From ggglobus@UCI.EDU Tue Mar 9 07:35:45 1999
Date: Mon, 8 Mar 1999 22:44:13 -0800
From: gordon g globus
Subject: [q-mind] Reply to Sarfatti on von Neumann/Wigner quantum
mechanics--Henry Stapp
From: Henry Stapp
Subject: Reply to Sarfatti on von Neumann/Wigner quantum mechanics.
I shall use Jack Sarfatti's posting of Mar 7 to explicate
the principles of the vN/W approach to consciousness by contrasting it
to Bohm's theory, and Sarfatti's. These principles are very simple,
but Jack's comments show that they are not universally understood.
>From ggglobus@UCI.EDU Sun Mar 7 11:49:27 1999
Subject: [q-mind] Response to Stapp--Jack Sarfatti
Subject: Re: [q-mind] Refutation of Stapp's Orthodox QM Theory of
Consciousness.
> [Jack - prev]
> On second reading I find that Henry's position above is logically
> inconsistent within the explanatory framework, or paradigm, of my
> heuristic formulation of post-quantum physics.
>
[Stapp]
A theory is not "refuted" by being different from an unproven one.
[Jack]
... you cannot explain consciousness inside your orthodox quantum theory.
You use "consciousness" as a primitive postulate to explain the
measurement problem in quantum theory.
[Stapp]
Orthodox vN/W theory assumes that our conscious experiences are part
of a reality that has mathematical properties; that some of the these
properties are expressible in terms of the concepts of quantum theory;
and that, in particular, the orthodox rules of vN/W QM give very accurate
predictions about correlations between aspects of our conscious experiences.
By means of von Neumann's analysis of the mathematical structure of
quantum theory all of the predictive success of Copenhagen QM carries
over to, and becomes supportive of, vN/W QM. The latter is extremely
parsimonious as regards basic elements, and eschews speculations based
on the idealization that was the conceptual basis of classical physical
theory, namely the extrapolation to the microscopic limit of the concept
of localized physical object. That concept is very useful in our practical
dealings with nature at the macroscopic level, but is not needed in
quantum theory, which encompasses all of the valid predictions of classical
physical theory, and much more.
[Jack]
In contrast, post-quantum theory, a larger theory with orthodox theory
as a limiting "zero back-reaction" sub-theory, explains consciousness
as the direct back-reaction of the motion of matter on its guiding
quantum information "pilot-field" in the sense of
Einstein-deBroglie-Bohm realism.
[Stapp]
Can one really "explain" consciousness by saying that it is an
action of a postulated classical world (a set of N moving classical point
particles) upon the wave function (a changing complex-valued function
defined over a 3N-dimensional space). How does one pass by any rational
process of reasoning from the existence of this action to the existence
of a conscious experience, say an experience of a patch of redness. How
can the existence of a "redness experience" be deduced from the existence
of an action between two mathematically defined functions: what
logically prevents the latter from existing without the former?
Bohm, in order to bring consciousness into HIS theory was led to conjecture
that there was an infinite tower of higher and higher type wave
functions, each acting on the next lower level one, and that consciousness
somehow emerged from the mystery of infinity. You, Jack, seek to make
the jump to consciousness by invoking back action. But I think anyone
can plainly see that it is not going to be possible to actually *deduce*
the existence of consciousness from the postulated existence of an
action between two mathematically defined functions. Lacking any
actual deduction of the existence of consciousness from your premises,
about action between a classically conceived world and a function defined
over 3N-dimensional space, you must postulate the needed connection, rather
than deduce it. You must bring it in because you know it exists, not
because it is the neccessary logical consequence of a postulated back action.
Orthodox QM also brings in human experiences because we know they
exist. The empirical evidence shows also that they are in fact correlated
to one another in just the way predicted by the orthodox theory, at least
to an accuracy so great that no deviation from these predictions has ever
been discovered, if one discounts claims of paranormal phenomema.
> [Jack - prev]
> The Copenhagen
> Interpretation is simply the approximation that "the wave function
> has no sources" (Bohm and Hiley, p.30 & 14.6).
>
[Stapp]
Not so! The essential point of the Copenhagen Interpretation is that ---
to avoid getting hung up on what is happening at the instruments ---
the instruments should be left out of the quantum theoretically described
system: the instruments should be described rather in terms of how we human
beings normally know and use them.
[Jack]
If you look on p.30 of Bohm and Hiley, you will see that the true cause
of quantum randomness is the absence of the source term.
[Stapp]
What B&H say there is:
"As we shall see ... quantum theory can be understood completely
in terms of the assumption that the quantum field has no sources or other
forms of dependence on the particles." What they say here, explicitly and
correctly, is that in order to get the predictions of quantum
theory out one should NOT have a source term: no back action.
B&H do not explain the true cause of quantum randomness: instead,
they make a very strange statistical postulate about how the single
unique real universe is, in some way, statistically distributed
according to a quantum probability rule associated with the
wave function. This postulate is where the quantum randomness
comes from in the Bohm theory. The lack of source merely keeps this
postulated statistical distribution intact: it does not cause or
explain it.
[Jack]
The entire basis for the statistical formulation that
you use with your projection operators springs from this lack of stabilizing
feedback-control loops between the pilot wave and the Bohm point in
configuration space.
[Stapp]
The orthodox statistical formulation neither refers to, nor in any way
depend upon, Bohm's theory, which came later. Thus it does not "spring"
from Bohm's idea, nor from the lack of your modification of Bohm's idea.
What is true, rather, is that if you add your back-action to Bohm's model
then you will upset Bohm's project of showing how the orthodox predictions
could be mimicked by his realistic and deterministic model, used in conjunction
with his odd statistical postulated: Bohm's theory would be upset by your
"improvement", but orthodox theory does not even contain the basis for your
back-action.
[Jack]
It's because of this, that Bohr's epistemological Copenhagen Interpretation,
and its spin offs like von-Neumann and Heisenberg et-al do make good sense
in a limited domain of validity.
[Stapp]
Thank you! Yes, orthodox ideas do indeed make good sense, which is why quantum
physicists use them. If you accept the Bierman presponse results, and wish
to accomodate them in quantum theory, then the simplest and most
parsimonious tack is to do nothing at all to the orthodox theory except to
relax the orthodox demand that the Hamiltonian be Hermitian. Normally in
science one tries at first to see whether a small change in existing theory
will do, rather than jumping to Draconian measures that involve wholesale
importation of radical ideas.
....
> [Jack - prev]
> "Probability" is used in the "ensemble" sense as a frequency. Given N
> identical simple systems completely independent of each other, e.g. no
> entanglements among members of the ensemble are permitted.
> .....
> But the point here is that this whole explanatory
> framework, at the foundation of Stapp's attempt at an orthodox theory of
> consciousness, is totally inappropriate to explaining the consciousness
> in a unique living human brain with a unique complex personality, set of
> memories etc. Henry is over-extrapolating a limiting case of a more
> general theory.
>
> [Stapp, prev]
> The orthodox stance as regards the objective probabilities that occur in
> quantum theory is that they refer to the individual quantum system:
> in Heisenberg's language they are objective tendencies, or potentia: in
> Popper's language they are propensities. Predictions involving these
> statistical weights
> are TESTED by looking, for example, at similarly prepared systems.
[Jack]
Exactly my point! So, pray tell, what possible "operational meaning", in P.W.
Bridgeman's sense (my course with Max Black at Cornell in 1957) can their be
to the
ensemble of "similarly prepared living Stapp brains"?
[Stapp]
I said "for example": the propensity interpretation of probability
requires no existence of similarly prepared systems. It is a property
of a single unique system, and it produces statistical predictions in
that real world if there should occur in that one world, a set of similar,
but nonidentical, experimental configurations.
[Jack]
That is "excess metaphysical baggage" IMHO.
[Stapp]
There is one unique physical world in which similar experimental situations
occur, and hence no excess baggage.
I have strongly emphasized that I regard the idea of randomness as
a mathematical tool that is useful in practice because of our lack of
knowledge of the variables that that are controlling the apparently random
"Dirac" Choices on the part of Nature, and I have *explained why*, in
the one deterministic universe in which we live, this lack of knowledge
should produce, in practice, a random distribution with exactly
the statistical weights prescribed by the quantum rules.
There is in Bohmian mechanics no comparable explanation of the
validity of the quantum statistical rules. Rather there is that
completely mysterious statistical postulate that one should imagine
the entire universe to be a member of an infinite ensemble of
universes that all have the same wave function, but in which the
classical worlds in these different universe are distributed in
accordance with the probability distribution specified by that wave
function. Talk about excess baggage!
But I *derive* the correct rule for the one unique world, without
bringing in any strange assumption!
[Quantum Ontology and the Mind-Brain Connection, Ch 10]
[Jack]
You cannot consistently fall back on David Deutsch's
"multiverse" of shadow Stapp clones in parallel worlds because
you have R-collapse which the multiverse does not have.
Check mate, again! :-)
[Stapp]
David Deutsch espouses a theory with many parallel worlds, whereas
I have one deterministic world with no shadow Stapp clones, and with
real ontological collapses.
This deterministic process is, to be sure, non-local. Moreover, it
involves our thoughts in a way that is not reducible to the local
deterministic Schroedinger evolution combined with the deterministic ---
though probably for all practical human purposes, random --- Dirac
process.
> [Stapp]
> Orthodox theory does put conscious experience in as basic.
[Jack]
Correction, your sufficient, but by no means necessary, version of orthodox
quantum theory does. The Bohm-Hiley-Vigier version does not do so.
[Stapp}
The term "orthodox" was the term used by Wigner to denote his rendition of
the von Neumann approach, which, like the Copenhagen interpretation, refers
to our knowledge, I have been using the word "orthodox" to mean basically
the knowledge-based approach of Copenhagen/vonNeumann/Wigner.
The Bohm and Everett interpretations are, in this way of using the term,
classified as unorthodox. I believe this is in accord with common usage
among quantum physicists. Copenhagen and von Neumann defined what was
orthodox: the alternative approaches by others who got the same
predictions from different starting assumptions are termed unorthodox. I
hope we can maintain some clarity by keeping this terminology: Bohm's
theory is not called orthodox quantum mechanics even by its supporters,
generally: it endeavours to make the same predictions as orthodox quantum
theory, and succeeds in certain simple nonrelativistic cases.
[Jack] (quoting Hiley)
"I will argue that while it is not possible to conclude that the
proposal of the direct intervention of consciousness to explain
the 'collapse' of the wave function is without substance, there is
very little direct evidence that such a process does actually occur."
[Stapp]
I would say no evidence at all, at least if paranormal phenomena
is excluded! Indeed, that is exactly the basic problem here: the
experiments are not decisive. This lack of decisive empirical data is
why there is dissension among physicists: they have been able to contrive
many empirically indistinguishable theories. All theories that yield the
orthodox predictions are on a par, empirically, and they can be evaluated
only on other grounds, such as parsimony.
(Hiley)
"I will also show that such an intervention is not necessary."
[Stapp]
I doubt that Hiley regarded this as a new result that he had discovered:
he was merely alerting his audience to the known facts. On the other hand,
there is a need to tie the elements of any proposed physical theory to our
conscious experiences. Hiley is not denying this. The issue, then, is how
are we to introduce into physical theory this tie-in to our conscious
experiences: Are the Cartesian assumptions that form the basis of
classical physical theory satisfactory? They have led to great disarray in
the philosophy of mind.
(Hiley)
I am extremely worried by the fact that we want to use something we know
very little about (i.e. consciousness) to explain away a problem which
I fear arises in our, as yet, rather poor attempts to understand the full
implications of the quantum formalism."
Basil Hiley p. 39 "Brain, Mind and Physics" IOS ISBN 90 5199 254 8
[Stapp]
The key question is not whether quantum theory can be understood without
consciousness: it is rather whether consciousness can be understood
without quantum theory.
Bohm seems to think not. And I was told that Hiley expressed agreement
about this at Tucson III. If Jack claims that consciousness
can be understood without quantum theory then his theory would collapse
in ruins.
[Jack]
I see no conceptual superiority [over my stipulation] of your
implicit, covered up stipulation of active conscious experience as
attached to R-collapse
[Stapp]
Your conception of my theory seems very different from
to my theory itself.
In my theory the state S of the universe is an objective property
of the real objectively existing universe, and a person's conscious
experiences are real objectively existing aspects of nature that are
tied to an objectively real physical system, his body/brain. The collapse
of the state S associated with a human conscious experience is an objective
change in both the state S of the universe and the state S_b of the
person's body/brain: the latter is obtained from the former by taking
a trace over the degrees of freedom that are not those of this body/brain.
The fact that the conscious experiences associated with one person's
body/brain cannot directly access, or know, the conscious experiences
associated with another person's body/braim is called the subjectiveness,
or subjective property, of these experiences. But the reduction of S
associated with a person's experience is an objective change in S.
The vN/W interpretation is an ontologicalization of the Copenhagen
interpretation. In vN/W the entire physical universe is represented
quantum mechanically. The whole quantum formalism is simply taken over
intact, the only difference being that in the vN/W interpretation
the projection operator P associated with a person's experience E acts
on the degrees of freedom of that person's body/brain: P picks out the
states that contain the "neural correlates of the conscious experience E".
In the Copenhagen interpretation this projection operator acts rather
on the degrees of freedom of a system that has been probed by an
instrument that is being examined by that person. The equivalence, in
good measurement situations, of the predictions via these two formulations
is what von Neumann's analysis showed. So although the two
interpretations are pragmatically equivalent in these good measurement
situations, and are hence empirically indistinguishable within that context,
the two interpretations are logically and metaphysically very different.
The Copenhagen separates the physical world into parts that are treated
differently, whereas the vN/W treats the entire physical world quantum
mechanically. Moreover, the Copenhagen interpretation is based on a
long-distance direct connection between the observer's experience and
some external-to-his-body system that has been probed by an instrument
that he is observing, whereas the vN/W interpretation connects a person's
experience directly to the neural correlate of that experience. This is
the connection that is directly appropriate to the huge body of experimental
work currently being done to probes directly the mind-brain connection.
The mathematical forms that lie behind these words are illustrated
in my recent posting of Theory of Presponse and Stapp's Knowledge (Mar 2).
Notice that these forms are exactly those of Copenhagen quantum theory.
In accordance with the Copenhagen principles, nothing ent%ers the computations
except the quantum mechanical representations of physical systems
(i.e., in terms of operators) and the quantum mechanical representations
of the possible experiences that the computations are about. The only
difference is that in vN/W theory the operator P corresponding to a
person's experience acts on the variables associated with that person's
brain/body, and picks out the neural correlates of that experience.
That change seems like a reasonable thing to try, if one is studying
the mind-brain connection.