## The role of observers in MWI

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I don’t see how that follows, sorry.
That’s quite alright. Thanks for your feedback.
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Nonetheless the observer - or, even better, agent or person - closes the loop in the sense that it is human experience that grounds quantum theory and the quantities that can be measured.
— Andrew M

That also seems true of say Newtonian theory.

Yes. Though, of course, we've found through observation that Newtonian theory is incorrect. Also, the "action-at-a-distance" aspect was suspect to Newton from the outset.

Is there some way in which human agency or observation makes a difference in (grounds) QT in a way that it doesn’t in NT? That would be a pretty incredible claim, that physics (and not just human theories/knowledge of physics) is different in the presence of humans than it is in a universe absent them.

No, my point is that quantum theory is constructed abductively from what we observe. As far as we know, it applies universally.
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My ontology has nothing to do with perception..

Consider the old saying, "you see what you want to see". There are principles of interpretation inherent within, built into, and therefore affecting the way that you perceive things. What you believe about reality (your ontology) has a very real affect on the way that you perceive things.

And that is just the tip of the iceberg, what we have access toward understanding, through sciences like psychology. Underneath, in the subconscious, there are all sorts of similar factors affecting the way you perceive things. If your ontology is the conscious manifestation of your attitude toward the reality of the things you are sensing, then underneath there is all sorts of intuitions and innate tendencies which feed your ontology, but also have an immense affect on the way things are perceived by you.

Usage of the word implies that quantum effects only occur when there is intent behind the measurements. There’s no evidence for that and heavy evidence against it.

There is always intent behind human actions, therefore intent behind measurements. If you removed it the acts would be random. I don't know on what basis you say there is no evidence of intent behind measurements.

Poor example I think since a magnifying glass doesn’t usually qualify as a measurement. They’re used in multiple places in typical laser experiments and they don’t collapse wave functions in them, else the experiments would fail. They’re not detectors, only refractors, and refraction wouldn’t work (wouldn’t bend light) at all if it constituted a measurement.

The magnifying glass was an analogous example, to demonstrate how the tool of observation (apparatus arranged for observational purposes) affects the observations, and why there is a need to have very good theory, and understand the theory, behind the use of the tool which is used.

In no way was I saying that a magnifying glass is used to make quantum measurements. I really cannot understand your mode of interpretation noAxioms. Have you no experience with reading examples or analogies?

But I wasn’t asking about descriptions. You say time requires observation. You didn’t say a description of time requires observation. I’d have agreed to that. So you’re evading the question instead by answering a different one.

No Axioms, "time" is a descriptive term, just like "space" is a descriptive term. The point is that you cannot use these descriptive terms to refer to anything other than something which is observational, because observation is inherent within, as "implied by", being an essential feature of, what the terms refer to.

So, what "time" refers to is something derivative from the observation of motions. What "space" refers to is something derivative from the observation of bodies. There is no such thing as time without observation, or space without observation, because these words refer to concepts which are derived from observation, having the observation data inherent within, as an essential aspect of the concept. If you remove the essential aspect of the concept (observation in this case), the concept referred to by the word is annihilated.

I am not evading the question, you are evading the reality. You say that's "idealistic", and your ontological attitude is to deny idealism, so you deny the reality because it doesn't jive with your ontology. Instead of recognizing that observation is inherent in, as an essential part of what "time" means, and realizing that you need to change your ontology because your ontology is inconsistent with this, your recourse is to deny the reality, that observation is necessary to the meaning of "time". That is an unreasonable response, to deny the evidence because it is inconsistent with your belief.

Don’t be silly. You know it does. It is the location of that which said ‘here’.

I have no idea where you are, and therefore no idea where "here" is when you say it. Imagine two people in a dark space, one says "here", the other hears "here". Ten seconds later this is repeated. Then the person who said "here" insists "I haven't moved because both times when I said "here" I was truthfully "here". That's how ridiculous your claim was, that because you were "here" now, and "here" later, you hadn't moved.

If I was being silly, it was because I was laughing at the ridiculousness of your claim.

But you said that being stationary was not possible, so you seem to exclude the possibility that you didn’t go anywhere during that interval. And as for my statement, had I indeed flown all around during that interval, at no time would I not be where I am, thus I’d always still be ‘here’. I’d simply not be inertial, so the coordinate system in which I am perpetually at the origin would not be an inertial coordinate system.

Please, stop with the ridiculousness No Axioms! However, I will oblige you with your solipsistic example if it will make you feel better.

Wherever you are is "here", and all the time you are always here, and "here" always refers to the same place, the place where you are, therefore you are never moving. Anything else in the world is totally irrelevant to you because in your solipsistic reality, nothing is ever changing places relative to you, which might make you think that you are actually moving.

Now, you said "If I’m here now and here later, that seems to be not-moving relative to ‘here’. OK, one might express that as motion at velocity (relative to here) of zero, which is arguably still motion." What in the world are you referring to when you say "not-moving relative to 'here'"?

To me, "here" signifies the place where you are, therefore it's obvious that you cannot be moving relative to here, because that would be contradictory. "Here", by the definition in the example, is always where you are. Do you agree, that this sort of tautology, or self-evident truth, that you are never moving relative to yourself, says absolutely nothing about whether or not you are "moving"? That is because 'you moving relative to yourself', or the more precise account, 'you moving relative to the place where you are', is a nonsensical thing to say, and to make it into something sensible would require a different definition of "moving".

To make sense of "I am moving relative to the place where I am' would require a completely different definition of "moving". This would be a definition which is completely inconsistent and incoherent in relation to any conventional definition of "moving", allowing that a thing is moving relative to the place where it is. So your claim of "not-moving relative to 'here'" is completely nonsensical without changing the definition of "moving" to something inconsistent and incoherent in relation with conventional definitions.

Therefore your example using "here" says absolutely nothing about motion as we understand motion. All you are saying is that "motion" in this nonsensical way, of myself moving in relation to the place where I am, is inconsistent with how "motion" is used in any conventional way. And your example says absolutely nothing about "motion" as used in any conventional way.
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No, my point is that quantum theory is constructed abductively from what we observe. As far as we know, it applies universally.
My point was that this abductive construction isn’t in any way something unique to quantum theory. That’s not what make it different, and it certainly doesn’t indicate that physical processes require the presence of humans. Sure, the human knowledge of physics requires humans, but that knowledge isn’t necessary for trees to fall in the forest when nobody is around.

I don’t see how that follows, sorry.
— noAxioms
That’s quite alright.
You choose not to defend it. That’s alright too I guess. I will instead offer a counterargument.
Consider a Wigner’s friend scenario. The friend is in a box, takes a measurement, and based on that measurement, either drinks a hot tea or eats ice cream. To Wigner, the friend is in a superposition of consuming tea and of eating ice cream. This superposition can be demonstrated. Wigner opens the box to find the ice cream case. My question is, what is it like to be the tea-drinking friend?
Different interpretations say different things. MWI and relational might say that the tea drinking friend is observed by a different Wigner or is real only to that other Wigner. The objective collapse interpretations are hard to figure. Does the experience of the tea-drinker just suddenly cease? Does the tea drinker not actually have any experience of it? Is there more than one identity of the friend, one hot and one cold, or are somehow both states experienced by the same friend, but only one remembered? How would you reply to something like that?

There is always intent behind human actions, therefore intent behind measurements.
You seem to be using the street definition of ‘measurement’ instead of the definition relevant to quantum theory. Please see the Bell quote in Andrew M’s post a few back which addresses exactly this naive mistake and the common misconceptions that result from such assumptions.
your ontological attitude is to deny idealism, so you deny the reality because it doesn't jive with your ontology
I’m not denying idealism, I’m merely not talking about it. Sure, under idealism, you (and nobody else) causes wave function collapse.

I have no idea where you are, and therefore no idea where "here" is when you say it.
That’s right. My coordinate system has no need for you to know where its origin is. But you can do it for yourself.
That's how ridiculous your claim was, that because you were "here" now, and "here" later, you hadn't moved.
That would be ridiculous since the frame reference was omitted from the assertion of not having moved, rendering it meaningless at best.
Anything else in the world is totally irrelevant to you because in your solipsistic reality, nothing is ever changing places relative to you
Where did I ever imply that? If you want to take my argument apart, surely you can do it without dragging in strawman stuff like that. So far, all I’ve seen is you applying the appeal to ridicule fallacy.

What in the world are you referring to when you say "not-moving relative to 'here'"?
Given a coordinate system in which some object is always at the origin, that object always at location zero and thus not moving relative to that coordinate system. This is tautologically true. That coordinate system would be an inertial coordinate system only if no external forces were acting on the object in question. Given the comment below, you seem to already know this.
Do you agree, that this sort of tautology, or self-evident truth, that you are never moving relative to yourself, says absolutely nothing about whether or not you are "moving"?
The bolded part of that statement gives no frame reference, so I would agree that nothing was said about that ambiguous statement. I will also say that something’s lack of motion relative to one frame does not imply lack of motion relative to a different frame, had an alternate one been specified.
To make sense of "I am moving relative to the place where I am' would require a completely different definition of "moving".
That depends on what the first definition (the one you apparently reject) was.
And your example says absolutely nothing about "motion" as used in any conventional way.
Agreed, but I’m not using conversational definitions of just about anything. I’m using physics definitions.
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I’m using physics definitions.

Don't you see a problem with that?

Physical definitions don't have to have any meaning either in conversational or in a philosophical sentence. Even in physics meaning is convenient but superfluous as long as the formulas invented/derived describe to a point of prediction of possible phenomena. Physical definitions relate hypothetical mathematical objects of pure intellect. When explored philosophically, which is really unnecessary except to aid students in bridging to a physical mode of thinking, physical objects, such as energy and so on become Platonic conditional abstractions.
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You seem to be using the street definition of ‘measurement’ instead of the definition relevant to quantum theory

Ha, ha, "street definition", that's funny. Is that the definition of "measurement" which the cop with the radar gun uses to prosecute in court? "I calibrated my machine in the lab according to...so that it would be accurate to within... on the street". On the street we don't really use definitions noAxioms.

Face it no Axioms, there's alwaya intent behind "measurement" no matter how you use the word. There must be or else there'd be no measurement. It determines what will be measured, when, how, all those decisions,

That would be ridiculous since the frame reference was omitted from the assertion of not having moved, rendering it meaningless at best.

Yes, and that was your assertion, that's why I said you were being ridiculous. "If I’m here now and here later, that seems to be not-moving relative to ‘here’." "Here" does not constitute a frame of reference. We went over that already. You are not adhering to proper definitions, as we discussed, and slipping back into street talk. You blabber on about "coordinate systems", then you assume that "here" constitutes one. The point of course, is that no frame of reference can use just one point, location must be established relative to another point. "Here" means nothing on its own. That's why I called your example solipsistic.

Given a coordinate system in which some object is always at the origin, that object always at location zero and thus not moving relative to that coordinate system. This is tautologically true. That coordinate system would be an inertial coordinate system only if no external forces were acting on the object in question. Given the comment below, you seem to already know this.

Are you proposing that you could map motion with a spatial representation that employs a coordinate system with only one locational point, a point zero, without any other points? How would that work? Let's see, object is always at point zero therefore object is never moving. What defines point zero? The place where the object is. Hmm, object never moves because object is always at point zero, 'here', and point zero is defined as "the location of that which said ‘here’". My spidey sense is tingling.

Don't you see a problem with that?
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Don't you see a problem with that? — magritte

You're taking that out of its context. It was only meant to help unravel an attempt at a correct subjectivist philosophy. Not only psychology but also some physics can only be seen that way. But how?
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My point was that this abductive construction isn’t in any way something unique to quantum theory. That’s not what make it different, and it certainly doesn’t indicate that physical processes require the presence of humans. Sure, the human knowledge of physics requires humans, but that knowledge isn’t necessary for trees to fall in the forest when nobody is around.

I agree. Trees have a separate existence and evolution to us. Nonetheless the idea of trees falling only has meaning in the context of human experience. We can point to a tree and to something falling and say that this is what is meant. That relational connection grounds our language.

Please see the Bohr quote in Andrew M’s post a few back

I think you meant the John Bell quote.
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Here's the current installment from the excellent Matt O'Dowd of PBS Spacetime on the reality of space and time (hey he's been working up to this title for a long while!) It is queued to a passage about Leibniz' view that space (and by implication time) are grounded, in some sense, in subjective perception rather than a truly mind-independent reality. Starts with 'Leibniz had another controversial idea...'

Leibniz felt that whatever it is that's out there that behaves like space only gains the subjective feeling of depth, breadth, height, and distance when our brains try to organise objects that are separated by an altogether more abstract property. — Matt O'Dowd

Although I would comment that it's not that it's abstract, simply that, because it is a fundamental constituent of conscious awareness, it's not something we can be aware of. It is, as Kant would later say, a pre-condition of conscious experience.
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Nonetheless the idea of trees falling only has meaning in the context of human experience.
This seems to be a point of contention because I’m not in any way talking about the meaning of the word trees or the human experience of one falling or lack thereof. I was referring to the tree itself falling in the total absence of human anything. It pains me to have to use human language to express that, but I’m not talking about the language, the expression, the concept, the fact that the tree happens to be my very distant cousin, or whatever. I’m talking about the tree.
It is me that nobody seems to get that? I’m not saying that the alternative (that noumena supervenes on human phenomena or human language) is necessarily wrong, but that such a stance utterly destroys any hope of acquisition of knowledge
I think you meant the John Bell quote.
Thx, fixed that. One 4-letter B-word is the same as another, no?

Ha, ha, "street definition", that's funny. Is that the definition of "measurement" which the cop with the radar gun uses to prosecute in court? "I calibrated my machine in the lab according to...so that it would be accurate to within... on the street". On the street we don't really use definitions noAxioms.
Face it no Axioms, there's alwaya intent behind "measurement" no matter how you use the word. There must be or else there'd be no measurement.
This is all using the common definition. It seems appropriate that one should use the quantum theory definition of ‘measurement’ when discussing quantum theory. So rather than admitting this obvious thing, you resort again to ridicule in attempt to salvage your assertions.
If I’m wrong to use that definition, then tell me why. Once again, see Bell’s quote above discussing why quantum theory should never have used the word ‘observer’ or ‘measurement’ for precisely the reason you are demonstrating: I leads the naive reader to suspect that humans are somehow necessary for physics to work, that the universe supervenes on you and not the other way around. Yes, it’s a solipsistic stance you seem to be taking.
"Here" does not constitute a frame of reference.
No, it doesn’t. I had specified the frame in which I was stationary.
The point of course, is that no frame of reference can use just one point, location must be established relative to another point.
Just a velocity reference is enough, which is usually defined by the object referenced in establishment of that frame. So I can say ‘the local inertial frame of the sun’ which defines the velocities of everything around it but not any particular coordinate system. To generate a coordinate system, with numbers assigned to every nearby event, would require specification of an origin and of the orientation of the spatial axes. Saying ‘the inertial frame of the sun’ implies the sun at the origin, but only specifies the orientation of one axis, not the other three. So from just that, I cannot specify say the coordinates of Earth at a particular moment in time. I need to know where the axes are, and for that, more than one additional reference must be given. The plane of the ecliptic might define one of those, but still not the other two. A distant reference (Betelgeuse say) might suffice to anchor the other two.
So your statement would be correct about a coordinate system, but a ‘frame’ does not require additional references.

Are you proposing that you could map motion with a spatial representation that employs a coordinate system with only one locational point, a point zero, without any other points?
As per the above, a specification of only the origin defines a frame but does not assign coordinates to events not at that origin. So I could for instance have a frame of a rocket with the origin at the nose, the very ‘front’. That point will always be at the origin no matter what the rocket does, but we need two more points to make a coordinate system of it. So say the rear-most point is on the x axis, and some feature on the side defines the y axis. The z is just orthogonal to the other two and requires no additional reference. Now it’s a coordinate system, and the ‘abort’ button is always (nearly) stationary in this coordinate system regardless of what the rocket does. The astronaut knows where the button is despite the motion of the rocket because he’s using that coordinate system when needing to hit that button. I say ‘nearly stationary’ because vibration and other stresses will move that button a mm or two now and then due to strain on the vehicle.
Let's see, object is always at point zero therefore object is never moving. What defines point zero? The place where the object is.
Very good, The latter half even constitutes the frame reference, which you almost always omit.
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Does the experience of the tea-drinker just suddenly cease? Does the tea drinker not actually have any experience of it? Is there more than one identity of the friend, one hot and one cold, or are somehow both states experienced by the same friend, but only one remembered? How would you reply to something like that?

I don't understand the point you're trying to illustrate. Nothing on the macroscopic level really exists in anything like the mathematical superposition of states that describe subatomic particles. It seems a version of the 'Schrodinger's cat' idea.

It pains me to have to use human language to express that, but I’m not talking about the language, the expression, the concept, the fact that the tree happens to be my very distant cousin, or whatever. I’m talking about the tree.

I don’t suggest things ‘are real’ in any objective sense.

Yet in another place, you say

The far side of the moon is still there when nobody looks at it since looking at it isn’t what makes it there.

And also that:

If I say the moon exists, I mean that I've measured it, which doesn't involve looking or any other conscious function.

So, what do you mean, really? Because it seems to me, despite your claims to the contrary, that your view is realist, i.e. that trees, the moon, the proverbial table or proverbial apple, are all quite real, independently of anyone's knowledge or experience of them. Isn't that the point at issue?
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It is me that nobody seems to get that? I’m not saying that the alternative (that noumena supervenes on human phenomena or human language) is necessarily wrong, but that such a stance utterly destroys any hope of acquisition of knowledge

I'm not saying anything like that. It seems to me obvious that without ordinary, everyday human experience we wouldn't be talking about trees falling in the forest, or quantum theory, or anything else. I'm not therefore saying that trees somehow depend on human experience. Obviously they don't.

I think you meant the John Bell quote.
Thx, fixed that. One 4-letter B-word is the same as another, no?

In this case ... no. ;-)
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I'm not therefore saying that trees somehow depend on human experience.
Well good then. I was beginning to wonder since all the conversation kept turning to human discourse on physics and not the actual physics.
Obviously they don't.
Not even obviously. Many times things that are obvious are also wrong. As my username implies, I don’t assume anything.
In the end, a few premises are needed though, and I explicitly list that one (that humans are not special, and reality doesn’t supervene on my experience). I even attempt a logical demonstration of it, but I don’t think it constitutes a proof.

I don't understand the point you're trying to illustrate.
I’m asking what it must be like to be the person who doesn’t win the wave function collapse.
Nothing on the macroscopic level really exists in anything like the mathematical superposition of states that describe subatomic particles. It seems a version of the 'Schrodinger's cat' idea.
Just because it is hard to do doesn’t mean the theory doesn’t support it. And it’s the Wigner’s friend idea, an extension of the cat idea. It works with the cat as well as long as you’re allowed to ask what it’s like to be the cat, which some deny.
And yes, I very much think that I undergo collapse like I describe since my choice of interpretation supports it. The experience is quite normal I assure you.

"I don’t suggest things ‘are real’ in any objective sense." — noAxioms

Yet in another place, you say "The far side of the moon is still there when nobody looks at it since looking at it isn’t what makes it there."
Translation: it is there relative to any person. Sorry that you found a case where I wasn’t explicit about the relation. I do not suggest that the moon is objectively real or even real relative to the universe.

And also that: "If I say the moon exists, I mean that I've measured it, which doesn't involve looking or any other conscious function."
Yes, there I am more explicit about the relationship and the nature of that relationship.

So, what do you mean, really? Because it seems to me, despite your claims to the contrary, that your view is realist, i.e. that trees, the moon, the proverbial table or proverbial apple, are all quite real, independently of anyone's knowledge or experience of them.
Independent of knowledge and experience, yes, but not independent of measurement (quantum definition, since everybody seems to presume otherwise). A rock measures the moon as much as I do, and so the moon exists to the rock. The relationship has absolutely nothing to do with one part of the relation being something living or perceiving or having any sensory apparatus.
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the moon exists to the rock

Only if they interact. Otherwise neither exists to the other.

The point is to look at what it means to 'exist' objectively, publicly, subject independently and time&space independently, as against exist subjectively with reason.

Subjectively the rock is the center of its universe without denying the possibility of the subjective universe of others. Without interaction nothing can exist.

Solipsism is an extreme scenario that denies other universes.
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A rock measures the moon as much as I do, and so the moon exists to the rock.

Inanimate objects don't measure anything. And measurement is a conscious process. The 'moon exists to the rock' is a meaningless statement.

'Imagine that all life has vanished from the universe, but everything else is undisturbed. Matter is scattered about in space in the same way as it is now, there is sunlight, there are stars, planets and galaxies—but all of it is unseen. There is no human or animal eye to cast a glance at objects, hence nothing is discerned, recognized or even noticed. Objects in the unobserved universe have no shape, color or individual appearance, because shape and appearance are created by minds. Nor do they have features, because features correspond to categories of animal sensation. This is the way the early universe was before the emergence of life—and the way the present universe is outside the view of any observer' ~ Charles Pinter, Mind and the Cosmic Order.

So - the observer creates the reality. This is not a figurative expression or a thought-experiment. It is actually happening moment-by-moment.
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the observer creates the reality.

Questionable in my opinion Wayfarer, the observer observes reality, and even as far as the observer has the ability to affect reality. Whether the observer CREATES reality runs into the problem of reality CREATING the observer.
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the moon exists to the rock
— noAxioms
Only if they interact. Otherwise neither exists to the other.
That's the relational view, yes.

The point is to look at what it means to 'exist' objectively, publicly, subject independently and time&space independently, as against exist subjectively with reason.
I didn't get that whole list. To exist is a matter of definition. Objectively seems to be in the absence of measurement. "There is a universe with 4 spatial and 2 time dimensions". That seems to be an objective statement of reality.
Publicly I suppose means that the rock and the water both measure the moon and each other. I didn't get the rest.

Subjectively the rock is the center of its universe without denying the possibility of the subjective universe of others. Without interaction nothing can exist.
The word 'subjectively' implies the rock has experience. I selected it because it doesn't.

So, realist.
No. Realist is counterfactual definiteness, existence in absence of measurement. Existence due to measurement is not that.

Inanimate objects don't measure anything. And measurement is a conscious process.
I expect such statements from @Metaphysician Undercover, but you also seem to fail to use the quantum theory definition of 'measurement' in a topic discussing quantum theory. Hence the rise (and fall) of the Wigner interpretation which, due to that language ambiguity, gave rise to the proposal that consciousness causes wave function collapse, an interpretation abandoned by Wigner himself due to it being driven to solipsism.

The 'moon exists to the rock' is a meaningless statement.
Thank you for you time then.

'This is the way the early universe was before the emergence of life—and the way the present universe is outside the view of any observer' — Charles Pinter, Mind and the Cosmic Order
I disagree with Charles here. Words were used by Pinter to describe this counterfactual reality. I agree that there'd be nothing to put words to the features of things, or to designate certain arrangements of matter as a 'thing' in the first place. But none of that stops physics from happening. It only stops physics from being meaningfully described by anything in that universe.

While I'm disagreeing with him, I'm also on record for stating that absence of life doesn't imply the necessary absence of language, as the quote suggests.
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But none of that stops physics from happening.

Physics is a human undertaking. Who is doing the measuring is just as much part of it as the object of measurement. The mistake is to believe that physics describes a universe as if there were no humans. All measures are made by humans. All that's happened throughout all this is that quantum physics has now made that obvious.
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Realist is counterfactual definiteness, existence in absence of measurement.

Just for the sake of clarity:

In physics, counter-factual definiteness is a concept related to the measurement problem in quantum mechanics. It refers to the idea that physical systems have definite properties, even if they are not measured or observed.

According to counter-factual definiteness, if a measurement had been made on a quantum system, it would have had a definite outcome, even if that outcome was not actually observed. In other words, the properties of a system exist independently of any measurements or observations made on it.
— ChatGPT

Existence due to measurement is not that.

So, you're still 'realist', but you are outsourcing measurement to everything that exists:

The relationship has absolutely nothing to do with one part of the relation being something living or perceiving or having any sensory apparatus.

So, 'measurement', for you, occupies the place that 'God' does, for Berkeley, i.e. it keeps everything in existence when not being observed, as Berkeley's God keeps everything in existence even while not being perceived.
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Once again, see Bell’s quote above discussing why quantum theory should never have used the word ‘observer’ or ‘measurement’ for precisely the reason you are demonstrating:

I read that. It in no way indicates that there is not intent behind measurement in quantum physics. The article suggests replacing "measurement" with "experiment". The use of "experiment" simply enforces the fact that there is intent. And I really do not see how you can conceive of any sort of measurement (experiment) without intent. I explained already why I think measurement without intent is impossible, now it's your turn to explain how you think there could be such a thing.

To begin with, do you recognize that a system is an artificial thing, a human creation, whether it is a theoretical system, with boundaries imposed by theory, or a mechanical system, with created physical boundaries? And, artificial things are created with intent.

A rock measures the moon as much as I do, and so the moon exists to the rock.

All you are saying here, is that you've never measured the moon, because the rock sure hasn't, by any definition of "measure", measured the moon.

Realist is counterfactual definiteness, existence in absence of measurement. Existence due to measurement is not that.

How are you using "measurement" here? If to interact is to measure and be measured, as you seem to think (which is a ridiculous definition of "measure" not consistent with any actual usage), then by what principle do you assume that there is any sort of "existence in absence of measurement"? That would mean you are assuming something which interacts with nothing.

I expect such statements from Metaphysician Undercover, but you also seem to fail to use the quantum theory definition of 'measurement' in a topic discussing quantum theory. Hence the rise (and fall) of the Wigner interpretation which, due to that language ambiguity, gave rise to the proposal that consciousness causes wave function collapse, an interpretation abandoned by Wigner himself due to it being driven to solipsism.

You are not paying attention to the article which you requested that I read. The article suggests reasons why "measurement" should not be used, because "measurement" to most people implies some real existing aspect of the universe which is measured, like when we count something we assume that there is an existing quantity which can be counted and it has some real existence as that quantity, prior to being counted. This is what Bell says is misleading in quantum mechanics. What is being "measured" has no real existence prior to the measurement. And so he suggest that "measurement" be replaced with "experiment".

I leads the naive reader to suspect that humans are somehow necessary for physics to work, that the universe supervenes on you and not the other way around.

The issue is not the relation between human beings and the universe, it is the relation between human beings and the "measurement". In order to make a measurement there are constraints placed on the universe. These controls are necessary in order that the measurement measures what it is supposed to measure. The form of an "experiment" for example is to follow a specific procedure. It is necessary to follow the procedure in order to fulfil the intent of the experiment, which is to test an hypothesis.

Humans are necessary for the measurement. But when you represent the measurement (being the confines of the experiment) as the universe, you step way outside the boundaries of the measurement. The measurement is not measuring the universe, it is measuring whatever is being controlled for, which is dictated by the intent behind the experiment.

No, it doesn’t. I had specified the frame in which I was stationary.

You did not specify a frame, you said "here".

Just a velocity reference is enough,

"Here" does not provide a velocity reference. And you've got things backward anyway. A frame of reference, with multiple location points is required to make a velocity reference, not vise versa.

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but a ‘frame’ does not require additional references.

Yes it does, and you've misrepresent "frame" as a point. A point is not a frame.

As per the above, a specification of only the origin defines a frame...

No, a point does not constitute a frame. You seem to have no technical understanding of this matter, insisting that the coordinate system is derived from the frame, rather than that the frame is a derivative of the coordinate system. You need to straighten out your logical priority. "Frame" implies "coordinate system". There is no frame without a coordinate system as you seem to believe.

So I could for instance have a frame of a rocket with the origin at the nose, the very ‘front’. That point will always be at the origin no matter what the rocket does, but we need two more points to make a coordinate system of it. So say the rear-most point is on the x axis, and some feature on the side defines the y axis. The z is just orthogonal to the other two and requires no additional reference. Now it’s a coordinate system, and the ‘abort’ button is always (nearly) stationary in this coordinate system regardless of what the rocket does. The astronaut knows where the button is despite the motion of the rocket because he’s using that coordinate system when needing to hit that button. I say ‘nearly stationary’ because vibration and other stresses will move that button a mm or two now and then due to strain on the vehicle.

Your "frame" in this example is a coordinate system which maps the rocket, not one point such as "here". And if you say that the rocket is one point, "here", this is a misrepresentation, because the rocket is mapped as a frame of reference, consisting of a coordinate system with multiple locational points.

Very good, The latter half even constitutes the frame reference, which you almost always omit.

This clearly demonstrates your misunderstanding. a point cannot constitute the frame of reference.
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In the end, a few premises are needed though, and I explicitly list that one (that humans are not special, and reality doesn’t supervene on my experience). I even attempt a logical demonstration of it, but I don’t think it constitutes a proof.

Per "reality doesn’t supervene on my experience", it seems to me that that is how me ordinarily use language. It works well, while other uses are problematic.
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I only skimmed this thread, but has the Born Rule problem really not come up?

To bring up the example before, it is like someone's spouse is either in spot A with probability 30% or spot B with probability 70%, except, get this, she is also in BOTH spots with probability 100%. Explaining that satisfactorily is going to be a doozy, and I don't think Dutch Book arguments really solve the problem.

There is also the issue of worlds existing where large systems, perhaps the whole universe, decrease in entropy over time. I can see why, if you're committed to reduction, it is tempting to kick the Second Law out to the status of "initial conditions," but I have never seen a satisfactory explanation of why we should find ourselves in the world that has increasing entropy, except in an appeal to the anthropic principle. This is a weak appeal though, as it is hard to show conclusively how sentient observers are only likely to exist in worlds with increasing global entropy.

The real problem here is with the notion of "the present universe". What Einstein reveals with the relativity of simultaneity is that "the present" is frame dependent. So the whole idea that there is such a thing as "the present universe" is an unsound premise because "the present" is something created by the observational perspective.

When we realize that "the present" is purely subjective, and we try to imagine an objective universe, independent from any observer, we have no place to insert "the present", because this would be an artificial insertion, therefore the creation of an observational perspective. Then we cannot possibly imagine such a universe, without a designated temporal perspective, (a point in time of now), because all things would exist everywhere, without some way of determining a specific point in time in their motions.

Relativity shows simultaneity is local, not that it is somehow arbitrary. It is not the case that relativity in any way prescribes eternalism, although this has not stopped popular science authors from making this claim (or others from continually coming along to debunk it; I have not seen the debunking debunked in turn however, and it convinced me).

No one present is privileged, but you can have a "many fingered time," with multiple time variables.

Not sure if that's what you meant by "subjective," but that is certainly a common misconception. That there are issues with positing the world as it is sans observers is quite true, but it is true even ignoring SR/GR.
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I only skimmed this thread, but has the Born Rule problem really not come up?

To bring up the example before, it is like someone's spouse is either in spot A with probability 30% or spot B with probability 70%, except, get this, she is also in BOTH spots with probability 100%. Explaining that satisfactorily is going to be a doozy, and I don't think Dutch Book arguments really solve the problem.

See the brief discussion earlier in the thread (with a link to Sean Carroll's solution).
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I see it now. Yes, I am aware of that solution, and while clever, it doesn't seem satisfactory. The whole Sleeping Beauty problem class seems to be misused in a lot of physics scenarios, IMO, in part because rational agent based models aren't reversible. For example, this is where Tegmark's first book (mentioned ITT) begins to start going off the rails. He starts talking about the Doomsday Problem, and "what are the chances that you would randomly be the nth member of X sentient species ," in terms of frequencies.

This is an area where frequentism starts to become incoherent if you apply it this way. MWI is deterministic. The person you are and the time you exist in history isn't random or independent, it is entirely determined in MWI. You can apply frequentism in plenty of physics cases and get away with it, but using it here in the context of cosmic inflation or MWI makes absolutely no sense.

In the Doomsday Scenario for instance, any early human would have been just as justified in thinking humanity will die out before even 5 billion people are born as Tegmark is today worrying about humanity going extinct before 250 billion people. But obviously, when one lives is not i.i.d. He's obviously a smart guy, and I enjoyed most of the book, but this and some Born Rule explanations could be part of a public awareness campaign called "this is your brain on frequentism. Just say no! (to calling probability and frequency identical)"

You can turn the Born Rule into an argument about which bets a person should place, but that doesn't answer why those bets are likely to be good ones except in terms of empiricism when the derivations of the Born Rule are circular (e.g. when using axioms originally added just for the Born Rule). It becomes a sort of hybrid frequentist-QBism in some solutions, which I don't even think is coherent if it is unpacked.

Or, to let someone else say it:

From these axioms they conclude that rational agents should bet on the outcomes of a quantum experiment with probabilities given by the Born rule. Who cares? Should we really believe that the statistics of an experiment will be constrained by rationality axioms? And conversely, if you can show that the statistics of a quantum experiment follow the Born rule, doesn’t it become obvious that rational agents should bet that they do, making the whole decision-theoretic argument superfluous? It’s worth noting that this same criticism applies to my derivation, as it is just a cleaned up version of the Deutsch-Wallace argument...

Let’s move on to Vaidman, Carroll, and Sebens. Their derivations differ on several important points, but I’m interested here in their common point: they passionately argue that probability is about uncertainty, that a genuine source of uncertainty in Many-Worlds is self-locating uncertainty, and that locality implies that your self-locating uncertainty must be given by the Born rule. Arguing about whether probability is uncertainty is a waste of time4, but their second point is well-taken: after a measurement has been done and before you know the outcome, you are genuinely uncertain about in which branch of the wavefunction you are. I just don’t see how could this be of fundamental relevance. I can very well do the experiment with my eyes glued to the screen of the computer, so that I’m at first aware that all possible outcomes will happen, and then aware of what the outcome in my branch is, without ever passing through a moment of uncertainty in between. Decoherence does work fast enough for that to happen.5 What now? No probability anymore? And then it appears when I close my eyes for a few seconds? That makes sense if probability is only in my head, but then you’re not talking about how Nature works, and I don’t care about your notion of probability.

I don't have these same concerns, but I think it is important than many proponents of MWI do list similar concerns about other theories in quantum foundations.

I like MWI for itself elegance; no ad hoc collapse. But there is a problem where theory is elevated above empirical results (i.e. the observation of apparent collapse), but then a crucial element of collapse, is then explained in terms of epistemology. Why prefer shifting the squishy part of the theory from one place to another?

This is also the issue of "splitting" versions of MWI. In these, there isn't one universal wave function that we see part of, but instead the universe actually "splits," during measurement. The problem is that, while physics is time asymmetrical as a whole, parts under consideration are not, making the "causal" relationship between measurement and "splitting" another thing that begs explanation (and this is true even if you argue "cause" is just another name for description). Splitting then seems as ad-hoc as collapse, whereas a seeming benefit of non-splitting versions is that such collapse/splitting is only an appearance.

Furthermore, because MWI is fully deterministic, it seems like we should have a block universe. But do we have a growing block universe where splits occur in the direction of time's passage? That is what the splitting versions of MWI seems to suggest. But if each world is its own four dimensional object then it seems we need a new, fifth, "time" dimension for the multiverse in which splitting occurs, this being true even if we take an eternalist view of such splits as having already occured/existing eternally. There is a state of the multiverse M1 before a split occurs where it has fewer branches than M2, the multiverse at a later time, but this change cannot occur across the same time dimension as the time dimension that each individual universe has, since a split is necessarily the spawning of a new, complete four dimensional object.

Then we have to consider that, if we have an eternalist view of things, why is it that, by reversing the direction of time, we have a universe where many universes begin to merge into a smaller number of universes? Is the direction of splitting the true arrow of time? If so, why (and why are there so many physicists who embrace eternalism, claim physics is ultimately reversible, and embrace MWI?) If the physics in question is reversible, why do we posit a splitting universe instead of a merging one, aside from the fact that having it split in both directions (forwards and backwards in time) is incoherent?

Perhaps whenever we make a measurement we merge universes, such that we progress by such merges to one of many potential end points, final conditions, of the universe, assuming ad hoc that it has an end? This might work, but it blows up the rational-agent based derivations of the Born Rule. Rational agent models are not reversible, we don't say, "given what I observe now, what must have happened in the future, what endpoint must I be most likely to be converging on?"

The problem might be worse, since splits occur vis-á-vis a parent, such that we can arbitrarily pick any starting point and then see a family tree descending from that current universe. If we have two such family trees, does it work to say that splitting in both occurs across the same dimension? I'm not sure it does, given the "multi-fingered" nature of time in our one observable universe, in which case you need even more time dimensions.
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Relativity shows simultaneity is local, not that it is somehow arbitrary. It is not the case that relativity in any way prescribes eternalism, although this has not stopped popular science authors from making this claim (or others from continually coming along to debunk it; I have not seen the debunking debunked in turn however, and it convinced me).

What I said in the quoted passage is that the idea that there is a present state of the universe, is shown to be unsound by special relativity, as a premise which is inconsistent with special relativity. This is consistent with "simultaneity is local". I wasn't talking about eternalism.

No one present is privileged, but you can have a "many fingered time," with multiple time variables.

Sure, but this presents a problem toward understanding any causal relations between "one present" and another present. The present is local, but there is still interaction between far away places, as the travel of light indicates.

That there are issues with positing the world as it is sans observers is quite true, but it is true even ignoring SR/GR.

I certainly agree with this. However, as a person who is a temporal realist, it is easy for me to see SR/GR as taking advantage of the fact that there are issues with positing the world as it is sans observers.

The issue is that knowing how the world would have been without observers is not a realistic counterfactual to entertain. This is because even if we could theoretically produce a "without observers" perspective, any sort of "knowing" which is derived from this perspective still implies observers, as "knowledge" has an observational aspect.

So the first thing that I notice, if I try to produce an observer-free perspective in theory, is that the "here" of "here and now" (here and now being the defining features of the observational perspective), could be anywhere, and the universe would maintain intelligibility. However, the now, since "now" must be restricted to a specific duration of time to make the universe intelligible, does admit to that freedom. If "now" were an infinite duration of time, the universe would be unintelligible because everything would be everywhere, now. The conclusion therefore, is that how we understand "now" determines which aspects of the universe will be intelligible to us.

So let me relate this to why I say SR/GR takes advantage of the problem with positing a world without observers. To understand the universe in its totality requires that we have a conception of "now", which accurately accounts for all the restrictions imposed by the reality of what now is. But SR/GR provides no real principles to account for the reality of now, thus allowing "now" to be defined by other principles. As explained above, this will render aspects of the universe (where the restrictions imposed by theory are not representative of the restrictions imposed in reality) as unintelligible.
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Physics is a human undertaking.
...
All measures are made by humans.
Fine. I googled ‘what is measurement in quantum mechanics’ and got this
In quantum physics, a measurement is the testing or manipulation of a physical system to yield a numerical result. — ”Wiki: Measurement in quantum mechanics”
This seems more a classical physics definition of measurement, but I concede the point that there is implied intent going on.
I don’t have a different word to use. Therefore we lack for vocabulary since ‘measurement’ and ‘physics’ are both human undertakings and apparently cannot be used for interactions not involving humans.
What do you call the actual mechanisms of the universe, as opposed to ‘physics’, the human undertaking to describe it? What would you call an interaction between systems of which humans are completely unaware, say where one system (some radioactive atom) emits an alpha particle which alters a second system (some molecule somewhere) by altering its molecular structure (and probably heating up the material of which the molecule is part). It isn’t a measurement because there’s no intent and no numerical result yielded, so what word describes this exchange between the atom and the molecule?
Bell complained of ‘measurement’ as well, saying it comes loaded with meaning from everyday life, meaning which is entirely inappropriate in the quantum context. This is exactly what I’ve been trying to convey.
Give me another word that you find acceptable that describes that which makes the state of system B collapse relative to system A. 'Interaction' seems a plausible candidate, but not all interactions constitute the state of B causing an alteration the state of A.

That of which I am speaking is the measurement in the quantum measurement problem, which has a different wiki page.
In quantum mechanics, the measurement problem is the problem of how, or whether, wave function collapse occurs. The inability to observe such a collapse directly has given rise to different interpretations of quantum mechanics and poses a key set of questions that each interpretation must answer.
The wave function in quantum mechanics evolves deterministically according to the Schrödinger equation as a linear superposition of different states. However, actual measurements always find the physical system in a definite state. Any future evolution of the wave function is based on the state the system was discovered to be in when the measurement was made, meaning that the measurement "did something" to the system that is not obviously a consequence of Schrödinger evolution. The measurement problem is describing what that "something" is, how a superposition of many possible values becomes a single measured value.
— ”Wiki: Measurement problem
This is what I am talking about. What precisely physically ‘does something’ to a system that makes its [past] state change, I say physically because I’m not talking about somebody’s mere knowledge or description of a system. I assure you it isn’t the determination of a numerical value by a conscious entity that changes the target system.
Now one can certainly posit that the universe supervenes on humans, and that physical systems collapse into a real state only when a human consciousness tests or manipulates a laboratory system in such a way to yield a numerical result. Such an idealistic interpretation does not concern me, but it is listed as one of the obscure interpretations.
There are various other interpretations. A counterfactual one (e.g. Bohmian mechanics) would say that the wave function never collapses and all systems are in one state, measured or not. Superpositions are an illusion, and apparent interference is due to something other than a system being in more than one state.
MWI would also say no collapse, and an interaction from B to A would simply entangle A with B’s superposition of different states, all of which are instantiated in various worlds. MWI is a realist interpretation that denies counterfactual definiteness, so that principle is not equivalent to a stance realism.
Others call out an arbitrary divide between A and B, or ‘system’ and ‘aparatus’ as Bell puts it. This wording implies again that quantum effects only occur when intentional apparatus is involved, but the interpretations do not suggest this. In Copenhagen, the Heisenberg cut delimits measurer and measured. It can be assigned arbitrarily and is entirely abstract. Actual physical systems have no meaningful boundaries of objects or systems.
A relational view is similar, where an arbitrarily defined system’s state relative to a different system changes upon some kind of interaction from one to the other.

[Counter-factual definiteness] refers to the idea that physical systems have definite properties, even if they are not measured or observed.
Given your definitions, this seems to translate to a system having properties despite the absence of humans, which is impossible since ‘system’ and ‘property’ are human terms, not meaningful in the absence of humans.
Alternatively, you perhaps suggest an epistemological definition of counter-factual definiteness, where in the absence of human measurement/observation, humans would not know of the thing, and existence is defined by human knowledge of it. Hence, again, by definition, nothing can exist in the absence of humans since no human could know of it. Counter-factual definiteness is therefore false either way.
Correct me where I’ve misinterpreted what you’ve been trying to tell me.

So, you're still 'realist', but you are outsourcing measurement to everything that exists
No, because ‘everything that exists’, lacking a relation, is meaningless in a view requiring such a relation. It’s worded as an objective statement. Only a realist gives meaning to such a phrase.
So, 'measurement', for you, occupies the place that 'God' does, for Berkeley, i.e. it keeps everything in existence when not being measured, as Berkeley's God keeps everything in existence even while not observed.
No. That’s still a cheap attempt to put objective existence on things, like it was a property instead of a relation. I also don’t see how a god (or anything not part of the quantum structure) could measure a closed quantum system.
Why do you find it so difficult to let go of your realist assumptions when being asked to consider an alternative? You seem only determined to pin the realist label on me, listing one strawman argument after another.
I think a god watching (if that is even meaningful) would put categorize things into ‘that which this god watches’, as distinct from that which it doesn’t, which would still be a relation with the god. It would only be realism if the god was real (sans relation).

do you recognize that a system is an artificial thing, a human creation, whether it is a theoretical system, with boundaries imposed by theory, or a mechanical system, with created physical boundaries?
I was going to agree with this until the last bit about physical boundaries. A system’s boundaries are an arbitrary abstraction, nothing physical about it. But the arbitrary designations are needed for description, not for the actual processes to work.
then by what principle do you assume that there is any sort of "existence in absence of measurement"?
Given this intentional definition of ‘measurement’, I cannot answer this question since I don’t define existence in terms of it, but it sounds like a version of the principle of counterfactual definiteness. I personally choose to deny that principle.

because "measurement" to most people implies some real existing aspect of the universe which is measured, like when we count something we assume that there is an existing quantity which can be counted and it has some real existence as that quantity, prior to being counted.
That’s pretty pragmatic to assume that, yes. It’s also pretty pragmatic to assume that I cannot choose to alter some event in the past, but it’s been demonstrated that one of those assumptions (if not both) are wrong.

You did not specify a frame, you said "here".
That one word was not where the frame was specified.

but a ‘frame’ does not require additional references.
— noAxioms
Yes it does, and you've misrepresent "frame" as a point. A point is not a frame.
I didn’t say a frame was a point. I can say ‘the frame of the sun’, and that defines a frame relative to which the velocity of things (Earth say) can be expressed. An additional reference is not needed to determine that Earth at a particular moment moves at about 30 km/sec relative to that frame. The statement does not assert that a frame is a point. The frame happens to be a velocity reference. It is limited. I cannot, given just that, specify the x y and z coordinates of Earth at a given moment. More definition is needed for that to be done.
If you disagree with that, then do you deny that Earth moves at about 30 km/sec relative to the sun? What additional references are required before that statement can be made?

As per the above, a specification of only the origin defines a frame...
— noAxioms
No, a point does not constitute a frame.
I didn’t specify a point, and I didn’t say it constituted the frame. The sun for instance is a worldline, not a point. A point would be an event, and an event indeed does not define a frame. A worldline defines a frame. An unaccelerated worldline defines an inertial frame. So before I said ‘my frame’ which is a frame defined by my worldline, and relative to that worldline, ‘here’ is always at the same location, and no, that worldline does not constitute the frame, it only defines it.

"Frame" implies "coordinate system".
It does not. For instance, there is the cosmological frame, an expanding metric that foliates most of the universe. The CMB appears isotropic to anything stationary relative to that frame. But coordinate system implies coordinates. One can measure the sun’s current velocity relative to that frame (not quite 400 km/sec in the direction of Leo), but one cannot specify the current coordinates of the sun relative to it. That would require a coordinate system. Hence a frame and a coordinate system are different things. The former is a velocity reference, but the latter assigns numbers (coordinates) to all events.
There is no frame without a coordinate system as you seem to believe.
I just gave multiple examples of them. If you disagree, then tell me the current coordinates of our sun (a number for x, y, and z, your choice of units). Remember, the only reference is the CMB here, not a worldline this time, but enough.

Your "frame" in this example is a coordinate system which maps the rocket, not one point such as "here"
No, because I didn’t define it relative to that which says ‘here’. I chose a different origin, which was the nose of the rocket. In fact, I never used the word ‘here’ in releation to the frame of the rocket.
And if you say that the rocket is one point
I never said that, so no worries. I referred to the very tip was a point where I assigned the origin. The rest of the rocket is not located at the tip, and so not at the origin. Other parts of the rocket have nonzero coordinates relative to the coordinate system described.
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The wave function in quantum mechanics evolves deterministically according to the Schrödinger equation as a linear superposition of different states. However, actual measurements always find the physical system in a definite state. Any future evolution of the wave function is based on the state the system was discovered to be in when the measurement was made, meaning that the measurement "did something" to the system that is not obviously a consequence of Schrödinger evolution — ”Wiki: Measurement problem

This will probably turn out to be really dumb, a lesson not to mess in physics when one is not a practitioner, but nevertheless: Here is a stripped down version of the Schrödinger equation, showing its simple solution. Note that the solution is originally dependent upon a constant, ${{C}_{0}}$. This is the measurement at time t=0. Whatever value this constant assumes will then determine the time evolution of the (wave) function.

There are an infinite number of solutions depending upon that constant (measurement) - a superposition. Then the measurement takes place and a "collapse" occurs giving a particular solution. Did the measurement "do something" to the system, or does one simply experiment to find the appropriate value of the constant? Where is the magic?

Being dumb in QM, I am missing some subtlety, I admit. :chin:

$\frac{d\psi }{dt}=ik\psi \text{ }\Rightarrow \text{ }\frac{d\psi }{\psi }=ikdt\text{ }\Rightarrow \text{ }\ln \psi =ikt+C\text{ }\Rightarrow \text{ }\psi (t)={{e}^{C}}{{e}^{ikt}}={{C}_{0}}{{e}^{ikt}}$

${{C}_{0}}=\psi (0)$
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I have never seen a satisfactory explanation of why we should find ourselves in the world that has increasing entropy

As opposed to what? A world at thermodynamic equilibrium?

And what do you mean by explanation here? We are bound to find ourselves in one world or another. How could you explain the fact that the world that we find ourselves in is this one? Explain in terms of what?
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Yes. Since there are more ways to be high entropy than low entropy we should have more worlds with high entropy than low. So why are we in a low entropy world if it is very statistically unlikely?

Some version of the past hypothesis, right? But then seeing a world where the past hypothesis is true is vanishingly unlikely, even if it occurs with probability 1, according to MWI derivations of the Born Rule.

Weyl curvature arguments are ok here, but both MWI and Cosmic Inflation tend to go for the Anthropic Principle to explain this.

"All possible worlds exist. Obviously we exist and our world is possible. And we can only exist in some narrow band of worlds in terms of initial conditions."

The obvious problem here is that this makes explanations from physics trivial. "Anything observed is physically possible and anything possible occurs so of course you see x even if x is a 1 in quadrillion event," is just "if you see it, it is possible, so it is."

All explanations about how stars, planets, life, etc. evolved in our particular history, the how and why of science, gets fobbed off onto "initial conditions, all of which are true."

Obviously, some cosmologists find this answer very deep, hence the popularity. However, it essentially reduces to "if it's possible it happens and if you see it, it is possible." This isn't a real answer. The answer we want in non-multiverse theories isn't actually addressed, which reformulated for an "all possibilities exist multiverse," is the question "why did our particular history occur such that we see x."

Also, apparently you should be bothered by extremely unlikely events in your experiments if you believe in MWI, since you should care about the Born Rule... except when it comes to identifying that you are in an incredibly low probability universe. Then, when doing cosmology, it is ok to jettison probabilities when making explanations and resort to "everything has to happen with p = 1."

If you follow the epistemological logic used for cosmology at the individual level, you shouldn't be surprised when jumping in front of a train doesn't kill you or standing in front of a firing machine gun leaves you unscathed (ala Tegmark's quantum suicide set up). If you were dead, you wouldn't see anything. Even if being alive is incredibly unlikely, that's all you're going to see, and so the anthropic principle, applied on the individual level, says there is nothing at all notable about throwing yourself into a volcano and surviving, etc.

It seems to me that either low probability events should always be surprising and make us ask questions or they never should, not a too cute mix of both. Just bite the bullet and say the Born Rule is meaningless, a total illusion, in that case.
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What would you call an interaction between systems of which humans are completely unaware, say where one system (some radioactive atom) emits an alpha particle which alters a second system (some molecule somewhere) by altering its molecular structure (and probably heating up the material of which the molecule is part). It isn’t a measurement because there’s no intent and no numerical result yielded, so what word describes this exchange between the atom and the molecule?

It's all descriptive. There's no way around it. That's why it becomes "the hard problem" for those who do not accept the reality that there's an unbridgeable gap between the map and the territory. And, the problem is that the description is completely different depending on the perspective one takes. That's the importance of understanding the true nature of relativity theory.

We can take "relativity" in two ways. 1) The world appears different to us, depending on the perspective we take. 2) The world is different from different points of view. The former is realist, as assuming a true way that things are, independent of the various perspectives. The latter assumes no such independent "real" point of view. And the problem is that to apply relativity theory, and make it work for us, we need to assume the latter. Since that position is adopted for the purpose of applying relativity theory, we cannot make the results derived from the application of relativity theory compatible with the realist assumption of a real independent world. We must recognize and respect this fact, that whatever results are produced from the application of relativity theory, these are fundamentally incompatible with that form of realism.

Consider "an apple hanging from a tree". That's one way of describing the scenario, it's a static scenario, though "hanging" is still a verb. But we could also describe it as a whole bunch of different molecules with atoms interacting, and the gravity of the earth interacting with the massive molecules, putting immense force on the stem, until with ripeness, the atomic and molecular interactions change considerably, and the apple falls.

Notice, the former is a very simple description, as a static state, it takes no account of the passing of time, except for the word "hanging". The latter description makes an attempt to account for the effects of time passing, by describing the scenario in terms of activity.

This is what I am talking about. What precisely physically ‘does something’ to a system that makes its [past] state change, I say physically because I’m not talking about somebody’s mere knowledge or description of a system. I assure you it isn’t the determination of a numerical value by a conscious entity that changes the target system.

This question is answered with "the passing of time". The passing of time "does something" to the system, and we have only the vaguest idea of what it does. Sometimes it's named by "entropy". But what the passing of time really does, is understood much better through terms other than "entropy". You see, we understand the future in terms of possibilities, what may or may not happen, and the past we understand in terms of actualities, what has actually happened. This leaves "the present" with a peculiar temporal position, as the time when possibilities are selected for as the ones which will be actualized. And this actualization of possibilities we observe as the activity which occurs at the present.

The significant and important thing to consider here is that when a vast multitude (even approaching infinity) of possibilities for the future is related to a single, or at least a very restricted number of actualities in the past, there is a need to assume a process of "selection". The determinist wants to describe the selection process as completely determined, while the free willie understands final cause as a type of causation which is not determined in that way. So the free willie concludes that if there is a way that the conscious human being can pick and choose from possibilities, as to which ones will be actualized, in an undeterministic way, so it must be in the greater universe in general, that something (traditionally "God") picks and chooses from the possibilities in an undeterministic way.

The wave function in quantum mechanics evolves deterministically according to the Schrödinger equation as a linear superposition of different states. — ”Wiki: Measurement problem

This "deterministic" evolution of the wave function is completely a feature of the type of description employed. It is described so as to be deterministic, when in reality, this description, the "superposition of different states", violates the law of noncontradiction, showing that this deterministic description is actually very faulty.

We can say, "the apple hanging on the tree" is a determinist description, and by Newton's laws that hanging apple will continue to hang, as an equilibrium, in its deterministic way, until a force causes it to fall. The deterministic wave function is analogous with the apple hanging, and we could place bets concerning the collapse, the fall. The deterministic bettor would look for the upcoming forces which would cause the fall. The undeterministic bettor would look at the passing of time itself, and the selective process which inheres within the passing of time itself (the Will of God), as a force which could potentially act on the apple. But the laws of physics, from the foundations of Newton's first law, which provides the basis for the deterministic perspective, do not have the required provisions for looking at the passing of time as a selective force. As Newton himself said, his first law takes the Will of God for granted. So if this implied selective process (as the Will of God) which is active at the micro scale, as time passes, actually makes selections, our determinist laws of physics have no way to account for these selections.

I was going to agree with this until the last bit about physical boundaries. A system’s boundaries are an arbitrary abstraction, nothing physical about it. But the arbitrary designations are needed for description, not for the actual processes to work.

You are not following the distinction I made between a system in theory, and an engineered system. The latter being a designed physically existing system created for the purpose of doing work. It has a physical boundary, and the energy lost to the system as entropy, may or may not escape somehow through this boundary, because where the energy which is lost to entropy actually goes to, is an unknown.

That’s pretty pragmatic to assume that, yes. It’s also pretty pragmatic to assume that I cannot choose to alter some event in the past, but it’s been demonstrated that one of those assumptions (if not both) are wrong.

Huh? I don't see how this follows at all. I don't think you understood what I said. I was taking that from the reference from Bell which you provided. I don't think you understand that quote very well. Here's the part:
When it is said that something is 'measured' it is difficult not to think of the result as referring to some pre-existing property of the object in question.

I discussed this principle in another thread with a number of participants. Suppose there is a jar with marbles in it. The marbles can be counted and this will determine the quantity. The others argued that the quantity is already determined, prior to the counting. The quantity is a "pre-existing property". But "quantity" is a human determination produced by the act of counting, and cannot exist prior to the counting. This idea, that the quantity determined by the act of measuring exists prior to the act of measuring, is what Bell is referring to here as a problematic way of looking at QM.

This faulty way of looking at reality is pervasive in the modern intellect. It seems to have been propagated by Platonism in mathematical axioms, which would imply that there is "a number" for the potential count, already in existence, and all we need to do is somehow find that number. The problem manifests deeply when the axioms deal with infinities, and assume that a "countable number" has some type of actual existence in the same way as a counted number.

I didn’t say a frame was a point.

This discussion is pointless (please excuse the pun, it just came out that way). You were arguing that "here" constitutes a frame. If you still can't admit to the fault in this, I really don't see the point to continuing.

If you disagree with that, then do you deny that Earth moves at about 30 km/sec relative to the sun? What additional references are required before that statement can be made?

Do you not see, that "the earth" and "the sun" involves two distinct places, unlike "here"?

It does not. For instance, there is the cosmological frame, an expanding metric that foliates most of the universe.

And "metric" doesn't imply "coordinate system" to you, in this context, such that a coordinate system is a logical necessity for a metric?

No, because I didn’t define it relative to that which says ‘here’. I chose a different origin, which was the nose of the rocket. In fact, I never used the word ‘here’ in releation to the frame of the rocket.

This is exactly the point. What we were discussing is the meaning of "here" in your previous example, and the ridiculousness of that example. Now you want to replace "here" with "the nose of the rocket", but you admit right here (excuse the pun again), that the two are not analogous.
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