From: Basto Jorge (jldcb199@ecs.soton.ac.uk)
Date: Mon May 28 2001 - 21:17:25 BST
Harnad, S. (2000) Minds, Machines, and Turing: The
Indistinguishability of Indistinguishables. Journal of Logic,
Language, and Information 9(4): 425-445. (special issue on "Alan
Turing and Artificial Intelligence")
http://www.cogsci.soton.ac.uk/~harnad/Papers/Harnad/harnad00.turing.html
> HARNAD:
>10. Level T5 (Grand Unified Theories of Everything [GUTEs])
>Toy models, that is, subtotal models, of anything at all, have the
>liability that they have more degrees of freedom than the real, total
>thing that they are modelling. There are always more different ways to
>generate a fragment of a system's function (say, chess-playing -- or
>simple harmonic motion) than there are to generate the system's total
>function (say, everything else a human mind can do -- or all of Newtonian
>or Quantum Mechanics), if for no other reason than that the Total model
>must subsume all the functions of the subtotal toy models too (Schweizer
>1998; cf. Lucas 1961).
>
>We spoke of Humean indeterminacy earlier; philosophers are not yet of one
>mind on the number of candidate Total Theories there are likely to be, at
>the end of the empirical/theoretical road for, say, Physics. At that
>Utopian endpoint, when all the data -- past, present and future -- are
>Totally accounted for, will there be one and only one Grand Unified Theory
>of Everything (GUTE)? Or will there be several rival GUTEs, each able to
>account for everything? If the latter, will the rivals posit an equal
>number of parameters? and can we assume that the rival GUTEs will just be
>notational variants of one another? If not, will we be right to prefer the
>miniparametric GUTE, using Occam's Razor?
>
>These are metaphysical questions, and physicists would be more than happy
>to have reached that Utopian stage where these were the only questions
>left to worry about. It is clear, however, that current physics is still
>at the stage of subtotal theories (it would be churlish for any other
>science to venture to call them "toys," as physics's are surely the most
>advanced such toys any science has yet produced). Subtotal models always
>run the risk of being very wrong, although that risk diminishes as they
>scale up toward a closer and closer approximation to totality (GUTE); the
>degrees of freedom shrink, but they may not vanish altogether, even after
>we have reached Utopia.
>
>Utopia is also the top Level T5 of the Turing Hierarchy. We will return to
>this after describing Levels T2-T4.
Basto:
just a comment on this section of this paper of yours.
I don't see your point with these complementar or competitive GUTE's.
Actually, in physics to and my knowledge there is GUT if we reach an energy
scale where we can unify three forces (weak, strong and electromagnetic)
into one single description and there is a TOE theory if can have a unified
system that also takes the 4th force into consideration (gravitational). Now
there is no need to think of several of these descriptions existing
simultaneously because the goal IS unification into a SINGLE one. So if
there are several descriptions I think a higher class would be created to
account for those views, just as there are two views (particle, wave) for
the same particle phenomena -we don't say there are several particle
theories as they are both part of the standard model. I can boil an egg with
water in a pan in the oven or I can (maybe) use the microwave. However, the
book to instruct on how to boil an egg will be just one with these several
alternatives written down. If there are competitive or complementary
speculations of unified theories (strings, super simmetry, and so on...)
that is because as to date there is no empirical data to go for any of them.
As soon as we are able to put them under empirical testing, the set of
choices will narrow; and if by the end there will be more then one then
those will be part of the SINGLE unified theory. Or am I completely wrong?
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