Stephen writes
> I would like to refute your [Lee's] "common sense Realism" and
> show that it is missing the most salient point of Realism: that
> it not have any "cracks" through which anything "unreal" might
> slip.
An interestingly stated goal: it *sounds* as though you've written
as preamble to the rest of your post that we need to abandon any
system that keeps out the unreal. Well, to each his own!
> > Stephen writes
> >> Just one point while I have some time and mental clarity. Can a Realist
> >> accept that "a wholly independent world "out there" exists and existed
> >> before he did" and yet can admit that the particular properties of this
> >> "independent world" are not *definite* prior to the specification of a
> >> particular observational context?
> > [LC]
> > My opinion is that realists, even those completely up to speed on quantum
> > physics, will assert that many macroscopic properties of the "independent
> > world" are indeed *definite* before specification of an observational
> > context (as you write).
>
> If we are to be consistent with the dictum "all is amplitudes that add"
Well, my phrasing of that observation of what QM really boils down to is:
"At the basis of things are amplitudes that add".
> we must admit that such assertions are a posteriori and not a priori, thus
> the problem of explaining the appearance of *definiteness*.
They are epistemologically later (as our knowledge of objects came first),
but ontologically prior. That is, we believe that QM provides a theoretical
basis to most of physics.
> It can be unassailably proven that one cannot embed a quantum universe
> inside a classical universe and that one can embed *at least one* classical
> universe within a quantum universe. What does this imply? It implies that
> the *property definiteness* that comes along with classical universes is
> something that cannot be taken as *existing prior to the specification* of
> an observational context!
I'm not too sure what you mean by "to embed". If we are seeking to *explain*
---if that is what you mean---then we cannot explain QM by classical physics,
but we *can* explain classical physics by QM. (I take our primary activity to
be---and the activity I'm most interesting in participating in---*explaining*.)
You speak of A existing prior to B. I'm not real clear what that means.
Ontologically or epistemologically?
> All of the claims that "many macroscopic properties of the "independent
> world" are indeed *definite* before specification..." are ignoring that that
> entire "independent world" is knowable AFTER the fact of comparing the
> observations of many observers. When we assume the contrary we are ignoring
> the fact that "what we know" - the content of our OMs as it were- was
> specified after the act of having the experience.
It seems rather false to me that the entire independent world is knowable
only AFTER the fact of comparing observations. Indeed no. The tiger, for
example, is a device for ascertaining the most important aspects of its
existence. Robinson Crusoe also makes hypotheses and conjectures (and
refutes many of them!) with help from no one. His primate nervous system
is pretty good at it. So a single "observer" can know quite a bit.
You say that what we know is specified (or becomes definite) only after
the act of having an experience. I submit that 99% of the knowledge of
a particular human does not work this way: the knowledge implantation
occurs at the same time that the experience occurs. It would have been
a costly mistake for nature to wait around for the "internal philosopher"
to ponder the importance of his experience before some knowledge generated
and some actions taken.
Time and space compel me to ignore the remainder of your long post, sorry.
Lee
> We can point to the idea that Numbers and their relationships exist as
> such without any dependence on some mathematician's scribbles on a
> blackboard, and I would say that that is true, but the notion of the
> "meaningfulness" of the concept of numbers, here a case of *property
> definiteness*, requires that at least one mathematician scribble on a
> blackboard somewhere AND that that scribbling "means" something to some
> other mathematician.
>
> A skeptic could point out that chickens scratching in the dirt could
> reproduce exactly the same arrangements of points, lines, etc. that make up
> "2+2 = 4", but does it mean anything to the chickens? No! Meaningfulness
> requires something *to whom it has meaning* and the same applies here to our
> idea of an "independent world".
>
>
>
> > [LC]
> > For example, if today I ascertain certain properties of, oh, say, the
> > relative sizes and populations of a number of North American cities,
> > then it is best to regard those as entirely fixed. That is, that they
> > are *completely* unaffected by measurement. (Which is entirely true
> > up to bone-picking.) Evolution in fact did not at all prepare me to
> > deal with things whose properties emerge only upon measurement, as
> > witnessed by the absolute and dumbfounded astonishment of early 20th
> > century physicists.
>
>
>
> [SPK]
>
>
>
> I strip and fall headlong over your use of the phrase "...then it is
> best to regard those as..."! This is what convinces me that you are arguing
> for a "common sense realism" and not a realism that can be used without such
> caveats!
>
> I have tried many times to talk to you on the phone about the problem in
> Einstein's quip, in reaction to Bohr's ideas, that "the Moon does not top
> existing just because he is not looking at it", or something along those
> lines. The problem is that Common Sense Realist, like yourself and Einstein,
> neglect the simple fact that while they are not looking at the moon
> directly, the particular world that they are contemplating includes causal
> relations that include the moon with its particular properties.
>
> The problem is that if we are going to be consistent with our claim that
> the properties of the world or anything in it are *fixed* and "*completely*
> unaffected by measurement" then one must be sure to remove each and every
> aspect of their actuality that goes into the act of fixing that
> definiteness. Here, again, is that "crack" that through which "unreality" is
> oozing.
>
> I do not like this unreality one bit and thus am trying to patch up
> Realism so it does not have this problem.
>
>
>
> > [LC]
> > My bottom line: the specification of a particular observational context
> > makes a difference *only* on the microscopic level. Now yes, it's true
> > that solid objects---according to our best theories---retain their
> > integrity only because of quantum effects, but in this and all normal
> > macroscopic effects, stability emerges as a statistical and overwhelmingly
> > probable phenomenon.
>
>
>
> [SPK]
>
>
>
> "*ONLY*"! I'm sorry Lee, but that does not cut it! Your argument is just
> too positivist for me... If we are going to be consistent then we have to
> own up to the REAL implications of your last sentence here:
>
>
>
> > solid objects---according to our best theories---retain their
> > integrity only because of quantum effects, but in this and all normal
> > macroscopic effects, stability emerges as a statistical and overwhelmingly
> > probable phenomenon.
>
>
>
>
>
> > > [SPK]
> >> I am claiming that we should not conflate *existence* with *property
> >> definiteness*.
> > [LC]
> > What is the harm for other than microscopic phenomena?
>
>
>
> [SPK]
>
>
>
> Oh my! Are we not expecting our models of the world to be consistent?
> This is like in the theory superstrings where everything is neatly explained
> and accounted for except for the pesky little things about not being
> background independent, no evidence of superpartners, etc.
>
>
>
> I am, working on an idea as to how the appearance of "property
> definiteness" comes to be, such that Common Sense Realism works *when we
> ignore little details*, but that is for another post. First I need to get
> you to admit that the assumption of a priori property definiteness is an
> obstacle to the advance of physics.
>
>
>
> Onward!
>
>
>
> Stephen
>
>
Received on Wed Aug 17 2005 - 09:21:25 PDT
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