From: Eugen Leitl (eugen@leitl.org)
Date: Fri Oct 25 2002 - 11:19:56 MDT
On Fri, 25 Oct 2002, gts wrote:
> This interesting little gem from scerir seems to have passed by almost
> unnoticed in yesterday's flurry of messages to this thread. I am
> reposting scerir's words without comment:
It is of course completely impossible to imagine quantum systems in the
same state which have not been cloned, yet are in the same state, eh. And
yet are indistinguishable (I repeat my usual recommendation to reread the
appendices for "The Physics of Immortality" for a sketch of a proof why
you would die instantly if this was not the case). I wonder why I keep
writing this, as no one seems to read my posts anyway.
As usually, physics (which I claim no specific understanding in, despite
having survived PCIII) is either being played fast and loose with, or sees
a highly selective interpretation. If you iterate this, you'll a mechanism
by which people with a clue are being silenced, or driven off the list.
Nevermind the fact that systems in the same quantum state are a gedanken
to illustrate a concept, while synchronizing large scale evolution of
deterministic systems is practically possible, and in fact trivial, albeit
done rarely as there is not much need for it in practice.
What I would really welcome to hear is a succinct explanation of evolution
of (macroscopic or nanoscopic) deterministic discrete systems given in
terms of quantum energy levels (rather, groups thereof) and transitions. I
have some very faint idea which I would like to put some meat on.
> > In QM no information can be cloned (xoxed)if
> > the number of states is equal or greater than 3
> > [Wootters, Zurek, 1982].
> >
> > Or, in other terms, a cloning (xoxing) of 2 non
> > orthogonal states violates the unitarity of evolution
> > [D'Ariano, Yuen, 1996].
> >
> > Or, in other terms, the linearity in QM (linear
> > superposition of quantum states) forbids the
> > perfect xoxing. Fortunately! Leibniz principle!
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