🚀 go-pugleaf

Hi folks,

In article <1992Sep30.191811.19619@lmpsbbs.comm.mot.com>
bhv@areaplg2.corp.mot.com (Bronis Vidugiris) writes:

> In article <1992Sep29.062215.18619@asl.dl.nec.com>
> terry@aslws01.asl.dl.nec.com (Terry Bollinger) writes:
>
> | How about the non-trivial issue in my same email -- that is, whether
> | my quantum/non-quantum bullet analysis is correct or not?  Anyone?
>
> I thought that was a pretty thought-provoking piece...

Hey, thanks!  The feedback is much appreciated.

> A couple of thoughts:
>
> 1) I think you were right on about the usefulness of talking about actual
>    experiments.  I was surprised at the amount philosophical differences
>    hindered the previous attempts at discussing QM on the net here.
>
> 2) Rather than looking at information 'left behind' might it not be
>    just as good to look at disturbance of the bullet?  So rather than
>    to regard the culprit behind not being able to measure the wave
>    function of a bullet when light was hitting it as an 'information'
>    problem, one could say that it was the disturbance of the photons
>    that made the difference...

Hmm.  Actually, it probably wouldn't be all that difficult to quantify
some of the issues, and possibly interesting to do.  Even though I'm in
the information trade, I'm certainly not adamant about the need to phrase
such a problem that way.

On the other hand, think of this:  When we speak of energy, there is an
assumption of proportionality for most reactions.  To excite one atom
to a higher state requires x units of energy, and (not too surprisingly)
to excite 100 atoms requires 100 x units.  No big deal.

INFORMATION AND DISPROPORTIONATE REDUCTIONS OF QM INTERFERENCE

But look what happens in thought problems where you are trying to decide
what the mix of classical and quantum statistics will be.  The effect of
a given unit of energy -- say a photon -- can no longer be modeled as
proportional.  One photon can do a lot of damage to the superposition of
states (wavelike behavior) of EITHER a single electron OR a single bullet.
Very curious, that, since the electron is an object on the same scale as
a photon, while the bullet is many, many orders of magnitude more massive.
The sense of proportionality is quite lost.

Think about it.  One photon can keep a real, physically definable event
(say the formation of interference patterns in a two-slit experiment)
from happening for a single electron.  Strange, of course, but no big
deal -- it's a classic in QM.

But if you accept the general description of the bullet QM problem that
I described, you can very probably arrange it so that that single photon
can also prevent a real, physically defineable (if very difficult!) two-
slit interference event from occurring to the QM bullet as well.  If you
stop and think about it, that's quite astonishing.  How can such a very
tiny unit of energy destroy the detectable interference effect of a huge
bullet?

For that reason I emphasis the concept "information," primarily for lack
of a better term to describe this bizarre aspect of how a single photon
can have such disproportionate physical effects.  Once a photon "extracts"
location information from either an electron or a bullet, the interference
effect (superposition of states) is largely or entirely lost.

We usually think of information as a rather nebulous little beast, even
though it is well known that it is subject to some well-known physical
constants.  E.g., information cannot travel faster than light by any
known mechanism (the FTL thread notwithstanding).

However, when you start talking about information *vacuums* -- that is,
experiments in which the ability to extract information about some set
of ongoing events has been eliminated or at least severely curtailed,
the idea "information" appears to take on a more precise meaning.  A
unit of information is somehow related (probably by a fairly simple
equation) to a level of reduction in QM interference effects exhibited
by various type and sizes of objects.  The more information is extracted
from the component within the information vacuum, the more that object
will behave in a classical fashion.

It also makes it a lot easier to explain why large objects don't behave
much like quantum objects.  The disproportionate impact of even a single
photon on objects of largish size makes in nigh on to impossible to
create an information vacuum that is sufficient to permit identifiable
quantum behavior in such objects.

Incidentally, once you start down this line of reasoning there is an
unavoidable consequence: it de-mystifies Schroedinger's Cat, at least
in a hand-wavy, ignore-the-operators sense.  Because the cat is not in
an information vacuum, no significant superposition of states CAN
occur -- the cat either lives or dies, PERIOD.  His life or death is
recorded not in the mind of some observer, but in the enormous number
of trace-leaving disturbances he makes to the box, air, and light all
around him.  The fact that such traces would for the most part be very
difficult to interpret in terms of life or death of the cat is not the
issue -- the *potential* to recover information is all that is needed.

In such a perspective the apparent continued existence of the cat in a
superimposed state would become more an artifact of the way the problem
was analyzed than an expression of what actually happened.  The constant
banging of the cat into the photons and atoms all around it would alter
and deposit changes (information) in such a fashion that *each* such
event would need to be considered an "observation" that closes down some
component of the wavefunction.  The cat simply never has an opportunity
to become quantum, because it is too huge to escape this kind of subtle,
non-human "observation."

COULD THE QM KITTY EVER EXIST?

Could you recreate Schroedinger's scenario in the same way as the bullet,
by placing him in an information vacuum (vs. the usual extremely leaky
box)?  I doubt it.  In the QM bullet the superposition was in terms of
the relation of the bullet to the universe from which it was isolated.
In the case of the kitty the issue of life or death is internal to the
cat, where no such information vacuum exists.  All you would gain by
placing the poor critter in an information vacuum is the possibility of
some QM interference with regards to where he lands -- not whether he's
dead or alive when he gets there.

By such a definition *no* living system could ever enter into any really
significant superimposed state, because a living system simply does not
provide any real potential for the development of information barriers.
Everything is a bit too touchy-feely from cell to cell to let things
drift very far into significant quantum uncertainty.

(No, I didn't plan to "solve" Schroedinger's Kitty when I started this
email.  Sigh.  Flames welcome, but if my bullet analysis is right, then
it becomes very hard not to notice its implications for the surly old
Cat of Many States.  Operator math still holds, you just have to remember
to look for all those zillions of little eyeballs in the very dust of the
air.  Interesting... Bell speaks of the "intuition" of setting up a QM
problem so that it works right, even in the absence of clear criteria
for where QM stops and classical begins.  A good physicist would in fact
almost unconsciously look out for "eyeballs" in a QM analysis by simply
trying to include all of the relevant interactions.)


A CHALLENGE: CAN REDUCTION OF SUPERIMPOSED STATES
BE USED TO ASSIGN PHYSICAL UNITS TO "INFORMATION?"

Some folks have griped in this group about information types trying to
redefine physics in terms of information.  To which I would like to
suggest:  Why don't you physicists do vice-versa?

What we really need is for someone to quantify issues such as the ones
I've just described and create a PHYSICS based definition of information,
one that directly relates the concept of information to the physically
defineable event of reduction of QM interference effects in objects of
various sizes.  I doubt that it would even be all that difficult to do,
and in fact I was planning to write a serious paper on this idea somewhere
down the road.  But I'm passing it out freely in hopes that someone with
a good eye for such things might be able to come up with a way to link
the currently abstract concept of information into specific mathematical
relationships to reduction of the superposition of states, as measured
by the presence of QM interference effects.  All I ask is that anyone who
is interested in the possibility please post it back to this group first,
since I think folks would be more than happy to take a whack or two at it.

Such a definition would probably also make it possible to formalize
the hand-wavy aspects of the bullet and QM kitty analyses.  I truly hate
using terms like "information vacuum," but in the absence of some units
for information that relate it to observable phenomena and standard
physical units, it's hard not to fall back on such relatively vague terms.

.....

> 4) Has anyone done interference effects with molecules?...

I believe it's been shown with whole atoms.  Dunno about molecules.

To me what would be truly intriguing would be to show interference with
a set of atoms large enough that they would have their own internal
"randomness" of, say, thermal vibrations.  That's about as near as you
could probably come in a real experiment to the idea of Smarty E. Coli
-- that is, to the idea that history can go on *within* a quantum
isolated system as well as in the universe that is *external* to it.
Experimental proof of such "isolated histories" with QM interference
still intact would be a bit mind boggling, at least to me.

.....

Gettin' late.  Later gators.  Look for a truly bizarre (but operationally
equivalent!) interpretation of spin correlations from me in a few days.
It's in the category of a cure that's worse than the cold.

				Cheers,
				Terry