Re: Quantum spookiness in the brain?

On 11 Apr, 15:52, Walter Bushell <pr...@xxxxxxx> wrote:
In article
<6286678b-3867-4aeb-826e-2e823255f...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,



Vend <ven...@xxxxxxxxxxx> wrote:
On 10 Apr, 00:41, Paul J Gans <g...@xxxxxxxxx> wrote:
Vend <ven...@xxxxxxxxxxx> wrote:
On 9 Apr, 21:27, r norman <r_s_norman@xxxxxxxxxxxx> wrote:
On Wed, 9 Apr 2008 12:08:26 -0700 (PDT), Vend <ven...@xxxxxxxxxxx>
wrote:

On 9 Apr, 19:51, r norman <r_s_norman@xxxxxxxxxxxx> wrote:
On Wed, 9 Apr 2008 16:30:42 +0000 (UTC), Paul J Gans <g...@xxxxxxxxx>
wrote:

<snip>

I believe that Penrose was dealing with what I will call
the "mechanistic view" of the mind. In that view two absolutely
identical brains will think absolutely the same thoughts and make
absolutely the same decisions.

Folks who think this are basically saying that there can be no
free will since thoughts are then totally dependent on the physical
details of the brain that thinks them.

For many, the only way out of this is to posit a supernatural
something that would allow absolutely identical brains to think
different thoughts.

Penrose, I believe, was pointing out that it is impossible to
have absolutely identical brains because of quantum uncertainty.

The rest of his thinking then took off from this point of departure.
And I agree that the rest of his thinking may be just so much
poop, but the problem of identical brains is a real one and I believe
it is solved by quantum uncertanty.

The notion that identical brains must think alike and act alike is,
indeed, logically equivalent to the notion that, given the details of
one brain, one can then compute presumably the future of what it will
do.

This assumes that the physical laws are computable, or at least can be
approximated by computable functions to any arbitrary level of
precision.
This is exactly the assumption that Penrose and Hameroff challenge.

All known fundamental physical phenomena seem to be described by
(approximately) computable laws, with the only exception of quantum
wavefunction collapse, which seems to be probabilistic.
Many interpretations of quantum mechanics have been formulated to try
to address this oddness. Some just accept it as it is while others
suggest that it might be actually a deterministic chaotic phenomenon.

Penrose and Hameroff instead suggest an interpretation where quantum
wavefunction collapse is governed by a (still unknown) uncomputable
physical law.

Their rationale for doing so is that they have convinced themselves
that certain aspects of human behavior (like mathematical intuition)
aren't compatible with a computable (and possibly probabilistic)
physics, thus they have cringed on the only not completely explained
fundamental phenomenon.

However, their argument for the non-computability of human behavior is
flawed (IMHO and in the opinion of most experts), making their
proposed interpretation unparsimonious.

I remember a time when Penrose argued that quantum gravity must be the
factor behind consciousness since it was the only part of physics left
unexplained.
Right, he thinks that when quantum gravity is explained, it will
explanation for quantum wavefunction collapse and provide the
mechanism to understand human consciousness.
If I remember correctly, his schema for explanation is:
- Particles with mass distort space-time.
- Particle quantum states can be in superposition.
- A superposition of states of a massive particle causes a
superposition states of space-time.
- When the superposed states of space-time become too much different
(respect to a threshold depending perhaps on h and c), the universe
forces the superposition to collapse towards one state of space-time
and hence one state of massive particles (and entangled mass-less
particles).

Hmmm.

I think it can be demonstrated that quantum wave function
collapse is a product of human-environment interaction.

Consider the Schrodinger's Cat Modified: We have a container
with the usual cat and random apparatus. One one side of the
container we have the usual wise observers who create a state
function for the cat that is a supersition of two states with
appropriate normalization constants.

On the other side, and hidden from the first observers by
a curtain or what have you, is another set of observers. Their
side of the container has a glass wall. Their state function
for the cat never collapses at all.

If the cat dies, their wave function does exhibit a state transition
from phi_{living} to phi_{dead}. This transition is akin to
an electronic transition.

What I am claiming, and think I have shown an instance of, is that
the wave function represents *our* knowlege of the system at any
time t. It is always a composite function to some extent, but the
more we know, the fewer terms are included.

Comments?

The Schrodinger's Cat thought experiment assumes that the box is an
isolated system up to the time the measurement is carried out.
In your version, either the second observer is in the box (and hence
isolated from the world) or he's outside.

If he is outside the box, then the box is not an isolated system and
then the first observer can't assume that the superposition (1/sqrt(2))
(|living> + |dead>) is kept until he opens the box.

If the second observer is inside the box, then from the point of view
of the first observer the second observer becomes an extension of the
cat as the state of the system becomes: (1/sqrt(2))(|living and seen
living by second observer> + |dead and seen dead by second observer>)

The problem is: can you consider the second observer a true observer?
And what is the nature of the wavefunction?

This problem is already present in Schrodinger's original thought
experiment. In fact, in the original formulation, the actual 'quantum'
system is the particle which may or may not decay and cat can be
considerd itself the second observer.

--
--- Paul J. Gans

Is why I have a preference for the transactional model, this observed
bit gets hairy fast, and the multiple universe is totally frightening in
its implications. A huge number of Universes where Hitler won the war
just for starters.

I know almost nothing of the transactional model (Wikipedia doesn't
seem to cover it well), do you have some reference for a non-
physicists?
And how does the Shrodinger's Cat experiment play out in it?


--
What is done in the heat of battle is (normatively) judged
by different standards than what is leisurely planned in
comfortable conference rooms.

.

Relevant Pages

  • Re: Quantum spookiness in the brain?
    ... identical brains will think absolutely the same thoughts and make ... have absolutely identical brains because of quantum uncertainty. ... Consider the Schrodinger's Cat Modified: ... and hidden from the first observers by ...
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  • Re: Quantum spookiness in the brain?
    ... identical brains will think absolutely the same thoughts and make ... wavefunction collapse, ... Consider the Schrodinger's Cat Modified: ... observer investigates the cat's status. ...
    (talk.origins)
  • Re: Quantum spookiness in the brain?
    ... something that would allow absolutely identical brains to think ... have absolutely identical brains because of quantum uncertainty. ... with the usual cat and random apparatus. ... either the second observer is in the box (and hence ...
    (talk.origins)
  • Re: Quantum spookiness in the brain?
    ... identical brains will think absolutely the same thoughts and make ... have absolutely identical brains because of quantum uncertainty. ... Consider the Schrodinger's Cat Modified: ... and hidden from the first observers by ...
    (talk.origins)
  • Re: Quantum spookiness in the brain?
    ... identical brains will think absolutely the same thoughts and make ... have absolutely identical brains because of quantum uncertainty. ... wavefunction collapse, ... Consider the Schrodinger's Cat Modified: ...
    (talk.origins)