[extropy-chat] Fwd: cryonicist living life in reverse

Stathis Papaioannou stathisp at gmail.com
Tue Mar 13 10:48:54 UTC 2007

On 3/13/07, Lee Corbin <lcorbin at rawbw.com> wrote:

Stathis writes
> > What if your program were broken up into minutes and the minutes run in
> reverse
> > order?
> Then within each minute, future states would causally depend on past
> states, and
> yes, I'd be conscious.  But that's because valid computations would be
> being
> performed within each of those minutes.

What about between the minutes? Consider a teleportation thought experiment,
where I am made to disintegrate mid-thought at A and reappear mid-thought at
B. At B, action potentials are travelling along my neurons just as if I had
stayed at A, even though the usual causal connection has been disrupted. I
really find it difficult to imagine how it is possible that you not
experience continuity of consciousness between A and B, given that the
physical processes are the same, regardless of the causal connection between
them. Even simpler, there is no need to introduce "continuity of
consciousness" as a separate entity: there is just the present moment of
consciousness, which contains information relating to past moments, but no
information as to whether those past moments actually occurred, or if they
did where or when they occurred. This is equivalent to saying that you would
not know it if you were created complete with false memories a nanosecond

But if the states are merely *stored* and then recalled (either in forward
> or
> reverse order), no computations are taking place!   Imagine a 3D movie, a
> version of "Casablanca" that manipulated each of the atoms in Humphrey
> Bogart's body around for him.  Unless the instants were causally
> connected,
> Bogart wouldn't be there, either as character or as actor.  No
> computation,
> no Cafe Americain.

Why not? Any physical process can be broken up into a series of snapshots,
and computation is just another physical process.

But isn't this really not germane to your main argument?  Aren't you really
> claiming that the laws of physics are time-reversible, and so a completely
> deterministic universe run in reverse would contain sentient beings?  I
> admit
> that this is possible.
> The reason that I doubt it, however, is that our current understanding of
> physics every year becomes more patently incomplete.  Smolin's book
> "The Trouble With Physics" really is brilliant, and especially intriguing
> are
> the little snippets about the new theories that are *causality* based.
> Causality---as readers of Judea Pearl well know---is a very complicated
> concept when reduced to the usual formulations that have stood us so well.
> Stood us so well, that is, until now.  A causality based physics, for one
> thing,
> could conceivably demand increasing entropy, which totally shoots down
> notions of our familiar time-reversed lives having any attendant
> experience.

Physics, causality, increasing entropy are needed to make computers or
brains so that they can have the series of physical states on which the
mental states supervene. In a simulation, physics doesn't apply: you can run
the clock as fast as you want, stop and start the program or run it
backwards. If you do any of these things, it will not be apparent from
inside the program because it isn't information made available to the
program. It's not as if the value of pi will change if it is calculated on a
fast or slow computer, or if the calculation is distributed in time and
space over several different machines; and since the calculation survives
fragmentation, you would have to attribute some special non-computational
property to the mind supervening on the calculation if you think that it
would be affected.

Stathis Papaioannou
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