Re: SUO: Ballot Comment - 3D versus 4D.
>Pat, Graham, and Matthew,
>
>I agree with Pat on the general issues, but I have a somewhat
>different way of expressing them. As I have said in some previous
>notes (and my KR book), I prefer Whitehead's 4D representation,
>which accommodates many different ways of describing physical
>entities:
Well, sorry to be a spoilsport, but I don't agree with all of this
(comments below.)
.But more to the point, I don't see why I (or anyone else) should be
obliged to agree with it all in order to make use of a standard
ontology.
> 1. W's basic physical entities are processes (which he calls
> actual occasions or actualities). Each such entity has a
> very short duration (not a zero-lenth instant, but a short
> interval that depends on granularity).
>
> 2. Enduring physical objects are extended processes that are
> characterized by various "forms of definiteness", such as the
> geometrical shape of a crystal or the DNA of a plant or animal.
That seems too restrictive to be useful, since enduring entities are
characterised by all kinds of different functional criteria. I would
want to be much more pragmatic about what counts as an enduring
physical object.
> 3. You can talk about variations over time or over space by looking
> at the first derivatives with respect to time coordinates or space
> coordinates. A slow change has a small continuous derivative,
> and a so-called discrete change has a very large derivative,
> which may be considered a discontinuity.
At one level that is a simple mathematical truism, but it is
potentially harmful in that it assumes a very strong underlying
continuity, and for many purposes it is more useful to assume various
kinds of discrete structure as primitive, as is done in much temporal
reasoning and in 'qualitative physics'. Whitehead was trying to
create a global scientific metaphysics, a project which was basically
sidelined by quantum theory. I don't want to get involved with such a
grand ambition in any case.
> 4. For both the en- and per- methods of description, the processes
> characterized by "forms of definiteness" are important. They are
> called "physical objects", and they can be described as "changing"
> through time, if one wants to use that way of talking. But the
> underlying actual occasions are identical from every viewpoint,
> and they form the basis for relating one description to another.
>
> 5. I agree with Pat that the per- descriptions are often more prolix
> than the en- descriptions for many common ways of talking about
> the world. That is partly because people have developed a large
> vocabulary of common expressions that would require very extended
> translations if mapped into the primitives of the per- perspective.
I agree that is probably the reason; but one should also consider
that these common expressions may have evolved in part because of
their utility.
> 6. Whitehead is often criticized for inventing his own highly technical
> vocabulary, but to a large extent, that criticism misses the point.
> W. was trying to develop a way of talking that could express
> the concepts that were significant for both the en- and per-
> vocabularies. Therefore, he had to coin many new words to express
> the highly general concepts that were missing from both.
>
>For an introduction to Whitehead's point of view, you can start with
>his 1920 book, _Concept of Nature_, which is available on the web:
Beware. Reading Whitehead is like setting out to go on a hike with a
large male lion. No matter how reasonable he seems to be, it is very
difficult to keep up your end of the conversation, and you will
probably find that if you want to turn left and he wants to turn
right, you will quickly find yourself convinced of the advantages of
acquiescing to his point of view.
> http://paradigm.soci.brocku.ca/~lward/Whitehead/White1_pref.html
>
>His vocabulary in this book isn't as technical, since he was just
>getting started in developing this point of view.
Right. This perspective is what I meant in an earlier message by '4-d
mereology', ie a theory of parthood applied to 4-d regions rather
than 3-d. The fun part is that the same axioms work for either case.
> (He had already
>written his book _Principles of Relativity_, in which he presented
>his own formalism as an alternative to Einstein's. For all results
>that were observable at that time, Whitehead's method and Einstein's
>gave equivalent results, but there are some newer results which
>agree better with Einstein's version than with Whitehead's. But
>in any case, W. certainly knew how to represent 4D.)
True, but bear in mind that the 4-d we have been talking about in
these lists is NOT the same 4-d that is used in relativity theory.
The latter is Minkowski space, which has many highly unintuitive
properties; we have been talking about a classical view of 4-d space,
one that pre-dates special relativity by about 50 years.
Pat
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