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From: pindor@gpu.utcc.utoronto.ca (Andrzej Pindor)
Subject: Re: Large-scale quantum effects (Was Re: Penrose's new book)
Message-ID: <Cxu1Dv.22n@gpu.utcc.utoronto.ca>
Organization: UTCC Public Access
References: <Cx967I.LzF@sun2.iusb.indiana.edu> <pja1.15.00F30E84@rsvl.unisys.com> <CxMF4D.Bro@gpu.utcc.utoronto.ca> <kovskyCxo4yx.EE5@netcom.com>
Date: Mon, 17 Oct 1994 19:41:55 GMT
Lines: 94

In article <kovskyCxo4yx.EE5@netcom.com>, Bob Kovsky <kovsky@netcom.com> wrote:
>In article <CxMF4D.Bro@gpu.utcc.utoronto.ca>,
>Andrzej Pindor <pindor@gpu.utcc.utoronto.ca> wrote:
>>In article <pja1.15.00F30E84@rsvl.unisys.com>,  <pja1@rsvl.unisys.com> wrote:
>>>
>>>"oxymoron" -- A rhetorical figure in which incongruous or contradictory terms 
>>>are combined, as in "a deafening silence" and "large-scale quantum action."
>>>
>>Hmm, how about macroscopic quantum effects, like superconductivity or
>>superfluidity? Quantum effects in lasers also extend over macroscopic
>>distances, i.e. their operation is based on "large-scale quantum action".
>>
>
>	How about computers, whose "semiconductor" microchips are 
>engineered according to quantum mechanical principles?  Or H-bombs?  Or 
>the processes that keep the sun burning?
>
There is a difference between macroscopic effects of quantum phenomena and
macroscopic quantum phenomena. Since atoms are governed by quantum laws,
any macroscopic effects is strictly speaking a result of quantum phenomena.
However in most cases, individual quantum effects are not correlated and, as
a result, quantum effects average out. For instance, many properties of
gases and liquids can be explained by assuming atoms in form of hard 
(classical) balls. Understanding working of a computer CPU does not require
considering quantum behavior of electrons in a silicon crystal - the same 
behavior would be exhibited (albeit much more slowly) by a set of water
pipes with valves (that is how peumonic elements work). 
    In contrast to the above, in certain situations (like superconductivity,
superfluidity or in lasers) individual microscopic quantum phenomena are
strongly correlated and quantum laws operate on macroscopic scale.
Such 'large-scale quantum action' is postulated by some people to play role
in the brain and is not an oxymoron. Whether it does indeed play role in
the brain is another story.

>	But the fact that quantum mechanical principles are useful in 
>accounting for large-scale phenonmena does not mean that such utility 
>extends to the functioning of the brain.  Order-of-magnitude calculations 
>suggest that quantum-mechanical fluctuations are too small to affect even 
>a single synaptic firing.  Moreover, that the functioning of the brain 
>is not dependent on the fine detail of synaptic firings (the accidental 
>loss of a neuron due to a cosmic ray accident does not create a problem).
>
Lasers are a counterexample to these order-of-magnitude calculations -
if a large number of atoms can correlate their quantum behavior, resulting 
quantum mechanical fluctuations can be quite substantial. Again, I am
not claiming that such mechanisms operate in the brain, just trying to
straigthen common mosconceptions about quantum phenomena.

>	A more interesting question from my perspective is why we believe
>that the "laws of physics" are universal.  These "laws" are formulated and
>implemented under highly constrained conditions, e.g., those of the
>physics laboratory or technological manufacturing plant.  Those highly
>constrained conditions are obviously different from the hurly-burly of
>processes that are going on in the brain.  The hypothesis that the "laws
>of physics" are universal is an interesting one, but only a hypothesis. 
>And there are good reasons to conclude that those laws are no more than
><approximations> that are highly accurate only under those highly
>constrained conditions. 
>
You might have perhaps noticed that there is a lot of things which operate
in natural environment but are built on the basis of laws derived 'under
highly constrained conditions'. The "laws of physics" may not be "universal"
in some sense, but not for the reasons you outline.

>	Instruments and representational techniques introduce systemic
>distortions into the images created.  Optical instruments create
>distortions in their images and introduce aberration, as well as being
>characterized by such matters as depth of field.  Preparing a plane map of
>an area on the globe results in errors that are expressed in a formula
>that has a formal similarity to the Heisenberg uncertainty principle
>(errors in angles x errors in area).  The fact that particular optical
>instruments can produce distortion-free images under a narrow range of
>conditions (e.g. placement, size of image) and the fact that the errors
>created by map-making can be reduced indefinitely by reducing the relative
>size of the area mapped does not avoid the systemic distortions.  Why do
>we assume that the instruments of experience and the functions of the
>brain produce "veridical" images reducible to differential equations?  So
>much evidence from daily life points in the opposite direction. 
>
We assume the above because such assumptions allow us to get practical
results. If you think that following "the opposite direction" will be more
fruitful in the above respect, please indicate how. If you are right, you
will gain fame and money.

Andrzej

>    Bob Kovsky          |  A Natural Science of Freedom 
>    kovsky@netcom.com   |  Materials available by anonymous ftp
>                        |  At ftp.netcom.com/pub/freeedom
-- 
Andrzej Pindor                        The foolish reject what they see and 
University of Toronto                 not what they think; the wise reject
Instructional and Research Computing  what they think and not what they see.
pindor@gpu.utcc.utoronto.ca                           Huang Po
