Re: Proof that macintosh is better than VMS

In article <4e7e482c-d37b-4084-8cec-1ce8dcc42976@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, AEF <spamsink2001@xxxxxxxxx> writes:
Hello,

Comments interspersed below. Sorry for the delay, but it took me a
long time to write this. I have tried to be as clear as possible while
still not spending too much time on it. The better thing to read is
Feynman's The Character of Physical Law and his Lectures on Physics
book.

Abstract: I'm showing how I'm basing my convictions on not just QM,
but on the wave-particle duality, the de Broglie relation, the results
of a vast array of experiments, one of which is described here in
detail. Nevertheless, QM is so amazingly successful for such a huge
range of phenomena, that there must be something very right about it.
All this leads me to conclude that Nature, at the level of atoms and
below, is intrinsically probabilistic, even if QM is eventually
superseded by a better theory.

It's a little long. Please be patient as it takes a little while to
explain it properly.

Enjoy.

AEF

On Mar 13, 11:01 am, davi...@xxxxxxxxxxxxxxxx wrote:
In article <42e3bcd3-a7d0-4fd6-badf-bc7623f68...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, AEF <spamsink2...@xxxxxxxxx> writes:

On Mar 12, 8:11 am, davi...@xxxxxxxxxxxxxxxx wrote:
In article <d605f298-85d8-491f-aeb7-3ba58aa7a...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, AEF <spamsink2...@xxxxxxxxx> writes:

On Mar 11, 1:19 pm, billg...@xxxxxxxxxxx (Bill Gunshannon) wrote:
In article <ueEuesurz...@xxxxxxxxxxxxxxxxxxxxxxxx>,
koeh...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (Bob Koehler) writes:

In article <960d254f-6ae7-4334-ab8e-e58e2b1ed...@xxxxxxxxxxxxxxxxxxxxxxxxxx>, Doug Phillips <dphil...@xxxxxxxxxxxx> writes:

You are confusing quantum mechanics math with reality. If you mean
that the mathematics of quantum mechanics is not concerned with
resolving apparent randomness, then you are correct. You might want to
look into the de Broglie-Bohm theory, more recently called Bohmian
Mechanics.

Quantum mechanics math vs. reality? You think reality differs?

I'll bet a lot of people do. When science requires faith than religion
in order to accept that which can neither be observed nor satisfactorily
proven I think more and more people will see the difference.

I assume you meant "When science requires *more* faith..."

Scientists have faith in the scientific method which requires
evidence. Religious people have what James Randi calls "blind
faith"[1]. That makes all the difference in the world.

[1] Seehttp://www.randi.org/jr/072503.html(Mostlya good article,
but I disagree with his opinion of the Wizard of Oz.)

As far as using local hidden variables to restore determinism that
only "appears" probabilistic, the experimental evidence ruling these
out is more compelling than ever. Many, many experiments have been
done and QM always, always wins.

This is a strawman since there are non-local hidden variable theories.

We're not talking about the
possibility of experimental error clouding the results. The skeptics
who complained that the early experiments could still allow local
hidden variables because of events missed by detectors because said
detectors were not 100% efficient. OK. But the efficiencies have been
greatly improved and the room for determinism has been all but wiped
out. Then there is the GHZ paradox which largely sidesteps the issue.
There is simply no way to explain the results of GHZ experiments using
local hidden variables.

These experiments rule out local realistic theories.
This just leaves two choices

1) non-locality

or

2) non-realism

But what about Feynman's argument?

All these things combined (which includes stuff I don't have time to
document here) leads me to believe that there is almost certainly no
way out.

To my mind the latter doesn't actually make much sense. If the wave function

What makes sense is not as important as experimental results. See, you
know the drill (Beginning of Chapter 6 and parts of Chapter 7).

doesn't actually have a physical existence and a particle doesn't have any
properties until you measure them then how are entangled particles actually
linked. (If the wave function does physically exist then it's collapse will be
a non-local effect so such versions of the Copenhagen interpretation are
non-local).

I think the realism quandary is a red herring. QM tells you what you
will observe and that is what you observe.

The problem I have is that such an interpretation is just

"thats the way it is"

which to me isn't a scientific statement. With non-local interpretations there
is at least some possibility that in the future it might be possible to explain
the non-locality. If you just take it thats "thats the way it is" then you are
in effect giving up on trying to find an explanation.

As to what's "scientific", please read Chapter 6 of The Character of
Physical Law and get back to me. (Parts of Chapters 1 and 7 are also
relevant.) You will find the answer to that in this book. Obviously
I'm not going to quote entire chapters of the book. But I'll say this
here: How does gravity work? Think about it. Any two masses, no matter
how far apart, attract each other. Isn't that kind of amazing? You say
there is a field that permeates all of space. Just what is this field
made of and how is it generated by mass? How can it be like that? But
we grow up with gravity from day 1 and it becomes so familiar we think
of it as being totally normal. So what mechanism could be behind this?
At the classical level, physics has indeed given up.

I wasn't going to respond to this but felt I had to respond to the above.

If by the classical level you mean excluding relativity then you are correct in
the sense that noone is looking for a mechanism - but that is because Newtonian
theory has been superseded.

If however by classical level you just mean excluding QM then that is rubbish.
The mechanism for Gravity is well understood - the curvature of space-time.
How mass/energy causes space-time to curve is well described by GR.
Why mass/energy has that effect on space-time isn't explained but undoubtedly
requires a better understanding of the structure of space-time.


In QM, it is
thought that it is the exchange of virtual gravitons that causes the
attraction, just like it is the exchange of virtual photons that
carries the electromagnetic force.

Quantum Gravity theorems are still extremely speculative eg Loop quantum
gravity, String theory. The existence/non-existence of the graviton and
it's properties would help either support these speculations or refute them.

The graviton does not fit into the QM standard model.


But these virtual photons -- or
gravitons -- materialize out of nowhere, travel between particles to
carry the force, and then disappear (thanks to a variation of the
uncertainty principle, a violation of conservation of energy is
allowed if it occurs over a short enough interval of time, and this
allows virtual particles to have their fleeting existences). And
you're still stuck with trying to find a mechanism for the virtual
particles. Good luck. We don't grow up experiencing QM at all, so it
seems really strange. But we are not to tell Nature how She's got to
be. [Until we detect actual gravitons, the existence of virtual
gravitons remains speculation. However, most physicists, AFAIK,
believe they must exist.]

So you're always going to reach a point at which you say, "But what is
that? What is the mechanism behind that?" I think with QM we've hit
rock bottom.

Here we disagree. Since QM is undoubtedly incomplete it is much much too early
to say we have reached rock-bottom. If you give up looking for mechanisms and
just accept that "that is the way it is" then you might as well join Boob and
put it all down to God's mysterious actions.



Note. All the interpretations agree on what you will observe so in that sense
it doesn't matter. However interpretations can give insight into how to produce
a more complete theory and as I have pointed out QM is not the final theory of
everything.

[I'm not basing my claims solely on QM. I still think a more accurate
theory will still not be able to get rid of the intrinsic
probabilistic nature of things. See below.]

And how will you test it? As for QM being "final", I think certain
aspects will survive. Note that Ehrenfest's theorem shows how quantum
mechanics goes over into classical mechanics at the macroscopic level.

Any future theory of everything will have to incorporate all the results of
QM experiments at least as approximate results just as GR incorporates
Newtonian theory.
That doesn't mean that the mechanisms of the theory will necessarily be
identical. We can see this by looking at the case of Gravity.
In Newtonian theory gravity is a mysterious force acting at a distance.
In GR it is the result of matter/energy curving spacetime.



Respond to this if you want but I won't be responding any further.




David Webb
Security team leader
CCSS
Middlesex University





This theorem gives an equation (derived from the QM equations) that
looks strikingly like F=ma. When the uncertainty in x is small, you
basically recover F=ma. In fact, this is related to "the
correspondence principle which in essence states that classical
physics results should be contained as limiting cases of quantum
mechanical results"[1] (e.g., when quantum numbers are large). In
fact, the correspondence principle was used in the early days of QM
development as a guide to guess the correct QM equations. So classical
mechanics not only survives, it is an essential part of QM in this
respect. Similarly, I believe the probabilities and the particle-wave
duality of nature will survive any future, better theory, as will the
reality of atoms.

Furthermore, many facets of classical mechanics still hold in QM --
conservation of momentum, conservation of angular momentum, and
conservation of energy, e.g. And this is not an approximation: these
quantities are conserved in QM just as they are in CM (well, aside
from temporary violations as in the creation and destruction of
virtual particles -- and you cannot directly observe these violations,
which is why the virtual particles are...well...virtual).

[1] Quantum Physics by Gasiorowitz

And I'm not basing my claims strictly on QM; I'm also basing them on
all the wild and wacky experiments, all of which show that particles
exhibit wave-like behavior and waves exhibit particle-like behavior.
That's very unlikely to change even if QM is superseded by a better
theory. (The fact that ordinary matter is made of atoms isn't likely
to change either!) Note that you can have one particle at a time go
through your apparatus and when you wait for enough statistics to
accumulate you still get an interference pattern, a sure sign of
waves, and strong evidence in favor of there being intrinsic
probability in nature. As Merzbacher says, "The conclusion is almost
inevitable that psi [the wave function] describes the behavior of
single particles, but that it has an intrinsic _probabilistic_
meaning." [His emphasis.]

Also, I've been there, done that. I wrestled with this problem myself
on and off over many years. I used to think it can't be "random" or
probabilistic. I even tried to come up with a hidden variables theory
to explain the spooky correlations seen in polarization experiments!
(I failed, of course.) And I have come to the conclusion that the
randomness (or as I prefer to put it, the probability) is almost
certainly an intrinsic apsect of nature. I know you're saying, "But
how can it be like that?" But as Feynman says, "No one knows how it
can be like that". (Not only is Feynman a great teacher, he is
strikingly honest, even about the shortcomings of physics.) I really
can't imagine that anyone will ever find a way out.

Look at the situation. You have wave phenomena such as interference
and diffraction of light. These things are strictly wave phenomena.
Then you find that these light waves are actually "quantized" into
little bundles of energy called photons. And the energy in each photon
follows a very simple relation: E = h*f where h is Planck's constant
and f is the frequency of the light (which is how many crests (or
wavelengths) pass you per second). So if you have monochromatic light,
all the photons have the same energy. There are no half-photons. They
come in fixed-size "lumps". Experiment has shown over and over again
that even when you reduce the intensity of the light so that only one
photon is traversing the apparatus at any given time, you STILL get
interference patterns. Consider reflection. Approx. 4% of the light is
reflected from clear glass. So if you have 100 photons striking the
glass, you know that on average 4 photons will be reflected. But which
photons? The same applies in the case of polarized light traveling
through a polarizer oriented so that only some of the light gets
through. A photon can either be absorbed or pass through. But which
particular photons will get through? There is no way to tell. What any
individual photon does in such situations (and more generally, what
any individual particle of any kind does) is unpredictable, but the
probabilities of the various possible outcomes are calculable via QM.
I don't see any way out of this other than intrinsic probability.

(See part 1 of the Feynman video at www.feynman.com (it's free!) for
an excellent explanation of this in more detail. I'm just more or less
summarizing here.)

Here's an excellent example to drive the point home. I saw a talk
about this in graduate school in the late 1980's. Consider the
following experimental set up:

F A B

[-LASER-]-----|-------\-----------------\
| |
| |
| - LCD
| |
| |
\-----------------\

C D

The laser beam is split by beam splitter A. It is reflected towards D
by mirrors B and C. The beams are combined by the re-combiner D. When
you put detectors around D you find that interference patterns are
produced.

Next, put an LCD "switch" in the BD segment. If it is ON (opaque) you
get some of the beam striking the LCD and the rest traversing ACD and
giving no interference patterns. If it is OFF (transparent), you
recover the interference because then the light then traverses two
different paths and exhibits interference when the two beams recombine
at D. OK. Everything seems okay so far. (Remember that interference
results from two light beams overlapping.)

Now, the laser beam intensity can be reduced by filter F so low that
only one photon traverses the apparatus at a time. If the LCD is ON,
then the photon either travels along ACD and is detected at D or it
strikes the LCD and is absorbed or reflected. The LCD then serves as a
detector that tells us which way the photon went after it goes through
A. If the LCD is OFF (transparent) you *still* get an interference
pattern after allowing many photons to individually traverse the
apparatus. So it looks like each photon travels over both paths. How
else can you get interference? But with the LCD on it travels only
over one path or the other. How are you going to explain this without
probability and the wave function of the photon being in a
superposition of it traveling in one path with it traveling in the
other? You cannot get interference without having two things
"interfere", yet you never see a single photon in both paths. With the
LCD on you always see it in one or the other, never both.

It gets better. The LCD can be switched ON or OFF rapidly enough so
that it can be switched AFTER the photon passes through A but BEFORE
the photon (if it's in the ABD path) reaches it (the LCD). You can
guess what happens. If you switch the LCD from OFF to ON while the
photon is in mid-flight, you lose the interference pattern. Some of
the photons traverse path ACD, thereby striking the LCD, and some
traverse the path ACD. No interference is observed. If you switch it
from ON to OFF with the photon in mid-flight, you regain the
interference patterns at D. So tell me how the photon, after being
"split" by beam splitter A and is therefore "committed" to one path or
the other or both, knows whether the experimenter is going to have the
LCD ON or OFF by the time it reaches it? How does the photon when it
is at A "know" whether it should randomly choose one path or the other
vs. "splitting up" (which we know photons never do!) so it can produce
the interference pattern? (Keen readers will notice that this is very
similar to the two-slit experiment, except that here it is made
painfully obvious that slit-1 photons and slit-2 photons are really in
totally different paths because here the distance between them is so
much greater, and we get the extra fun of the rapidly switching LCD
detector which makes it clear that when you detect the photon in the
two-slit experiment, you are doing so AFTER it has already gone
through the beam splitter, or the two slits, and is therefore
"committed" yet can't know in advance whether it will be detected
before it hits the screen or not. Also, there is no significant
overlap of the wave function between the two paths, unlike the two-
slit experiment.)

The bottom line in all interference experiments is this: If it is
possible, even in principle, to somehow determine which of the two
interfering paths the photon takes, you lose the interference. If you
see the interference, you cannot even in principle determine which
path the photon took. And you can delay your observation until after
the photon passes through the beam splitter A and therefore has to be
"committed" to one path or the other or both, and somehow the result
is the same. (How else could things be self-consistent?) It's still
"spooky".

Now the question becomes: can you predict which path the photon will
take after passing through the beam splitter A with the LCD ON? Hidden
variable theory says you could do this by observing something at or
upstream of A. But if you could do that, then it makes no difference
whether the LCD is ON or OFF. Anything you observe with the LCD ON you
can observe with it OFF, and at the time of this observation, the
state of the LCD when the photon gets to it is still unknown. And if
you can successfully predict which path the photon will take, you
can't ever get the interference pattern with the LCD OFF, because an
interference pattern cannot be produced by photons traveling along a
single path, and an interference pattern is completely different from
what you would see if photons only traversed one path or the other.
And there can't be any "secret communication" between the LCD and the
source or beam splitter at A because you can change the state of the
LCD AFTER the photon has passed through beam splitter A. Therefore,
even with the LCD ON, there is no way to predict ahead of time which
path the photon will take if the apparatus is set up in such a way
that it can produce interference patterns with the LCD off. Please see
Feynman's Chapter 6 of The Character of Physical Law (from which this
explanation is borrowed) for the full story (well it's the full story
at the layman's level -- if you know about how the wavelength of light
affects resolution, and are comfortable with the de Broglie relation,
you can go a little deeper, but the essential points are covered by
the layman's version -- for the deeper version, see Feynman's Lectures
on Physics. Also, Feynman's explanation is most likely clearer than
mine!).

[Some progress has been made: It used to be thought that this comes
about because any detector gives an unavoidably large enough impulse
to the particle due to the uncertainty principle [for an explanation
of this, see, e.g., Feynman's Lectures on Physics], but it has since
be found that this is not always the case. Still, you cannot follow
the path of a particle that has contributed to an interference
pattern, and still, what any individual particle does is still
unpredictable.]

Add to all this other "delayed-choice" experiments, variations of the
Aspect experiment, the GHZ experiment, the recent results with quantum
erasers, all of which always give the same results I have just
described. So you end up banging your head against the wall until you
start hemorraging. At that point, you might say to yourself that maybe
nature really is intrinsically probabilistic and can then begin the
healing process. But keep in mind that the probabilities have well-
determined values that can be calculated using the formalism of QM.

It seems to me that this is the inevitable consequence of particles
that come in fixed energies for any given wavelength (or frequency)
acting statistically as waves do. It is that, and experiments like the
ones I have described, more than QM itself, that leads me to my
convictions. IOW, even if QM isn't "exactly right", you will still
have everything being particles and waves with the energy given by E =
h*f for light and the very similar de Broglie relation for the
momentum of a particle of matter (which actually yields E = h*f for
light) because this has been established by experiment aside from QM.
Even so, QM has been so spectacularly successful in describing such a
humongous range of phenomena that there must be something very right
about it.

What you have here, if you wish to keep with "realism", is that the
photon splits up into two parts at A (even though you will never
directly detect the photon in both paths: any attempt to do so will
find it in either one path or the other) and interferes with itself at
D if the LCD is OFF at the time the photon reaches it; or, if the LCD
is ON when the photon reaches it, one "photon-half" somehow jumps
across space to join its other half. I don't see how your going save
the day with "realism", or save "realism" itself, in light of this.

There are many other experiments like this. There are the quantum
eraser experiments, the GHZ experiments, and so on. They all produce
the same results as I have already described.

And you're going to explain this with "realism"? Good luck.

I suppose with the Bohmian theory you can have the particle in one
path with the "pilot wave" in both, but when the pilot wave strikes
the LCD you have the pilot wave itself "collapsing", so what is
gained? Nothing as I see it. And how is the pilot wave going to work
when split up into two spatially distinct parts, only one of which has
the photon? And how will it work at the re-combiner? It doesn't seem
reasonable to me, though I can't explain why here. And what about the
Aharonov-Bohm effect in which the interference patterns of electrons
traveling around a fully contained magnetic field are shifted by
varying the strength of the magnetic field, even though the electrons
never travel THROUGH the field! How does Bohm's theory work with that?
(Maybe it does, I just don't have the time to keep going, and this
post is already long enough, no?!)

The Bohm theory seems (to me) to say that the particle is where it
would be if you could observe it without disturbing it in any way,
which to me doesn't say much. But I think it also gets into trouble
with the GHZ experiment. You still must have collapse of the wave
function, or, as Merzbacher puts it in his "Quantum Mechanics"
textbook: "reduction of the state (or wave packet)".


As for the "collapse of the wave function" I think of it more as
"altered". The experimenter becomes part of the system.

But where is the boundary. If the experimenter becomes part of the system
without the wave function collapsing then why not the whole Universe.
I think you've just moved from the Copenhagen interpretation to the Many
Worlds interpretation.

The wave function still collapses. You're talking about the wave
function that includes both the system and the experimenter? I'm not
prepared to comment on that at this time. I've already spent a lot of
time on this post and I must stop and post it already.

I am NOT an adherent of the many-worlds interpretation. It seems to me
that having entire universes created for every "collapse of a wave
function" is vastly more unreasonable than Copenhagen. I like the
phrase "shut up and calculate", but that's a bit overkill. Work is
still being done on this question. Then there is the issue of locality
and seperability for which there is landmark paper. But I'll save that
for another post if needed.

Anyway we have discussed this in the past ad-nauseum and as Doug Phillips
said this is off topic for comp.os.vms.

But you posted again, so I responded. I mean really -- you're saying
that you can have the last word because it's off-topic anyway. Sorry.
And I did add some new stuff.

AEF


David Webb
Security team leader
CCSS
Middlesex University

[...]
.

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