sci.physics.research

In article 6aa060aa578e@>, dougsweetser@
says...
> Hello Gerry:
>
> I found your "Simplified Schrodinger's Cat Experiment" amusing to
> think about :-) It opened up a question: why is the system not
> really like quantum mechanics? My reply is that cats have all kinds
> of unique identifiable parts. With a group of electrons or a vast
> pool of photons, one cannot pick out one in particular, and say, the
> electron left of Ginger is Gilligan. No amount of money can label two
> electrons. We can tell if they happen to be in different states, but
> the electrons could swap positions while we were not looking, and we
> would not be able to tell.

Well - even leaving the Pauli Exclusion Principle out of it - that's not
really the difference. You could say the same of atoms. Yet a solid
structure built out of identical atoms behaves classically, and even
individual atoms in such a structure can behave in some ways
classically. Suppose you took a flat facet of an iron crystal and used
a scanning tuneling microscope to place iron atoms on it so they spelt
your name. Those iron atoms will be persistent; they can be imaged
repeatedly; they don't do anything crazy at all. They behave
classically, at least insofar as their position is concerned.

The difference, of course, is that the atoms aren't in a 'cloud'; they
are in a solid, and their interaction with their environment is such as
to lead to rapid decoherence. They are entangled with each other in
such a fashion that the probability of observing a superposition state
is infinitesimal.

This also, obviously, applies to a cat. And cats also generate entropy,
which can be considered a measure of the number of measurements carried
out and recorded by the system. So while you might, if you handled the
system very carefully, be able to observe some quantum superposition
properties of the iron atoms, you have no chance with the cat.

> In my SSCE, there would be 1000 boxes, each with 1000 Siamese cat
> clones. In about 500 boxes, the cat has died, in the other 500, the
> cat clone is alive. Take a picture of all cats in all boxes with your
> mega pixel Nikon D300, import into the Gimp, overlay all the
> images and average. One thing you notice immediately: the cat looks
> like a gas! Superimposing this many images makes what was once so
> solid look very flimsy indeed. I did this for animations of a simple
> harmonic oscillator which was quite cool (URL at end). You could tell
> from the ghostly image that many of the states of the cloned cat in a
> box have a dead cat in it.

I assume you are not actually taking a picture of each cat, which would
correspond to an observation, negating the point of the experiment. So
your picture corresponds to an ensemble of expected classical results.
I don't see where quantum statistics come into it.

> Now you do the experiment of picking one of these 1000 boxes, which is
> an act of observation, not of action. You open a box - you cannot
> number it and say it is box 27 because the boxes are all
> indistinguishable - and see a dead cat. Repeat 50 times, and about
> half the time the cat is dead, half the time alive. The observation
> is NOT killing the cat. The superpositon does look half alive/half
> dead because that is exactly what goes into the Gimp from the D300.

I feel you are missing the point here. Your combined image isn't a
picture of a quantum superposition state; it is a picture of 1000
classical states, classically superimposed on each other (with additive
probability).

(And you also can't make the boxes indistinguishable, for reasons
similar to those already discussed.)

- Gerry Quinn