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Old 30-July-2008, 10:54 PM
Len Moran Len Moran is online now
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Quote:
Originally Posted by Joe Durnavich View Post
I don't know enough about QM is know what you mean by “predicted observations of a particle.” I thought QM did a sum-over-histories type of statistical prediction. I thought that QM specifically did not speak to any sort of underlying mechanism. “Shut up and calculate!” as they say.
Well since this thread has come back to life a little, perhaps I can take the opportunity to reply to your post above. I only really want to deal with this one point - the rest of your post has helped me see where you are coming from. It does seem clear that within this holistic approach that you take, the very notion of a mind independent reality introduces a separation between being fully immersed in reality (as you put it) as sentient beings and a reality that stands outside of that. So even if I went along with your perspective, at some point I seem to come up against empirical evidence that suggests such a separation occurs.

If we have an observer and a source that can emit (say) electrons in line with a screen separated by vacuum, landing positions will appear on the screen. We have no idea what exists in between the source and screen during this process, whatever it is is not directly accessible to us. Now just that fact for me places the whole experiment in the category of a model, i.e. we think of electrons leaving a source and hitting a screen with no direct knowledge of what is really happening in between - the picture is a simplification of what may be the underlying reality. However, your holistic approach neatly side steps that issue (assuming of course that I do have a grasp of your perspective) by treating this setup as a "whole", the results obtained are a state of knowledge that are part of this setup - the fact that we cannot account for the bit in between in terms of observation has no relevance to this state of knowledge that allows us to predict the probabilities of the landing positions of what we call "electrons". For you, the relationship of this experiment to any deeper reality is a non issue - "electrons" (whatever they are, I of course consider them to be a human representation of the absolute - a model!) and unobservable events are not simplifications of a deeper reality detached from our involvement, they are part of our involvement and should be viewed as such.

But what are we left with when we realize that this holistic picture cannot escape from implying a notion of mind independent reality? It means that in fact there is an aspect of reality that is "out there" and inaccessible - something that is clearly distinguishable in principle from your holistic state of knowledge that admits to no modeling of an absolute. You cannot under any circumstances assimilate mind independent reality into your holistic state of knowledge, it stands out like an unreachable beacon always separated from our involvement. So it is not philosophy that forces a duality on to us, it is experimental physics and the results it gives!

However I think I know what your answer is going to be, it is this posted by you early on in this discussion (post 31):

Quote:
If we cannot get a handle on this "absolute mind independent reality," then, it means it has no consistent, detectable effect on us. We don't have to worry about it. We are free to form and take advantage of multiple, overlapping, and competing theories. We should feel fortunate that there is more than one way to skin a cat, so to speak, and that many of those ways work adequately well.
But are you really happy with this response? It seems to me that the notion of mind independent reality gives a context to the way we represent nature in terms of having this "bottom line" of reality - out of reach, but none the less real. It places into context all our notions of particles and fields, space and time as being real enough for us, but in the context of nature itself, they are human representations of some underlying inaccessible reality. I don't think of this notion as being some philosophical entity that can be safely ignored. At the level it is pointed to by physics, it seems very real to me, not in the sense of something material, rather in the sense of "something" quite separate from our involvement with nature, however you wish to view that involvement, either from your very holistic perspective of "states of knowledge" or from a perspective of "models all the way down".

I agree with what I think Ken G and (possibly) Disnfo Agent are saying in that you can choose to view science from your very holistic perspective if you wish, maybe as part of an overall personal philosophical standpoint you have with regard to our place in the world, but what real advantage does it offer? For me, it offers no advantage, it just seems to complicate the relationship we have with nature at its most fundamental level in the form of mind independent reality. I don't want to hide from that relationship, I want to acknowledge it.

The notion of mind independent reality I gleaned from Ken G in my early involvement with this forum. But the notion I refer to here specifically (in terms of quantum mechanics) stems from Bernard d'Espagnat who has written extensively regarding it from his position as a physicist and philosopher. d'Espagant outlines the nature of quantum mechanics in terms of predicted observations - the idea that a particle is localized independently of our knowledge is not assumed. The Born rule yields probabilities not for the particle to be present at such and such places at such and such times, rather probabilities for the particle to be found at such and such places and times if it is looked for - there and then - by means of some appropriate device (the screen). He defines this process as being weakly objective as explicitly or implicitly referring to some human procedure, or to put it more formally:

"A statement is "weakly objective" when it implies (directly or indirectly) the notion of an observer but is of such a form (or occurs in such a context) that it implicitly claims to be true for any observer whatsoever."

d'Espagnat is specifically here referring to outcomes that cannot be separated from the notion of an observer, thus the experiments themselves point to "something" underlying our inseparable involvement with the experiment, an underlying mechanism that is not accessible. You are right to say that QM does not provide us with any details of this underlying reality, all it can do is to offer us the notion.

I doubt that my knowledge of Quantum Mechanics is any greater than yours, so if you were to contest the validity of this notion of mind independent reality in terms of the technicalities of quantum mechanics I suspect we wouldn't get very far. Whilst I feel that I pretty much understand what d'Espagnat is saying, ultimately I admit to making use of his thesis on his terms. But I do find it striking that his thesis matches Ken's perspective regarding mind independent reality, albeit, the notion is arrived at in different ways - Ken does not see a sharp distinction between QM and classical physics in the way I think d'Espagnat does.

Hence if you were to contest this notion of mind independent reality as being pointed to by quantum mechanics, then I suppose this post becomes a little irrelevant, but what really interests me is the way in which you would reconcile a possible agreed concept of mind independent reality with your holistic perspective of science, although as I stated above, I think I have a hint of what your approach would be - out of sight, out of mind, but is that not skirting the issue to some extent?
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