Re: Is a fact something that has been proven?

ave1 wrote:
David Ewan Kahana wrote:
ave1 wrote:
David Ewan Kahana wrote:
ave1 wrote:
Steven J. wrote:
ave1 wrote:
Oxidized wrote:
ave1 wrote:
Oxidized wrote:

ave1 wrote:
So it's your contention that the electrons go through the slits as
particles instead of a wave because an observer saps energy from the
electrons? How does observing sap energy?

Here's an easy example. A solar observatory captures light from
the sun. The shadow of the observatory saps energy which would
otherwise heat the ground "behind" the observatory, now in shadow.


So exactly what does this have to do with someone knowing something
about the path the electrons are taking?

You don't know about the path of the electron until you sap
some energy from it.

Why is it that energy *doesn't* get sapped when the person who would
otherwise gain the knowledge is purposely prevented from gaining it,
but the detectors are still "on"?

What is it about these photons or waves of light that can distinguish
whether or not a nearby person's thought is/willbe of the electron
pathway or something other than that (maybe last night's dinner)?

Unless you have a cite from the _Journal of Clairvoyance in Applied
Particle Physics_ to prove me wrong, I'm going to maintain that you
can't determine anything about the path of an electron merely by
thinking about it.

Well, then you are denying the facts revealed about quantum theory via
experimentation over the past 70 years.


No, he's got the facts exactly right.

It's in the knowing that the light's form is determined. He's denying
that, so he's wrong.


Citation, please, directing me to an actual experiment in the peer reviewed literature
demonstrating that `it's in knowing that the light's form is determined,' whatever the hell
that is supposed to mean.

http://xxx.lanl.gov/pdf/quant-ph/9903047 --> "A Delayed Choice Quantum
Eraser", by Yoon-Ho Kim, R. Yu, S.P. Kulik, Y.H. Shih, and Marlon O.
Scully


This paper describes an experiment carried out using a pair
of quantum entangled photons: not an experiment on
determining the path of a single electron in a double slit
experiment, and not about their ability to `distinguish
whether or not a nearby person's thought is/willbe of the
electrons pathway.'

Your discussion above with Steven J. in the first place is
about electrons, not about quantum entangled photon
pairs. Indeed, you state:

Why is it that energy *doesn't* get sapped when the person who would
otherwise gain the knowledge is purposely prevented from gaining it,
but the detectors are still "on"?

What is it about these photons or waves of light that can
distinguish whether or not a nearby person's thought is/willbe
of the electron's pathway or something other than that (maybe
last night's dinner)

The answer is, there is nothing about either photons or
electrons that can distinguish `what a nearby person's
thought is/willbe.'

The plain fact is that there is nothing in the experiment or
the paper by Kim, et al. to support your position.

Furthermore in a double slit experiment with single
electrons there is no quantum entanglement, since
only one, not two electrons are involved.

So I'll repeat it: the Kim et al. experiment is not
comparable to a double slit experiment with incoherent
single electrons.

Further: there is NO claim whatsoever made in Kim et al.
that the thoughts of the experimenters influence
the behaviour of the initially undetected photon in the
quantum entangled pair in any way.

In their conclusions Kim et al. specifically state
the following:

`In conclusion, we have realized a quantum eraser
experiment of the type proposed in ref. [3]. The
experimental results demonstrate the possibility
of observing both particle-like and wave-like
behaviour of a light quantum via quantum mechanical
entanglement. The which path or both path information
of a quantum can be erased or marked by its
entangled twin even after the registration of
the quantum.'

Note that their conclusion is NOT what Ross Rhodes directly
states about double slit experiments with incoherent
electron singles:

So it seems that an arbitrary choice (represented by the
politician who has no personal interest in the experiment)
made hours, days, months, or even years after the
experiment is "complete," will change the result of that
completed experiment. And, by changing the result, we mean
that this arbitrary, delayed choice will affect the actual
location of the electron hits as recorded by the electron
detector at the back wall, representing an event that was
supposed to have happened days, months, or even years in
the past. An event that we suppose has taken place in the
past (impingement of the electron on the detector) will
turn out to be correlated to a choice that we make in the
present. Imagine that.

This would imply that quantum mechanics is acausal.

This statement that Rhodes makes about single electron
double slit experiments is not supported by the results of
Kim et al. on quantum erasers.

The following web page deals with the experiment
on quantum entangled photon pairs.

Did you read this bit?

[S]pontaneous parametric down conversion (SPDC) is used to
prepare the entangled two-photon state. SPDC is a
spontaneous nonlinear optical process from which a pair of
signal-idler photons is generated when a pump laser beam is
incident onto a nonlinear optical crystal.

This is explained in-depth at:
http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm

Ross Rhodes's description was provided to Yoon-Ho Kim before it was
posted, and he approved of the correlations made between this
experiment and the double slit experiment.


Where is the evidence for this claim of yours that Kim
approves of any `correlations' that Rhodes makes between his
experiment on quantum entangled photon pairs and the double
slit experiment on single electrons?

I see that Rhodes quotes one line that he says came from
Kim:

"I do not think that there is anything wrong with your
explanation." - Yoon-Ho Kim

Even if Kim did say this, it is obviously a statement made
in reference to Rhodes description given at the page above
of Kim's experiment.

It is not a statement in reference to Rhodes description of
the single electron double slit experiment, which is what
I was discussing and which is given on this page:

http://www.bottomlayer.com/bottom/reality/RealityFrame1.html

I see that Rhodes has provided another useful endnote
on this page:

Endnotes

1. Your commentator wishes to thank Dr. Kim for reviewing
this commentary before posting.

I should like to see the rest of Dr. Kim's `review,' if it
existed.



In fact, in the source
material at http://xxx.lanl.gov/pdf/quant-ph/9903047 we read, "Fig. 3,
4, and 5 report the experimental results, which are all consistent with
prediction. Figs. 3 and 4 show the "joint detection" rates R01 and R02
against the x coordinates of detector D0. It is clear we have detected
the standard Young's double-slit interference pattern." Right after
that is a description of an experimental pathway which actually
provides "which-path" information. At that point in the experiment
there is a clumping pattern of photons (a "non-interference pattern")--
which, again, are all consistent with the prediction that we'd expect
from quantum theory.


So what?

This is neither here nor there. It has nothing at all to do
with experiments on single electrons.


As I stated before, it's in the knowing that the light form is
determined (independent of the detector equipment's being "on" or
"off").

This is irrelevant to double slit experiments on single
electrons.


This is also confirmed by talk.origins regular r. norman here:
http://groups.google.com/group/talk.origins/msg/12854952faa2249b?hl=en&;

So according to you, r. norman is the ultimate authority?

Come off of it. R. Norman states specifically:

`No, that is not the proper way of explaining things,
but it will do."

Norman is right: using the words `the light knew' is not the
proper way of explaining things. It will do fine in an
answer to a naive question about interference effects.

He's not referring to Kim et al. here, in any case, and what
he wrote in his post doesn't support your position.


"Light (photons? waves?) ALWAYS shows interference as long we have some
means of detecting what happens. If there is absolutely no way of
telling whether or not it shows interference then there is absolutely
no way of knowing what it does. But if you try to set up an
experiment "without detectors" but then later cheat and peek into what
happened, the light "knew" you were going to look and interfered with
itself. Even a single photon "knew". No, that is not the proper way
of explaining things, but it will do."

This is like a computer program. It is set up to get light (whatever
it really is) to propagate itself one way or the other based on whether
or not the measurement brought about with sentience is accomplished.


In your post on June 13th to Zoe in the "To AC -- on electrons" topic,
you stated this: "But then, the Copenhagen interpretation says, there
occurs a
measurement process, by which the experimenters eventually become aware
of what has actually happened in the experiment.

Now clearly, this measurement process is not very well specified so
far, so there is ambiguity there."



[snip]

This is patently false.


Nonsense.

I'm just describing the Copenhagen interpretation, and
referring to the fact that it doesn't specify any physical
theory of precisely what happens when a measurement takes
place.

In the Copenhagen interpretation, a complete quantum
mechanical description of the measurement process is never
even attempted. It is simply assumed that there are some
macroscopic devices (detectors) whose behaviour can be
directly observed by the experimenters, and for which a
change in the macroscopically observable state indicates
that something has happened ... eg.: we hear a click
indicating that the position of an electron has been
determined when the electron hits the detector.

Specific ways are given in the Copenhagen interpretation in
which one can predict the probability of a given measurement
of an observable. One calculates the expectation value of a
quantum mechanical operator corresponding to some measurable
quantity, in the wavefunction appropriate to the
experimental situation.

But without a complete description of the process including
the wavefunction of the measuring device, there remains some
ambiguity about the description of the process.

I made a statement about the Copenhagen interpretation which
is true on its face.

Your problem is that you don't actually know what the
Copenhagen interpretation is, though you are clearly happy
to lecture others about it.

Some people may be interested to learn that the measurement
problem is a very intricate one indeed. People have devoted
their entire lives to studying it, without ever having
resolved it fully.

http://scholar.google.com/scholar?q=measurement%20problem%20in%20quantum%20mechanics&hl=en&lr=&oi=scholart

The measurement effect has been strongly
upheld in the experiment put forward by Kim, Kulic, Shih, and Scully.
What is so ambiguous? The authors of the paper state (asterisks
mine)--"It is *clear* we have detected the standard Young's double-slit
interference pattern." They didn't state "it is *vaguely seen* that we
*might be detecting* the standard Young's double-slit interference
pattern."


There is no vagueness in the result of Kim's experiment.
Nor did I or anyone ever imply that there was.

You are equivocating on the words `measurement effect.'

You can't seriously imagine that Kim et al. have given a
description of the whole quantum mechanical process by which
they became aware of the results of their experiments?

Including the precise details of the behaviour of the wave
functions of their photon detectors interacting with the
detected photons, and even going further, to include the
wavefunctions of their brains that encode their own
thoughts?


It appears you are purposely trying to skew people's opinions of the
expectations of quantum theory.

It appears that you wish to impute nefarious motives to me,
without having any obvious reason for doing so.

As r. norman says: "And no, some of the ideas really
don't make sense. But when you do the experiments, that is really what
happens! "


So? What was r. norman referring to when he said that?
He was not referring anything in Kim et al..


The difference between r. norman's view and mine, is that to me this
isn't nonsensical when one considers that the laws of the universe were
established by an intelligent source.

This is purely your assertion: there is no experimental
support to be found for it.




[snip]


That's a bold claim, the second one you've made,
and the first in another long series of such which
you don't back up.

Consider it backed up at this point.


Don't be ridiculous.



You can start by presenting evidence for your
statement directly above.

The problem is that the discussion at the website you are
referencing has been written in a deliberately deceptive
manner,

Sounds like a bald assertion to me.

Maybe you need to adjust your `hearing' in that case: it's my
conclusion based on my analysis of what was said at the site.

Yoon-Ho Kim has given his approval to Ross Rhode's description of the
article which was a description of his scientific work. See:
http://www.bottomlayer.com/ (scroll down to the 7th article in the list
to see Yoon-Ho Kim's actual statement).


You are equivocating and arguing from authority again.

Kim did not approve the statements that I quoted made by
Ross Rhodes about single electron double slit experiments.

Kim didn't approve Rhodes entire website: not by a long
shot.

But what would it matter if Kim *did* approve of what Ross
Rhodes says?

What Rhodes says about single electron double slit
experiments is still wrong.


in order to support the incorrect, and insupportable
description and interpretation of the double slit experiment
that is given there, and which you are trying to propagate
here: that the behaviour of electrons depends upon some
thinking observers *knowledge* of the electron's paths
through the experimental apparatus rather than just
upon the interactions of the electrons with the experimental
apparatus. Indeed it is precisely those interactions that
provide the experimenters with their knowledge.

. . . but the propagation of light as a wave occurs when it goes
through the slits (with the detectors turned on) when human knowledge
is lacking about of the path of the electrons, and the propagation of
light as particles occurs when it goes through the slits (with the
detectors on) when a human gains the knowledge.


This is word salad.

I was saying that light reveals itself in a wave pattern when the
detectors are working, as long as the measurement effect cannot occur
(let's say a quantum eraser is inherent in the experimental setup).
This wave pattern also is an expectation when the detectors aren't
measuring, of course.

From what I've seen, it's your position (along with the position of
Oxidized, Steven J., and Tracy Hamilton) that when detectors are
present (and "on") the light will only propagate in the clumping
pattern (which is an exhibition of the particle aspect of its duality).
This has been shown to be a wrong position to take now that the
quantum eraser experiments have been accomplished. See above.


No. Tracy, myself and the others have all expressed the
position that the thoughts of the experimenters, as well as
the state of knowledge of the experimenters do not affect
the results of any experiments, including the quantum eraser
experiments. The outcomes of the experiments are predicted
perfectly well by the theory of quantum mechanics, which
NEVER takes any such things into account.

This is just as correct a statement for the quantum eraser
experiments as it is for any other quantum mechanical
experiments.

Even Ross Rhodes has to agree that quantum theory predicts
the results of Kim et al.:

Comment: To the physicist, the results "are all
consistent with prediction."

There is no spooky clairvoyance or intelligence principle
included in quantum theory, despite your protestations
to the contrary.


The discussion is about electrons, not light.

So are you about to take a position that electrons might quantumly
behave differently than photons? On what basis do you want to make this
differentiation?


Certainly I am. I already have. Reread the post I made in
response to Zoe, describing some basic facts about electrons
and photons.

Electrons are:

(1) Massive.
(2) Charged.
(3) Have non-zero magnetic moment.
(4) Have spin 1/2.
(5) Obey Fermi statistics.

Photons are:

(1) Massless.
(2) Neutral.
(3) Have spin 1.
(4) Obey Bose Statistics.


Moreover there are experiments showing that the behaviour of
electron gases is (when, for example adsorbed on the surface
of a crystal) is fundamentally different than the behaviour
of photon gases, as for example, in lasers.

Because electrons and photons are so different, an
experiment involving quantum entangled _electron pairs_, if
such could be done, for example, would have a very different
theoretical description than one involving quantum entangled
photon pairs.



"Following the convention of particle physicists, we will use
"elementary particles" to refer to objects such as electrons and
photons, with the understanding that these "particles" display
wave-like properties as well. All the particles and their interactions
observed to date can be described by a quantum field theory called the
Standard Model." http://en.wikipedia.org/wiki/Particle_physics



So what? You think this supports the idea that electrons
behave the same as photons `quantumly' or otherwise?

It doesn't.

In the standard model, there are explicitly different fields
for electrons and photons.

The quantization of these fields is very different in the
two cases.

Don't even bother mentioning supersymmetry here:
supersymmetry is strongly broken in nature, and there is, so
far, no experimental evidence for it.

Electrons and photons (particles of light) are in
fact profoundly different from each other.

But in an experiment which tries to establish a quantum understanding
of the characteristics of elementary particles, do you have evidence
that we should expect quantum measurement effects of photons and
electrons to differ?


What experiment, and what `quantum measurement effects' are
you talking about? Your question is far too vague to even
begin to answer it.



Photons
are massless bosons, electrons are massive
fermions. Photons are chargeless, and they are
(formally) always completely destroyed by their
interactions with matter, electrons have mass,
electric charge and a magnetic moment, and thus
they can interact with matter without being
destroyed.

The whole point of the second chapter of the Ross Rhodes's website is
that "solid" things like particles (electrons) behave-- in the
measurement effect-- in a way that's no different than something less
particle-like (ie. photon). On what basis would you say
he is wrong?

I've discussed elsewhere and at length what is wrong with
what Ross Rhodes has to say.

Are you aware that the Schrodinger equation applies to all quantum
units and events up to and including the wave function of the universe?



Are you aware that electrons obey the Dirac equation,
not the Schroedinger equation?

The Schroedinger equation is non-relativistic, for
a start, so your claim is obviously wrong, even
disregarding the nonsensical claim you make about
it applying to the `wavefunction of the universe.'







The standard interpretation of quantum mechanics
is that light propagates as a probability wave all
of the time. Electrons also propagate as
probability waves all of the time.

We can write quite definite equations to describe
their behaviour in quantum mechanics given any
particular experimental apparatus.

No one ever even attempts to include the
observer's thoughts in any quantum mechanical
calculations at all, nor is it necessary to.

Well, they certainly see the effect of sentient measurement in the
experiments. Remember what r. norman wrote above?


Why should anyone care what r. norman wrote here?

He was speaking loosely in that post, indicated that he was
doing so, and in any case he didn't say anything that
supports what you say above about electrons being
sensitive to the thoughts of nearby people.

But
the calculations nevertheless explain the results
of any experiments that have been done so far.

The important point here is that, self-evidently,
if there are no interactions whatever, then no one
at all can possibly have any knowledge of the mode
of propagation, either of light or of electrons.

There could be no evidence of where they went in
that case.

This doesn't seem to argue against my position in any way, so I'll
leave it at that.


You must be kidding, right?

We don't have to take account of or pay attention
in any way in our theories to this critical
piece of information, which you say matters
crucially to what's observed in experiments:
the state of knowledge of the experimenters.

But the theory nevertheless works in all
cases.

OK.

If you think that doesn't vitiate your position, then I'm
willing to leave it at that, too.

So how can you say that?


See above. If something doesn't interact there is
no way anyone can measure or know how, or where
to, that something has propagated.

But we certainly have seen cases where detectors are-- in essence--
"on", yet then erased to keep us from measuring-- and we still get an
interference pattern (just like when the detectors are "off". This is
an indication that Oxidized, Steven J., etc. . . are not representing
things properly.

The relevant part of the description begins here:

http://www.bottomlayer.com/bottom/reality/chap2.html#examine

(skip down to the question: Why?)

We would like to think that the particle detectors at the
slits are affecting the passage of the electron -- perhaps
deflecting it, or modifying it's path, or in some other way
influencing the experiment. We could accept such an
explanation.

In fact we *do* accept such an explanation. It is, and it
remains, the standard interpretation of the double slit
experiment with uncorrelated single electrons.

Persuade me then.

For the standard interpretation of quantum mechanics
I would suggest reading:

P A M Dirac 1958 The Principles of Quantum Mechanics
(Oxford University Press).

For a basic discussion of the standard interpretation of
the double slit experiment I would suggest the Feynman
lectures:

R P Feynman, R B Leighton and M Sands (1963)
The Feynman Lectures on Physics.

Quantum mechanics is treated in vol 3 as I recall,
and there is discussion of the double slit
experiment therein.

For actual data on double slit experiments, I suggest a
look at the extensive literature on electron interference.

An early experiment was that by Claus Jönsson in
1961 (Zeitschrift für Physik 161, 454). In fact,
this experiment showed that the theoretically
predicted interference patterns are built up with
multiple slits. However, the flux of electrons in
the experiments was high, so one couldn't be sure
that the electrons passed through the apparatus
one at a time.

There was no way of detecting which path the
electrons followed through the apparatus.

The first conclusive experiment I know of, showing
that when single electrons passed through a double
slit experiment, an interference pattern was still
formed was carried out in 1989, and reported by
Akira Tonomura et al. (American Journal of Physics
57 117-120). In this case, the electron beam was
definitely weak enough that it could be
ascertained that electrons were passing through
the apparatus one at a time, and nevertheless the
interference pattern was built up over time. (The
flux was only 1000 electrons per second on
average.)



So it should be emphasized that the claim that Rhodes makes
next, as well as being startling, is false:

But that does not seem to be the case. A series of
experiments have been conducted to test just such a
hypothesis, and the results are uniformly negative. I will
quickly run through some of the more ingenious attempts to
isolate and remove any possible influence stemming from the
detectors located at the slits.[2]

Now the first thing to do, when reading a claim that some
experiment or experiments have been done that prove
something or other that someone wants to tell you is the
God's own truth, especially something with amazing
implications, is to chase down and read the descriptions of
the actual experiments by the people who did them in the
first place.

The author of the website kindly provided links to
descriptions of the experiments which supposedly support the
rest of his discussion, in his endnote [2], so that's where
one should go immediately. The first reference to the
literature given there is:

http://xxx.lanl.gov/pdf/quant-ph/9903047

Which was published in Phys. Rev. Lett. 84, 000001 (2000):

http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=PRLTAO&CURRENT=NO&ONLINE=YES&smode=strresults&sort=rel&maxdisp=25&threshold=0&allprl=1&pjournals=PLRAAN%2CPRBMDO%2CPRVCAN%2CPRVDAQ%2CPLEEE8%2CPRLTAO%2CRMPHAT%2CPRABFM%2CPHRVAI%2CPHRVAO%2CPRSTCR&pjournals=PRLTAO&possible1=quantum+eraser&possible1zone=multi&OUTLOG=NO&viewabs=PRLTAO&key=DISPLAY&docID=10&page=1&chapter=0

At either of these links one can find a paper entitled: `A
Delayed Choice Quantum Eraser.'

The abstract of the paper reads:

This paper reports a "delayed choice quantum eraser" experiment
proposed by Scully and Druehl in 1982. The experimental results
demonstrated the possibility of simultaneously observing both
particle-like and wave-like behaviour of a quantum via quantum
entanglement. The which path or both-path information of a quantum
can be erased or marked by its entangled twin even after the
registration of a quantum.

Well, that's a bit odd -- it seems that the paper is all about a
`quantum eraser' and `quantum entanglement,' and the
abstract is talking about a quantum and its quantum entangled
`twin'. There's nothing there at all about a double slit experiment
involving single electrons!

Until you demonstrate that the content of the entire article cannot
relate to double slit experiments, it's not "a bit odd".


Come off of it.

It's not necessary for me to do that. It is odd.

Not at all. Elementary particles have quantum behavior that's quite
well-known, and the measurement effect is also quite well-known (and I
have yet to see any really good reason to think that an electron will
do something different than a photon when it comes to the measurement
effect).


It's clearly odd to base a long discussion of an experiment
involving single electrons on the results of an experiment
that critically involves quantum entangled photon pairs.




It is self-evident that an experiment on quantum
entangled photon pairs does not directly relate to
a double slit experiment with single electrons.

I'd say the correlation is very direct, and the statement from Kim,
Kulic, Shih, and Scully in their paper demonstrates that.


Say what you like. Assertion is very easy.

The fact that Kim et al. mention the words double slit in
their paper, or that they see double slit interference
patterns on some occasions is not sufficient to establish
the result that Rhodes claims for single electron double
slit experiments.


You are the one who needs to demonstrate that
anything in the experiment reported by Scully and
Druehl shows that any result in the experiment
depends upon the `knowledge' of the experimenters.

Demonstrated above.


Nothing at all has been demonstrated, except that
you don't know what you are talking about.

In fact here's a statement from
http://www.benbest.com/science/quantum.html which indicates that the
experiment has a close correlation to the double slit experiment: "An
experiment involving circular diffraction, and the famous two-slit
experiment, illustrate the most perplexing behavior of subatomic
particles/waves."


Na, und?

So, I take it you don't think trust anything that website has to say,
now that I've cited it?


You take it wrong. My statement was: so what?

And indeed, the description given of the experiment later on
in the paper is as follows:

Two atoms lableled by A and B are excited by a laser
pulse. A *PAIR* OF ENTANGLED PHOTONS, photon 1 and photon
2, is then emitted from either atom A or atom B by atomic
cascade decay. Photon 1, propagating to the right, is
registered by a photon counting detector D_0 which can be
scanned by a step motor along its x-axis for the
observation of interference fringes. Photon 2, propagating
to the left, is injected into a beamsplitter. If the pair
is generated in atom A, photon 2 will follow the A path
meeting BSA with 50% chance of being reflected or
transmitted. If the pair is generated in atom B, photon 2
will follow the B path meeting BSB with 50% chance of being
reflected or transmitted. Under the 50% chance of being
transmitted by either ...

[my emphasis]

Lo and behold!

The reference describes an experiment dealing with quantum
entangled photon *PAIRS*, not a double slit experiment
involving *SINGLE* uncorrelated electrons. The paper does
not contain any description or any interpretation of a double
slit experiment with uncorrelated electrons, much less of
any attempt to `remove any possible influence stemming
from the detectors located at the slits, in any such experiment.

Now an experiment dealing with uncorrelated electrons is an
entirely different matter from an experiment dealing with
correlated photon pairs.

A two-body wavefunction is NOT the same thing as a one-body
wavefunction.

It may not be the same thing, but there certainly can be close
correlations made.


No correlations have been made that demonstrate
the truth of any of the statements that Ross
Rhodes makes about the dependence of the results
of single electron double slit experiments on the
knowledge of the experimenters.

I'd say you are wrong.


So what.

You don't even know that electrons obey the Dirac equation,
you are quoting r. norman, who I believe is a non-physicist,
as an authority on the matter.

I would advise everyone and anyone to dismiss the contents
of your posts about quantum mechanics in their entirety.


I invite you to go right ahead and make any
correlations you are able to, explicitly.


Your failure to do so is noted.

The second reference given in endnote [2] is:

http://arxiv.org/pdf/quant-ph/0512207

This preprint, similarly, describes an experiment using
quantum entangled photon pairs, not a double slit experiment
with uncorrelated single electrons.

So when the author writes, in his endnote [2], that he
continues to use electrons as the quantum units under
discussion purely _for pedagogical purposes_, I suggest
that he is being rather disingenuous:

For pedagogical purposes, I have continued to use electrons
as the quantum units under discussion. With recent
successes in achieving entanglement among atoms, it seems
likely that these experiments may be repeated in the near
future with various quantum units of matter (if this has
not already been achieved). QM being what it is, there is
no question but that the results will be consistent with
those obtained with photons.

Now despite all of these rosy predictions above by Ross
Rhodes about what might be achieved in the future, his
discussion of the single electron double slit experiment is
not supported in any way by actual double slit experiments,
or by the experiments that he refers to, which deal with
quantum entangled photon pairs, where indeed, it is once
again the interference between the two photon wavefunction
and the experimental apparatus that matters, and NOT the
knowledge of the experimenters.

I don't see this as disingenuous at all. He sees as strong correlation
and has confidence in that correlation.


You and I will simply have to agree to disagree on
this.

If Ross had had any confidence in the `strength'
of any `correlation,' then I suggest that he would
have described in full the experiments that were
done with quantum entangled photon pairs, and
shown how *they* demonstrate the truth of his
assertion that those results depend on the state
of the experimenter's knowledge of what happened.

Instead, Ross pretends that some of the results of
an experiment employing quantum entangled photon
pairs can be given the interpretation he provides,
and that these have proven the truth of what he
says about the outcomes of experiments done with
uncorrelated single electrons: that they have been
shown to depend on the state of knowledge of the
experimenter.

What he says there is simply not at all supported
by any experiments, either on single electrons or
on photon pairs.

It is completely dismissable, whether it is
disingenuous or not.

You can dismiss it. Just don't think that most scientists would follow
suit.


I don't care what `most' scientists would do. Most
scientists don't have my level of knowledge of the physics
involved.


Now, Ross does give on the site the impression
that he is being perfectly frank about the results
of single electron double slit experiments, and he
is implying that it makes no difference that he is
actually drawing on the results of experiments
dealing with quantum entangled pairs of
photons. He clearly knows this to be the truth.

I think he knows better.

He knows there's a strong correlation--as does Yoon-Ho Kim-- and that
it's not a real problem to talk of quantum physics in this way.


You are shading the truth.

Kim did not approve of Rhodes whole argument: at most he
approved the description of his experiment therein.

So, I consider that for him to imply that actual
single electron, double slit experiments support
any of his conclusions is insincere. But he gives
the impression that he is being frank: there is no
doubt at all expressed in the footnote, neither is
there any statement about a `strong correlation'
or `confidence in that correlation.' The
implication, on the contrary, is that what he says
is essentially proven.

By my definition, that is being disingenous.

By definition, you are off the deep end.


Seeing that it comes from you, I will take that as a high
compliment.


Let me continue to look at Rhodes' discussion, just for fun,
to see precisely where he goes wrong. Immediately following
the paragraph that I initially quoted, there occurs the
following discussion:

1.TURN OFF THE ELECTRON DETECTORS AT THE SLITS. Suppose we
take our modified double slit set up -- with electron
detectors at the slits -- and leave everything
intact. But, we will conduct the experiment with the
electron detectors at the slits turned off, so that we
will not actually detect any electrons at the slits.

_The result upon analysis_: an interference pattern at the
back wall. So it seems that mere passage through the
electron detectors at the slits does not affect the
electron, so long as those electron detectors are not
functioning.

So far this is correct. This is indeed what happens in an
actual double slit experiment performed with uncorrelated
electrons. With the electron detectors turned off, an
interference pattern is observed.

Then Rhodes continues:

2.LEAVE THE ELECTRON DETECTORS ON, BUT DON'T GATHER THE
INFORMATION. Suppose we take our modified double slit
set up -- with electron detectors at the slits -- and
still leave everything intact. And we will keep the
electron detectors at the slits turned on, so that they
will be doing whatever they do to detect electrons at
the slits. But, we will not actually look at the count
of electrons at the slits, nor will we record the count
at the slits in any way, so that we will not be able to
obtain any results from these fully-functioning electron
detectors.

_The result upon analysis_: an interference pattern at the
back wall. So it seems that the electron detectors
located at the slits do not themselves affect the
electron, even when the equipment is fully functioning
and detecting (in a mechanical sense) the electrons, so
long as we don't obtain the results of these
measurements.

But this is *completely* wrong.

This is *not* what happens in an actual double slit
experiment done with single electrons. In fact, in such an
experiment, it doesn't matter *at all* whether we actually
record the counts at the slits or don't record the counts at
the slits, or whether we obtain any results at all from the
detectors at the slits.

If you are correct, then why does the Keith Mayes at
http://www.thekeyboard.org.uk/Quantum%20mechanics.htm (I found this
link here:http://en.wikipedia.org/wiki/Double-slit_experiment ) state
this:


None of that was inconsistent with anthing I've
said, but this fellow Mayes does have an odd
tendency to talk about photons as if they are
thinking individuals.

[snip]


Once you've read this, please reflect on why Ross Rhodes
(bottomlayer.com) has been persuaded to say what he has said about the
detectors not being central to quantum theories strange "measurement
effect".


I'm not interested, particularly, in why he has
been persuaded to say it.

I'm interested in the fact that what he says is
not supportable by any experiment.

Go ahead and deny the importance of the Kim, Kulic, Shih, and Scully
experiment in all this. . .



I will go ahead and continue to dismiss it and I will be
justified in doing so because it doesn't support Rhodes.

Even Rhodes admits that quantum mechanics predicts the
results of that experiment.

It's not the detectors that sway the outcome, but the
intelligent observers themselves having knowledge of that which
happened quantumly. Anyway, on to the write-up


Bullshit.

This is another unsupported suggestion of your own.

You have not supported your position with anything any experts have
said, but I have brought forward the pertinent evidence that supports
my position.

You've brought forth a lot of verbiage and a great deal
obfuscation, but you haven't brought forth any evidence that
supports your position.

I, on the other hand, have supported my position with my own
arguments.

I'm confident that the readers will be able to tell the
difference.


[snip]


Ross Rhodes didn't invent the Copenhagen interpretation of quantum
mechanics, but he certainly knows much about it.


He does, apparently, know enough to deceive you, at least.

I'd say you would have to say Kim is trying to deceive people if you
think Ross Rhodes is out to deceive people.


I'ld say you have a tendency to leap to unsupported
conclusions.

All you can point out in support of that is one line quoted
from Kim approving some part of Rhodes website describing
the paper by Kim et al., a part of the website that I was
not even referring to.


In NO case is an interference pattern formed at the back
wall when the electron detectors are on. That's because
the electron detector influences the motion of the electron.

So you assert.


You are free to provide a specific counter-example
in the form of a citation to the peer-reviewed
physics literature any time you want.

Until then, my assertion will stand.

Are you not going to at least try to convince me with any substantial
expert testimony?


Would you like a reference to a description of how a charged
particle detector works? I will be happy to provide one, but
that all of them do influence the motion of electrons is for
certain.

So far as I am aware, no one has managed to do any *real*
double slit single electron experiment which it is possible
to turn on and off and detect the path of the electron
through the two slits.

It's hard to make electron detectors tiny enough you
see.

The descriptions are all of gedanken experiments. In a
gedanken experiment, which employs quantum theory for its
framework, it is possible to demonstrate that the prediction
of quantum mechanics is that the detectors will influence
the motion of the electron. That's because the electrons
*must* interact with something in order to be detected. The
wavelength of that something must be sufficiently small to
localise the electron to the extent that it can be said to
have gone through slit 1 or slit 2.

It's a consequence of the Heisenberg uncertainty relation
on position and momentum that the disturbance will always
sufficient to destroy the interference pattern, if it
can be detected what path the electron followed.

Violate the Heisenberg uncertainty relation, and
you violate a basic prediction of quantum mechanics.

No such violation has been observed.


No interference pattern is ever observed when there is even
the *possibility* of the experimenters measuring the path
that the electrons actually follow through the experimental
apparatus.

Do you have evidence that this is true?



There is no report of any such experiment being
done in the literature that I've ever heard of.

You are free to provide me with an example of such
for single uncorrelated electrons in a double slit
experiment.

As of yet, I'm not aware that this has been accomplished,

I see. So then: either I'm correct that it hasn't been done
then, or else you don't know where to look to find out.


but I see no
reason to think that the results would be any less in line with the
quantum theory-predicted results of the measurement effect which
occured in the Kim, Kulic, Shih, and Scully experiment.




Oh, really, you don't? And this is your expert opinion on
the matter?


[snip]


The experiment done with single electrons in fact differs
critically from the experiments done with two quantum
entangled photons.

It differs in the following obvious way: there are two
photons involved, and these have initially, a common,
correlated two-body wavefunction. The detection of one of
the two photons at some later point in time in the `quantum
eraser' type experiments can thus be used to *deduce*
information about what has to have happened to the other of
the two photons, without necessarily destroying an
interference pattern.

This means that an entirely different analysis is required
for such experiments.

But there are definitely correlations which relate to the double slit
experiments. Here's another excerpt from
http://www.lifesci.sussex.ac.uk/home/John_Gribbin/quantum.htm

"But then Chiao and his colleagues ran the same experiment with
polarising filters in front of each of the two slits. Any photon going
one way would become "labelled" with left-handed circular polarization,
while any photon going through the other slit is labelled with
right-handed circular polarization. In this version of the experiment,
it is possible in principle to tell which slit any particular photon
arriving at the second screen went through. Sure enough, the
interference pattern vanishes -- even though nobody ever actually looks
to see which photon went through which slit.

Now comes the new trick -- the eraser. A third polarising filter is
placed between the two slits and the second screen, to scramble up (or
erase) the information about which photon went through which hole. Now,
once again, it is impossible to tell which path any particular photon
arriving at the second screen took through the experiment. And, sure
enough, the interference pattern reappears! "

This represents a close correlation to the double slit experiments when
it comes to the measurement effect. I don't know how you're getting
that it's unrelated.


I didn't say it's unrelated, I said that it
_differs_. It differs sufficiently that Ross
can't draw the conclusions that he does from it
about single electron double slit experiments
depending on the knowledge of the experimenters.

See my comments above about Kim.


I am underwhelmed by your comments about Kim.

We shall need to theoretically
describe the interactions of both photons with the
experimental apparatus to say what will happen in various
configurations.

I don't see what the problem is, though, when it comes to the
measurement effect and how it works similarly in both experiments. And
that is the heart of what Ross Rhodes is writing about at his website.


The problem is that the analysis for two photons
is considerably different from that for a single
electron, and that what Ross reports about single
electron experiments simply does not happen.

Entanglement still follows predictions of quantum theory. Why would we
think that predictions of quantum theory wouldn't apply to nonentangled
elementary particles?


Nice evasion. Who said that predictions of quantum theory
wouldn't apply?




But it remains the case that all that is important in the
theoretical analysis is the interactions of the pair of
photons with the experimental apparatus itself. The state of
knowledge of the thinking observers is completely irrelevant
to the results of the experiment.

Then I suppose the Copenhagen interpretation of quantum theory is just
nonscience then. . . *rolls eyes*


Well then, since you claim to be rolling your
eyes, it's too bad for you that you clearly don't
understand anything whatsoever about quantum
mechanics, or classical mechanics for that matter.

Do you seriously imagine that when one works out
the quantum theory of a single electron double
slit experiment one has to write down a
Hamiltonian of the following form?

H(total) = H(electron + experimental apparatus) + H(experimenter's
brain)

And that one then needs to solve a Schroedinger
equation of the form:

H (Psi) = - i d/dt (Psi)

Psi = psi(electron) * psi(experimenter's brain)

You are very deeply confused, if that's what you
imagine takes place.

This is ridiculous.


Yes, I agree that it is ridiculous.

It's what you are proposing.

That the state of knowledge of the experimenter, after or at
the time the experiment is done determines the paths of
electrons, or photons in quantum mechanics, rather than the
physical configuration of the apparatus.


The real mathematics of quantum physics can be demonstrated in
experimentation.

Mathematics can't be demonstrated in experiments.

Ultimately, though, the experiments end up showing
the measurement effect-- which has
perception-of-the-universe-and-knowledge-itself
implications.

Experiments show all sorts of things. What is meant by `the
measurement effect'?


The
implications of the experiment may not necessarily be represented by
mathematics, but are nonetheless understood by scientists to be worthy
of notice.


For all the experiments done on quantum mechanics that we've
discussed here the mathematics of quantum theory works, and
that theory *does not* take the knowledge of the
experimenters into account.


My statement about this is correct, independent of
what interpretation of quantum mechanics is
correct.

The psi formulas are not a fair representation of what my sig is all
about.


Is this gem by Rhodes a fair representation of what the
website is about?

`The universe is the manifestation of a computer and its
programming.'

Tell me, did Kim approve of that, too?

It's hardly a statement for which any evidence exists.

I'ld advise those who enter there to take extreme care.


We do not need to take into account the thoughts of the
experimenters when we do experiments in quantum mechanics.

I am not sure you've looked deep enough into this, because you don't
seem to understand the implications.


Could you please attempt to say something more arrogant?

You see. the difference between you and me is that
I have spent a good portion of my life actually
solving problems in quantum mechanics. Never yet
has it been necessary for me to explicitly include
the effects of the state of my own thoughts or
knowledge, or anyone else's, in my calculations.

That's just a strawman of my position.

Strawman?

Possibly you are using some other definition for the word?

Here is *your* original rhetorical question about photons,
waves of light, electrons, and their ability to distinguish
what people nearby are THINKING.

What is it about these photons or waves of light that can distinguish
whether or not a nearby person's thought is/willbe of the electron
pathway or something other than that (maybe last night's dinner)?

This is a counterargument to Oxidised who stated correctly:

You don't know about the path of the electron until you sap
some energy from it.


[snip]


You can be thinking about
last night's dinner, as long as you use the instruments to make the
measurement.

-- [snip]

-- Steven J.

Call me crazy, but maybe you want to actually back up what your saying
about the measuring devices interfering with the results with something
that seems persuasive (other than assertions).



If I were you, and I wished to preserve my credibility, I
would modify my signature.

The signature stands. At this point, the credibility problem is with
you.


One more assertion without any support.

I'm still waiting for any support for your position besides a few
references to psi-related mathematical formulas and bald assertions
about electrons being somehow unable to follow a major prediction of
quantum theory (as do entangled photons) when it comes to the
measurement effect.

The real problem for you is that if the knowledge of the
experimenters really had to be taken into account in
predicting experiments, then there is no way that
quantum theory could be made to work at all.



Did mind come before matter in the universe or matter come before mind?
Chapters 1 and 2 have your answer:
http://www.bottomlayer.com/bottom/reality/Intro.html


There's no answer to the question posed to be found on that
website. Instead there is a farrago of error and deception.

David

Or maybe you just don't like the implications of quantum theory. . .


No that's not the case at all.

I'm quite happy with the implications of quantum
theory, having understood them not to include any
such nonsense as a dependence of the behaviour of
electrons in an experimental apparatus on the
thoughts of the experimenters, which are, in any
case, occurring in a causally disconnected part of
spacetime.

It's you and Ross who want to say that quantum
theory implies that the motion of electrons in
single slit experiments depends upon the knowledge
of the observers.

Double slit.


That should read: `single electron double slit.'

The burden of proof remains on you to support
such an outrageous statement.

Ross makes real enough errors in his `pedagogical'
description of single slit experiments.

I'm sticking to my description of his site as a farrago
of error and deception.

You may feel free to go right on deceiving yourself,
if you like.

Cheers!

David

Well, the only farrago of error and deception I'm seeing
here

[snip]

Why am I not surprised that you don't see the errors?

I pity anyone who tries to learn about quantum mechanics by
reading anything you have to say about it, or anything you
have to say about what Ross Rhodes has to say about it, or
Yoon-Ho Kim's irrelevant one liners about Ross Rhodes'
description of Kim et al.'s experiment, or anyone reading
your misinterpretation of what you claim r. norman has to
say in support of your position.



HTH. HAND.

David

This will be my last reply to you.


.

Relevant Pages

  • Re: Is a fact something that has been proven?
    ... So it's your contention that the electrons go through the slits as ... through the slits (with the detectors turned on) when human knowledge ... A *PAIR* OF ENTANGLED PHOTONS, ...
    (talk.origins)
  • Re: Is a fact something that has been proven?
    ... So it's your contention that the electrons go through the slits as ... experiment and the double slit experiment. ... experiment "without detectors" but then later cheat and peek into what ... Even a single photon "knew". ...
    (talk.origins)
  • Re: Is a fact something that has been proven?
    ... So it's your contention that the electrons go through the slits as ... description and interpretation of the double slit experiment ... through the slits (with the detectors turned on) when human knowledge ... A *PAIR* OF ENTANGLED PHOTONS, ...
    (talk.origins)
  • Re: Basic Double Slit Question
    ... sensitive" measure of negative charge located at each slit they have ... measurement" of the electrons passage and the results so far reported ... first or second slit and the interference pattern is still present, ... not produce an interference pattern on the tube face, ...
    (sci.physics.research)
  • Re: Double Slit Puzzle Explained (?)
    ... slippery slope of saying that light passing through a slit changes into ... So if you are hurling photons or electrons or neutrons or neutrinos at ... Here waves go to the antenna, ... But the two patterns are essentially identical. ...
    (sci.physics.electromag)