Stephen P. King (stephenk1@home.com)
Fri, 15 Oct 1999 14:46:08 -0400
Dear Lance,
This is a great post! My comments are interleaved below...
(Corrections, criticism, requested!)
"Lancelot R. Fletcher" wrote:
>
> Stephen,
>
> Thanks for posting the Julian Barbour article from New Scientist. I have
> pre-ordered Barbour's new book (The End of Time) -- you can get it from
> Amazon.com or bn.com for about $17.50 -- it's due to come out in a day or
> two). You might want to read an interview with Barbour at
> http://www.edge.org/.
I'll probably get the book as soon as I can... First I need to get a
couple of other books that are more expensive
(http://www.amazon.com/exec/obidos/shopping-basket/002-4241213-6209007)...
> Based on a quick, first review, here are some reactions:
>
> 1. I was struck by the fact that Barbour wants to retain the big bang
> theory within his timeless universe. You could call that wanting to eat his
> cake and have it too, but it also strike me as a curious lack of imagination
> within the framework of what is intended to be a bold departure (the
> subtitle of his new book is something like "the next revolution in
> physics"). One of the great advantages of envisioning the possibility that
> the universe as a whole is without time is that it invites one to look
> seriously for alternative explanations for the phenomena that are said to
> give us the big bang theory. Barbour seems not to have ventured outside the
> box in this respect.
The "Big Bang", in my thinking, relates to the reification of the
subjective "view" of an LS to ontological status, e.g. since each
observer can only observe a finite universe having a unique beginning,
such naively assumes that all other observer's "exits" with in the same.
It is hard to reconcile the facts that observers are fundamentally
solipsistic and there exist more than a single observer. We so much
unconsciously desire that the universe that each observer observes is
"THE Universe". We fix this naivety by showing that each LS has its own
"absolute universe" and the "world of common experience" is merely that
which we bisimulate in common.
> 2. Barbour does not seem to have a well-developed notion of local time and,
> by the same token, he does not seem to have a coherent notion of the
> possibility of action, which is one of the principle strengths of Hitoshi's
> notion of local time. I may be mistaken about this, of course, since my
> reading of the Barbour article was pretty cursory (as an advocate of slow
> reading, I am apologetic for this). One of the things that leads me to this
> conclusion, however, is Barbour's repeated statements that time is an
> illusion. This is one of a number of examples:
I agree!
> >>All this seems a far cry from the reality of our lives. Where is the
> history we read about? Where are our memories? Where is the bustling,
> changing world of our experience? Those configurations of the Universe for
> which the probability mist has a high density, and so are likely to be
> experienced, must have within them an appearance of history-a set of
> mutually consistent records that suggests we have a past. I call these
> configurations "time capsules". <<
>
> Perhaps I am mistaken, but this sounds pretty similar to the notion of a
> "block universe" that Huw Price advocates in "Time's Arrow and Archimedes'
> Point".
I am strongly reminded of Matti's "geometric time" by this quote! We
must not forget that the "block universe" is the Special Relativistic
model and does not allow acceleration within itself, and thus "force" is
an alien concept within it.
> That impression is reinforced, I think, by the following example:
>
> >>What is more, we are somehow directly aware of the passing of time, and we
> see motion-a change of position over time. You may feel these are such
> powerful sensations that any attempt to deny them is ridiculous. But imagine
> yourself frozen in time. You are simply a static arrangement of matter, yet
> all your memories and experience are still there, represented by physical
> patterns within your brain-probably as the strengths of the synapse
> connections between neurons. Just as the structure of geological strata and
> fossils seem to be evidence of a past, our brains contain physical
> structures consistent with the appearance of recent and distant events.
> These structures could surely lead to the impression of time passing. Even
> the direct perception of motion could arise through the presence in the
> brain of information about several different positions of the objects we see
> in motion.
>
> And that is the essence of my proposal. There is no history laid out along a
> path, there are only records contained within Nows.<<
This is the problem, time is defined as merely being an illusion but no
consistent and formal explanation is given for the necessity of the
"illusion"! We can not just say that time is an illusion without
justifying the necessity of such or providing a consistent model of how
the illusion is generated. To relegate the illusion to "the presence in
the brain of information about several different positions of the
objects we see in motion" fails to show the necessity thereof.
It is impossible to derive change, or more to the point, Becoming, from
purely static Being, but it is possible to define Being if we assume
Becoming as fundamental. (This follows from my reading of Prigogine's
work...)
We need to ask: "How is it that these "records" can be meaningful?".
This leads directly into information theoretic considerations!
> Perhaps it is unfair to burden Barbour with the limitations of an example,
> but what is most striking about the example is this notion of a static or
> frozen arrangement. The problem, of course, with that image is that an
> arrangement can be static or frozen, only in time. Barbour seems to think
> that a timeless universe can also be described as "unchanging", but, if that
> is what he thinks, it is a radical misconception.
Yes!
> 3. Although Barbour distinguishes his theory from that of Lee Smolin, on one
> crucial point they seem to agree -- which is the point that you mentioned in
> your message to Jerry Malsam: they seem to agree in assuming that, if the
> universe as a whole is timeless, it follows that all the finite parts of the
> universe are also timeless. I think Hitoshi needs to be given enormous
> credit for noticing this assumption, since for most people this appears so
> obvious that it seems like a necessary truth, so they are not aware that
> there is any possible alternative. And, in Time V, Hitoshi shows, with what
> I think is an extremely elegant proof, that the absence of global time is
> entirely constent with the existence of local time.
Yes! I remember well the excitement that overtook me when I first read
Hitoshi's papers! Eureka!
> 4. In this, as with so many other recent discussions about time in physics I
> am left with the feeling that what is missing is an adequately grounded
> philosophical critique of the notion of time. To the extent that Barbour
> ends up with a notion of the world from which the possibility of action is
> absent (which looks to me like the case), he has simply found himself driven
> into the arms of Zeno of Elea. But, unlike Barbour, Zeno's intention was
> not to argue that time and motion are non-existent. His intention was to
> show that what I call "vulgar Pythagoreanism," the mathematical physics of
> his time, involved a defective understanding of time and existence which
> would necessarily drive one into these paradoxical conclusions. Every
> important philosopher, from Parmenides, Plato and Aristotle, through
> Descartes, Spinoza, Leibniz and Kant, has recognized that time cannot be a
> thing, something that exists in the world. The most prevalent view --
> certainly that of Spinoza, but largely shared by others -- is that time is a
> measure of duration, while duration is the contingent mode of existence
> proper to finite things. The universe cannot be finite, since "finite" is
> imply a Latinate word for "limited," and if there is anything that limits
> the universe, then there is something which the so-called universe does not
> include, hence it is not universal. Therefore the universe is necessarily
> infinite, but if duration is the mode of existence proper to a finite thing,
> then duration does not pertain to the universe. The traditional term for
> the mode of existence proper to an infinite thing is "eternity." Eternity,
> however, is not correctly understood as "sempiternity," i.e. "existing
> always." Sempiternity is simply an imaginational projection of contingent,
> durational existence.
Yes, we desperately need to discuss "clocking". I am strongly
suggesting that we consider the ideas contained in Peter Wegner's
papers, especially http://www.cs.brown.edu/~pw/papers/math1.ps . We have
a way to overcome the "initiality" problem! This, to me, speaks directly
to your point concerning "sempiternity". The "imaginational projection
of contingent, durational existence" is part and parcel a key aspect of
the bisimulational model of interaction!
Each observer "simulates" the properties of others and thereby alters
itself in apparent response to the "actions" of the others and this
"simulation" is a "imaginational projection of contingent, durational
existence" reified to a mathematical formal model. (I see Matti's q-jump
computation as a direct example of this "simulation"!) We then see
bisimulation as what happens in the situation of multiple observers,
each projecting a simulation of the behavior of other observers that
each is capable of simulating. The limitation here implied, I think,
speaks to your next statement! ;^)
> The great problem, philosophically, has been to understand the relationship
> between the eternal and the durational modes of existence -- to understand
> how the eternal and infinite nature of the universe is necessarily expressed
> in the durational existence of apparently finite components. The great,
> really extraordinary, merit of Hitoshi's work, in my opinion, is that he has
> situated his approach to the questions about the nature of time in physics
> and the problem of reconciling quantum mechanics and the general theory of
> relativity in exactly the same "logical space" as the classical problem of
> relating the eternal and durational aspects of the universe. This
> correspondence of questions is what Aristotle calls "a beautiful
> perplexity."
>
> Lance Fletcher, President
> The Free Lance Academy Foundation
> http://www.freelance-academy.org
> lance@interactive.net
I firmly believe that we will find the answer to this problem when we
look into the "logical dynamics" of the situation. This is, yet again, a
validation of Pratt's enigmatic dualism conjecture!
Onward to the Unknown,
Stephen
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