[time 397] Re: [time 396] Re: [time 391] Re: What are observers


Hitoshi Kitada (hitoshi@kitada.com)
Tue, 8 Jun 1999 15:52:58 +0900


Dear Matti,

----- Original Message -----
From: Matti Pitkanen <matpitka@pcu.helsinki.fi>
To: Hitoshi Kitada <hitoshi@kitada.com>
Cc: <time@kitada.com>
Sent: Tuesday, June 08, 1999 3:14 PM
Subject: [time 396] Re: [time 391] Re: [time 388] Re: [time 384] Re: [time
380] Re:[time 376] Whatare observers

[snip]

> > >
> > > In TGD approach different sectors D_p of configuration space (p prime)
> > > correspond to quantum theories in different p-adic number fields and
> > > at first it seems that unitarity is broken down dramatically!
> >
> > Do you also think the universe evolves along a common time?
> >
> Depends on what one means with time. This will be a long list!
>
> a) Time development operator U_a is counterpart of
> exp(iHt) in QM and acts in the space of *'quantum histories'*:

I understand this as the totality of 'quantum histories' in the universe.

> a is lighcone proper time but U_a obviously does not have the
> ordinary interpretation (interaction on at a=0 and off at a--> infty).
> a is just a formal parameter of operator exponential.
> One could however say that entire universe=quantum history in a well
> defined sense evolves with respect to a and hence global time
> is in question. But this formal time is certainly not what we
> experience!
>
>
> c) Configuration space possess geometric time (coordinate a):
> 3-surfaces have cm time coordinate. This is certainly a global time.

Is "cm" the center of mass of the total universe?

>
> c) There is geometric time associated with spacetime surfaces
> and this is the Einsteinian time. Spacetime sheets (LS:s) have their
> own geometric times, which can be usually chosen to be Minkowski
> time in the rest system of spacetime sheet. Not a global time.

Spacetime sheet seems to correspond to the space-time of my notion of LS.

>
> d) Subjective time defined by sequence of quantum jumps. Ordered sequence
> of ordered 'ticks' with no 'metric'. Not a global time.

I am still unclear with your "quantum jumps." You seem to relate it with
consciousness. What makes quantum jumps happen?

>
>
> > > One can however define generalized S-matrix which obeys generalized
> > > unitarity. S-matrix for transitions leading
> > > from any D_p1 to D_p is C_p valued.
> > >
> > > The restriction of S-matrix to transitions D_p to D_p IS unitary!
> > > Despite the fact that S-matrix elements D_p to D_p1 , p_1 neq p can
> > > be nonvanishing!! Sounds highly paradoxical!
> > >
> > > The point is that total p-adic probability for transition D_p to D_p1,
p_1
> > > neq p can *vanish*! This is something genuinely p-adic and highly
> > > paradoxal and nonsensical from the real point of view.
> > > Therefore p-adic unitarity allows something which
> > > is not unitary in real context.
> >
> > I question what necessitates the unitarity. Unitarity is a notion which
is
> > introduced to assist the human reasoning in regards to the understanding
of
> > nature.
> >This is an idealistic notion, which gives us some balance sheets of
> > probabiltiy as the law of conservation of energy, etc. give. From the
> > viewpoint that the observer is fundamental that is contrast to your
view,
> > the observer has some implicit assumption about what he sees, without
which
> > he can not make any judgements/estimates about nature. As Einstein has
ever
> > said, we have an image of nature in mind already before we observe
nature.
> > What remains is how the image can be applicable and adjustable to
nature.
> >
> >
> Probability conservation is certainly something which one cannot
> give up (the nonconservation of probability is identity).

This is the expression of the observer's (your and our) desire. My sense in
the above statement is that when we organize any theory we have to assume
such kind of a priori assumptions.

>
> The requirement that *probability is conserved* for any
> state together with *linearity of time evolution operator* implies
> unitarity as one can easily find. <UPsi,UPsi>= <Psi,Psi> for any Psi
> inplies U^daggerU=1 and hence unitarity.

Here is your basic assumption. The requirement is your requirement and maybe
all of us. This is not required by nature. What makes it necessary is the
frame of our mind.

>
> When one gives up the idea of LINEAR GLOBAL evolution one
> gives also the unitarity. In case of LS:s the diffusion
> of particles to other LS:s would presumably require
> the use of nonunitary time evolution: OK?.

I might agree in the sense that the loss of information holds in
observation. But when viewing the universe as a whole as in the case a) and
the first c) in your statements above, maybe one wants to assume the
probabilty conserves?

[snip]

Best wishes,
Hitoshi



This archive was generated by hypermail 2.0b3 on Sat Oct 16 1999 - 00:36:05 JST