the light from the same source as having a different speed. Einstein saw that as very impractical, (and of course the difference is very small in proportion), so he suggested that we just stipulate that the speed of light is always the same, and we produce principles to make adjustments to the different frames of reference accordingly.

    Therefore, he does not bring light "into PoR" as you suggest. He leaves light as exempt from PoR and makes adjustments to PoR to allow that light can be related to it. So we have the substance of material bodies (mass) understood as obeying the principle of relativity, and light which is in a separate category of substance which does not obey relativity. Special relativity states the principle by which these to distinct substances can be related to each other. General relativity works out the details of this relation. The problem is that the whole idea that we can employ the relativity principle, and arbitrarily exempt something like light from it, for simplicity sake, is fundamentally flawed. That special exemption produces all sorts of problems which cannot be resolved. The result is two distinct and fundamentally incompatible (evidenced by "relativistic mass") temporal perspectives, space and time from the theoretical framework of light, and space and time from the theoretical framework of mass.

    But it’s motion IS relative to material bodies, or rather relative to any inertial frame including the one in which the material body is stationary. The second premise says that directly.noAxioms

    You are using "relative" ambiguously, and you need to be careful not to equivocate. In the relativity principle, the motion of bodies is "relative" in the sense that velocity varies according to the frame of reference. But the motion of light is constant, "an absolute" in relation to the motion of material bodies, not variable or relative in that sense. Therefore it is not "relative" in the sense of the relativity principle. So when you say the motion of light is "relative to material bodies" you are using "relative" in a way other than it is used in relativity theory, because every body regardless of its relative motion (according to relativity principle) is essentially at rest "relative" to light.

    But those are all frame effects, not observer effect. For instance, a clock coming at you fast will tick slow in your inertial frame, but it will be observed to run fast. Observer effects and frame effects are not the same.
    There are objective demonstrations of say length contraction, contraction that is real regardless of observer or choice of frame. That makes length contraction part of ‘a true perspective’, if that phrase is to have any meaning.
    noAxioms

    I think our respective understanding of terms is too far apart for me to properly address this, but I'll try anyway. To put it simply, the observer chooses the frame, so "frame effects" are observer effects. They are effects produced by interpretive theory. Special relativity impairs the observer's capacity to employ the relativity principle by producing those special effects. Those effects are the result of giving light the special status which exempts it from the relativity principle, yet still allowing light a special relation to the bodies whose motion the relativity principle is applicable to.
  • Janus
    16.3k
    It would be better to simply recognise there are things science is unable to ascertain and leave it at that. As a general rule, knowing you don’t know something is preferable to thinking you know something that you don’t.Wayfarer

    The irony in this statement is that it seems to be based on you thinking that you know what science can and cannot ascertain, rather than leaving it as an open question to be determined by further inquiry.

    That said, I agree that when it comes to first person experience; there seems to be no imaginable way that science could study it apart from accepting first person reports as to what it is, or what it seems to be, since it is not an inter-subjectively observable phenomenon. Because their veracity does not seem to be independently checkable, accepting first person reports would seem to be outside the scope of the scientific method as generally conceived.

    But does it follow that no one should try to come up with some approach that has not been previously thought of or tried? It seems that Dennett has proposed something along these lines with his heterophenomenology. I don't know enough about current neuroscientific work to say whether this kind of approach is actually being practiced, or practiced widely. Another approach which I think is being practiced, possibly more widely, is neurophenomenology
  • Wayfarer
    22.5k
    The irony in this statement is that it seems to be based on you thinking that you know what science can and cannot ascertain, rather than leaving it as an open question to be determined by further inquiry.Janus

    It's not just my opinion. I think what is known as the 'Copenhagen interpretation' and also QBism both acknowledge this. Remember Heisdenberg's ''What we observe is not nature itself, but nature exposed to our method of questioning.' I think the 'Copenhagen intepretation' (which is not a theory or an hypothesis but an attitude) is very mindful of what can't be said on the basis of quantum physics. Whereas those interpretations that insist on preserving so-called 'objectivity' are then obliged to posit infinitely dividing universes to accomodate their requirements.
  • Janus
    16.3k
    Apparently I thought I was in a different thread; so I was addressing what I thought was a claim that science can never investigate the first person nature of consciousness. I should have looked more closely before responding.

    That said, I think the MWI is just another speculative attempt to address the apparently paradoxical character of the collapse of the wave-function. The Copenhagen interpretation, decoherence and hidden variables are others, as far as I know, and what counts as an "observer" seems to be the crux of the issue, but admittedly I don't know much about the subject.

    If I am right and they are all just interpretations, then it would seem there could be no decidable resolution as to which is the "correct" one. In any case which interpretation is the correct one, even if it were possible to decide, really has no bearing on the practice of QM. Scientific theories are never provably true; we just know they work or don't work as predictive tools.
  • Agent Smith
    9.5k
    Schrödinger's cat (call PETA asap) is both dead and alive (this is impossible in one world)
    — Agent Smith
    Shouldn’t the cat simply be dead or alive then? What’s the difference when the box hasn’t yet been opened, other than the epistemological one where the lab guy doesn’t know the state of the cat. That would be a classic state like a coin tossed and caught, but not yet revealed. What makes the cat different if the world has already split?
    noAxioms

    I thought that superposition is a fact and not just a hole in our knowledge. In other words the coin is heads and tails and not that it's either heads or tails, only we don't know which.
  • PhilosophyRunner
    302
    I thought that superposition is a fact and not just a hole in our knowledge. In other words the coin is heads and tails and not that it's either heads or tails, only we don't know which.Agent Smith

    You thought correctly. And importantly this is a testable hypothesis that has been experimentally verified.
  • Agent Smith
    9.5k
    You thought correctly. And importantly this is a testable hypothesis that has been experimentally verified.PhilosophyRunner

    I should've worked harder in high school.
  • Metaphysician Undercover
    13.2k
    But it’s motion IS relative to material bodies, or rather relative to any inertial frame including the one in which the material body is stationary. The second premise says that directly.noAxioms

    Try looking at it this way noAxioms. By the principle of relativity no body can be truly at rest unless all bodies are at rest. So "inertial frame" is a sort of arbitrary designation requiring only constancy, uniformity. Motion which stays the same as time passes is the principle of relativity's "rest". And as you say, the motion of light "c" is relative to any inertial frame. But "inertial frame" is a feature of the theory, it is a theoretical observational tool derived from the uniformity observed in the passage of time. What defines the "inertial frame" is the uniform, constant passage of time. Therefore the speed of light is not grounded in, or relative to any material bodies, it is relative to the defining feature of the "inertial frame", which is the uniform passage of time.
  • jgill
    3.8k
    I thought that superposition is a fact and not just a hole in our knowledge. In other words the coin is heads and tails and not that it's either heads or tails, only we don't know which.Agent Smith

    Wikipedia:
    Quantum superposition is a fundamental principle of quantum mechanics. It states that, much like waves in classical physics, any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state; and conversely, that every quantum state can be represented as a sum of two or more other distinct states. Mathematically, it refers to a property of solutions to the Schrödinger equation; since the Schrödinger equation is linear, any linear combination of solutions will also be a solution(s)
    . . .
    In quantum physics, a quantum state is a mathematical entity that provides a probability distribution for the outcomes of each possible measurement on a system

    The cat really is either dead or alive, not in some mystical sense, both. Probabilities, on the other hand, are not definitive.
  • Agent Smith
    9.5k
    Well then what explains all the Sturm und Drang mon ami?! Why the hullabaloo if the cat is simply dead OR alive?
  • jgill
    3.8k
    ↪jgill
    Well then what explains all the Sturm und Drang mon ami?! Why the hullabaloo if the cat is simply dead OR alive?
    Agent Smith

    No one really knows exactly whats going on at the quantum level. If you simply follow the math and avoid all this metaphysical stuff, you do well at predicting. Apparently. Once the science popularizers get into the game, however, you see the Earth in basketball nets. Best to let the Q-physicists argue it out. My opinion. FWIW. Not much.
  • Agent Smith
    9.5k
    No one really knows exactly whats going on at the quantum level. If you simply follow the math and avoid all this metaphysical stuff, you do well at predicting. Apparently. Once the science popularizers get into the game, however, you see the Earth in basketball nets. Best to let the Q-physicists argue it out. My opinion. FWIW. Not muchjgill

    Danke! I recall saying that Schrödinger's =n is not a mathematical contradiction but is an English (natural language) contradiction.
  • Metaphysician Undercover
    13.2k
    No one really knows exactly whats going on at the quantum level. If you simply follow the math and avoid all this metaphysical stuff, you do well at predicting. Apparently. Once the science popularizers get into the game, however, you see the Earth in basketball nets. Best to let the Q-physicists argue it out. My opinion. FWIW. Not much.jgill

    Leave the metaphysics to be done by the physicists? Surely that's a mistake. Metaphysics consists of different principles which physicists have not been trained in.
  • jgill
    3.8k
    Metaphysics consists of different principles which physicists have not been trained in.Metaphysician Undercover

    Suppose I am a typical Q-physicist, following the mathematics but paying little attention to authorities in my subject babbling woo about interpretations. Please elucidate the training program in metaphysics I would need to complete to be considered competent in metaphysics. Be specific as possible.

    Would I need to attend the University of Metaphysics? Would a bachelor's degree be sufficient?
  • Andrew M
    1.6k
    What if the ratio isn’t rational?noAxioms

    Any irrational number can be approximated to an arbitrary degree of accuracy by a rational number. From the associated paper:

    For any wave function with irrational squared-amplitudes there exist arbitrarily similar wave functions with rational squared-amplitudes (as the rationals are a dense subset of the reals).Self-Locating Uncertainty and the Origin of Probability in Everettian Quantum Mechanics - Sebens and Carroll, 2015

    "While the laws of physics are the same for all observers, they may describe things differently from their respective reference frames." - Andrew M

    That’s quite different than the interaction (measurement) actually changing the system being measured, which is what this topic is about.
    noAxioms

    Yes, it is quite different. As is the effect you mention of a clock travelling fast towards you that appears to be ticking faster than it is. Perhaps we can call them (classical) perceptual effects, (relativistic) frame effects, and (quantum) measurement effects to disambiguate them for the purposes of this discussion.

    Anyway, whether or not the interaction changes the system being measured is what the Deutsch quantum AI experiment would test. That is, whether physical collapse occurs and interrupts the unitary evolution.

    A related test has been carried out at a microscopic level (using photons instead of AI's) where it was shown that physical collapse does not occur.

    In a state-of-the-art 6-photon experiment, we realise this extended Wigner’s friend scenario, experimentally violating the associated Bell-type inequality by 5 standard deviations. If one holds fast to the assumptions of locality and free-choice, this result implies that quantum theory should be interpreted in an observer-dependent way.Experimental test of local observer-independence - Proietti, et al., 2019

    So I'll give you the gist in a more straight forward way.Metaphysician Undercover

    Unfortunately, I didn't find your comment straightforward - I'm now not clear whether you accept special relativity or not. Can I suggest focusing on a single point, and stating it concisely. It might also be helpful to provide a quote from an authoritative source (such as SEP or a peer-reviewed paper) that backs up your point (or, alternatively, that you're disputing).
  • noAxioms
    1.5k
    The principle of relativity makes all motions equally relative to each other.Metaphysician Undercover
    Not quite. All motion can be specifed relative to a frame, specifically an inertial frame. Light speed is specified relative to (and is fixed only relative to) any inertial frame, so it isn’t an exception.
    To stipulate that one movement, "c", is exempt from that principle
    Never said that. You’re saying it, and it’s wrong since it would exempt it from the principle. Light has no special status in this regard.
    You seem to see an exception when I don’t. Mathematically, how does this work? How does it differ from say a neutrino (a massive particle) traveling here at almost c, such that we actually detect it from a supernova before we detect the light? Are neutrinos now also exceptions? We could have the Alice & Bob scenario with the train and the platform, but use neutrinos (or buses) instead of light, with the same result. Are we going to add these things to your exception list then?
    is to remove it from the application of that principle, "relativity", and give it special status, and we are left with "special relativity".
    The principle of relativity is one of the postulates of special relativity. Being part of that theory doesn’t mean anything gets special status. The word ‘special’ means a special case of no gravity being involved. With gravity, there are no longer non-local inertial frames and fixed speed of light goes away.

    I think you are "seeing" it incorrectly then.
    I realize you think that, and I’m trying to actually grok your opinion to the contrary. But as I say, mathematically it doesn’t work. Light obeys the same rules as everything else, just like PoR says it should.
    Prior to Einstein there appeared to be no way to make the motion of light compatible with the principle of relativity.
    This statement also seems to contradict what you’re asserting. Anyway, post-Michelson–Morley at least, new rules were needed since Newton’s application of PoR wasn’t working. In particular, relative velocity addition needed modification.
    It was a practical problem involving the difficulty in measuring the speed of light. If light was included within the application of the relativity principle, then the person on the embankment, and the person in the train car, would have to measure the light from the same source as having a different speed.
    First of all, one-way SoL still cannot be measured by any means, hence the speed being fixed being an additional premise, not something derived or measured. Secondly, the assertion you make (that these two observers would have to measure different speeds) does not follow from PoR.
    There are alternative theories that do not posit identical light speed relative to any frame. I think you’d like them. AFAIK, it took around a century to come up with a generalized version of such a theory, but it has been done. It involved doing away with the big bang and black holes and such, but empirically, it seems to hold water.
    The problem is that the whole idea that we can employ the relativity principle, and arbitrarily exempt something like light from it, for simplicity sake, is fundamentally flawed.
    Again I agree that such an exception would constitute a fundamental flaw, but this seems to be exactly what you’re suggesting.
    space and time from the theoretical framework of light
    This has no meaning under relativity theory, or for that matter any of the alternatives.
    You are using "relative" ambiguously, and you need to be careful not to equivocate. In the relativity principle, the motion of bodies is "relative" in the sense that velocity varies according to the frame of reference.
    Not necessarily so. Velocity might be specified relative to a frame of reference, but it just might by chance be the same from one frame to the next. PoR does not demand otherwise.
    But the motion of light is constant, "an absolute" in relation to the motion of material bodies, not variable or relative in that sense.
    It is exactly relative in that sense. For one thing, a given pulse of light might be heading north relative to one frame and east relative to another. But the magnitude of that velocity would be the same, yes, which is exactly what you’d compute if you performed a Lorentz transform from one frame to another You find this fixed speed to be a contradiction, but PoR does not forbid it. It just says the rules of physics are frame independent. You cannot locally detect your motion in an inertial frame. If you can show how that could be done, then I’d accept that some kind of exception was being made. It could be done under Newtonian physics, and M+M tried to measure just that: a detection of local motion as the understanding of the PoR suggested at the time.
    Therefore it is not "relative" in the sense of the relativity principle. So when you say the motion of light is "relative to material bodies" you are using "relative" in a way other than it is used in relativity theory, because every body regardless of its relative motion (according to relativity principle) is essentially at rest "relative" to light.
    When you say ‘relative to light’, it is you that is using the term incorrectly. ‘Light ‘does not specify a frame, and you know that (or at least I hope you at least know that much).

    I'll try anyway. To put it simply, the observer chooses the frame, so "frame effects" are observer effects.
    OK, I choose a roller-coaster track in a circle, and the frame where that track is stationary. We pack it with cars with no space between them. Then we get them going around the track together, and due to length contraction, spaces form between the cars. Are you going to tell me that there is an observer somewhere that doesn’t measure these spaces between the cars? That’s what I mean by the effects (length contraction in this case) being real, not just coordinate effects.

    By the principle of relativity no body can be truly at rest unless all bodies are at rest.Metaphysician Undercover
    Not even then, but motion would admittedly be pretty meaningless in a universe where time itself is meaningless.
    So "inertial frame" is a sort of arbitrary designation requiring only constancy, uniformity.
    Sounds like you’re now in denial of what an inertial frame is, perhaps suggesting that any inertial frame with something moving (or accelerating) in it isn’t a real one
    Motion which stays the same as time passes is the principle of relativity's "rest".
    The principle does not define ‘rest’, and certainly does not suggest that there is but one rest frame, a direct violation of the principle.
    And as you say, the motion of light "c" is relative to any inertial frame. But "inertial frame" is a feature of the theory, it is a theoretical observational tool derived from the uniformity observed in the passage of time. What defines the "inertial frame" is the uniform, constant passage of time.
    OK, this is pretty much rhetoric from the relativity denialist literature. You’re entitled to this opinion, but none of this is part of relativity theory.
    Therefore the speed of light is not grounded in, or relative to any material bodies, it is relative to the defining feature of the "inertial frame", which is the uniform passage of time.
    OK, so where should light be at the rate of one hour per hour (just guessing at the rate)? IOW, what the heck does that statement even mean? What if time passed at one second per day? How would that affect where goes or what we see?

    I thought that superposition is a fact and not just a hole in our knowledge.Agent Smith
    Yes, so we either have two or more worlds in a box, or they’re not really worlds. Either way, it’s different than there being just one state and we just don’t know.
    OK, they’re not actually going to do it with a cat because there’s no way they’re going to get a live cat state to interfere with a dead cat state. The cat may be both dead and alive in the box, but superposition is more than that, requiring some sort of interaction (interference) between the two states.

    Any irrational number can be approximated to an arbitrary degree of accuracy by a rational number. From the associated paper:Andrew M
    Ouch. It would really such if nature allowed such approximations. I’d always envisioned pure mathematics behind the physics, not digital mathematics where all numbers are representable with finite states.

    Yes, it is quite different. As is the effect you mention of a clock travelling fast towards you that appears to be ticking faster than it is. Perhaps we can call them (classical) perceptual effects, (relativistic) frame effects, and (quantum) measurement effects to disambiguate them for the purposes of this discussion.
    The discussion was about observer effect (the observer causing effects), not observed effects (effects merely noticed by the observer), Relativity effects seem to fall under the latter category, prompting my foul call.
    A related test has been carried out at a microscopic level (using photons instead of AI's) where it was shown that physical collapse does not occur.
    Not sure what this is. Got a link for this one?
  • Andrew M
    1.6k
    Ouch. It would really such if nature allowed such approximations. I’d always envisioned pure mathematics behind the physics, not digital mathematics where all numbers are representable with finite states.noAxioms

    We may still be able to have a precise geometrical representation. For example:

    Geometrically, the square root of 2 is the length of a diagonal across a square with sides of one unit of length; this follows from the Pythagorean theorem.Square root of 2

    So a balanced beam splitter will have a 1/sqrt(2) amplitude for each path. Nature doesn't encode a digital representation of that number (either finite or infinite), but the information content is there by virtue of the beam splitter being balanced.

    The discussion was about observer effect (the observer causing effects), not observed effects (effects merely noticed by the observer), Relativity effects seem to fall under the latter category, prompting my foul call.noAxioms

    Fair enough.

    "A related test has been carried out at a microscopic level (using photons instead of AI's) where it was shown that physical collapse does not occur." - Andrew M

    Not sure what this is. Got a link for this one?
    noAxioms

    It was in the earlier post:

    In a state-of-the-art 6-photon experiment, we realise this extended Wigner’s friend scenario, experimentally violating the associated Bell-type inequality by 5 standard deviations. If one holds fast to the assumptions of locality and free-choice, this result implies that quantum theory should be interpreted in an observer-dependent way.Experimental test of local observer-independence - Proietti, et al., 2019
  • Agent Smith
    9.5k
    Yes, so we either have two or more worlds in a box, or they’re not really worlds. Either way, it’s different than there being just one state and we just don’t know.
    OK, they’re not actually going to do it with a cat because there’s no way they’re going to get a live cat state to interfere with a dead cat state. The cat may be both dead and alive in the box, but superposition is more than that, requiring some sort of interaction (interference) between the two states.
    noAxioms

    I'm just surprised that the statement that describes the Schrödinger =n isn't that of ignorance (The cat may be dead or the cat may be alive, we don't know) but of knowledge (the cat is both dead and alive, we know).
  • jgill
    3.8k
    You're dealing with probabilities in the quantum world, not deterministics. The probability of the cat being alive might be .3 and dead .7. Doesn't mean the poor cat hovers between life and death. It may be alive.

    Wikipedia:
    Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.
  • Wayfarer
    22.5k
    'Whenever I hear of Schrodinger's cat, I reach for my gun' ~ Stephen Hawking.
  • Wayfarer
    22.5k
    Please elucidate the training program in metaphysics I would need to complete to be considered competent in metaphysics. Be specific as possible.jgill

    I don't know if there's a course about it, but there are a number of books by qualified quantum physicists who are deeply versed in it, beginning with Werner Heisenberg's Physics and Philosophy. There's Bernard D'Espagnat, who studied under the quantum pioneers and was a senior scientist at CERN, whose books also include one called Physics and Philosophy. Shimon Malin, Nature Loves to Hide, is another. Another two recent books that I've read cover-to-cover are Quantum, Manjit Kumar, and Uncertainty, David Lindley. There's a writer called Tim Maudlin who writes on the metaphysics of physics. I'm sure there'd be graduate course on physics and metaphysics floating around which makes reference to one or more of these books. There's probably a bunch of lectures on Youtube. Michel Bitbol's lecture on Kantian Quantum Physics is a good one.
  • Agent Smith
    9.5k
    So it was all hype, no substance, but then the absurdity.
  • Wayfarer
    22.5k
    'What did you do the cat, Erwin? Looks half dead!' ~ Ms Schrodinger.
  • Metaphysician Undercover
    13.2k
    Suppose I am a typical Q-physicist, following the mathematics but paying little attention to authorities in my subject babbling woo about interpretations. Please elucidate the training program in metaphysics I would need to complete to be considered competent in metaphysics. Be specific as possible.

    Would I need to attend the University of Metaphysics? Would a bachelor's degree be sufficient?
    jgill

    I would say any university with a good philosophy program, and adequate courses in metaphysics. I'm not about to judge the merits of any particular university though.

    Not quite. All motion can be specifed relative to a frame, specifically an inertial frame. Light speed is specified relative to (and is fixed only relative to) any inertial frame, so it isn’t an exception.noAxioms

    I think you've distorted the reality here noAxioms. An "inertial frame" is a theoretical derivative. It is derived from any situation with a body assumed to have uniform existence. Without the mass showing uniform existence there is no inertial frame. Therefore the body at uniform existence which provides for the inertial frame is prior to, and the defining feature of, any particular inertial frame. So there is at least one motion which is necessary and absolute to the inertial frame, therefore not relative to it.

    You seem to see an exception when I don’t. Mathematically, how does this work?noAxioms

    As I said, the speed of light is relative to the passage of time, as is the inertial frame. By the basic principle of relativity (not special relativity) all frames employ the same passage of time, and their motions are relative. The inertial frame show no change over a duration of time. By special relativity, every frame is inertial relative to the motion of light, no change over a period of time, in relation to light. That is an absolute, hence the motion of light is exempt from the principle of relativity. Because of this exemption, the passage of time must be conceived of as unique to each frame. The mathematics is simple, the required length contraction and dilation of time. But the math gets more complicated when dealing with acceleration (general relativity).

    You seem to see an exception when I don’t.noAxioms

    I've made my case. You insist otherwise, making claims supported only by equivocation. So I see no point in proceeding because you simply continue to insist on a perspective which cannot be supported.

    It is exactly relative in that sense.noAxioms

    I explain how it is "absolute" and you say this is exactly how it is "relative". Yes, "relative" in that sense, but that is not the sense of the principle of relativity, which formulates all motion as equally relative. So when you say that the motion of light is always the same relative to any moving body, that claimed "relative" is an absolute, which is an exception to the principle of relativity.

    Sounds like you’re now in denial of what an inertial frame is, perhaps suggesting that any inertial frame with something moving (or accelerating) in it isn’t a real onenoAxioms

    An accelerating body cannot be the basis of an inertial frame the two are incompatible. The inertial frame is theory, therefore categorically distinct from any bodies. To speak of an inertial frame with something accelerating "in it" is just deception. The accelerating thing is not "in" the inertial frame, it is relative to it.

    OK, this is pretty much rhetoric from the relativity denialist literature. You’re entitled to this opinion, but none of this is part of relativity theory.noAxioms

    You are clearly the one in denial. The characterization of simultaneity is the central aspect of special relativity. This is because both the "inertial frame" from the traditional principle of relativity, and "c" are grounded in the passage of time. This is how Einstein relates the motion of light to bodies involved in the relativity principle, by making stipulations about the passage of time and simultaneity. Rejecting facts simply because they are the facts reported in "relativity denialist literature" is not good academic practise.

    OK, so where should light be at the rate of one hour per hour (just guessing at the rate)? IOW, what the heck does that statement even mean? What if time passed at one second per day? How would that affect where goes or what we see?noAxioms

    Your mind appears to be absolutely void in the conception of time. Do you agree that the passage of time is an essential aspect of the concept "inertial frame", a duration of time is necessarily implied by "inertial frame"? I think we'd better get agreement on this fundamental feature before we start to discuss whether that duration is a day, an hour, or a second, because we can go two ways toward determining the length of that duration, by relating that duration to the motion of bodies, or relating it to the motion of light.
  • jgill
    3.8k
    I would say any university with a good philosophy program, and adequate courses in metaphysics.Metaphysician Undercover

    Amongst the myriad of courses in numerology, astrology, meditation, noetic sciences,chakras, auras, divination, spiritualism, angels, etc., I found an introductory course at Oxford that looks legit:

    Introduction: what is metaphysics? An introduction to the distinctive character of metaphysical questions: the history of the idea of metaphysics, understood as the most general and abstract inquiry into the nature of reality.

    Existence: what is existence? What is it to exist? People disagree about what exists; but how can we understand this disagreement? Are there things which do not exist?

    Universals and particulars: in addition to particular objects and events, our world seems to contain general or universal features of things, like their colours and their shapes. Is this an illusion or does the world really contain such features, known as 'universals'?

    Realism and idealism: does the world exist independently of our minds? Realism is the view that it does; idealism is the view that reality is mind-dependent. Are any features of the world mind-dependent?

    The freedom of the will: we think our actions and decisions are free, or up to us, but this idea seems to be in conflict with the apparent fact that everything which happens is determined by what happens before it (this is known as 'determinism'). Does determinism imply that free will is an illusion, or are free will and determinism really compatible after all?

    Cause and effect: what is it for one thing to cause another, or to make something happen? Is there more to cause and effect than the mere regularity of things happening after one another? If so, is causation a physical process, or is mental causation also possible?

    The nature of time and space: what are time and space? Is there no more to them than the temporal and spatial relations which hold between events and objects? Or should they rather be conceived as the 'containers' in which things exist and events occur? Are the past, present and future genuine aspects of reality, or are they merely 'subjective' features of our experience of time?

    We strongly recommend that you try to find a little time each week to engage in the online conversations (at times that are convenient to you) as the forums are an integral, and very rewarding, part of the course and the online learning experience.

    I encourage any Q-physicist reading this post to consider enrolling in this course. :cool:

    (or simply pull up all the threads on TPF relating to these subjects. Much profound stuff therein.)
  • Metaphysician Undercover
    13.2k
    I encourage any Q-physicist reading this post to consider enrolling in this course.jgill

    I would say, only if they are inclined to speculate about the true nature of reality. Otherwise they should be satisfied to carry on with the calculating.
  • Wayfarer
    22.5k
    I encourage any Q-physicist reading this post to consider enrolling in this coursejgill

    If you mean this https://www.conted.ox.ac.uk/courses/reality-being-and-existence-an-introduction-to-metaphysics-online - I've had that course bookmarked a long while but have never found the time to enroll. But I agree, I think it looks a worthwhile undertaking.
  • noAxioms
    1.5k
    ... where all numbers are representable with finite states. — noAxioms
    We may still be able to have a precise geometrical representation.Andrew M
    I can still express the length √2 with two characters, a very finite state. Humans deal only with such representable numbers, and they’re countable. Actual numbers in nature (such as the ratio of the half lives of two specific isotopes) are not in this countable set. I have a hard time with a model of the universe that requires only the former sort of number, such as one would get in a simulation. Actual numbers are more analog, like ‘so big’ with your hands held apart.
    Nature doesn't encode a digital representation of that number
    Maybe it does, such as if our universe is digitally simulated. In this case, the amplitudes of the split beam would not be √2, but close.
    In a state-of-the-art 6-photon experiment, we realise this extended Wigner’s friend scenario, experimentally violating the associated Bell-type inequality by 5 standard deviations. If one holds fast to the assumptions of locality and free-choice, this result implies that quantum theory should be interpreted in an observer-dependent way.
    — Experimental test of local observer-independence - Proietti, et al., 2019
    Going to get back to you on this one. Interesting read, but the introduction is already full of interpretation dependent assumptions, such as counterfactual statements. I will look at it from my relational perspective which doesn’t make those assumptions, but thus far I’ve not read enough to really comment on it.

    I'm just surprised that the statement that describes the Schrödinger =n isn't that of ignorance (The cat may be dead or the cat may be alive, we don't know) but of knowledge (the cat is both dead and alive, we know).Agent Smith
    There’s actually no empirical difference between those two cases. There is if there was a true superposition, but there isn’t in the cat case. It’s been demonstrated with macroscopic objects, but under conditions which would kill any cat (such as being in a vacuum and almost 0°K).

    An "inertial frame" is a theoretical derivative.Metaphysician Undercover
    I guess so. I would have said it is an abstraction, an assignment of coordinates to events.
    It is derived from any situation with a body assumed to have uniform existence.
    This is nonsense. You have a reference to such a crazy definition from a consensus physics reference from the last century? What even is uniform existence? That a body must be the same everywhere? A carrot cannot taper? I presume you to be an absolutist and maybe get your definitions from the sites supporting such, but this is not the consensus definition as used by physicists.
    perhaps suggesting that any inertial frame with something moving (or accelerating) in it isn’t a real one — noAxioms
    To speak of an inertial frame with something accelerating "in it" is just deception.
    Case in point.
    Do you agree that the passage of time is an essential aspect of the concept "inertial frame", a duration of time is necessarily implied by "inertial frame"?
    No, not at all. I can for example reference the inertial frame of Earth when referencing the twins scenario. No duration is specified or necessary when identifying that frame.

    I encourage any Q-physicist reading this post to consider enrolling in this course. :cool:jgill
    There were lots of basic topics covered, down to interpretations of time near the bottom, but I didn’t see quantum interpretations mentioned at all, which requires probably a whole separate course.
    The course description might devote an hour or three on each listed topic. Nice introduction, but you can get it just by reading each topic in places like Stanford philosophy.
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