Re: All possible worlds in a single world cosmology?

From: Bruno Marchal <>
Date: Wed, 21 Jul 2004 18:45:23 +0200

At 23:12 21/07/04 +1000, Stathis Papaioannou wrote:
>In reply to posts by Hal Finney and Bruno Marchal--
>I found the paper you referred to, and it certainly has some very
>interesting ideas, for example the idea that the arrow of time is actually
>an anthropic artefact. I admit that I have much reading to do if I am to
>understand the paper properly, but I am not sure what I was proposing -
>that all possible worlds will at some stage exist - is the same thing as
>the Poincare recurrences discussed in this paper. It possible that only a
>subset of possible events (everything that has occurred so far, and then
>some) will cycle endlessly, and if so, as Nietzche commented, that'll suck
>(or words to that effect). I probably gave the wrong example when I
>proposed as my unlikely event the formation of an exact copy of our solar
>system and its inhabitants in far future interstellar space; much more
>interesting would be a rather different copy, where you would be
>resurrected with intact personality and memories of your past life, with
>enhanced intelligence and physical abilities, and a whole new civilization
>with scientific wonders, intelligent aliens, and things so strange that
>no-one today has even imagined them, all to explore. Of course, you will
>also experience burning in hellfire as the flipside to this happy state,
>but who was it that said it was better to burn than to disappear?


>I agree that my four assumptions are dubious, but I chose them, for the
>sake of argument, as being (a) most inimical towards Many Worlds theories,

Thank you for your frankness. And your clarity.
As far as I feel concern you can be as inimical
as you want when you still play honest.

>(b) closest to what most people would think of as common sense,

I said once that common sense is the only tool
we have to go beyond common sense.
I'm afraid the "common sense" you mentioned
is just Aristotle theory of mind and matter.

>and (c) least controversial/ most conservative in the scientific community.

1) This is not an argument (I guess you know that)
2) It is related to b, so reread my answer to be (or just recall it).
3) The scientific community is putting the mind-body problem under the
carpet. A
     brilliant simplification and a partially successful strategy but I
don't seriously think
     that can last forever: The data are too big!

>I do think they are internally consistent, even if they are completely wrong.

It is here that we really differ. I do think they are inconsistent, unless you
manage to have only little universes, or sequence of little universes, so that
you never get a complete (never stopping) execution of a universal dovetailer
(giving that you accept comp). This follows from the UDA.
And with the FGA (filmed graph argument) that moves is also prohibited.
More easy to abandon comp, I think.

>I do not understand your comment that by saying the universe is unique,
>finite, expanding and cooling forever, it is contradictory to allow that
>my example of an unlikely event will occur as time approaches infinity.

I have not criticize this. (?) I only say that if you keep comp
and want to remain physicalist then you must find a way no
UD runs forever, + do a magical trick to link our private
feelings with individuated little universe. If not you fall in the UDA's
consequences. (reread UDA or UDA step by steps perhaps,
help you perhaps with the pictures in my recent Paris paper, see
my url below). Don't hesitate to ask question. I am aware it is
rather counter-intuitive, and you might suffer from some
metaphysical vertigo. Nobody asks you to believe a word of it.

> The increase in entropy and cooling which go with the model I suggested
> are average trends over time. It is possible within this long term
> decline to have pockets of order/ decreasing entropy, both in classical
> statistical mechanics and quantum mechanics. It is a mathematical fact,
> independent of the actual physics, that given enough time (and eternity
> is certainly enough time), any event that is possible, however close to
> zero its probability per unit time, will occur with probability
> arbitrarily close to 1. What rather surprised me, however, is the fact
> that the last statement is only true in general if the probability per
> unit time stays constant or increases with increasing time; if it
> decreases, limiting towards zero as time approaches infinity, then it is
> possible that this event, which still always has non-zero probability per
> unit time, may never actually occur. For example, if Pr(P)=1/(t^2), as t
> goes from 2 to infinity, the cumulative probability that P will occur at
> some point is 1/2.


Received on Wed Jul 21 2004 - 13:17:37 PDT

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