Günther Greindl wrote:
> Hello Brent,
>
>
>> That was my point. The SWE indicates that every microscopic event that
>> happens or doesn't happen stochastically splits the wave function. But
>> these events don't generally cause a split of Kory or other classical
>> objects. Those "objects" are not in some pure state anyway. They are
>> already "fuzzy" and their interaction with the environment keeps the
>> fuzzy bundle along the classical path. There are microscopic splittings
>>
>
> good that you address this topic, I have also wondered a lot about how
> superposition/MWI/decoherence transfer to the macroscopic arena.
> Although I am not so quick to discard "splitting" of macroscopic objects.
>
> For instance, you don't have to perform a QM-experiment with explicit
> setup, looking around is enough - photons hit your eyes with different
> polarizations; why should no splitting occur here?
>
It does in mathematical formalism. But the different splits are still
very close together and so classically they don't make any observable
difference - since "you" aren't a pure state in QM the mixture is still
"you".
> Why only in the case where you perform an up/down-amplification experiment?
>
Because in that case the split gets amplified enough to make a
noticeable difference in "you" (and other large macroscopic things like
instruments).
> And the experiments of Zeilinger Et al (Superposition of Fullerenes) do
> suggest that there is no scale at which superpositions stop.
You mean this paper:
http://arxiv.org/abs/quant-ph/0402146 ? I thought
it showed that any large warm body, even one as small as C70 would
exhibit decoherence just from it's own interchange of IR photons.
> We are only
> not aware of the other persons/objects due to decoherence.
>
Right. Decoherence makes superpositions inaccessible. But my point
was that you, as a large classical object, are continually being
entangled with your environment by interactions via photons, etc. This
makes it impossible to separate out the strands of your superpositions,
but in most cases it also ensures that the strands stay close together
along the classical path and so the whole bundle can be regarded as a
single classical object, "you". Only when micrscopic QM events get
amplified to create a classical difference will there be an observable
split of "you", e.g. into the you who saw "up" and the you who saw "down".
> Can you recommend a paper which addresses this question (of macroscopic
> object splitting)?
>
There's a very good review article by Schlosshauer:
http://arxiv.org/abs/quant-ph/0312059
I should qualify all the above by saying that it's how most physicist
think things will work out - but they haven't really been worked on
yet. It isn't exactly clear how the classical arises from the quantum -
it has it's own "white rabbit problem
http://arxiv.org/abs/0807.3376
http://arxiv.org/abs/gr-qc/9412067
Brent
> Cheers,
> Günther
>
> >
>
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Everything List" group.
To post to this group, send email to everything-list.domain.name.hidden
To unsubscribe from this group, send email to everything-list+unsubscribe.domain.name.hidden
For more options, visit this group at
http://groups.google.com/group/everything-list?hl=en
-~----------~----~----~----~------~----~------~--~---
Received on Mon Nov 17 2008 - 20:22:23 PST