# Re: Quantum Time Travel

From: <GSLevy.domain.name.hidden>
Date: Tue, 11 Apr 2000 20:09:04 EDT

In a message dated 04/07/2000 2:53:30 PM Pacific Daylight Time,
jackmallah.domain.name.hidden writes:

> --- GSLevy.domain.name.hidden wrote:
> > jackmallah.domain.name.hidden writes:
> > > OK. The advantages of my approach are
> > > 1) It does not require any special definition
> > of identity, while your
> > > approach seems to give one a fundamental role.
> > >
> > > 2) In principle, it allows all kinds of
> > (statistical) retrodictions.
> > > Your approach seems to only allow a few kinds.
> > >
> > > 3) It is unclear how you deal with time based
> > on your previous and current statements. In my
> > approach it is clear that each observer-moment has
> > > some measure, and a set of related observer
> > moments can be used for a 'person'
> > > if desired, so that the person's total measure is
> > the sum of that of his constituent observer-
> > moments. This clearly rules out QTI.
> > >
> > > 4) In the MWI of QM the measure of an observer
> > in a 'branch' is defined.
> > > This is proportional to
> > > dM(total)/ d tau [where dtau ~ dt * clock speed]
> > > in my approach.
> > > In your approach it must be divided by an
> > identity-dependent factor
> > > resulting in possible near-zombies.
> > >
> > 1) True. I do require definition of identity or more
> > precisely of the self.
> > However this requirement is absolutely trivial.
>
> Then state the precise definition.
>
> > a) First, no matter how the self is defined, (i.e.,
> > what boundaries you draw
> > around it) the normalized measure for the self is
> > always unity.
> > Normalized Measure = M(Self) / M(Self)
> > Which is nice and very egalitarian. We all have the
> > same measure.
>
> Then why don't people similar to us, but who see
> white rabbits, have the same measure?

You are correct! But only from the third person point of view. I define
"third person point of view" as a perspective which does not affect the
survival of the observer! There are two kinds of white rabbits. The rational
ones which I shall discuss now, and the irrational ones which I shall discuss
in the next section. Different people "similar to us" do see rational white
rabbits. They win the lottery, are hit by lightning and sometimes even
receive a meteorite on the head. The number of these people, however is very
small. Their measure RELATIVE TO AN UNINVOLVED OBSERVER is very low. For very
very very few in the whole observable universe, the second law of
thermodynamics may even revert temporarily.

However, their own measure RELATIVE TO THEMSELVES is unity.

> > b) Second, the assumption of the self is absolutely
> > essential no matter what
> > method (yours or mine) is used. We MUST start with
> > the assumption "I think."
> > Otherwise it's not even worth thinking about nature
> > or anything.
>
> Observer-moments exist. At least one I can vouch
> for; the rest I must extropolate.

OK. We agree on that.

> > 2) I don't understand. Maybe you should come up with
> > an example.
>
> Ok. Suppose there are two possible kinds of
> people: those that are (at least as far as they can
> tell) physically the product of a Darwinian evolution
> process, and those that just came into being due to
> random fluctuations. In my approach, given the laws
> of (AUH or whatever) I can in principle predict that
> the former is more 'probable' than the latter. But
> for you, everyone has the same measure, so you can't.

I shall now discuss irrational White Rabbits. I assume that consciousness is
the product of a rational mind. In computer science parlance, it could be
simulated by a TM. Furthermore, because of anthropic considerations,
rationality of the mind requires a rational physical environment. Hence, if
someone exists he must be able to make sense of his surrounding and observe
the cause for his own existence. So irrational White Rabbits cannot be
observed.

Hence any conscious entity must be capable of observing the reason for his
own origin, Darwinian or Design (for an human designed intelligent computer
for example)

I repeat, from the third person point of view, everyone does not have the
same measure. From the first person point of view, our own measure is unity.

> > 3)
> I already explained this to you: cardinality isn't
> the issue. Just take a limit in the right way.

I know, I know. You just take the limit. As if it was that simple. It's not!
Let me give you an example.

Consider the set of integers from 1 to N. Let S1 be a sequence representing
that set.

S1 = {1, 2, 3, 4, 5, ...N}

It is clear that as N -> infinity, S1/ S1 -> 1

Now consider another sequence:

S2 = {2, 4, 6, 8, 10, 1, 12, 14, 16, 18, 20,...98, 100, 3, 102, 104,.. 998,
1000, 5, 1002...N}
The odd integers are placed only where the number of digits is incremented
(i.e., 100, 1000, 10,000, 100,000,....)

Now find the ratio between S2/S1. It is obvious that in the limit as N ->
infinity the ratio will tend toward a number slightly below 2. AND YET, WHEN
N REACHES INFINITY WE ARE GARANTEED THAT THE SET CORRESPONDING TO SEQUENCE S2
CONTAINS ALL INTEGERS JUST AS SEQUENCE S1!!! So S1 and S2 contains the same
integers but their ratio is not equal to 1.

Taking the sum of an infinite set depends on the way the element of that set
are SEQUENCED!

I think that when infinite sets are involved, the concept of limit must be
applied very carefully.

> > 4) I don't understand. Are you trying to calculate
> > the output measure in a
> > branch, given the total input measure? What are tau
> > and t? I can't comment on zombies.
>
> No, just the contribution of each branch to the
> total measure of some defined set of observer moments.
> t is time, and tau is brain-computer proper time.
> If you simulate a brain on a Pentium, it gives rise to
> more measure per unit time than the same algorithm on
> a 8086.

My response is the same. You are right but only from the third person
perspective.

> > With my method, you must distinguish between first
> > person and third person
> > observations. Third person observations match
> > classical physics. First person
> > observations do not. White rabbits do appear
> > especially if they are essential
> > in maintaining the existence of the observer. In our
> > case, for example, the
> > Big Bang which is definitely a first person event.
>
> Sounds crazy.
> With my method, there is no such distinction.
> There's a measure distribution. White rabbits appear
> only with very small effective probability.
> "Maintaining an observer" is undefined until
> "observer" is defined.
>

George Levy
Received on Tue Apr 11 2000 - 17:14:10 PDT

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