Dear FISers and Micheal, Rafael and Gordana,
In reply to your posting Michael:
I am sympathetic to your view since most of us are raised under the same
evangelisation. As physicist I believed in realism for a long, long time -
seduced (?) by my tutors - but when I turned to computer science in the late
1960-ties I simple could make this easily come by view to work any more. If
you take reality to be pre-given and common to all people you cannot simply
develop computer software that people find useful - on the contrary you
risked to fail. Then I started to look for the reasons for the different
perspectives of the world - and finally found it in the tacit assumptions
behind the classical Newtonian paradigm. People see the world differently
and do it for good (and useful) reasons -- to my mind the idea of knowing a
single and common world is a misconception caused by the Biblical myths.
> There is an essential reason, I believe, why nearly all physical
> scientists are realists. There would be no physical science without
> realism.
According to my claim you are in part right since according to SOA the
physical/non-physical (i.e., real/non-real) is non-scientific because of
undecidabiliy. But in this situation "physics" turn into
a theory of knowledge, where the phenomena we normally call physical - are
renamed to perceptual stablities (in time). So there is still a science even
without the term "realism" namely the "theory of stable phenomena" - that
would then count as "physics"
I think the main reason for realism is tradition. Our beliefs are still so
anchored in language and the Christian creation myths - there is one God and
his unary creation - and therefore one world. A prerequisite for all of us
to know the "same" world is that our perceptual apparatuses are "fairly"
similar. This is a bold assumption - and misleading unfortunately. Gordana
says: "The same world might be for some other animal (say cephalopoda) very
much different - in terms of inputs and outputs as well as information
processing mechanisms, memory, reaction patterns... Who knows what
cephalopoda would say the "real world" looks like? " Well, this saying
applies to any living. I do not know your experience - and you do not know
mine but for sure they are different, we must at least proceed from this
assumption.
Maybe Demokritos was the first realist - and as such guided by the creation
myths - and then it all went on - Aristotle, Galileo, Newton, Einstein - the
spell of tradition is very strong and QM has not yet succeded in changing
this situation.
>Perhaps the most fundamental assumption upon which physical science depends
>is the conviction that all of us are imbedded in the same, objective
>physical reality.
Yes - but objective, physical and reality has become buzz-word in a physical
science that is dedicated to detached observation (and therefore outside) as
the only mean of confirmation. My "realist-riddle" question is an attempt to
make us wake up from this dogmatic slumber. There is so much else to know
about but perceptual stabilities.
> I understand that one cannot prove this deductively, but the inductive
> evidence seems, to most of us, to be overwhelming. From the very
beginning
> of physical science, through to the present, all of our scientific
> accomplishments rely on a description of nature that is observer
> independent.
After G�del we know that we cannot prove anything - in its classical sense.
Realism cannot be proved or disproved and neither can anti-realism (which is
a collection word for all -isms that apposes all forms of realism) - but the
point is that this (and similar) distinctions must be aborted for science to
become scientific. Science cannot deal with questions that are undecidable -
this is the point. And when one take such a conclusion for useful (not
true!) the troublesome dualism of modern science - implodes into monism,
that is to say one domain of knowing - experience. And since experience is
personal one must take off the build-up of science from the individuals
subjective experience. This is why we must apply a Subject-Oriented Approach
rather than a Object-Oriented one. "Physics" works very well from the
internalist's perspective - as a matter of fact even better I assure you.
>We�ve incorporated Gallilean relativity into the fundament of classical
>physics. All the classical equations of motion are observer independent.
>Would there be anything at all left of the physical sciences if we
>discarded classical mechanics?
Yes there would. Furthermore the classical equations of motion are not
observer-independent. Take for instance F = m*a F is a force abstraction
(an analogue to the force of impact we feel when acted upon by diverse
phenomena). The magnitude of this impact we can calculate by juxtaposing it
to m*a. Mass is a hypothetic property we assign to a visual (thing/particle)
impression (audible in QFT) that is mathematically multiplied by the
visually observed change of acceleration assigned to this thing/particle.
Observer-independent????????
> It is exactly the consistency and usefulness of the physical sciences that
> argues, irrefutably, I believe, for the validity of the axioms upon which
> physical science depends.
No, no the wrong way - physics is the result of its foundations - not the
proof of the validity of the foundations.
>Statistical mechanics, hydrodynamics, electrodynamics, and others cannot
>stand without classical mechanics.
I do not agree.
> So, we physical scientists must adamantly refuse to concede that because
> realism is not deductively derivable, it might not be correct.
> I note that Einstein built both his theories of relativity, special and
> general, on the postulate of observer independence. Should we throw out
> those extraordinarily valuable and consistent theories because we wish to
> debate the lack of a deductive argument for realism?
They are valuable to natural sciences only. I will repeat myself - they are
unfortunately not consistent. We shall not throw them out - we shall revise
our theories to make them consistent and more general exactly in the same
way the theories of relativity changes the physicists framework of
modelling. It is not only physical forces and movements that are relative to
the observer - ALL KNOWLEDGE IS RELATIVE TO THE KNOWER (not observer) - this
is the base line of subjectivity erected in the SOA framework which is
different from the prevailing.
>
>I sure that quantum mechanics (which also employs classical mechanics via
>the Hamiltonian formalism, Poisson Brackets, etc.) does not imply observer
>dependence, though some eminent physicists, like Wigner and von Neumann,
>have read it that way.
> The accepted understanding of the wavefunction, Psi, was given in the
> early 1920s by Max Born. As you know, If we wish to calculate the
> probability for each possible measured value of the system we take the
> projection of the eigenfunction for that value on the wave function, then
> calculate the inner product with Psi*.
See for yourself - you are talking about PROJECTING your knowledge of
particles/wavefunctions UPON the "out-the-ness" to estimate some coming
experience of your awareness.
>That we are predicting a probability for a measured outcome does not, at
>all, imply that human consciousness plays any part in the measurement. In
>fact, as Hawking, Penrose, and so many other physicists have so carefully
>calculated, there is every reason to believe that quantum mechanics
>described the cosmos billions of years before any humans and their
>conscious minds existed.
I do not agree - to take measurements and be conscious are almost
identical - let be that some instruments eventually are made of hardware for
the sake of stability.
> In general, measurement is information exchange between two separate
> physical objects. Neither object need be human, of course.
No - but the process of information exchange presumes an observer - don't
you agree.
>The canonical model for a measurement that transfers one bit of information
>is the bi-level atom located along one arm of the Stern-Gerlach apparatus
>described in 1978 (Physics Reports) by Scully, Shea, and McCullen. When a
>spinning molecule collides with the bi-level atom, a single quantum of
>energy is transferred to the atom. This is a real, physical, energetic
>signal that carries information about the change in energy of the molecule
>to the atom. Since energy is always conserved, the energy jump in the
>detector atom always records the exact information about the change in
>energy of the molecule.
Yes, this is a both beautiful and useful model we use to describe
information exchange in physics - but we must not be mislead to take it for
real. Real and physical are simply words (and misleading unfortunately).
Classical physics works very well under the assumtion human perception works
as a binocular - i.e., is involved in linear mapping. This is far to simple
an assumtion - human perception is best charachterised by adaptiveness - not
invariance.
> One may, of course, still ask how human beings are able to observe
> properties of our shared physical reality.
Yes and this was the point with my presention of the "realists dilemma" -
and asking for a solution. But up till now nobody has proposed one.
Nevertheless I hope we can deepen the discussion about the misunderstood
human's capacity of perception outgoing from these remarks.
>I�m convinced that at the most basic level of human percepta, more
>fundamental than learned, or perhaps innate, shapes and objects, we all
>look at the same pattern of minute color specks and see (and describe) the
>same specks. The key here is to look only for each speck of color, as one
>might do to a pointillist painting by Signac, say, ignoring any impression
>of physical objects that the artist may have portrayed. If necessary,
>scientists could employ such a basic technique to insure that the pattern
>which carries information about results of a measurement (like the face of
>an ammeter, for instance) really is observer independent. I�m convinced
>that there are no cultually-inculcated tendencies at this most basic
level.
Personally I think we have good evidence to assume there is a reality
(probably common) behind the stable entities of our perception
- BUT THIS SHOULD BE THE MOST LIKELY CONCLUSION DRAWN BY A MATURE SCIENCE
--- AND NOT SOMETHING THAT WE TAKE FOR GRANTED AT THE OUTSET. IN THE LATTER
CASE THE "REALITY"
CONCEPTION CAN NEITHER BE REFUTED - OR NEITHER CONFIRMED.
This bring me to protest against Rafael's oversimplification: "Declarations
of faiths are declarations of faith. Nothing more, nothing less." One faith
(model) can be more useful but another model - and this is really something
more - some models are more useful because they better predict coming
experience. And some faiths must be dismissed from scientific discussions
because they cannot be fitted into a decision procedure.
The poverty of reductionism is not a povery of its methodology - but the way
we try to apply it in the hope to find some ultimate explanation is a sign
of poverty. The latter quest is in vain - in all knowledge discourses. In
the case we will avoid the endless regression (to bring out an answer) - we
must abort the endless looping by using our personal will (to bring out
one). No God, Evolution or Mathematics can assist us in provide an end
criterion in that matter. It seems our imagination is endless - but not the
time we have at our disposal. Therefore we must cut of the regression - at a
level specified by usefulness, which in turn depends on the goal we have in
mind. THEREFORE WE MUST FIRST OF ALL ASK AS TO WHETHER A SPECIFIC GOAL IS
REACHABLE - OR IF A CERTAIN DECISION CAN BE MADE AND HOW - EVEN BEFORE WE
ENTER UPON THE QUEST. In that view Quine's proposal of a pursuit of truth
is vainly.
Best wishes Arne
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Received on Wed Jun 28 14:06:27 2006
