[ExI] Bad Epistemology?

[Russell Wallace]

On 7/16/07, Eliezer S. Yudkowsky <sentience at pobox.com> wrote:
>
> On the one hand, I know the theory (timeless physics) lacks definitive
> experimental proof, as yet.
>
> On the other hand, an irrevocable ratchet has ticked forward in my
> brain; I am no longer capable of conceiving what a "timeful" universe
> would be like.
>
> It is not so much that Barbour convinced me of his viewpoint but that
> he rendered me incapable of seeing the universe in any other way.


I'm getting the same puzzled expression here that I did reading Barbour.
This doesn't strike me as a matter of physics.

Definition: Time is a dimension in which there is continuity, so that slice
t+1 can be derived from slice t [1].

When we look at a universe (which can be our own, or a subset or variant
thereof) with, say, two spatial dimensions, we must represent these by
mapping them onto features of our own universe. Typically, to exploit
special purpose hardware, we map them onto two of our own spatial
dimensions. (The process becomes notoriously more difficult as the count
climbs past three.)

With a time dimension of the universe being studied, we have two major
options: A) map it onto our own time dimension, or B) onto one of our
spatial dimensions. Each is convenient for different purposes.

Examples of A: speech, song, movies, animation of all kinds, imperative
programming, wind tunnels, most types of simulation.

Examples of B: writing of all kinds, sheet music, calendars, timelines (the
literal ones you sometimes see in history books, horizontal line with
significant dates marked to scale), comic strips, certain types of
functional and logic programming, light cone diagrams, 1D cellular automata
simulations of the type that lay out the successive states vertically down
the screen.

It seems self-evident to me that irrespective of the detailed laws of
physics, there is no basis for claiming A or B is more true than the other,
and all Barbour is doing is "discovering" B, writing an admittedly very
evocative description of it, and then for some strange reason claiming A
isn't true.

[1] With various caveats regarding things like probability and
approximation, I'm not a mathematician.
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