Gertie wrote: ↑July 28th, 2018, 7:07 am
You'll have to explain Bell's Theorem to me and how it's relevant, as I've never heard of it.
Wiki page is poorly written, but has useful parts. I'll quote a bit of it in italics.
"
In its simplest form, Bell's theorem states: No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics."
It means that no matter how complicated your interpretation, the basic tenets of physical theory (Realism: stuff is real, with state. Locality: earlier events cause later effects, confined by light speed) cannot be all correct.
From history section:
"
In the early 1930s, the philosophical implications of the current interpretations of quantum theory troubled many prominent physicists of the day, including Albert Einstein. In a well-known 1935 paper, Boris Podolsky and co-authors Einstein and Nathan Rosen (collectively "EPR") sought to demonstrate by the EPR paradox that quantum mechanics was incomplete. This provided hope that a more complete (and less troubling) theory might one day be discovered. But that conclusion rested on the seemingly reasonable assumptions of locality and realism (together called "local realism" or "local hidden variables", often interchangeably). In the vernacular of Einstein: locality meant no instantaneous ("spooky") action at a distance; realism meant the moon is there even when not being observed. These assumptions were hotly debated in the physics community, notably between Einstein and Niels Bohr.
In his groundbreaking 1964 paper, "On the Einstein Podolsky Rosen paradox", physicist John Stewart Bell presented an analogy (based on spin measurements on pairs of entangled electrons) to EPR's hypothetical paradox. Using their reasoning, he said, a choice of measurement setting here should not affect the outcome of a measurement there (and vice versa). After providing a mathematical formulation of locality and realism based on this, he showed specific cases where this would be inconsistent with the predictions of quantum mechanics theory."
Effectively, one of locality or realism is wrong.
The first way out of this pickle is to discard Lorentz invariance, or locality (short for local relativistic causality). Lorentz transformations are used to translate coordinates and reorder events (points in spacetime) from one inertial reference frame to another. One physical principle is that cause must precede effect, regardless of reference frame. The "regardless of reference frame" bit is Lorentz invariance. Without that, cause and effect might be ambiguously ordered, or worse, unambiguously effect-before-cause as demonstrated by strange experiments like before-before where measurements are affected by future choices not yet made.
The other one discusses realism, or what is now more formally known as 'counterfactual definiteness', which has its own (better written) wiki page. It is "the ability to assume the existence of objects, and properties of objects, even when they have not been measured". The apple exists even if not measured. This is not so much the idealistic idea that the apple blinks out when you close your eyes, since QM says it is very likely still there. It is talking about something that has never been measured by us like planet Claire 8 billion light years away. Realism says that despite our lack of knowledge or measurement of it, there is in fact a specific planet located nearest to some arbitrary point that we define from here, like 8BLY thataway. Interpretations that discard counterfactual definiteness deny this fact. There is just superposition of possible nearest planets, all of which have a probability that is negligible, yet finite.
I'd say there's an ontological fact of the matter as to whether the green apple I'm pointing to exists. And there's a fact of the matter as to whether it exists only when observed, or independent of observation.
Hence it takes a leap of faith to claim anything is 'objectively true' or exists, apart from my subjective experiential states.
You observing it makes it a subjective fact only. Sure, it exists because it was observed a moment ago, but that still makes it dependent on observation. I think some idealists might posit that it ceases existence between direct observations.
The singular ontological fact of the matter following from this subjective observation is a realist stance, an assertion of counterfactual definiteness, which yes, is a leap of faith. All of philosophy is a leap of faith of sorts.
Then there's a separate epistemological issue as to whether I or we can know these facts of the matter. Here's how I see it -
I take the position that the only thing I can know for certain are my own (subjective) direct experiential states (sensory perceptions, sensations, memories, imaginings, emotions, thoughts, etc).
That is still a subjective measurement, not proving you are objectively real. Your direct experiential states are real to your direct experiential states.
I personally have discarded realism as the easier thing to let go, but I'm not asserting that my choice is the correct one. I'm a relativist. We exist relative to each other, and that's enough. Ontology and objective facts don't seem to make any difference to anything that matters to me and even run into self-inconsistency (like the cosmological problem), but those matter very much to some whose beliefs require objective identity. So they discard locality with a shrug. If find that more distasteful, that my choices are a function of actions and choices made by future events.
There is no reliable 'bridge of knowing' from my direct experiential states, to the things those experiential states refer to (eg my body, green apples, an 'external' universe). I can infer that when I experience seeing a green apple, there is something 'out there' which I am observing (roughly, imperfectly, limitedly, perhaps at a certain level of granularity and as a created representaion). But I can never be certain.
But there is more than one of us, and we agree on the apple experience. Not proof, but heavy evidence of the apple being as real as we are, and not a byproduce of any one of us in particular. The various QM interpretations might comment differently about your relationship with the apple.
But still, 'acting as if' my experiential states (roughly, imperfectly) actually do refer to independently existing stuff... works. And if I don't 'act as if' the world out there is real, then I wouldn't bother eating because my body isn't real, I would smash my head into walls, kill people, etc - and that doesn't work.
This would imply that being real matters to the choices you make. It shouldn't. You are real to yourself, to your peers, and to the world with which we all interact. This is enough to bother eating and do the right thing. Objective or not makes no difference to that.
In my model of the 'world out there' there are other people who seem much like me. And our models are remarkably consistent. This forms our Shared Model. And when I ask you if you see a green apple, and you say yes, we can agree to say it's true - objectively.
I would agree that it is true, objectively only in the sense that it isn't privately true. A shared model is not a private one. The apple is not a lie. I totally accept the shared model. We see the same apple, and we exist exactly as much as it does. I don't think humans or anything else is special in that regard.
By which we mean we've compared notes, and they tally. And if I ask a hundred other people, and only one disagrees, then we might wonder if the problem lies with the one person disagreeing, than with our Shared Model, and check that out.
Majority consensus is not truth, but it does make for a workable relationship with one's peers. There are those that conclude that they have no choice and thus are not responsible for their actions. But if they act on that belief, they die from not bothering to make good choices, which sounds an awful lot like they were responsible for their continued living.
Purpose of my post was to point out that realsim and locality are incompatible with QM. You need to choose the one that seems more important to you. There is a wonderful chart 60% of the way down in
https://en.wikipedia.org/wiki/Interpret ... _mechanics where there are 2 columns near the right showing local dynamics and counterfactual definiteness. None of the 14 interpretations listed have both, and some discard both. Having a heavy background in physics and science, I find objectively defined state to be utter unimportant, so I chose to drop that one. My personal preference is relational (2nd to last in the list). Theists sort of need that one, else the omniscient being has no state to know or predict. But theists have already discarded science, so Bell's theorem seems of little concern to them. I've not seen any church state which QM interpretation is compatible with its claims.
Now the problem I point out with some of the things Tam and some others say, is consistency. You have to justify jumping back and forth between accepting the evidence our Shared Model presents to fit your hypothesis. So if you use our Shared Model of the world to accept Evolution, for example, that this is the way the world works, then you have to justify also claiming that evolution is dependant on Subjects, when our Shared Model evidence is that it doesn't. All the evidence suggests the universe existed independently prior to the existence of Subjects to experience it.
I stated up front that anything that can take a measurement (a rock for instance) is a subject that defines state. Tam is the one that says it must be a life form and thus abiogenesis being inconsistent. (Evolution posits nothing about the origin of life, only changes to it once existing). I think his answer was something on the order of life existing at any time in history makes the whole history exist, not just the time period with the life, just like Mars exists, not just the one planet with the life on it. This seems reasonable to me, except for the whole ontology-controlled-by-life thing, which really violates the Copernican and Mediocrity principles. But hey, my post was all about a core principle needing to be discarded. I didn't want to add those to the list as well.
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