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A Malleable Universe

Wayfarer June 25, 2018 at 05:32 13650 views 48 comments
The notion of a completely objective reality is the bedrock principle of science, which is the main reason Einstein was so uncomfortable with Bohr’s “nothing exists without observation” take on quantum theory. Yet Christopher Fuchs, a physicist now at the University of Massachusetts, and Ruediger Schack of Royal Holloway University of London disagree. They contend that Bohr was on to something: Our notion of an objective reality needs modification. The physical world cannot be separated from our own efforts to probe it. How could it be otherwise, since we ourselves are embedded in the very world we’re seeking to understand?*

They call their way of looking at quantum mechanics QBism, a modified version of a theory they developed with University of New Mexico physicist Carlton Caves called Quantum Bayesianism. QBism combines quantum mechanics with Bayesian probability, a variation on standard probability in which the odds of any given event are revised as one gains more knowledge of the many possible conditions tied to the event. For example, if a patient complains of headaches to a doctor, the initial odds of a diagnosis of brain cancer might be low. As the doctor examines the patient, the odds of a cancer diagnosis may go up or down.

... QBism applies similar reasoning to physics experiments: Whenever physicists perform an experiment, they are updating their own subjective knowledge. There is no fixed underlying reality that different observers can independently experience. Just as a doctor must assess each patient individually, so too must a physicist approach the fresh, ever-changing phenomena presented by the quantum world. In QBism, the experimentalist cannot be separated from the experiment — both are immersed in the same living, unpredictable moment.

“If QBism says one radical and important thing about the nature of reality, then observer participancy is it,” says Schack. “Subjects matter. And reality, if QBism is right, cannot be conceived without always including the subject. That’s certainly a bold statement about the real world, about reality. It’s just a feature of reality that is very fundamental.”


From The War Over Reality, Discover Magazine. See also Interview with Christopher Fuchs, Quanta Magazine.

*Max Planck: 'Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are part of nature and therefore part of the mystery that we are trying to solve.'

What I take this to mean, is that objectivity cannot be absolute. And I think the reason this is controversial is that it undermines realism, which is the (usually instinctive) idea that the Universe simply exists as it always does, and that we humans come into it and go out of it in an instant, relative to the vastness of space and time which science observes. But this undermines that view, because it illustrates the sense in which the observer is inextricably part of the picture. We don't, actually, stand outside of, or apart from, the Universe which we are analysing; so what we're analysing cannot be absolutely objective.

Andrei Linde makes this exact point at 3:16 in this Closer To Truth interview.

Comments (48)

Shawn June 25, 2018 at 06:03 #191015
How do you reconcile the above notion with a solipsistic entity, which I have come to understand that we are to some degree?

For example, you can assert that "god" is the ultimate solipsist or the 'wavefunction' here; but, then that would be redundant if we too were in some sense solipsists also partaking in his wavefunctional dream...
Streetlight June 25, 2018 at 06:34 #191018
The problem with these kinds of claims is that they take a tautology - the fact that the results of measurement cannot occur with without acts of measurement - and try and wring from it a substantive claim that does not follow: that as a result, the universe itself is existentially dependent upon those acts of measurement.

Or put otherwise, it is simply trivially true that the experimenter cannot be separated from the experiment: and this speaks to the nature of experiments (as conducted by human/other experimenters) and not, as it were, the universe itself. So one needs to be very careful about how to treat these kinds of claims. It is undeniably true that the observer is always part of the picture - insofar as it is only ever a picture.

Or put yet otherwise, because this is a hard point to grasp: the relation between measurement and universe is absolutely asymmetrical. Of course any measurement of the universe will depend on the fact of it being so measured: that is what it means to be part of the universe. But it does not follow that the universe depends, 'existentially', on measurement. But this attempt to wring a substantive from a tautology is just the kind straightforward logical fallacy committed by quantum-woo charlatans day after day.

It is true that this does require a reevaluation of what 'objectivity' means: measurement isn't just about attaining a POV 'from nowhere'. It is always a kind of POV 'from somewhere'. But this speaks to the enterprise of measurement itself, and not anything else.
Snakes Alive June 25, 2018 at 07:03 #191024
Quoting StreetlightX
StreetlightX


This is true so far as it goes, but there is a lurking problem: there are parts of the universe that are dependent ontologically on the act of measurement. But then, these are precisely the things that are likely to be involved in what's gleaned from the measurement itself.

In other words, if you take seriously the idea that measurements only reveal things qua measured, and there's no reason to think that it's possible to measure things qua things as they are independent of or prior to measurement, then you immediately end up in Kantianism.

How, then, do we know what effect the measurement has? Presumably, we measure this too...and so on ad infinitum.

The worry therefore is not as trivial as you make it out to be.
Wayfarer June 25, 2018 at 07:03 #191025
Reply to Posty McPostface Beats me, Posty. There’s a lot of physics heavyweights who don’t know what to make of it.

Reply to StreetlightX I think you misunderstand the significance of the ‘measurement problem’ and what has come out of it. The point is, it came to light precisely in the attempt to measure and understand the ostensible ‘fundamental building blocks of the Universe’. What it seems to do is undermine the presumption of the mind- independent nature of the objects of physics - the very ‘principle of objectivity’, as the article says. It’s a big deal. This implication is what made Albert Einstein so uncomfortable about it - it is why he famously asked the question ‘does the moon continue to exist when we’re not looking at it?’ Whereas Bohr and Heisenberg were not nearly so bound to a realist attitude - hence their so-called ‘Copenhagen interpretation’.

If it were only saying what think it is, then indeed it would be ‘trivially true’ - but it’s not.
Snakes Alive June 25, 2018 at 07:07 #191027
Here is an easily digestible illustration of the problem:

User image
Streetlight June 25, 2018 at 07:25 #191031
Quoting Snakes Alive
In other words, if you take seriously the idea that measurements only reveal things qua measured, and there's no reason to think that it's possible to measure things qua things as they are independent of or prior to measurement, then you immediately end up in Kantianism.


But this would only be the case if you ignore the specificity of the experiments involved. The cool thing that QM teaches us is that measurement is just another kind of physical interaction. It places us on the same footing as everything else in the universe. That's just what it means to say that 'we are part of what we are trying to measure'. The whole import of QM is that it demolishes any pretence to human exclusivity - we don't stand apart from the world, we are already of it. There's no need to try and attempt to 'get outside' because one is 'already inside', if I may put it that way. This in turn bars any Kantian interpretation of QM, insofar as it denies any attempt to make of us exceptions to the rule.

Quoting Wayfarer
’. What it seems to do is undermine the presumption of the mind- independent nature of the objects of physics


Thanks for not addressing my point, charlatan. Now is about the time you post a coat-of-arms picture I believe, or whatever other detritus you usually spew in lieu of argument.
Snakes Alive June 25, 2018 at 07:27 #191033
Quoting StreetlightX
There's no need to try and attempt to 'get outside' because one is 'already inside', if I may put it that way.


I'm sorry, I don't see how this addresses my post. Can you explain?
Streetlight June 25, 2018 at 07:32 #191034
Reply to Snakes Alive Measurement = physical interaction = not exclusive to humans = no Kantianism.
Snakes Alive June 25, 2018 at 07:34 #191035
Quoting StreetlightX
?Snakes Alive Measurement = physical interaction = not exclusive to humans = no Kantianism.


We seem to be talking past each other. I don't understand what this has to do with my post.
Streetlight June 25, 2018 at 07:35 #191036
Quoting Snakes Alive
In other words, if you take seriously the idea that measurements only reveal things qua measured, and there's no reason to think that it's possible to measure things qua things as they are independent of or prior to measurement, then you immediately end up in Kantianism.


?
Snakes Alive June 25, 2018 at 07:39 #191038
Quoting StreetlightX
?


The comic is a more intuitive explanation of what I was talking about. I didn't say anything about measurement not being physical, exclusive to humans, etc.

The point is just that many things in the world are unquestionably dependent on measurement, no matter what your view of it is. Those things include the very things we're interested in as data when conducting expriements – say, impressions produced on our sense organs and so on.

Thus, we only ever measure things as they are while being measured. To the extent that what is recorded is an artifact of the measurement, we are not recording what the thing is independent of that measurement. This is a problem because we have no way of 'subtracting' the effect of the measurement except via more measurement.

This becomes especially odd when we consider that, say, even in looking at things, the info we get is from visual stimulus, the entirety of which is dependent on the 'measurement' – no measurement, no visual stimulus. Thus, so the classical problem goes, when we see something we indeed see it (and perhaps not an illusion), but what we see about it is how it hits our eyes, and so learn nothing about what it is as apart from that interaction with our eyes.
Streetlight June 25, 2018 at 07:51 #191040
Quoting Snakes Alive
we are not recording what the thing is independent of that measuremen


What is this 'the thing' 'independent of that measurement'? It's like asking 'what does red look like in the absence of light?': it's not that it looks other than it does in light, it's that the question is wrong. It misunderstands what it means to be red, which is just to look like that in the presence of light. That doesn't make it an 'artefact': good measurements really do capture something of what is so measured: red 'really does' look like that. But: 'what does it look like in the absence of a look?' - this is just a badly formed question, leading to false puzzles.
Snakes Alive June 25, 2018 at 07:54 #191041
Quoting StreetlightX
It misunderstands what it means to be red, which is just to look like that in the presence of light.


Very well – but if you say all properties of the thing we're interested in are relative to the measurement in this way (what it is to have that property just is to look a certain way under certain conditions), then this collapses into Kantianism. We deal with phenomena, and we learn about things only that they look certain ways to us.

Quoting StreetlightX
But: 'what does it look like in the absence of a look?' - this is just a badly formed question, leading to false puzzles.


This is not what I said, though.
Streetlight June 25, 2018 at 07:55 #191042
Quoting Snakes Alive
Very well – but if you say all properties of the thing we're interested in are relative to the measurement in this way (what it is to have that property just is to look a certain way under certain conditions), then this collapses into Kantianism. We deal with phenomena, and we learn about things only that they look certain ways to us.


But what is the status of 'us'? You're treating 'us' as an exception that is somehow different from 'everything else'; but this is just what is unwarranted.
Snakes Alive June 25, 2018 at 07:57 #191043
Quoting StreetlightX
But what is the status of 'us'?


"Us" would be whoever's measuring.

Quoting StreetlightX
You're treating 'us' as an exception that is somehow different from 'everything else'; but this is just what is unwarranted.


How am I doing this?
Streetlight June 25, 2018 at 07:59 #191044
Quoting Snakes Alive
How am I doing this?


By assuming this entails Kantianism.

Quoting Snakes Alive
"Us" would be whoever's measuring.


And what is measuring? A: A physical interaction.
andrewk June 25, 2018 at 08:00 #191045
Reply to Wayfarer
The notion of a completely objective reality is the bedrock principle of science
This sounds like the sort of thing Stephen Hawking would say, and it is wishful thinking on the part of people that would like to co-opt science in their evangelical quest to spread reductive materialism.

But science will not be co-opted.

The claim is belied by the rest of the post, in which four scientists: Planck, Bohr, Fuchs and Schack - two of them in the veritable pantheon of physicists - disagree with it. We could add Heisenberg and Bohm to that for a start.

In no sense at all is that notion of objectivity a bedrock of science. Science is silent on that topic. That people like Hawking claim it is a bedrock does not make it so. It may be a bedrock of scientism, but it is certainly not a bedrock of science.
Snakes Alive June 25, 2018 at 08:02 #191048
Quoting StreetlightX
By assuming this entails Kantianism.


I don't follow. Can you explain?

Quoting StreetlightX
And what is measuring? A: A physical interaction.


I don't understand. I never denied this, and I don't see why it's relevant.
Wayfarer June 25, 2018 at 08:21 #191050
Quoting andrewk
The claim is belied by the rest of the post, in which four scientists: Planck, Bohr, Fuchs and Schack - two of them in the veritable pantheon of physicists - disagree with it. We could add Heisenberg and Bohm to that for a start.


What about Einstein, though? He was rather the odd man out in this respect, don’t you think?
Streetlight June 25, 2018 at 08:47 #191052
Quoting Snakes Alive
But if you say all properties of the thing we're interested in are relative to the measurement in this way (what it is to have that property just is to look a certain way under certain conditions), then this collapses into Kantianism


Consider modifying this bold bit to something like: 'what it is to have that property is just to be interacted with in a certain way under certain conditions". Is this a Kantianism? But there are no noumena here: the idea is that all properties are relational in this way: any interaction whatsoever will yield a 'result' appropriate to that interaction. There's only a Kantianism if one tries to substaintialize an 'object' apart from these interactions (like a 'red' without the conditions of 'red': a nonsense). There's nothing special about measurement. If there were no measurement, the universe would still be there, quite independent of it, insofar as measurement is just a subclass of physical interactions, which take place all the time, everywhere. The charge of Kantianism only holds if measurement is not understood to belong to the larger class of physical interactions - that is, if you exceptionalize measurement. But this is just what the QM shows to be false: we are no different to anything else in the universe.
Snakes Alive June 25, 2018 at 09:26 #191062
Quoting StreetlightX
Consider modifying this bold bit to something like: 'what it is to have that property is just to be interacted with in a certain way under certain conditions". Is this a Kantianism? But there are no noumena here: the idea is that all properties are relational in this way: any interaction whatsoever will yield a 'result' appropriate to that interaction. There's only a Kantianism if one tries to substaintialize an 'object' apart from these interactions (like a 'red' without the conditions of 'red': a nonsense). There's nothing special about measurement. If there were no measurement, the universe would still be there, quite independent of it, insofar as measurement is just a subclass of physical interactions, which take place all the time, everywhere. The charge of Kantianism only holds if measurement is not understood to belong to the larger class of physical interactions - that is, if you exceptionalize measurement. But this is just what the QM shows to be false: we are no different to anything else in the universe.


Would it help if the label "Kantianism" were dropped?

We are still left, on your purported solution, with the inability to ascertain any properties except those that are in relation to the measurer.

That all properties are relational, if they are, doesn't seem to help. When we seek knowledge of things, we don't generally think of ourselves as just reporting how the measured thing affects the measurement apparatus (ultimately, us). But your out seems to be exactly what a hardcore correlationist or idealist would accept: that the only properties we can possibly measure, are those that are artifacts of the measurement.

Whether the universe "is" independent of this is also irrelevant, because those things that "are" independent of the measurement are precisely what the act of measurement locks us out of ascertaining.

Quoting StreetlightX
if one tries to substaintialize an 'object' apart from these interactions (like a 'red' without the conditions of 'red': a nonsense).


Or, put another way: what is this, but an admission of what you tried to deny? You warn: do not substantialize the object outside of the interaction of measurement! But that seems to be the point of the OP.

Also, note that you deny the noumenon while affirming it: the universe is, you say, outside of our measuring it, but all we ascertain in measurement are our interactions with it!
Wayfarer June 25, 2018 at 09:33 #191068
Quoting StreetlightX
If there were no measurement, the universe would still be there


‘The measurement problem’ is called ‘a problem’ precisely because this is what it calls into question. It sounds preposterious; just the kind of thing a charlatan would say.
Streetlight June 25, 2018 at 09:58 #191074
Quoting Snakes Alive
When we seek knowledge of things, we don't generally think of ourselves as just reporting how the measured thing affects the measurement apparatus


This 'just' here is doing a lot of work, and it hides over an equivocation: a measurement on its own doesn't really yield any knowledge whatsoever; a measurement is nothing other than a motivated physical interaction - and it's the motivation that matters. One observes particle decay in the ATLAS detector: what is its significance? Well, you need to place that observation within a theoretical framework in which it has a place (even if that place is, at it were, 'out of place' - perhaps this means you need a new theory, etc). But measurement qua measurement is just setting things up to bump into each other in a certain way. Ideally this bumping tells you something about the phenomena, if you know what you're looking for: if it bumps in this way and not that, it means...; otherwise, it means...; significance is never given in the mere observation itself.

Quoting Snakes Alive
the universe is, you say, outside of our measuring it, but all we ascertain in measurement are our interactions with it!


But this is a false dichotomy through and through. All we ascertain in measurement are our interactions with it, yes, but who gives a fuck about us? Why are we the 'measure or measure', as it were? It's only by elevating measurement itself into a transcendental principle of 'universe-constitution' that you can get the kind of idealist peddling that Wayfrer would like. But that's unwarrented, unscientific hogwash.

Snakes Alive June 25, 2018 at 10:05 #191077
Quoting StreetlightX
Ideally this bumping tells you something about the phenomena,


But there's the rub: what it tells you is only that some bumping took place. In what way would this ever amount to bumping-transcendent facts? This I take it is the worry about being unable to 'exclude ourselves.' We "want" knowledge of things independent of measurement: but by design, that is never what measurement actually gives us.

Quoting StreetlightX
But this is a false dichotomy through and through. All we ascertain in measurement are our interactions with it, yes, but who gives a fuck about us? Why are we the 'measure or measure', as it were? It's only by elevating measurement itself into a transcendental principle of 'universe-constitution' that you can get the kind of idealist peddling that Wayfrer would like. But that's unwarrented, unscientific hogwash.


I agree that nothing follows from this about the universe being constituted by measurement; what does follow is that the only thing measurement ever allows us to partake in are those things that are ontologically dependent on it, and hence that the rest of the universe is, or might conceivably be, independent of it, doesn't seem to matter to the actual process of knowledge-seeking. It might be an interesting metaphysical hypothesis (a transcendent one that we could never in principle verify), but that's it.

I don't think I believe the Kantian conclusion here, but I just don't see how what you've said coherently escapes from it. There are two ways to read the OP: one as Deepak Chopra, one as Kant. I think Wayfarer's "real" intention is to be Deepak Chopra, which I agree is silly. But the video he posted with the time stamp seems much more like Kant, and I'm aware of no good argument against this general picture of things.

Quoting StreetlightX
but who gives a fuck about us?


We're the ones that have to try to figure it out; hence we 'give a fuck about us,' because we have our limitations to work with in trying to figure it out.
Streetlight June 25, 2018 at 10:49 #191095
Quoting Snakes Alive
what does follow is that the only thing measurement ever allows us to partake in are those things that are ontologically dependent on it


But how is this not just a fancy way of phrasing a tautology (and thus a triviality)? 'The only things we can measure are those things that we can measure.' Once you deny the 'constitution' route, that's all one is really left with.
Snakes Alive June 25, 2018 at 10:55 #191102
Quoting StreetlightX
'The only things we can measure are those things that we can measure.'


That's not what I said.

What I said was, "the only thing measurement ever allows us to partake in are those things that are ontologically dependent on it."

That measurement changes the object, insofar as it's being measured, means that we can't ever see something except qua measured, and so can't know what it is independently of that measurement occurring. This is not tautological. Again, look at the jellyfish example.
andrewk June 25, 2018 at 11:07 #191103
Quoting Wayfarer
What about Einstein, though? He was rather the odd man out in this respect, don’t you think?

I feel that Einstein eludes classification. He was undoubtedly deeply philosophical, and I think his ideas changed greatly during the course of his life, which I see as a sign of an open mind. His large collection of memorable sayings is so varied that people of all different conflicting philosophical positions like to claim him as one of their own, but I I doubt he belongs to any neatly labelled philosophical school, or maybe he belonged to many of them, one after another.

His 'God does not play dice' and 'the moon is still there when nobody is looking at it' are indications of a lifelong inclination towards an anti-idealist position, perhaps materialism. But I very much doubt he was a reductive materialist, and I suspect he would have recoiled in distaste at the sort of scientism that is popular in some circles these days. After all, he said it was God that doesn't play dice, not The Universe. He was such a chameleon that he probably meant different things by the word God from one day to another, but I feel convinced that he thought there were great, deep mysteries out there, that we could never approach just by empirical experiment.

What are your thoughts on Einstein?
Streetlight June 25, 2018 at 11:10 #191107
Quoting Snakes Alive
That measurement changes the object, insofar as it's being measured, means that we can't ever see something except qua measured, and so can't know what it is independently of that measurement occurring.


But this seems to be an incoherency: what you want to ask is something like: how can we know something that, in principle, be known? But this is not a question that makes sense. The idea seems to be that there is some set of knowable-things that, in principle, could be known if only we could... know it otherwise than though how we come to know things; but that's not how knowledge - or really anything - works. It's a category error to expect knowledge to be 'operative' independently of the kinds of thing which make it knowledge. It's not 'you can't know'; it's 'you're using the word knowledge wrong'. It's the attempt to wring blood out of an (oxymoronic) stone.

Reworded: Measurement changes the object, insofar as it's being measured, means that we can't ever see something except qua measured, and so... it makes no sense to speak of knowledge otherwise than this.
TheMadFool June 25, 2018 at 13:33 #191129
Reply to Wayfarer I guess we're talking about scientific objectivity here. The first thing that comes to mind is instrumental observation. Instruments come with their own error margins but that doesn't seem to be be what you're getting at.

Perhaps you mean to say that no observer, including instruments, is without causal force in the act of observing. We think the experiment is conducted without being influenced by the experimenter but that, some claim, is not the case. The very act of observing, by us or with instruments, has an effect on the thing being observed.

Does this harm our claim to scientific objectivity?

Yes, because if this claim is true then objectivity isn't achievable.

However, what do you make of repeatibility - the fact that experiments conducted at different places and at different times yield same or similar results?

To say the least it seems the subjective component in the act of observation is shared among ALL observers in exactly the same way. In short we can ignore it without consequence as it doesn't hamper the scientific enterprise.

It would be a real problem if the same experiment produced different results when done at different places and separate times. That would be chaotic.
Snakes Alive June 25, 2018 at 15:43 #191150
Quoting StreetlightX
Reworded: Measurement changes the object, insofar as it's being measured, means that we can't ever see something except qua measured, and so... it makes no sense to speak of knowledge otherwise than this.


Yes, that seems to be the point of the OP, and it is the Kantian conclusion.
Streetlight June 25, 2018 at 15:53 #191154
Reply to Snakes Alive You understand the OP and Kant differently from I then.
Snakes Alive June 25, 2018 at 15:56 #191156
Reply to StreetlightX How do you understand the OP?

I can let Wayfarer speak for himself, but this is what was bolded:

"The physical world cannot be separated from our own efforts to probe it. How could it be otherwise, since we ourselves are embedded in the very world we’re seeking to understand?"

And this was the 'take-home:'

"What I take this to mean, is that objectivity cannot be absolute. And I think the reason this is controversial is that it undermines realism, which is the (usually instinctive) idea that the Universe simply exists as it always does, and that we humans come into it and go out of it in an instant, relative to the vastness of space and time which science observes. But this undermines that view, because it illustrates the sense in which the observer is inextricably part of the picture. We don't, actually, stand outside of, or apart from, the Universe which we are analysing; so what we're analysing cannot be absolutely objective."
Streetlight June 25, 2018 at 16:30 #191161
Quoting Snakes Alive
"The physical world cannot be separated from our own efforts to probe it.


Yeah, this is rubbish. Or at least, it does not follow.
Wayfarer June 25, 2018 at 21:23 #191189
Quoting andrewk
What are your thoughts on Einstein?


He wasn’t a materialist nor really reductionist. Despite the efforts of people like Dawkins to enlist him for militant atheism, he always denied being atheist, although he certainly disdained organised religion. He had quite an expansive philosophical attitude, sometimes bordering on the mystical, which comes across in many of his popular writings and aphorisms from later in life. But given all that, he was a very determined realist. One of the very good popular books on Einstein and Bohr’s relationship was Manjit Kumar’s ‘Quantum’. It goes into some depth about Bohr and Einsteins’ tussles over this matter which usually consisted of Einstein dreaming up some ‘gedanken’ [thought experiment] and then Bohr labouring to come up with a response. This happened over decades - but Bohr was never bested, according to the book.

The climax of all of that was the EPR paradox, which of course was never able to be made subject to experimental analysis in Einstein’s lifetime, but was to become the subject of the famous Alain Aspect experiments which proved once and for all ‘spooky action at a distance’.

The discomfort that I feel is associated with the fact that the observed perfect quantum correlations seem to demand something like the "genetic" hypothesis. For me, it is so reasonable to assume that the photons in those experiments carry with them programs, which have been correlated in advance, telling them how to behave. This is so rational that I think that when Einstein saw that, and the others refused to see it, he was the rational man. The other people, although history has justified them, were burying their heads in the sand. I feel that Einstein's intellectual superiority over Bohr, in this instance, was enormous; a vast gulf between the man who saw clearly what was needed, and the obscurantist. So for me, it is a pity that Einstein's idea doesn't work. The reasonable thing just doesn't work.


John Stewart Bell, quoted in Quantum Profiles, by Jeremy Bernstein [Princeton University Press, 1991, p. 84]

The point that impresses me about Bohr and Heisenberg, was that their so-called ‘Copenhagen Interpretation’ was not at all a theory or hypothesis, but just musings on what could and couldn’t be said on the basis of what they had discovered. I suppose Einstein’s frequent complaint that quantum physics could not be considered ‘complete’ amount to him saying that it doesn’t provide a conceptually coherent causal chain - a foundational hypothesis. Science had wanted to provide a complete, realist account, and instead stumbled into a mystery which is remains unsolved; the ‘nature of reality’ still remains a Rorschach test.
Snakes Alive June 25, 2018 at 22:09 #191200
Reply to StreetlightX Depending on how it's read, it seems to me perfectly unobjectionable given what you've said in this thread. I'm not sure what your issue is.
TheWillowOfDarkness June 25, 2018 at 22:25 #191204
Reply to Snakes Alive

It's rubbish because we are defined by our seperation from other things. The issue isn't that our experiences are somehow seperate from the world (and perceptions). Rather, it is no matter this connection of our experiences, things that I encounter are not me.

The mountain I see in the distinct is not me. Another's body I see across the room is not me. Any connection I have with the world around me doesn't undo or remove this seperation.

In any instance were we are investigating the world, this seperation is necessary defined. My experience of investigating the flight of birds is not the flying birds themselves. The birds are other beings who would fly just as well without my investigation.

Andrew M June 26, 2018 at 06:51 #191284
Quoting Wayfarer
But this undermines that view, because it illustrates the sense in which the observer is inextricably part of the picture. We don't, actually, stand outside of, or apart from, the Universe which we are analysing; so what we're analysing cannot be absolutely objective.

Andrei Linde makes this exact point at 3:16 in this Closer To Truth interview.


What Linde is saying is that, taken as a whole, the universe is predicted to be static and unchanging (per the Wheeler-DeWitt equation). In order to predict a dynamic and changing universe, as we all observe, you have to split the universe into subsystems, i.e., you, the observer + the rest of the universe.

For some experimental results on this, see Quantum Experiment Shows How Time ‘Emerges’ from Entanglement

That doesn't challenge the idea of objective reality. It just means that what is measured depends on one's frame of reference.

I think the potential philosophical problem is actually at 6:04 in the video where Linde is asked how it is that the universe seems to have been around a lot longer than sentient creatures. He says, "This brings me to the interpretation of quantum mechanics ... Everything becomes real at the moment it is observed ... Before you make an observation there is no such thing as real existence of anything there. But once you make an observation everything looks as if it existed all the time before it happens."
Andrew M June 26, 2018 at 06:58 #191285
Quoting Wayfarer
The climax of all of that was the EPR paradox, which of course was never able to be made subject to experimental analysis in Einstein’s lifetime, but was to become the subject of the famous Alain Aspect experiments which proved once and for all ‘spooky action at a distance’.


It hasn't been proven - it's an interpretational issue. Per the quantum interpretations table on Wikipedia, roughly half are local interpretations, including QBism.
Wayfarer June 26, 2018 at 10:27 #191299
Reply to Andrew M Thanks, fascinating article. I notice this point:

It suggests that time is an emergent phenomenon that comes about because of the nature of entanglement. And it exists only for observers inside the universe. Any god-like observer outside sees a static, unchanging universe.


Again - the role of the observer is inextricable; you can't assume 'a view from nowhere'. What I think all of this is showing is the role of the observing mind in the establishment of duration. After all, time exists on a scale - if you were a being who lived for a billion years, your sense of duration would be completely different from that of the human. But which is the most accurate? Well, it's a meaningless question; 'accuracy' can only be judged, given a scale.

Quoting Andrew M
That doesn't challenge the idea of objective reality. It just means that what is measured depends on one's frame of reference.


What I had said was:

Quoting Wayfarer
objectivity cannot be absolute.





Andrew M June 26, 2018 at 11:53 #191312
Quoting Wayfarer
Again - the role of the observer is inextricable; you can't assume 'a view from nowhere'.


Agreed.

Quoting Wayfarer
What I think all of this is showing is the role of the observing mind in the establishment of duration. After all, time exists on a scale - if you were a being who lived for a billion years, your sense of duration would be completely different from that of the human. But which is the most accurate? Well, it's a meaningless question; 'accuracy' can only be judged, given a scale.


Yes.

Quoting Wayfarer
objectivity cannot be absolute.


Do you mean there can be different standards for measurement, depending on the context?
Wayfarer June 26, 2018 at 22:57 #191371
Reply to Andrew M What is being measured? There is no absolute material unit or ultimate object. The classical idea of the atom was an indivisible point-particle - a form of the absolute, but conceived in such a way that it can give rise to the myriad things. That, anyway, is the atomism of Lucretius, carried on from Democritus. So I think that is what so disturbed Einstein about the so-called ‘quantum leap’, uncertainty, non-locality and the other aspects of quantum physics - they all tend to undermine the concept of an ultimately existent object. And that has deep philosophical ramifications: it is why the essay in the OP is about ‘the war over reality”. David Lindley’s book Uncertainty is sub-titled ‘the battle for the soul of science’; Major Kumar’s book is sub-titled ‘the great debate about the nature of reality’. It is a front in the so-called ‘culture wars’. Suffice to say I am of one of those with the view that physics itself has definitively undermined scientific materialism. That is the source of the angst that often boils over in these debates. And, it is unresolved.

See The Debate between Plato and Democritus, Werner Heisenberg

Quantum mysticism: gone but not forgotten, Lisa Zyga.


Janus June 27, 2018 at 01:46 #191395
Quoting Wayfarer
So I think that is what so disturbed Einstein about the so-called ‘quantum leap’, uncertainty, non-locality and the other aspects of quantum physics - they all tend to undermine the concept of an ultimately existent object. And that has deep philosophical ramifications: it is why the essay in the OP is about ‘the war over reality”.


But does QM undermine the very notion of their being anything ultimate or fundamental? I mean, why not 'field' or 'process'?

Wayfarer June 27, 2018 at 02:46 #191410
Reply to JanusBecause they're kind of, you know, vague.
Janus June 27, 2018 at 02:52 #191412
Reply to Wayfarer

There is a Quantum Field Theory, isn't there? Are you saying that it is vague?

In any case, if you are drawing a distinction with objects here, what makes you think that objects in general are not vague? For example you see a tree and I see the same tree, it happens all the time: but what precisely is that entity which we both see?

Anyway you didn't answer the first question.
Wayfarer June 27, 2018 at 03:02 #191414
My understanding is that it was the discovery of the non-existence of anything that could be understood as a real, fundamental particle that precipitated the crisis of interpretation. You know - if atoms aren't real, then what is everything made from?!? That’s the impression I got from reading David Lindley’s book Uncertainty, and Manjit Kumar’s book Quantum, both of which were about the Einstein-Bohr-Heisenberg debates (Kumar's was better IMO). That’s why I keep referring to the well-known exclamation of Einstein’s - ‘Doesn’t the moon continue to exist when you’re not looking at it?’ This was an expression of exasperation - it was meant to prompt the answer, ‘well of course it does!’ Einstein thought the whole business an offence to common sense, basically ridiculous. That’s why he kept insisting that quantum mechanics couldn’t be a complete theory. He spent many of his Princeton years trying to find some way of proving this - to no avail, as I understand it.

A similar kind of exasperation lay behind Schrodinger’s cat - he was pointing out how ridiculous the implications of his equation were with a real-life analogy. He wasn’t just being mischievous:

[quote=Erwin Schrodinger]God knows I am no friend of probability theory, I have hated it from the first moment when our dear friend Max Born gave it birth. For it could be seen how easy and simple it made everything, in principle, everything ironed and the true problems concealed. Everybody must jump on the bandwagon. And actually not a year passed before it became an official credo, and it still is.[/quote]
Letter to Einstein (13 June 1946), as quoted by Walter Moore in Schrödinger: Life and Thought (1989)

For everyone involved there was real angst; Heisenberg recalled being reduced to tears around Bohr’s kitchen table on some occasions, so bitter were the arguments (he was very much the junior partner.)

And I don’t think it’s ever really been resolved. I think basically the discoveries enabled such an bonanza that after the war questions of interpretation became passé. There was gold in them thar hills, even if nobody knew how it got there. Shut up and calculate. That’s why, when Everett came along, the field was ripe for the picking:

Everett’s scientific journey began one night in 1954, he recounted two decades later, “after a slosh or two of sherry.” He and his Princeton classmate Charles Misner and a visitor named Aage Petersen (then an assistant to Niels Bohr) were thinking up “ridiculous things about the implications of quantum mechanics.” During this session Everett had the basic idea behind the many-worlds theory, and in the weeks that followed he began developing it into a dissertation.


From a Scientific American profile (and worth a read; tragic character that he was.)

Everett's interpretation now has many followers. And this is still where it’s at, although a straw poll of physicists published on Sean Carroll's blog looked like this:

User image

Andrew M June 27, 2018 at 06:30 #191443
Quoting Wayfarer
So I think that is what so disturbed Einstein about the so-called ‘quantum leap’, uncertainty, non-locality and the other aspects of quantum physics - they all tend to undermine the concept of an ultimately existent object. And that has deep philosophical ramifications: it is why the essay in the OP is about ‘the war over reality”.


More recent philosophical discussion has moved on from the reality versus mysticism debates between the founders of quantum mechanics. "The war over reality" essay is about whether the quantum state describes the underlying world (intrinsic realism) or information about observers (participatory realism). Fuch's QBism and Rovelli's RQM are examples of the latter (characterized as Type-II in the paper linked below).

Quoting Interpretations of quantum theory: A map of madness
Type-II interpretations do not deny the existence of an objective world but, according to them, quantum theory does not deal directly with intrinsic properties of the observed system, but with the experiences an observer or agent has of the observed system.


Quoting On Participatory Realism - Chris Fuchs
What I want to emphasize at the moment is that I cannot see any way in which the program of QBism has ever contradicted what Einstein calls the program of “the real.”

Wayfarer June 27, 2018 at 06:45 #191444
Reply to Andrew M I’ll settle for ‘participatory realism’ but I would be surprised if Einstein, had he been around, would have agreed with it.

//ps// from the Fuchs article:

These views have lately been termed “participatory realism” to emphasize that rather than relinquishing the idea of reality (as they are often accused of), they are saying that reality is more than any third-person perspective can capture.


:up:

//ps//Because ‘participatory realism’ means, not that the conversation has ‘moved on’ from reality v mysticism, but that the mystics won.
Andrew M June 28, 2018 at 05:04 #191669
Quoting Wayfarer
//ps// from the Fuchs article:

These views have lately been termed “participatory realism” to emphasize that rather than relinquishing the idea of reality (as they are often accused of), they are saying that reality is more than any third-person perspective can capture.


So the argument is that is necessary to index the quantum state to a participant (broadly conceived). As an analogy, there is nothing mystical about ordinary statements like, "The apple is red" or "I am in pain". But they are statements that are only meaningful when indexed to individual sentient creatures with particular sensory capabilities. There is no intrinsic "redness" or "pain" in the world.

The way QBism conceives of indexing compared to RQM is different (Bayesian probabilities versus relative reference frames). But the general idea is that there needs to be a natural integration of first and third person perspectives - a view from somewhere - to make proper sense of quantum mechanics.

Which, as it happens, is something that the natural and holistic approaches of Aristotelian hylomorphism and Peircean pragmatism, to name but two, both do.