What evidence for photons?
Franz Heymann
"Martin Green" <btes...@home.com> wrote in message
news:BmX49.122759$f05.6...@news1.calgary.shaw.ca...
> Bilge wrote:
>
> > I did give you a reason, but let me make it clearer. In order to
to
> > explain the behaviour of a small antenna using a wave picture that
doesn't
> > violate conservation of energy, you have to have a very complex
> > explanation and a theory of antennas and matching networks, and even
then
>
You seem to make a habit of putting words into otherfolks' mouths. Cut
it.
Franz Heymann
Steve Carlip
> I may have misunderstood your starting point. From your
> response, I take it that I'm allowed to assume that matter is
> quantized; you're asking why I can't treat the electromagnetic
> field as a classical wave interacting with such quantized
> matter.
> In that case, I agree that the photoelectric effect won't do. After
> all, most of the results can be computed (by undergraduates!)
> in a quantum mechanics course in which the electromagnetic
> field is treated as a classical perturbation of the Hamiltonian.
I may have spoken too quickly. While it's true that the overall
statistical properties of the photoelectric effect won't do, there
are features in the timing that might.
Consider a very low intensity electromagnetic field, one that,
say, ejects one electron per minute. In a quantum picture, the
field has some fairly random distribution of photons (make
it a thermal source, say). The first photon may arrive any
time in the first minute; when it does, it's absorbed and ejects
an electron. In particular, there's a finite probability of an
electron being ejected very soon after the source is turned on.
In a semiclassical picture, the quantum effects occur in the
atom-radiation interaction. There's an absorption/ionization
cross-section, which you can compute semiclassically, which
gives a probability of ejecting an electron per unit time. There
is no question that the statistical predictions agree with those
of the full quantum theory, at least up to extremely small
QED corrections.
But consider the energy balance, in a situation in which an
electron is ejected, say, a few seconds after the source is turned
on. In the semiclassical picture, this will have happened long
before the required energy has arrived. Similarly, there's a
finite probability of two electrons being ejected in the first
minute, even though the first minute's worth of radiation only
has enough energy to eject one electron. Energy conservation
is no longer exact; it holds only statistically.
While I don't know an experimental reference off hand, I'm sure
experiments of this sort have been done. (They're mentioned,
though without a citation, in Bransden and Joachain's text,
for instance.) I do't know whether this statistical conservation
of energy is incompatible with experiment, but it should be at
least enough to make one uncomfortable with the semiclassical
picture.
Steve Carlip
Steve Carlip
> Steve Carlip wrote:
>> There is actually a standard answer to your question, though:
>> photon antibunching. It's possible, though only fairly recently
>> so, to set up beams of light in which the two-photon correlation
>> functions are incompatible with classical wave-like behavior.
>> There's a very nice preprint by Carmichael, quant-ph/0104073,
> At the risk of sounding arbitrary, I really don't think this qualifies
> as an "undergraduate level" explanation. It's certainly not the
> explanation they gave me when I was an undergraduate.
It may not be commonly taught to undergraduates, but surely
it could be. It's not really that hard---the classical inequality
that's violated comes in a very straightforward manner from
the triangle inequality, which undergraduates routinely see in
the derivation of the uncertainty relations.
> I did a graduate course on Quantum Optics once where I did
> some "bunching" calculations from a semi-classical point of
> view. I was able to reproduce some of the basic quantum
> results.
Bunching, yes. Antibunching, no---it's strictly prohibited
classically.
> I really don't believe this area lends itself to clear-cut
> theoretical demonstrations of the kind we're talking about,
> partly because of discrepancies both in the manufacturing
> of the light, and in the detection end... detector efficiencies,
> etc.
The theoretical derivation of the relevant inequalities is easy.
The experimental results are by now unambguous. The details
of the experiments can be somewhat hard, but that's true
for lots of experiments described in undergraduate courses.
(How many texts have a detailed description of even, say, the
Stern-Gerlach experiment?)
As a matter of fact, I think I may introduce this next time I
teach quantum mechanics.
Steve Carlip
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:aiuor6$bv5$2...@woodrow.ucdavis.edu...
>> It's usually pretty accurate to compute interactions of radiation and
>> matter in a semiclassical approximation, in which matter is treated
>> quantum mechanically but the electromagnetic field is treated as a
>> classical wave. It's not so easy to find simple examples in which the
>> quantum properties of the EM field itself are both important and
>> intuitive.
> Of course there are processes in which that approach works. After
> all, the correspondence principle has to hold. However, there is a
> preponderance of interactoins in which this simplified approach
> does not work. Here are a few:
> Differential cross section for bremsstrahlung
> Differential cross section for the Compton effect.
> Differential cross section for pair production
> Differential cross section for photon photon elastic scattering
> Mean life of Positronium
Certainly all of these processes require QED corrections to get the
right answer. In some cases (photon photon elastic scattering, for
example), there isn't a semiclassical approximation at all. In others
(bremsstrahlung, for example), the semiclassical approximation is
usually pretty good.
But I don't think anyone is arguing against QED per se. The question,
as I understand it, is whether any of these examples (or others) is
*instructive* at the undergraduate level---that is, whether you can
point to one of them and say, ``Here's the place where it becomes
obvious from the experimental result that light is quantized.''
This is not so easy; I don't want to have to teach my undergraduates
how to do Feynman diagrams in QED in order to demonstrate that
light is quantized, and I'd rather not just say, ``Trust me, when you
take field theory in grad school you'll see that this picture is right.''
Steve Carlip
Tom Potter
> "Tom Potter" <t...@earthlink.net> wrote in message
> news:f76e0bb3.02080...@posting.google.com...
> > "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> news:<aiuhb2$im0$3...@helle.btinternet.com>...
> > > "Tom Potter" <t...@earthlink.net> wrote in message
> > > news:3d51...@post.newsfeed.com...
> > > > *** post for FREE via your newsreader at post.newsfeed.com ***> > > > news:aisabd$hf0$1...@woodrow.ucdavis.edu...
> > > > > In sci.physics Martin Green <btes...@home.com> wrote:
> > > > >
> > > > > > I said previously, and I continue to maintain: there is no
> > > > > > honest argument that can be made at the undergraduate
> > > > > > level to justify the assertion that light is made up of
> particles
> > > > > > rather than waves.
> > > > >
> > > > > How about prompt electrons in the photoelectric effect?
> > > > > Look at the photoelectric efect with a very low intensity light
> > > > > source. If light is a classical wave, it should take time for
> it
> > > > > to build up enough energy to eject an electron. Instead,
> > > > > one observes that the first electrons are emitted with no
> > > > > delay.
> > > >
> > > > Let's say we use a 1 MHz "light" as the source in
> > > > a photoelectric experiment,
> > >
> > > If I were you, I would not bother, as it would be a complete waste
> of
> > > time.
> > > 1 MHz is well below the threshold for producing photoelectrons. You
> > > need something in the region of 10^9 MHz at least.
> > >
> > > > and we use 1000 MHz "light" as our clock
> > > > to measure the time interval between
> > > > the initiation of the source "light"
> > > > and the ejection of electrons.
> > > >
> > > > As there is space (A measurable time interval.)
> > > > between the source "light" and the target electron source,
> > > > there should be a time interval equal to Einstein's
> > > > "stationary rigid body" (Measuring stick)
> > > > between the initiation of the cause
> > > > (Turning on the "light".)
> > > > and the effect (The ejection of the electron.).
> > > >
> > > > It seems to me, that the time interval between cause and effect
> > > > would be the "space time interval" plus the time period of
> > > > the "light" used to eject the electrons.
> > > > In other words, the longer the wave length used to
> > > > "eject the electrons", the longer the time delay.
> > > >
> > > > Does anyone know what the experiments have shown
> > > > for such an experiment?
> > >
> > > Yes indeed.
> > > No photoelectrons at all will be produced. There is a well defined
> > > threshold frequency which depends on the particular material which
> forms
> > > the photocathode. It is simply given by
> > > f = eV/h
> > > where f is the threshold frequency
> > > e is the electronic charge
> > > V is the work function of the cathode surface
> > > h is Planck's constant
> >
> > Are you suggesting that 1 MHZ electromagnetic waves
> > do not interact with electrons?
>
> No, I did not suggest that. You should read what I said. I said that a
> 1 MHz EM wave cannot participate in the photoelectric effect.
You should read what I said.
I said:
"It seems to me, that the time interval between cause and effect
would be the "space time interval" plus the time period of
the "light" used to eject the electrons.",
and I wanted references to experiments.
I didn't "say" I wanted to quibble about semantics.
ie. Whether "photo-electric" means an interaction
between a charge and an EM wave, or what frequency
it takes to eject an electron from a particular material, etc.
Do you know of any references that discuss whether or not
the ACTUAL time interval between an EM source and a charge,
is affected by the time period of the wave?
In other words, if I generated ONE complete EM wave
at some distance from a charge, would the time period
of the wave affect the time delay?
As I posted, I think it does.
Tom Potter
Franz Heymann
Usually only in limited regions of the phase space available for the
process.
>
> But I don't think anyone is arguing against QED per se. The question,
> as I understand it, is whether any of these examples (or others) is
> *instructive* at the undergraduate level---that is, whether you can
> point to one of them and say, ``Here's the place where it becomes
> obvious from the experimental result that light is quantized.''
>
> This is not so easy; I don't want to have to teach my undergraduates
> how to do Feynman diagrams in QED in order to demonstrate that
> light is quantized, and I'd rather not just say, ``Trust me, when you
> take field theory in grad school you'll see that this picture is
right.''
I cannot see what is wrong with the usual approaches of
Black body spectrum, Photoelectric effect and Compton effect
>
Franz Heymann
Martin Green
> .....In the semiclassical picture, this will have happened long
> before the required energy has arrived. Similarly, there's a
> finite probability of two electrons being ejected in the first
> minute, even though the first minute's worth of radiation only
> has enough energy to eject one electron. Energy conservation
> is no longer exact; it holds only statistically.
>
> While I don't know an experimental reference off hand, I'm sure
> experiments of this sort have been done. (They're mentioned,
> though without a citation, in Bransden and Joachain's text,
I've askes people for citations in the past, and have been
given nothing but the Meyers Gerlach paper....which is
totally irrelevant.
> for instance.) I do't know whether this statistical conservation
> of energy is incompatible with experiment, but it should be at
> least enough to make one uncomfortable with the semiclassical
> picture.
That's why the case for photons should be so easy to prove: it
calls for a very dramatic violation of energy conservation.
There should be such an experiment, and it should be
reasonably famous. I don't understand why no one
can point to it.
It is also very odd to me that this violation of energy
conservation, which would be very compelling
evidence for the existence of photons, is never
citied in the textbooks when they deal with this
issue. Instead, they use the much weaker (and
totally erroneous) argument about the power
density of the beam compared with the cross-sectional
area of the individual atom.
Martin Green
http://www.onforeignsoil.com
The book that starts in English
and turns to Yiddish.
Don Palermo
"Franz Heymann" wrote ...
>
> "Steve Carlip" wrote
> > This is not so easy; I don't want to have to teach my undergraduates
> > how to do Feynman diagrams in QED in order to demonstrate that
> > light is quantized, and I'd rather not just say, ``Trust me, when you
> > take field theory in grad school you'll see that this picture is
right.''
>
> I cannot see what is wrong with the usual approaches of
> Black body spectrum, Photoelectric effect and Compton effect
These are good examples that leave many to
suspect the particle nature of light as well as Pair
Production. Keeping in mind that in general, moving
from the Photoelectric effect, to the Compton effect
and on to Pair Production represents a decrease in
wave lengths and and increase in photon energy.
Although Steve, problems arises when one attempts
to attach the human perception of locomotion onto
EMR's "energy quanta".
The wave nature of EMR that is taught to your
students is easily grasped via the many experiments,
observations, and known phenomena.
The real issue, and "leap of faith" that occurs
is when we are forced to take "as is" and "un-
modifiable" the notion that the particles of EMR
literally traverse non-zero distances, i.e.that they
move the full distance from the point of emission
to the point of detection. The bullistic _notion_ of
photons, simply does not fit in with the wave
nature of EMR. Which is exactly why you are
faced with finding an "instructive" example for
you students.
Tell your students that *possibily* light, and
all EMR is a propagating wave of non-moving
"energy quanta".
The effects listed above can be fair (or excellent)
instructive expamples for the quantization of EMR,
i.e. that light also displays the "discontinuous" (quantum
mechanical) behavoirs as matter. The problem is that
we humans have assumed real motion towards light's
energy quanta.
I suggest that we take one more level of "discontinuity"
and apply the notion that EMR's energy quanta do not
in fact traverse non-zero distances (or any distance at
all).
Once you students are taught to blindly accept
that photons literally _move_, then the lid will be
closed on the box, with no way out, or even a
window to grasp the realities of nature.
There is _no_ experiment that remotely suggests
that light's energy quanta physically traverses non-
zero distances. In this regard you will not find _one_
collaborative "thing" to point to. Albeit, there is
immense value in utilizing the notion that light is a
wave of non-moving particles, as well as the value in
accepting the "relative" motion of such particles.
--
Kind Regards
Don Palermo
Franz Heymann
You were talking about the time delay for an electron to be ejected.
That refers to the photoelectric effect.
The photoelectric effect will not occur at all if the incident radiation
is 1 MHz, as you suggested.
Franz Heymann
kdthrge
was
> pure hogwash from someone who really does not know any physics.
>
> Franz Heymann
......................> >
hey look dufus fuck, for someone who posts his shit all over the
physics channel, you are totally ignorant of basic physics. There is
physics which is based on confirmed physical laws, and then there is
theoretical physics. You are unable to distinguish between them and
unlearned in basic physics. This you demonstrated well in another
discusion in which you presumed that I don't know that amplitude is
the energy of a wave. If you increase the amplitude of a wave in water
the wavelength increases also. The frequency of these waves remain the
same. Even in a bell, you idiot, a system of standing waves exist. The
harder you hit the bell the amplitude increases. It increases because
more standing waves are added AT THE LONGER WAVELENGTHS, which have
more energy.
Your posts are little rote repitition of what you have heard.
Mossbauer spectroscopy is bombardement of nuclei with gamma radiation.
Since the mass and energy of a nucleus remains specific and unique, an
absorbed gamma photon is re-emmited. The recoil of the nuclei in this
event are important. The theoretical discusion of this I am sure is
limited because present theory cannot deal with this phenomena. You
and the bullshit you call physics can't deal with any issue of
momentum. You and your brothers in fantasy probably don't even resent
that Bohr completly perverted Kepler's laws. FACT: An orbital body
that gains energy assumes a orbit of lesser area. Bohr is the duffus
of duffus fucks and your theoretics stem from him.
Your anal mentality cannot stand anything that does not fit your
little rote repitition psycology. You fools can forge your fake wave
mechanics which explain the difference in normal light and laser
light, but it has nothing to do with nature or science. Diffraction is
the only means to split light at higher frequencies since glass or
quartz absorbs the photons. In diffraction higher frequencies are bent
less.
Martin Green
> There's a nice 1985 experiment by Grangier et al., Europhys.
> Lett. 1 (1986) 173, that looks at this. They use an atomic cascade
As a small point, I finished my undergraduate degree in 1982,
so this experiment could not have helped my professors
to convince me of the existence of photons....
> as a light source, using the first photon to trigger a shutter that
> lets the second photon into a beam-splitter. Of course there is
> a small probability of accidentally getting two photons, from
> two transitions, through the shutter; but there are some strict,
> easily derived classical inequalities for coincidence probabilities
> that very clearly fail experimentally. (After five hours of running,
> they saw nine coincidences, where any semiclassical theory would
> require more than 50.)
>
> This is an experiment that is easily explained at the undergraduate
> level, and easily described as well.
I think you are unfairly minimizing the complexities of an
experiment that has not only a source and a detector,
but an attenuator and a shutter. How can we be sure the
physics of all these devices have been modelled correctly?
And even if this experiment should turn out to be correct,
it is still not satisfying on a fundamental level. There was
something very powerful about the "wrong" explanations
for photons, like the photo-electric effect and the Compton
effect. According to those arguments, photons were
absolutely necessary because they made things happen
that would have otherwise been impossible. The implications
were enormous and far-reaching. Now you want me to
believe that all these important phenomena can actually
be explained by the wave theory of light....EXCEPT...if
you examine a light beam with a very powerful microscope,
you can actually see that it is made of particles and not
waves.
The compelling nature of the case for the photon was
always tied up with the fact that it claimed to offer the
only viable explanation for all kinds of phenomena
at the macroscopic level. If all these macroscopic
effects can, after all, be handled adequately by the wave
theory, then where is the motivation for photons? They
appear as a totally un-necessary complication that
crops up only if you look very closely at certain
microscopic effects, rasing the basic question: why
do we need them?
Franz Heymann
"kdthrge" <kdt...@yahoo.com> wrote in message
news:1eb8d2f6.02081...@posting.google.com...
> "> You may rest assured that your impression is correct. The essay
> was
> > pure hogwash from someone who really does not know any physics.
> >
> > Franz Heymann
> ......................> >
> hey look dufus fuck, for someone who posts his shit all over the
> physics channel, you are totally ignorant of basic physics. There is
> physics which is based on confirmed physical laws, and then there is
> theoretical physics. You are unable to distinguish between them and
> unlearned in basic physics. This you demonstrated well in another
> discusion in which you presumed that I don't know that amplitude is
> the energy of a wave.
If you think that the amplitude of a wave is the energy of a wave you
are totally wrong.
The *power flow density* of a wave is proportional to the *square* of
the amplitude.
> If you increase the amplitude of a wave in water
> the wavelength increases also.
That is complete balderdash. The wavelength is determined solely by the
frequency and the phase velocity.
The wavelength and amplitude of a wave are independently controllable
parameters. Did you realise that you are effectively saying that a loud
passage in a piece of broadcast music would require you to tune to a
different frequency than when you are listening to a soft piece of
music?
> The frequency of these waves remain the
> same. Even in a bell, you idiot, a system of standing waves exist. The
> harder you hit the bell the amplitude increases.
It is true that the amplitude increases if you hit the bell harder.
> It increases because more standing waves are added AT THE LONGER
WAVELENGTHS, >which have
> more energy.
That sentence, however, is complete nonsense.
>
> Your posts are little rote repitition of what you have heard.
Not at all. I taught most of the stuff I post about.
> Mossbauer spectroscopy is bombardement of nuclei with gamma radiation.
That indicates a gross misunderstandng of what constitutes the Mossbauer
effect. I suggets you read up about it befopre diving deeper into the
shonga.
> Since the mass and energy of a nucleus remains specific and unique, an
> absorbed gamma photon is re-emmited. The recoil of the nuclei in this
> event are important.
Yes, but in a manner of which you show zero knowledge so far.
The theoretical discusion of this I am sure is
> limited because present theory cannot deal with this phenomena.
The Mossbauer effect is fully understood.
The rest of your post sank even deper than usual into the kazi, so I
snipped it in case the smell lingers on my screen.
If your next post is as assinine as this one, I will not bother
replying, but will put you on my killfile without further ado
Franz Heymann
Franz Heymann
Franz Heymann
[snip]
>
> You were talking about the time delay for an electron to be ejected.
> That refers to the photoelectric effect.
> The photoelectric effect will not occur at all if the incident
radiation
> is 1 MHz, as you suggested.
It strikes me that the following example might give you an idea of the
time delays (or lack thereof) which are involved when EM radiation
interacts with an electron:
Na22 emits a photon and a positron very, very nearly simultaneously, so
detecting the positron tells you when the photon was launched. Allow
the photon to stike a scintillating target. In the vicinity of the
target are two additional counters placed in kinematically favourable
positions for detecting a recoil photon and a scattered electron arising
from a Compton scattering event. The equipment is compact enough for
the transit times of the particles to be small enough to be equalised by
judicious choice of the cable lengths associated with the detectors.
(Standard procedure in all particle physics experiments). Coincident
counts are observed which are unambigously interpretable as being
composed of :-
The positron emitted by the Na22 source ( and therefore also a photon)
An event in the target
A recoil electron
A scattered photon
The coincidence resolving times of the experiment was approximately
10^-8 seconds.
The experiment was performed successfully as a project by a pair of my
final year undergrads in about 1980 and was subsequently used as a
routine final year experiment for a few years.
The Compton spectrometer is essentially an elaborate and profesionally
designed piece of equipment which has been used to investigate the
differential crossection for the Compton effect. In the professional
version, not only were the angular correlations tested, but the energies
of the final electron and photon were measured by recording the pulse
heights in the counters.
Franz Heymann
Bilge
Re: What evidence for photons? to usenet:
>Bilge wrote:
>
>> I did give you a reason, but let me make it clearer. In order to to
>> explain the behaviour of a small antenna using a wave picture that doesn't
>> violate conservation of energy, you have to have a very complex
>> explanation and a theory of antennas and matching networks, and even then
>
>using a coil?
The part of the above paragraph you snipped answers your question. Just
a couple of sentnces later, I stated:
"I can much more easily justify the incident radiation in terms of
a particle flux and leave the efficiency to the ability to transfer
the power to the receiver in the matching network."
Which part is not clear? A coil is not part of the antenna. It's
part of the receiver.
-------
Now, you stated in <zit49.116974$f05.6...@news1.calgary.shaw.ca that:
"The damage is much worse at the other end of the scale. Graduate
students who go on to become professional physicists get used
to accpting the "truth" of arguments based on appeal to authority
instead of logic."
I claim that the reason you accept the wave description is exactly
that for which you fault physicists for believing in photons. You've
never questioned the validity of the analogies given to you as the
basis for it. I'll pose the same "challenge" you gave in reverse:
Debunk the particle picture of light using only arguments that the
average undergraduate can understand. (If you intend to analogize the
interference to something waves in a ripple tank, don't forget to
justify the fact that we can't measure the amplitudes of the fields
in E&M and if you questionb the argument closely enough, the analogy
won't work).
David Evens
>"Franz Heymann" <Franz....@btopenworld.com> wrote in message news:<aiuhb2$im0$3...@helle.btinternet.com>...
He pointed out (for the benefit of those, like Tom Potter, who have
spent their lives doing things like driving useful corporations out of
business by conspiring with others to vandalise them with frivilous
lawsuits instead of something useful) that microwave photons lack
sufficient energy to produce photoelectrons, and the ABSCENCE of
photoelectrons is OBSERVED.
Tom Potter
"David Evens" <dev...@technologist.com> wrote in message
news:3d538ed8...@news.falls.igs.net...
Apparently, this poster, like Franz Heymann,
has a reading comprehension problem.
I suggest that I made it very clear,
that I was interested in getting references to experiments
that gave the time interval between a cause and an effect,
taking the wavelength of the EM wave involved.
I said:
"It seems to me, that the time interval between cause and effect
would be the "space time interval" plus the time period of
the "light" used to eject the electrons.",
and I wanted references to experiments.
I didn't "say" I wanted to quibble about semantics.
i.e.. Whether "photo-electric" means an interaction
between a charge and an EM wave, or what frequency
it takes to eject an electron from a particular material, etc.
I suggest that if this poster knows of any experiments,
that he post them, and if he wants to flame someone,
that he should visit the alt.flame newsgroup,
and interact with the young boys with ego problems.
Tom Potter
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Franz Heymann
Take a running jump at yourself. The discussion up to the stage of your
question was concerned with the photoelectric effect. On the assumption
that you were asking a question relevanyt to the topic, I gave you a
completely correct answer.
>
> I suggest that I made it very clear,
> that I was interested in getting references to experiments
> that gave the time interval between a cause and an effect,
> taking the wavelength of the EM wave involved.
>
> I said:
> "It seems to me, that the time interval between cause and effect
> would be the "space time interval" plus the time period of
> the "light" used to eject the electrons.",
> and I wanted references to experiments.
>
> I didn't "say" I wanted to quibble about semantics.
> i.e.. Whether "photo-electric" means an interaction
> between a charge and an EM wave, or what frequency
> it takes to eject an electron from a particular material, etc.
>
> I suggest that if this poster knows of any experiments,
> that he post them, and if he wants to flame someone,
> that he should visit the alt.flame newsgroup,
> and interact with the young boys with ego problems.
OK. I take it then that you are not enquiring about the photoelectric
effect. You must be talking about Thomson scattering of free electrons.
The answer to your question then becomes the following:
At 1 Mhz (that is the frequency you yourself were enquiring about) the
interaction is way, way in the classical regime, and you simply have to
use the normal classical Lorentz force in the classical equation of
motion to determine the behaviour of the electron.
If you want to see any quantum effects, you would still have to use a
frequency something like 10^9 or so larger than 10^6 Hz.
Franz Heymann
kdthrge
interest in science and nature. Therefore I should only like to
suggest that you take time and critisize directly a simple study which
I have outlined at my website,
http://www.geocities.com/kdthrge/sub3.htm
If you are an objective scientist you can do this. Do not bother me
with indirect critisicm or the statements from your theoretical
science. I only want a direct critisicm of the principles I have tried
to outline very simply. My e-mail address is there if you are able to
point out the fallacy of my engineering.
If a person has several hours to recreate this study, one will achieve
definite results. This study outlines a PROOF. As simple and accurate
proof as was ever derived. This proof, if valid, proves a secondary
proof of the error of theoretical physics. It is very simple and
absolute. I am looking at this proof. Until you can show me otherwise,
I am the judge looking at the video of kids stealing candy. The
denials and lies are meaningless.
If you have any validity as a scientist you can objectively critisize
this study. The principles to be critisized are of structural
viability of which I am an expert. In my field of profession, there is
no room for fooling oneself. Any errors become catastrophic. If you
cannot objectively remove me from my beliefs, I have no respect for
you or your creed. Your waste of money and young peoples minds is
unforgiveable and you have not the objective intelligence to check the
validity of your work. The day will come also when I can achieve an
objective critisism of this study.
Kent Deatherage
David Evens
<Franz....@btopenworld.com> wrote:
>"Tom Potter" <t...@earthlink.net> wrote in message
>news:3d56...@post.newsfeed.com...
Yes, this is unrelated to the photoelectric effect, which is an
experimental observation of the relationship between voltage and
incident photon energy and current and incident photon flux. Einstein
demonstrated those pairs of relationships in the experimental data,
and the abscence of other relationships. He got a Nobel Prize for it,
too, although people like you who are ignorant of science generally do
not know that.
>> I didn't "say" I wanted to quibble about semantics.
>> i.e.. Whether "photo-electric" means an interaction
>> between a charge and an EM wave, or what frequency
>> it takes to eject an electron from a particular material, etc.
>>
>> I suggest that if this poster knows of any experiments,
>> that he post them, and if he wants to flame someone,
>> that he should visit the alt.flame newsgroup,
>> and interact with the young boys with ego problems.
>
>OK. I take it then that you are not enquiring about the photoelectric
>effect. You must be talking about Thomson scattering of free electrons.
>The answer to your question then becomes the following:
>At 1 Mhz (that is the frequency you yourself were enquiring about) the
>interaction is way, way in the classical regime, and you simply have to
>use the normal classical Lorentz force in the classical equation of
>motion to determine the behaviour of the electron.
>If you want to see any quantum effects, you would still have to use a
>frequency something like 10^9 or so larger than 10^6 Hz.
We use gamma rays when we do this in physics lab. First year
experiment, by the way.
Tom Potter
I suggest that it is very clear that I am talking about getting
references to ANY experiments that clearly show what the time
delay is between a cause and an effect involving "photons"
and "electrons".
And it should be clear that I am trying to determine,
if there are delay times in causes and effects, that are
frequency sensitive. In other words, is the time interval
(The actual space) between a cause and and effect
a function of specific causes and effects. If this is the
case, "spaces" reside in "sources" and the "sinks."
I put quotes around "photon" because as I have asserted before,
"photons" are imaginary objects. One could just as correctly
assert that angels conveyed a change between a cause and an
effect, as the only thing that can be measured is an
interaction time.
I have zero interest in any particular "effect".
These are side issues that obscure the issue and generate noise.
I want to know something more basic and general.
I want to know where "space" resides.
Tom Potter
Bill Nelson
>
> If you have any validity as a scientist you can objectively critisize
> this study. The principles to be critisized are of structural
> viability of which I am an expert. In my field of profession, there is
> no room for fooling oneself. Any errors become catastrophic. If you
> cannot objectively remove me from my beliefs, I have no respect for
> you or your creed. Your waste of money and young peoples minds is
You have a pretty poor method of judging others. There are many that
cannot be objectively convinced that they are wrong - such as fanatics,
the insane, those unwilling to listen and those that cannot understand
the counter arguments.
--
Bill Nelson (bi...@peak.org)
Tom Potter
"Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:aj417b$1kn$4...@paris.btinternet.com...
>
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> news:aj39ln$5ud$1...@venus.btinternet.com...
>
> [snip]
> >
> > You were talking about the time delay for an electron to be ejected.
> > That refers to the photoelectric effect.
> > The photoelectric effect will not occur at all if the incident
> radiation
> > is 1 MHz, as you suggested.
>
> It strikes me that the following example might give you an idea of the
> time delays (or lack thereof) which are involved when EM radiation
> interacts with an electron:
>
> Na22 emits a photon and a positron very, very nearly simultaneously, so
> detecting the positron tells you when the photon was launched.
Let's stop here, and address a couple of issues before we go on.
1. What is the wavelength (Frequency) of the photon?
2. What is "very, very nearly simultaneously" in picoseconds?
3. Does anything affect the "very, very nearly simultaneously" time?
(Detector distances, angle, type of detector, electric field, magnetic
field, etc?)
Note that the cable length delays,
and the differences in the devices used to detect photons and electrons,
must be taken into account in order
to determine the actual time difference.
I must also mention, that it has been my experience as
an instrumentation sales engineer, to find that many
experimenters did not know that high frequency
oscilloscopes have a "delay line" in the vertical circuit
in order to give the sweep time to start, so the leading edge
of a pulse can be seen. Obviously, if one assumes that the
vertical and horizontal channels have equal time delays,
and use Lisajou patterns for high frequency
phase measurements, they can be off significantly.
This is all I need to know.
Thanks.
--
Tom Potter http://home.earthlink.net/~tdp
Randy Poe
>
> "> You may rest assured that your impression is correct. The essay
> was
> > pure hogwash from someone who really does not know any physics.
> >
> > Franz Heymann
> ......................> >
> hey look dufus fuck, for someone who posts his shit all over the
> physics channel, you are totally ignorant of basic physics. There is
> physics which is based on confirmed physical laws, and then there is
> theoretical physics. You are unable to distinguish between them and
> unlearned in basic physics. This you demonstrated well in another
> discusion in which you presumed that I don't know that amplitude is
> the energy of a wave. If you increase the amplitude of a wave in water
> the wavelength increases also.
This is not true of sound waves. It is true of surface waves, for
complicated nonlinear reasons. Surface waves with an amplitude
much more than about 1/7 of the wavelength go nonlinear and
"break".
For most other waves, amplitude and wavelength are varied
completely independently. This is also true in a ripple tank
where you are making small surface waves. Increasing the
amplitude does not increase the wavelength.
> The frequency of these waves remain the
> same.
Not for the water waves you are talking about. Long wavelengths
have lower frequencies.
> Even in a bell, you idiot, a system of standing waves exist. The
> harder you hit the bell the amplitude increases.
Yes. Because the amplitude is the size of the vibration. Hitting
the bell makes a bigger deformation.
> It increases because
> more standing waves are added AT THE LONGER WAVELENGTHS, which have
> more energy.
Uh, no. Resonant modes are set by the basic geometry. Hitting
harder doesn't change that, even for complicated things like
bells and drums.
- Randy
Randy Poe
> > >> > Let's say we use a 1 MHz "light" as the source in
> > >> > a photoelectric experiment,
> > >>
> > >> No photoelectrons at all will be produced.
> > >Are you suggesting that 1 MHZ electromagnetic waves
> > >do not interact with electrons?
> >
> > He pointed out that microwave photons lack
> > sufficient energy to produce photoelectrons, and the ABSCENCE of
> > photoelectrons is OBSERVED.
>
> Apparently, this poster, like Franz Heymann,
> has a reading comprehension problem.
>
> I suggest that I made it very clear,
> that I was interested in getting references to experiments
> that gave the time interval between a cause and an effect,
> taking the wavelength of the EM wave involved.
You were much more specific than that. You said, as can be
seen in the above quote, "suppose we use 1 MHz as the source
in a photoelectric experiment." You made it very clear that
you were asking about photoelectrons.
The responders are pointing out that you won't produce
any photoelectric electrons, and therefore that a photoelectric
experiment is not the right way to look for the time delay
you are asking about.
- Randy
Franz Heymann
> interest in science and nature. Therefore I should only like to
> suggest that you take time and critisize directly a simple study which
> I have outlined at my website,
> http://www.geocities.com/kdthrge/sub3.htm
>
> If you are an objective scientist you can do this
Firstly,
From your various postings here, it is clear that you are a crank.
Secondly,
I am getting old and do not have many years to go before I hand in my
dinner pail. I don't intend spending any of my time musing over a
crank's crap.
Franz Heymann
Franz Heymann
> *** post for FREE via your newsreader at post.newsfeed.com ***
>
>
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> news:aj417b$1kn$4...@paris.btinternet.com...
> >
> > "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> > news:aj39ln$5ud$1...@venus.btinternet.com...
> >
> > [snip]
> > >
> > > You were talking about the time delay for an electron to be
ejected.
> > > That refers to the photoelectric effect.
> > > The photoelectric effect will not occur at all if the incident
> > radiation
> > > is 1 MHz, as you suggested.
> >
> > It strikes me that the following example might give you an idea of
the
> > time delays (or lack thereof) which are involved when EM radiation
> > interacts with an electron:
> >
> > Na22 emits a photon and a positron very, very nearly simultaneously,
so
> > detecting the positron tells you when the photon was launched.
>
> Let's stop here, and address a couple of issues before we go on.
>
> 1. What is the wavelength (Frequency) of the photon?
No idea. Work it out for yourself. The energy is 1.3 MeV
> 2. What is "very, very nearly simultaneously" in picoseconds?
Too short for us to have measured. Certainly less than 100 picoseconds.
> 3. Does anything affect the "very, very nearly simultaneously" time?
> (Detector distances, angle, type of detector, electric field, magnetic
> field, etc?)
Na22 source mounted on plastic scintillator on photocathode of PM tube.
Source only a fraction of a microcurie.
Ring shaped plastic scintillator for recoil electron.
5" NaI crystal on PM for scattered photon.
Small plastic scintillator as target for Compton interactions.
All fitted on a footprint of roughly 50 cm square
Typical time resolution 10 ns
>
> Note that the cable length delays,
> and the differences in the devices used to detect photons and
electrons,
> must be taken into account in order
> to determine the actual time difference.
Don't try to teach your grandmother how to suck eggs.
>
> I must also mention, that it has been my experience as
> an instrumentation sales engineer,
If I may make so bold, as a sales engineer you do not have the
experience to tell me anything about how to design or run a particle
physics experiment.
> to find that many
> experimenters did not know that high frequency
> oscilloscopes have a "delay line" in the vertical circuit
You must have come across some pretty bum physicists in your life.
> in order to give the sweep time to start, so the leading edge
> of a pulse can be seen. Obviously, if one assumes that the
> vertical and horizontal channels have equal time delays,
> and use Lisajou patterns for high frequency
> phase measurements, they can be off significantly.
Thanks for the tips. I will engrave them on my heart.
But it might interest you that the experiment did not need the use of an
oscilloscope in the data taking phases. We relied on fast coincidence
circuits, counters and pulse height analysers.
>
> This is all I need to know.
You are mistaken. You also need to know our typical data taking rates.
These were typically only in the region of a few dozen events per
minute.
>
> Thanks.
I trust that you will make good use of the information.
Steve Carlip
>> There's a nice 1985 experiment by Grangier et al., Europhys.
>> Lett. 1 (1986) 173, that looks at this. They use an atomic cascade
>> as a light source, using the first photon to trigger a shutter that
>> lets the second photon into a beam-splitter. [...]
>> This is an experiment that is easily explained at the undergraduate
>> level, and easily described as well.
> I think you are unfairly minimizing the complexities of an
> experiment that has not only a source and a detector,
> but an attenuator and a shutter. How can we be sure the
> physics of all these devices have been modelled correctly?
I'm sorry, but now you're just being silly. It's a very simple
experiment, both conceptually and in practice. Very little
modeling of the devices is needed, and what there is is
completely straightforward. There's no attenuator, by
the way; I don't know where you got that from. I suggest
that you read the paper.
> And even if this experiment should turn out to be correct,
> it is still not satisfying on a fundamental level.
On the contrary, it's as fundamental as you can get. The
most fundamental distinction between a wave picture and
a particle picture is that waves are continuous, while in a
particle picture, energy comes in indivisible quanta. What
better way to test this than to isolate what ought to be one
quantum and see if you can divide it?
> Now you want me to believe that all these important
> phenomena can actually be explained by the wave
> theory of light....EXCEPT...if you examine a light beam
> with a very powerful microscope, you can actually see
> that it is made of particles and not waves.
I'm sorry, but I simply don't understand your point. You
seem to be arguing that a direct check to see whether light
is made up of photons, by isolating a photon and looking
at its properties, is less convincing to you than a much more
indirect argument that photons can be used explain certain
more complicated macroscopic phenomena. That can't be
what you mean, can it?
(When asked about the existence of atoms, do you find
arguments about how thin you can beat gold foil more
convincing than electron microscopic pictures of single
atoms?)
> The compelling nature of the case for the photon was
> always tied up with the fact that it claimed to offer the
> only viable explanation for all kinds of phenomena
> at the macroscopic level. If all these macroscopic
> effects can, after all, be handled adequately by the wave
> theory, then where is the motivation for photons?
The macroscopic effects *can't* be explained quantitatively
by a wave theory. But if one is free to postulate arbitrary
interactions of matter with waves, one can cook up a model
that's close enough, and complicated enough, that it takes
a fair amount of effort to show why it doesn't work.
> They appear as a totally un-necessary complication that
> crops up only if you look very closely at certain microscopic
> effects, rasing the basic question: why do we need them?
Maybe because they're really there? Maybe because nature
doesn't particularly care about your preferences for one
kind of experiment over another? Maybe because theories
with photons give quantitatively correct predictions where
wave theories don't?
Steve Carlip
Martin Green
> >> There's a nice 1985 experiment by Grangier et al., Europhys.
> >> Lett. 1 (1986) 173, that looks at this. They use an atomic cascade
Martin Green replied:
> > I think you are unfairly minimizing the complexities of an
> > experiment that has not only a source and a detector,
> > but an attenuator and a shutter. How can we be sure the
> > physics of all these devices have been modelled correctly?
Steve Carlip replied:
> I'm sorry, but now you're just being silly....
Then I guess the discussion is over.
Bennett Standeven
Don't forget to explain any similar phenomena occuring with electrons,
atoms, etc., if such exists.
Chosp
> Excuse the insults etc.
No.
The point with all of this should be a
> interest in science and nature. Therefore I should only like to
> suggest that you take time and critisize directly a simple study which
> I have outlined at my website,
> http://www.geocities.com/kdthrge/sub3.htm
<<snip>>
>The day will come also when I can achieve an
> objective critisism of this study.
That day has come and gone. Where were you?
Bilge
Re: What evidence for photons? to usenet:
>> >> There's a nice 1985 experiment by Grangier et al., Europhys.
>> >> Lett. 1 (1986) 173, that looks at this. They use an atomic cascade
>> >> as a light source....
>
>Martin Green replied:
>
>> > I think you are unfairly minimizing the complexities of an
>> > experiment that has not only a source and a detector,
>> > but an attenuator and a shutter. How can we be sure the
>> > physics of all these devices have been modelled correctly?
>
>Steve Carlip replied:
>
>> I'm sorry, but now you're just being silly....
>
>Then I guess the discussion is over.
Try looking up "quantum beats". The explanation is very straight-
forward and requires only the ability to comprehend interference.
Since the interference arises from the inseparability of of a quantum
state, it has no classical explanation.
Steve Carlip
> Steve Carlip wrote:
>> While I don't know an experimental reference off hand, I'm sure
>> experiments of this sort have been done. (They're mentioned,
>> though without a citation, in Bransden and Joachain's text, [...]
> I've askes people for citations in the past, and have been
> given nothing but the Meyers Gerlach paper....which is
> totally irrelevant.
OK. This took me about an hour in the library---perhaps
you should try the same.
1. The idea of a theory in which electromagnetic radiation
is classical and wavelike, but interactions with matter is
quantized, was proposed and developed by Bohr, Kramers,
and Slater in 1924 (Philos. Mag. 47 (1924) 785; Z. Phys. 24
(1924) 69). BKS, as well as Einstein and others, immediately
noticed that the theory entailed only statistical conservation
of energy and momentum. The BKS model was experimentally
refuted by Geiger and Bothe (Z. Phys. 32 (1925) 639) and
Compton and Simon (Phys. Rev. 28 (1925) 889) who looked
for, and confirmed, conservation of energy and momentum
in individual Compton scattering events.
2. The idea that in analyzing the photoelectric effect one should
consider an absorption cross-section that goes as the square
of the wavelength of light, rather than the size of an atom or
molecule, goes back to Rayleigh (Phil. Mag. 32 (1916) 188).
But as an explanation for the observed characteritics of the
photoelectric efect, this was ruled out by an experiment of
Elster and Geitel (Phys. Zeits. 17 (1916) 268), who used very
dim blue light, intensities as small as 3x10^-9 erg/cm^2 sec.
At these intensities, one would classically expect a delay of
about 10^4 sec.; instead, no observable delay was seen.
3. Lawrence and Beams (Phys. Rev. 32 (1928) 478) showed, using
a very fast optical shutter, that photoelectrons appeared with
a time delay of less than 3x10^-9 sec. Marx and Lichtenecker
(Ann. Phys. 41 (1913) 124) used a rotating mirror to vary the
time of illumination of a photocell, and found that any
``accumulation time'' would have to be less than 10^-7 sec.
> It is also very odd to me that this violation of energy
> conservation, which would be very compelling
> evidence for the existence of photons, is never
> citied in the textbooks when they deal with this
> issue.
Textbooks are not, for the most part, interested in the history of
the subject, or in introducing wrong theories and explaining
why they are wrong.
> Instead, they use the much weaker (and
> totally erroneous) argument about the power
> density of the beam compared with the cross-sectional
> area of the individual atom.
I just looked at the eleven quantum texts I have in my office.
(I get lots of free samples from publishers hoping I'll use
them in a course.) None of them gave anything like this
argument. Two barely mentioned the photoelectric effect
at all. Four (Bransden and Joachain, Galindo and Pascual,
Gasiorowicz, and Messiah) discussed the issue of timing and
prompt electrons. One, Bialynicki-Birula et al., mentioned
cross-sections and power, but used a cross-section on the
order of the square of the incident wavelength, as you like,
not the area of an individual atom. The rest just talked
about the work function and the proportionality of energy
and frequency.
Perhaps you could tell me which texts you have in mind.
Steve Carlip
Franz Heymann
"Martin Green" <btes...@home.com> wrote in message
news:1eY59.136860$Ag2.6...@news2.calgary.shaw.ca...
> Steve Carlip wrote:
> > >> There's a nice 1985 experiment by Grangier et al., Europhys.
> > >> Lett. 1 (1986) 173, that looks at this. They use an atomic
cascade
> > >> as a light source....
>
> Martin Green replied:
>
> > > I think you are unfairly minimizing the complexities of an
> > > experiment that has not only a source and a detector,
> > > but an attenuator and a shutter. How can we be sure the
> > > physics of all these devices have been modelled correctly?
>
> Steve Carlip replied:
>
> > I'm sorry, but now you're just being silly....
>
> Then I guess the discussion is over.
For which we are truly thankful.
Amen.
Franz Heymann
Franz Heymann
You are drivelling. Do you insist on using 1 MHz EM radiation or do you
want to know about time delay effects in the interaction of photons with
elactrons?
>
> And it should be clear that I am trying to determine,
> if there are delay times in causes and effects, that are
> frequency sensitive. In other words, is the time interval
> (The actual space) between a cause and and effect
> a function of specific causes and effects. If this is the
> case, "spaces" reside in "sources" and the "sinks."
You appear to be drivelling, as is your wont.
>
> I put quotes around "photon" because as I have asserted before,
> "photons" are imaginary objects.
Your asserion is your own business. It has nothing to do with reality.
> One could just as correctly
> assert that angels conveyed a change between a cause and an
> effect, as the only thing that can be measured is an
> interaction time.
>
> I have zero interest in any particular "effect".
> These are side issues that obscure the issue and generate noise.
>
> I want to know something more basic and general.
> I want to know where "space" resides.
Fool.
Franz Heymann
Steve Carlip
> In sci.astro Martin Green <btes...@home.com> wrote:
>> Instead, [textbooks] use the much weaker (and
>> totally erroneous) argument about the power
>> density of the beam compared with the cross-sectional
>> area of the individual atom.
> I just looked at the eleven quantum texts I have in my office.
> (I get lots of free samples from publishers hoping I'll use
> them in a course.) None of them gave anything like this
> argument.
On the other hand, I did find one first year undergraduate
text that made this mistake (Lea and Burke, example 35.1).
And there's a phrase in Tipler's text that probably could be
given that interpretation, though it's mentioned only in passing.
None of the other six first year textbooks I checked made the
same error; most had a mention of prompt electrons and the
disagreement with classical theory, but with no specifics.
Steve Carlip
Jon Bell
Steve Carlip <car...@dirac.ucdavis.edu> wrote:
>In sci.astro Martin Green <btes...@home.com> wrote:
>> Instead, they use the much weaker (and
>> totally erroneous) argument about the power
>> density of the beam compared with the cross-sectional
>> area of the individual atom.
>
>I just looked at the eleven quantum texts I have in my office.
>(I get lots of free samples from publishers hoping I'll use
>them in a course.) None of them gave anything like this
>argument.
For what it's worth, I have two that do: Beiser's "Concepts of
Modern Physics" (1995 ed.) and Eisberg and Resnick's "Quantum Physics"
(1985).
--
Jon Bell <jtbe...@presby.edu> Presbyterian College
Dept. of Physics and Computer Science Clinton, South Carolina USA
Martin Green
time. I don't know why Steve seems to be challenging
me on this point.
Just to clarify things, there are quite a few different
ways in which this argument is commonly made:
In addition, all these arguments can be made either
with or without a supporting reference; and the
reference given may or may not in fact support
the argument:
1. Prompt electrons cannot be explained by
classical e-m (no specific mention of how they
would be calculated.)
2. Prompt electrons cannot be explained by
classical e-m because of the power density
compared to the atomic cross-section.
3. Prompt electrons cannot be explained by
classical e-m because of the power density
compared to the "lambda-squared" scattering
cross-section of an atom.
4. Prompt electrons cannot be explained by
classical e-m because of the total energy
flux over the area of the cathode.
The arguments I see most often are (1) and (2).
I have never seen argument (3) made until
Steve posted an interesting reference earlier
today. I have encountered argument (4) several
times in sci.physics, although never with a reference.
I think Steve himself made this argument at one
point.
The truth seems to be that many so-called examples
of prompt electrons can indeed be explained by
a semi-classical theory. Of the possible exceptions,
case (4) would certainly be the most convincing
argument against the wave theory of light. However,
it comes very close to violating the conservation of
energy. I wonder if it's ever been verified experimentally?
Martin Green
http://www.onforeignsoil.com
The book that starts in English
and turns to Yiddish.
"Jon Bell" <jtbe...@presby.edu> wrote in message
news:H0szM...@presby.edu...
Tom Potter
It looks to me like this poster is bucking for Varney's job.
Give it up.
I knew Varney, and you are no Varney!
Tom Potter
Mike Varney
"Tom Potter" <t...@earthlink.net> wrote in message
news:f76e0bb3.02081...@posting.google.com...
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
<SNIP>
> > Fool.
>
> It looks to me like this poster is bucking for Varney's job.
The pay sucks and the hours are long.
> Give it up.
> I knew Varney, and you are no Varney!
Since you actually know nothing Potter, your statement (along with all of
your statements) is vacuous.
Bilge
>If you are an objective scientist you can do this. Do not bother me
>with indirect critisicm or the statements from your theoretical
>science. I only want a direct critisicm of the principles I have tried
>to outline very simply. My e-mail address is there if you are able to
>point out the fallacy of my engineering.
Here's a direct criticism of one of your comments:
"Quantum theory does not effectively deal with the issue of the Coulomb
repulsion or how this powerful force of the protons is integrated into the
nuclear Z value."
That is patently false. Have you ever heard of the nuclear shell model?
>If a person has several hours to recreate this study, one will achieve
>definite results. This study outlines a PROOF. As simple and accurate
>proof as was ever derived. This proof, if valid, proves a secondary
>proof of the error of theoretical physics. It is very simple and
>absolute. I am looking at this proof. Until you can show me otherwise,
>I am the judge looking at the video of kids stealing candy. The
>denials and lies are meaningless.
Since you have no results, you can claim anything.
>If you have any validity as a scientist you can objectively critisize
>this study.
Since you don't believe nuclear forces exist, explain the selection
rules for beta decay, since those are experimentally observable.
Explain parity violation.
Bilge
>
>I suggest that it is very clear that I am talking about getting
>references to ANY experiments that clearly show what the time
>delay is between a cause and an effect involving "photons"
>and "electrons".
Then by picking microwaves, you answered your question very simply.
You can "shine" a microwave on potassium metal forever and it won't emit
electrons from the surface.
[...]
>I put quotes around "photon" because as I have asserted before,
>"photons" are imaginary objects. One could just as correctly
>assert that angels conveyed a change between a cause and an
>effect, as the only thing that can be measured is an
>interaction time.
>
>I have zero interest in any particular "effect".
Of course not. Those would ruin your notion that photons are imaginary
constructs.
>These are side issues that obscure the issue and generate noise.
>I want to know something more basic and general.
Go study the lamb shift.
>I want to know where "space" resides.
It resides between "things".
Tom Potter
"Mike Varney" <var...@collorado.edu> wrote in message
news:ajcq15$on5$1...@peabody.colorado.edu...
Oh!
So Franz Heymann and Mike Varney
are one and the same!
--
Tom Potter http://home.earthlink.net/~tdp
eshal
"Steve Harris" <sbha...@ix.RETICULATEDOBJECTcom.com> wrote in message
news:aiso85$511$1...@slb5.atl.mindspring.net...> news:HFi49.114598$f05.6...@news1.calgary.shaw.ca...
> > That's an interesting argument. I've seen the numbers: the
> > calculation involves multiplying the power intensity of the
> > wave by the cross-sectional area of the target atom, and
> > finding a huge discrepancy.
> >
> > This is a very deceptive argument and a very wrong one.
> > There are two cases to analyze...the bulk photo-electric
> > effect (light incident on a metal plate), which is the
> > common textbook case, and the single-atom effect,
> > e.g. the photo-ionization of monatomic hydrogen.
> >
> > First the photo-ionization of hydrogen: in a semi-classical
> > analysis, this is similar to power being absorbed by a
> > small antenna. The superposition of the bound electron
> > and the free electron states gives you the oscillating
> > charge...that's the antenna. The incident light is the
> > e-m wave driving the antenna. And the reason it
> > works with no delay is purely classical: it is a little-known
> > result of classical e-m theory that a small, lossless, tuned antenna
> > actually absorbs power over a cross-sectional area many
> > times larger than the size of the antenna....in fact, its
> > absorption cross-section is on the order of the wavelength
> > of the incident radiation.
>
>
> COMMENT:
>
> Yeah, we've all seen it-- that little ferrite antenna in an AM transistor
> radio is absorbing kHz radiation out of a much larger cross sectional area
> of the field than can possibly be hitting it. I think the classical
> explanation is that the driven antenna sets up its own field which is much
> bigger than it is, and this goes out and anhihilates the EM field passing
> by, over a large area.
I like that idea.. It brings to mind that the antenna sets up it own field
as a standing wave in the Aether. These waves do not so much as establish
extension by expanding the properties of the antenna, so much as, the
standing field works like the formation of an optic image. That is, the
image always fits upon the lens.
So the suggestion would be to consider these 'standing waves' so more
'focus' the incoming EM in such manner, as any relative size between the
actual wave amplitude is always suffice for the area of exposure of the
antenna.
No matter how big or how small we make our lens, the image formed is always
the right size for its frame. So the idea of an epicentre of Aetheric
standing waves would in effect supply the necessary geometry to 'guide in'
the energy covering a wider area.
> But how do you make that mechanism work for single photons? It's not a
> problem for the antenna in your AM radio because the energies are never
low
> enough to be absorbing single photons. But for an atom, the mechanism has
> problems, because classically now you have to have this counter-inductioin
> field going out from the atom and grabbing energy out of a big cross
> sectional area,
Isn't that unusual it should behave as such. I am putting some ideas
together regarding this now. We are going to be able to find the correct
solutions by running it through the right geometric operations.
I think there are surprising results to be gained by considering the notion
for standing wave centres in the Aetheric substructure. This would explain
how a particle is able to be so informed about its environment and at the
same time be so informative.
These waves are going to present a new class of physical study.
How the synchronicity is arcing across this ng.
> and the nearby atoms which may be within that area are
> supposed to know that they're not to be doing the same thing, but have to
> keep quiet, since the atom that is going to be doing all the absorbing in
a
> given volume has already been "chosen." That's pretty hard to believe
> classically. It's sort of like having a bunch of AM radio's in a box, and
> the radio wave is so low powered that only one of the radios ever plays at
a
> time. One plays, then it stops and another picks up the tune, and so on.
>
> Explain that, Maxwell.
Yes, I think the idea of an epicentric standing wave could rise to the
occasion and give a geometric explanation to the behaviours as such you have
raised as concern.
(-:
em
Edward Green
It's unfortunate that it seems impossible to attack arguments and
logic without being perceived to attack the whole edifice.
I've had the same experience in the past. When I have merely tried to
suggest that the typical discussions of the two slit experiment taken
to demonstrate "weirdness" leave open a range of possibilities to the
critical reader, this has been instantly generalized to "attacking
quantum mechanics". Indeed, such an erudite and educated poster as
Michael Weiss, who is probably sharper than either me or you, Bilge,
could hear no other message.
It's as if one were trying to make a simple proposition in logic about
the fidelity of a man's wife. Emotion and anger quickly overwhelm
logic. But all we are talking about is whether some simple effects or
thought experiments really establish what they are believed to
establish.
The honor of quantum mechanics and physics remains intact.
Physicist's wives are, so far as I know, faithful to them.
eshal
>
> "Martin Green" <btes...@home.com> wrote in message
> news:HFi49.114598$f05.6...@news1.calgary.shaw.ca...
>
>
> > For the bulk photo-electric effect, the logic is a bit different,
> > but again, it hinges on a misconception of the correct
> > absorption cross-section. The size of the atom has nothing
> > to do with it...it is "well-known" that the overlapping wave functions
> > of electrons in metal fill the whole volume of the metal.
> > So there is no reason to think that the energy should have
> > to concentrate itself in a single atom.
>
> This is what is called having your cake and eating it.
> If you want to talk classical physics, stick to classical; physics.
> Don't drag in red herrings like electron wave functions. How the hell
> are you going to calculate classically the rate of energy transfer
> between a classical EM wave and an "electronic wave function"?
>
> Franz Heymann
We thought you could manage that... (-;
em
Chuck Simmons
Hmmm! In the parent thread to this thread, you did not manage very well
when I tore to shreds your idea of photons "organizing" themselves by
using geometric optics alone. There seems to be a problem in recognizing
the domain of applicability of theorys resulting in a lot of mixing
apples and oranges and labeling them as pomegranates.
Chuck
--
... The times have been,
That, when the brains were out,
the man would die. ... Macbeth
Chuck Simmons chr...@webaccess.net
Mike Varney
> *** post for FREE via your newsreader at post.newsfeed.com ***
>
>
> "Mike Varney" <var...@collorado.edu> wrote in message
> news:ajcq15$on5$1...@peabody.colorado.edu...
> >
> > "Tom Potter" <t...@earthlink.net> wrote in message
> > news:f76e0bb3.02081...@posting.google.com...
> > > "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> > news:<ajb06t$9ge$6...@helle.btinternet.com>...
> > <SNIP>
> > > > Fool.
> > >
> > > It looks to me like this poster is bucking for Varney's job.
> >
> > The pay sucks and the hours are long.
> >
> > > Give it up.
> > > I knew Varney, and you are no Varney!
> >
> > Since you actually know nothing Potter, your statement (along with all
of
> > your statements) is vacuous.
>
> Oh!
> So Franz Heymann and Mike Varney
> are one and the same!
Another vacuous statement.
QED.
Pmb
> In sci.physics Martin Green <btes...@home.com> wrote:
>
> > I said previously, and I continue to maintain: there is no
> > honest argument that can be made at the undergraduate
> > level to justify the assertion that light is made up of particles
> > rather than waves.
>
> How about prompt electrons in the photoelectric effect?
> Look at the photoelectric efect with a very low intensity light
> source. If light is a classical wave, it should take time for it
> to build up enough energy to eject an electron. Instead,
> one observes that the first electrons are emitted with no
> delay.
>
Actually Einstein never really liked the idea of photons. More
recently Willis Lamb (Nobel Lauriate i.e. "lamb shift") wrote a paper
"Anti-Photon", published in Applied Physics B. where he argues that
photons don't exist, or rather one never needs to invoke the idea of a
photon.
Or in Lamb's own words (See http://www.aro.army.mil/phys/proceed.htm)
"Over a period of over fifty years, I have come to a number of
conclusions about quantum mechanics. I will enumerate some of them as
eight numbered statements:
[...]
(8). There is no such thing as a photon. There is a quantum theory of
radiation, and conservation laws for energy, momentum and angular
momentum are built into it. Only in very simple special cases, hard to
realize in practice does it make sense to talk about photons."
Pmb
Martin Green
Lamb might have written that after spending a day
or two lurking in sci.physics.
Martin Green
http://www.onforeignsoil.com
The book that starts in English
and turns to Yiddish.
> > > I said previously, and I continue to maintain: there is no
Steve Carlip
> Thanks, Jon. Of course this argument is made all the
> time. I don't know why Steve seems to be challenging
> me on this point.
I was completely prepared to believe this. But then---call
me a fool---I decided I might as well take fifteen minutes
to check the books I had sitting beside my desk, and I
found, to my surprise, that most were better than I had
expected.
> Just to clarify things, there are quite a few different
> ways in which this argument is commonly made:
> In addition, all these arguments can be made either
> with or without a supporting reference; and the
> reference given may or may not in fact support
> the argument:
> 1. Prompt electrons cannot be explained by
> classical e-m (no specific mention of how they
> would be calculated.)
This is by far the most common approach in the
books I looked at.
> 2. Prompt electrons cannot be explained by
> classical e-m because of the power density
> compared to the atomic cross-section.
This occurs occasionally, but empirically it's
rare---at least to the extent that ``unsolicited
textbooks sent to me by the publishers'' is a
good sample, and I don't see why it shouldn't
be.
> 3. Prompt electrons cannot be explained by
> classical e-m because of the power density
> compared to the "lambda-squared" scattering
> cross-section of an atom.
This is also empirically very rare.
> 4. Prompt electrons cannot be explained by
> classical e-m because of the total energy
> flux over the area of the cathode.
I've never seen this one.
I actually think approach #1 is a sensible one. The
discussion of the photoelectric effect usually takes
place in a ``historical introduction'' section, whose
purpose is to motivate quantum mechanics, not to
``prove'' it or to discuss all other possible theories.
In particular, semiclassical theories are clearly wrong
---they're not going to give you the Lamb shift, or
the photon-photon scattering cross section, or
antibunching of photons in resonance flourescence
---and I don't see much point in distracting students
who are just beginning to learn the subject.
By analogy, the problem of Mercury's anomalous
precession was known for decades before general
relativity, and lots of elaborate explanations were
concocted, almost all of which failed for reasons
unrelated to Mercury's orbit. Reading about them
is entertaining. But I don't think there's anything
wrong with giving the precession of Mercury as a
piece of evidence for general relativity, without
spending a week explaining why ``Zodiacal light''
doesn't work or giving evidence against Vulcan.
Steve Carlip
Steve Carlip
> But all we are talking about is whether some simple effects or
> thought experiments really establish what they are believed to
> establish.
That's easy, though... the answer is always, ``No.'' No single
experiment, thought or otherwise, ever establishes a theory
or has a unique explanation. Theories become accepted
because of the overwhelming weight of evidence, typically
from many different and independent sources, and because
of the lack of reasonable alternatives. (And because of a
host of other factors, from elegance to fruitfulness to the
degree they fit with other theories.)
Thought experiments, and for that matter the relatively
small sample of real experiments used in introductory
courses to motivate a theory, are a form of propaganda.
They're deliberate oversimplifications, designed to give
students a reason to slog through the enormous amount
of learning they'll have to do to really understand the
experimental basis of the theory.
And there's nothing wrong with that.
Steve Carlip
Martin Green
that can be made against the wave theory of light:)
> > 4. Prompt electrons cannot be explained by
> > classical e-m because of the total energy
> > flux over the area of the cathode.
Steve Carlip replied:
> I've never seen this one.
Then what argument were you yourself making on
August 9th when you wrote:
" ..............................................................there's a
finite probability of two electrons being ejected in the first
minute, even though the first minute's worth of radiation only
has enough energy to eject one electron. Energy conservation
is no longer exact; it holds only statistically.
"While I don't know an experimental reference off hand, I'm sure
experiments of this sort have been done. (They're mentioned,
though without a citation, in Bransden and Joachain's text......"
Martin Green
> > But all we are talking about is whether some simple effects or
> > thought experiments really establish what they are believed to
> > establish.
Steve Carlip replied:
> That's easy, though... the answer is always, ``No.'' No single
> experiment, thought or otherwise, ever establishes a theory
> or has a unique explanation. Theories become accepted
> because of the overwhelming weight of evidence, typically
> from many different and independent sources
And later in the same later, Steve appears to justify the
shoddy arguments found everywhere in textbooks to
debunk the wave theory of light with the following
excuse:
> They're deliberate oversimplifications, designed to give
> students a reason to slog through the enormous amount
> of learning they'll have to do to really understand the
> experimental basis of the theory.
>
> And there's nothing wrong with that.
If theories are accepted, as Steve says, on the basis of
a preponderance of evidence from many different sources,
how can he say there is nothing wrong with deliberately
"padding" that evidence through false and misleading
arguments?
Tom Potter
"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
news:slrnalkcr...@radioactivex.lebesque-al.net...
> Tom Potter said some stuff about
> >
> >I suggest that it is very clear that I am talking about getting
> >references to ANY experiments that clearly show what the time
> >delay is between a cause and an effect involving "photons"
> >and "electrons".
>
> Then by picking microwaves, you answered your question very simply.
> You can "shine" a microwave on potassium metal forever and it won't emit
> electrons from the surface.
Are you asserting that the photo-electric effect and the work function
concepts are
applicable across the entire EM spectrum and for all materials?
> [...]
> >I put quotes around "photon" because as I have asserted before,
> >"photons" are imaginary objects. One could just as correctly
> >assert that angels conveyed a change between a cause and an
> >effect, as the only thing that can be measured is an
> >interaction time.
> >
> >I have zero interest in any particular "effect".
>
> Of course not. Those would ruin your notion that photons are imaginary
> constructs.
How would you set up an experiment to determine whether a change
is conveyed between a cause and an effect by a photon or an angel?
> >These are side issues that obscure the issue and generate noise.
> >I want to know something more basic and general.
>
> Go study the lamb shift.
>
> >I want to know where "space" resides.
>
> It resides between "things".
What is the density of space?
How do you differentiate between a space, an aether, and a field?
Does it move around between "things" or just sit there?
Is there one or two spaces between a pair of things,
or do all "things" share the same space?
What kind of experiment would you use to determine
if space was between "things", or in "things"?
Thank you in advance for sharing your knowledge with me
and the group on this subject.
dlzc@aol.com (formerly)
> If theories are accepted, as Steve says, on the basis of
> a preponderance of evidence from many different sources,
> how can he say there is nothing wrong with deliberately
> "padding" that evidence through false and misleading
> arguments?
Try teaching QM to a kindergartener. You build the picture up in steps,
like the blind men describing the elephant. They don't teach you about
negative numbers until you are ready either.
Does the garbage man need to know that light is a whole lot less like a wave
than a particle? He could probably live a long happy life in his civil
service job...
David A. Smith
James Hunter
"dl...@aol.com (formerly)" wrote:
> Dear Martin Green:
>
> Try teaching QM to a kindergartener. You build the picture up in steps,
> like the blind men describing the elephant. They don't teach you about
> negative numbers until you are ready either.
>
> Does the garbage man need to know that light is a whole lot less like a wave
> than a particle? He could probably live a long happy life in his civil
> service job...
The garbage man needs to know what "a whole lot less" means,
so that when they accidently dump toxic waste on scientists,
that can just say:
Not my problem, just go sue some unemployed physicist moron,
since I'm only a Professor of Mathematics.
>
> David A. Smith
Franz Heymann
[snip]
> > 4. Prompt electrons cannot be explained by
> > classical e-m because of the total energy
> > flux over the area of the cathode.
>
> I've never seen this one.
I observed this in the 1970's. I have no doubt that other folk who were
interested in calibrating the single photoelectron pulse height spectra
of photomultipliers also observed it. I certainly considered the
phenomenon to be too trivial to bother publishing the results.
Franz Heymann
Bilge
Re: What evidence for photons? to usenet:
>> Try looking up "quantum beats". The explanation is very straight-
>> forward and requires only the ability to comprehend interference.
>> Since the interference arises from the inseparability of of a quantum
>> state, it has no classical explanation.
>
>It's unfortunate that it seems impossible to attack arguments and
>logic without being perceived to attack the whole edifice.
Huh?
>I've had the same experience in the past. When I have merely tried to
>suggest that the typical discussions of the two slit experiment taken
>to demonstrate "weirdness" leave open a range of possibilities to the
>critical reader, this has been instantly generalized to "attacking
>quantum mechanics".
Then, you've missed my entire point, which is that what you are
referring to as "a range of possibilities to the critical reader", I'm
suggesting is due to you being insufficiently critical in the reasoning
that would lead you to believe there is some advantage to the alternatives
as though quantum mechanics is only accepted with reluctance and lack of
something "better". I have no doubt that, for any given phenomenon, you
(or at least someone) can arrive at a perfectly reaonable and perhaps even
useful phenomenological model. Nuclear physics is sort of the ulitimate
example of this, because one has no choice.
I claim that you were _never_ justified in equating classical wave
phenomena to light, by any argument meeting the same criteria that was
given to justify the existence of photons (i.e. the average undergraduate)
Furthermore, any classical wave is equivalent to a description in terms of
classical particles. Specifically, let me quote from "Classical
Mechanics", 2nd ed. goldstein. I think most will agree he is well versed
in the subject. If you have the book, it's from Section 10-8 on
geometrical optics and wave mechanics, pg 489:
"It is now clear why Huygens' wave theory and Newton's light
corpuscles were able to account equally well for the phenomena
of reflection and refraction, for both theories of geometrical
optics are formally identical."
and further below:
"All that has been determined is that the wavelength must be very
much smaller than the spatial extension of the forces and potentials.
Further than this we cannot go within the realm of classical mechanics.
As a species of geometrical optics, classical mechanics is precisely
the field in which phenomena depending upon wavelength (interference,
diffraction, etc.) cannot occur."
In other words, a classical wave is incapable of exhibiting interference
phenomena in the realm in which you truly have interference rather than
an artifact of the geometrical optics limit. For a classical wave,
you can count the crests and troughs from each source. The interference
pattern is determined by just looking at the phase of each wave indepen-
dently and summing the amplitudes. If you try that with two light sources,
even of same frequency, you won't get an interference pattern. Using
a classical argument that doesn't involve any quantum mechanics, explain
what determines whether two light waves should be summed coherently or
incoherently.
>Indeed, such an erudite and educated poster as
>Michael Weiss, who is probably sharper than either me or you, Bilge,
>could hear no other message.
>
>It's as if one were trying to make a simple proposition in logic about
>the fidelity of a man's wife. Emotion and anger quickly overwhelm
>logic. But all we are talking about is whether some simple effects or
>thought experiments really establish what they are believed to
>establish.
And I think you have missed the point. I'm questioning the validity of
every single assumption upon which you are basing the thought experiments
in the first place, not whether you can assume your assumptions are valid
and explain the effects. That to which I am objecting is your implication
that the lack of "critical reading" is on my part, due to an unwillingness
to follow your arguments. Following your arguments is not the issue and
in my opinion, what is being accepted uncritically is the premises upon
which you could possibly base _any_ argument. Have you ever considered
the possibility that interference in classical phenomena and quantum
phenomena bear nothing but a superficial similarity and that conditions
for quantum interference are precisely those which the conditions for
classical interferare rule out? In efect, "quantum wierdness" as you put
it, _is_ quantum interference. You get classical interference once the
"quantum weirdness" has been averaged out.
Aleksandr Timofeev
Well. Whether you can give physical interpretation of principles of
operation for an VLBI interferometer from the photon point of view?
There are two graphic schemes illustrating the description:
Step 1.
The microwave interferometer with superlong basis. Part 1.
----------------------------------------------------------
Block scheme.
. [videotape 1] [videotape 2]
. ^ ^
. | |
. radio-receiver 1 radio-receiver 2
. | |
. | Length of VLBI basis >= Earth diametr |
. |<--------------------- {snip} ------------------>|
. /^\ antenna 1 antenna 2 /^\
.^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ {snip} ^ ^ ^ ^ ^ ^ ^ ^
.| | | | | | | | | | | | | | | | | | | | | | |
. Noise microwave radiation
VLBI interferometer simultaneously record the information
reflecting a state of an electromagnetic field in space of each
slot (from the antenna) on a magnetic tape, it is natural that
for each slot/antenna we use a separate magnetic tape.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Step 2.
. The microwave interferometer with superlong basis. Part 2.
. ----------------------------------------------------------
. "Interference picture"
. ^
. |
. [videotape 1] ------> [ COMPUTER ] <---------- [videotape 2]
The VLBI interference is a new kind of an interference -
so-called postponed in time or virtual interference, i.e.
abstractly or mathematically realizabled interference in the
computer.
In any time, convenient for us, we input the information from
macroscopic magnetic tapes in the computer and mathematically
on any required (demanded) algorithm (which can be changed at any
time) we obtain an interference in representation, necessary for us.
The physical principles of operation of an VLBI interferometer
enable physically to divide two physical processes:
Step 1. Process of transiting of electromagnetic radiation through
slots of an interferometer.
Step 2. Process of shaping of an interference picture.
Note 1. The interference picture in VLBI interferometer is pure
mathematical abstraction, since the construction of an interference
picture is carried out in the computer.
Note 2. Here there is no direct physical process of addition "
of waves " passing through slots!
How does the possibility of addition
" of parts of a single photon " from two magnetic tapes?
Is it possible? Or is it impossible?
http://groups.google.com/groups?selm=e16a4a22.0205290718.4a5d6982%40posting.google.com
Regards
Aleksandr Timofeev
>
> Steve Carlip
Randy Poe
> "Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> news:slrnalkcr...@radioactivex.lebesque-al.net...
> > You can "shine" a microwave on potassium metal forever and it won't emit
> > electrons from the surface.
>
> Are you asserting that the photo-electric effect and the work function
> concepts are
> applicable across the entire EM spectrum and for all materials?
Are you reading a sentence that you WON'T see a photoelectric
effect with microwaves, and interpreting it to mean that you
WILL see a photoelectric effect with microwaves?
- Randy
Pmb
> Thanks, Pmb. What a great link (to Lamb's letter)!
> Lamb might have written that after spending a day
> or two lurking in sci.physics.
You're welcome. Yeah. It was a cool paper i.e. I have the paper he
wrote on the subject. Photon's! Tricky stuff. After reading that paper
I decided to not take the concept as a given anymore.
Pmb
Pmb
> Thanks, Pmb. What a great link (to Lamb's letter)!
> Lamb might have written that after spending a day
> or two lurking in sci.physics.
Cool quote of the day
"All these fifty years of pondering have not brought me any closer to
answering the question, What are light quanta?" - Albert Einstein (in
letter to Besso 1951)
:-)
Pmb
Edward Green
> Martin Green wrote:
> > > First the photo-ionization of hydrogen: in a semi-classical
> > > analysis, this is similar to power being absorbed by a
> > > small antenna. The superposition of the bound electron
> > > and the free electron states gives you the oscillating
> > > charge...that's the antenna. The incident light is the
> > > e-m wave driving the antenna. And the reason it
> > > works with no delay is purely classical: it is a little-known
> > > result of classical e-m theory that a small, lossless, tuned antenna
> > > actually absorbs power over a cross-sectional area many
> > > times larger than the size of the antenna....in fact, its
> > > absorption cross-section is on the order of the wavelength
> > > of the incident radiation.
>
>
> > Yeah, we've all seen it-- that little ferrite antenna in an AM transistor
> > radio is absorbing kHz radiation out of a much larger cross sectional area
> > of the field than can possibly be hitting it. I think the classical
> > explanation is that the driven antenna sets up its own field which is much
> > bigger than it is, and this goes out and anhihilates the EM field passing
> > by, over a large area.
>
>
> > But how do you make that mechanism work for single photons? It's not a
>
>
> > problem for the antenna in your AM radio because the energies are never
> low
> > enough to be absorbing single photons. But for an atom, the mechanism has
> > problems, because classically now you have to have this counter-inductioin
> > field going out from the atom and grabbing energy out of a big cross
> > supposed to know that they're not to be doing the same thing, but have to
> > keep quiet, since the atom that is going to be doing all the absorbing in
> a
> > given volume has already been "chosen." That's pretty hard to believe
>
> But my physics textbooks tell me that classical e-m CANNOT explain
> the early photo-emissions. I have gone ahead and done the calculation
> that explains it for the single atom case. I object to your by-passing that
> example and requiring me to now do the (much more difficult) multi-atom
> calculation. Remember, the terms of my "challenge" were that you should
> be able to de-bunk classical e-m with an argument that can be understood
> at the level of undergraduate physics.
>
> > classically. It's sort of like having a bunch of AM radio's in a box, and
> > the radio wave is so low powered that only one of the radios ever plays at
> a
> > time. One plays, then it stops and another picks up the tune, and so on.
>
> with each other. Do you doubt that one will get louder while
> another gets softer? In any case, unlike an AM radio, an atom is
> a perfectly lossless scattering element. So unless it aborbs enough
> energy to go from an S to a P level, whatever it takes in will be
> returned to the ambient field. Why shouldn't one of the atoms
> in the ensemble eventually hold on to the quantum of energy?
>
> > Explain that, Maxwell.
>
> Not my responsiblity.
> I never claimed I could solve the three-body problem, or do
> any calculation that someone posted on the Internet. Remember
> the terms of my challenge: you (not me) were asked to show, using
> arguments understandable at the undergraduate level, that there
> are physical phenomena that absolutely cannot be explained
> using classical e-m.
Lamb's comment is interesting: he says there is a quantum theory of
radiation, which only rarely manifests itself in ways describable as
"photons".
BTW your comment on the photoelectric effect in metals is interesting:
since we know the electrons are distributed in delocalized bands, why
should we expect that the absorbtion cross-section is on the order of
an atomic cross-section?
Notice that you have been inelectably drawn into the role of defender:
by merely suggesting that certain story book experiments do not close
the logical loop on "photons", you are cast as the hostile outsider;
as a friend once said, it's a religious issue ... "what if she were
not a virgin ...?".
Patrick Reany
Martin Green wrote:
That a theory is accepted as a good theory does
NOT mean that its models are TRUE. And the
fact that someone believes that a model is FALSE
does NOT mean that the model can't be successfully
used in a theory! Physical concepts are free creations
of the human mind, and are not, uniquely determined
by the external world (Einstein).
Patrick
Patrick Reany
Pmb wrote:
> [snip]
> > How about prompt electrons in the photoelectric effect?
> > Look at the photoelectric efect with a very low intensity light
> > source. If light is a classical wave, it should take time for it
> > to build up enough energy to eject an electron. Instead,
> > one observes that the first electrons are emitted with no
> > delay.
> >
> > Steve Carlip
>
> Actually Einstein never really liked the idea of photons.
How about some references for this claim of yours?
> More
> recently Willis Lamb (Nobel Lauriate i.e. "lamb shift") wrote a paper
> "Anti-Photon", published in Applied Physics B. where he argues that
> photons don't exist, or rather one never needs to invoke the idea of a
> photon.
>
> Or in Lamb's own words (See http://www.aro.army.mil/phys/proceed.htm)
>
> "Over a period of over fifty years, I have come to a number of
> conclusions about quantum mechanics. I will enumerate some of them as
> eight numbered statements:
> [...]
> (8). There is no such thing as a photon. There is a quantum theory of
> radiation, and conservation laws for energy, momentum and angular
> momentum are built into it. Only in very simple special cases, hard to
> realize in practice does it make sense to talk about photons."
>
> Pmb
Patrick
Martin Green
> > Thanks, Pmb. What a great link (to Lamb's letter)!
> > Lamb might have written that after spending a day
> > or two lurking in sci.physics.
>
> You're welcome. Yeah. It was a cool paper i.e. I have the paper he
> wrote on the subject. Photon's! Tricky stuff. After reading that paper
> I decided to not take the concept as a given anymore.
>
> Pmb
My own personal "epiphany" came as an electrical
engineering grad student, when I first did the calculation
of the absorption cross-section of a small dipole antenna.
That's when I realized the physics textbooks had no
business in using the physical cross-section of an atom
as the appropriate cross-section for calculating the
"impossibility" of prompt photon emission with the
wave theory. I find it hard to understand why seemingly intelligent
people in this newsgroup continue support the use
of this kind of sophistry.
Franz Heymann
"Edward Green" <null...@aol.com> wrote in message
news:2a0cceff.02081...@posting.google.com...
The fact that the electronic wavefunction is spread over the whole
crystal does not mean that that is the size of the electron. The
wavefunction simply tells us someting about the likelihood of finding an
electron somewhere. (It tells us other things as well, of course!)
[snip]
Franz Heymann
Steve Carlip
Pretty muchb what I said: that I'm sure the experiments have
been done, but I haven't seen a reference.
(Perhaps you lost track of the context: the ``I've never seen this
one'' that you quote is in my description of what I found when
I looked at a sample of textbooks. The Bransden and Joachain
reference is vague enough that it's unclear what specific comparison
they're making.)
Steve Carlip
Bilge
>
>
>"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
>news:slrnalkcr...@radioactivex.lebesque-al.net...
>> Tom Potter said some stuff about
>> >
>> >I suggest that it is very clear that I am talking about getting
>> >references to ANY experiments that clearly show what the time
>> >delay is between a cause and an effect involving "photons"
>> >and "electrons".
>>
>> Then by picking microwaves, you answered your question very simply.
>> You can "shine" a microwave on potassium metal forever and it won't emit
>> electrons from the surface.
>
>Are you asserting that the photo-electric effect and the work function
>concepts are applicable across the entire EM spectrum and for all
>materials?
>
>> [...]
>> >I put quotes around "photon" because as I have asserted before,
>> >"photons" are imaginary objects. One could just as correctly
>> >assert that angels conveyed a change between a cause and an
>> >effect, as the only thing that can be measured is an
>> >interaction time.
>> >
>> >I have zero interest in any particular "effect".
>>
>> Of course not. Those would ruin your notion that photons are imaginary
>> constructs.
>
>How would you set up an experiment to determine whether a change
>is conveyed between a cause and an effect by a photon or an angel?
the decay of a nucleus by positron emission left the daughter in an
one of several low-lying states which subsequently decayed by emission
of a gamma ray. Furthermore, the gamma ray detectors were compton
supressed HPGe. A large fraction of the gammas that compton scatter
and don't deposit all of their energy in the Ge, end up in the compton
shields and you can easily tag the compton scatters and see it in the
spectra.
>> >These are side issues that obscure the issue and generate noise.
>> >I want to know something more basic and general.
>>
>> Go study the lamb shift.
>>
>> >I want to know where "space" resides.
>>
>> It resides between "things".
>
>What is the density of space?
I believe you can find that data at nasa or jpl. For intergalactic
space it's something like 1 hydrogen atom in a cubic meter.
>How do you differentiate between a space, an aether, and a field?
What do you mean how do I differentiate between them? That's
like asking how does one differentiate between a car, santa clause
and a shoe.
>Does it move around between "things" or just sit there?
Does what move? Space? No. That's why it's space. Things move.
>Is there one or two spaces between a pair of things,
>or do all "things" share the same space?
If "things" didn't have the space between them in common, "things"
could not interact with each other. You seem to take this space bit
too seriously. Give objects a label with numbers on them. The
distance between them is the difference in the numbers on the label.
>What kind of experiment would you use to determine
>if space was between "things", or in "things"?
I stand up and notice that my face isn't staring point blank into
the wall. I decide to define that experience as an observation of
space.
Look. The reality is that what you can measure is reality. I
suggest making the most of it, since anything you can't measure
can't affect the outcome of anything, nor can you ever hope to
deduce such an unmearsurable quantity, since it would have a
non-effect on everything, which would be a serious handicap as
far as hints go.
Martin Green
Steve Carlip wrote:
> (Perhaps you lost track of the context: the ``I've never seen this
> one'' that you quote is in my description of what I found when
> I looked at a sample of textbooks.
Then you probably should have said, "I didn't see this one."
Steve Carlip
> And later in the same later, Steve appears to justify the
> shoddy arguments found everywhere in textbooks to
> debunk the wave theory of light with the following
> excuse:
>> They're deliberate oversimplifications, designed to give
>> students a reason to slog through the enormous amount
>> of learning they'll have to do to really understand the
>> experimental basis of the theory.
>> And there's nothing wrong with that.
> If theories are accepted, as Steve says, on the basis of
> a preponderance of evidence from many different sources,
> how can he say there is nothing wrong with deliberately
> "padding" that evidence through false and misleading
> arguments?
You've never taught an undergraduate quantum mechanic
course, have you?
Here at UC Davis, we have about 23 hours of class time,
including a midterm, after which students are supposed
to know how to solve the Schrodinger equation for a free
particle, a finite square well, barrier penetration, and the
harmonic oscillator; understand and use the probabilistic
interpretation (not easy, since most of them have had little
exposure to even basic classical probability theory) and
calculate probabilities and probability currents for things
like superpositions of Gaussians; be able to work with
operators (which, again, most of them have never seen
before) and compute expectation values and uncertainties;
derive and understand the uncertainty relations; quickly
perform Fourier transforms between the position and the
momentum representations (they've had minimal exposure
to Fourier transforms at all), and also express wave functions
in other bases like the energy basis; and be comfortable
with the creation and annihilation operator approach to
the harmonic oscillator.
If they can't do this, and do it well, they'll be lost when they
get to the second quarter, also about 23 hours of class time,
at the end of which they should be able to derive the spectrum
of the hydroge atom, including fine structure corrections and
the Stark effect; understand the algebra and representation
theory of angular momentum, including spin 1/2 and at least
a little about Clebsch-Gordan coefficients and the addition
of angular momentum; compute spin precession in a magnetic
field; understand the exclusion principle and be competent at
symmetrizing and antisymmetrizing wave functions; derive
both nondegenerate and degenerate perturbation theory;
derive and understand Fermi's Golden Rule and do actual
computations of such things as the semiclassical photoelectric
effect; know enough time-dependent perturbation theory to
be able to compute electron-proton scattering in the Born
approximation; and understand and be able to compute
scattering cross-sections and lifetimes.
This, like most courses in quantum theory, is not a course for
dilettantes. The assumption is that our students are going to
be *using* quantum mechanics, and that they have to learn
the concrete, nitty-gritty details.
You are proposing a redesign of this and similar courses that
would, as far as I can tell, require that I spend about a third
of the course on ``experimental evidence for photons.'' It's
not even clear how I would do that: how do I explain, say, the
anomalous magnetic moment of the electron in any sort of
convincing way before the students have seen spin 1/2? How
much time should I spend on classical electrodynamics, to
derive the classical cross-section of a small resonator, before
explaining that while this gives a classical explanationof some
aspects of the photoelectric effect, it fails to explain others?
How much time should I spend on theories that are known
to be wrong, like the BKS model?
I certainly agree that one shouldn't lie to students. One should
not claim, for instance, that the photoelectric effect by itself
conclusively disproves a wave theory of light. If you point to
specific instances where textbooks make such false claims, I
will happily join you in your objection.
I also think many texts and courses could be made better by
focusing less on the rather uneven historical development of
quantum mechanics, and more on modern experiments
(single photon in a beam splitter, cavity QED, etc.) that, by
virtue of improved technology, allow for much more clear-cut
demonstrations of inherently quantum phenomena. But when
I've given examples of such experiments, you've consistently
objected, for no clear reason that I can see.
Steve Carlip
Pmb
> How about some references for this claim of yours?
I've read them over the years. I can't recall exactly where I read
them all though but they stuck in my mind. Maybe it was in Willis
Lambs paper.
However I did find a comment by Einstein on photons.
In a letter of December 12, 1951 Albert Einstein wrote to his
long-time friend Michele Besso:
"The whole fifty years of conscious brooding have not brought me
nearer to the answer to the question `What are light quanta?'.
Nowadays every scalawag believes that he knows what they are, but he
deceives himself."
I'll try to find the one I was thinking of.
Pmb
Jon Bell
relativity or astronomy. ]
In article <ajh5d9$avl$4...@woodrow.ucdavis.edu>,
Steve Carlip <car...@dirac.ucdavis.edu> wrote:
>
>I also think many texts and courses could be made better by
>focusing less on the rather uneven historical development of
>quantum mechanics, and more on modern experiments [...]
I wholeheartedly agree with this, for the introductory "modern physics"
course that usually precedes a full-blown quantum mechanics course. Most
books for this course retrace the historical development of atomic
physics, and thereby spend a lot of time on details of the semiclassical
Bohr model of the atom. Students generally tend to give extra weight to
the first things that they learn about a topic, so they grab onto the
Bohr-model picture of tiny charged balls orbiting in circles (or maybe
ellipses) around the nucleus. They tend to interpret everything else they
see afterwards in terms of that picture, which causes problems later on.
Lately, I've been skipping over more and more of the details of
pre-Schroedinger quantum theory, including Bohr's derivation of the
Rydberg constant, and the common "explanation" of Bohr's quantization
rules in terms of circular deBroglie waves. Instead, I focus on the basic
idea of discrete atomic energy states or "levels" and the
emission/absorption of photons when atoms make a transition between them.
I say something like: "Bohr came up with an explanation for the specific
values of the hydrogen energy levels that turned out to give the wrong
answers for other things. You can see some of the details in your book,
but I'm not going to hold you responsible for them because they're
ultimately incorrect."
--
Jon Bell <jtbe...@presby.edu> Presbyterian College
Dept. of Physics and Computer Science Clinton, South Carolina USA
Tom Potter
> Tom Potter said some stuff about
> Re: What evidence for photons? to usenet:
> >*** post for FREE via your newsreader at post.newsfeed.com ***
> >
> >
> >"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> >news:slrnalkcr...@radioactivex.lebesque-al.net...
> >> Tom Potter said some stuff about
> >> >
> >> >I suggest that it is very clear that I am talking about getting
> >> >references to ANY experiments that clearly show what the time
> >> >delay is between a cause and an effect involving "photons"
> >> >and "electrons".
> >>
> >> Then by picking microwaves, you answered your question very simply.
> >> You can "shine" a microwave on potassium metal forever and it won't emit
> >> electrons from the surface.
> >
> >Are you asserting that the photo-electric effect and the work function
> >concepts are applicable across the entire EM spectrum and for all
> >materials?
>
> Did I say that anywhere?
I suggest that you inferred that,
more than I inferred that I "picked microwaves".
I suggest that I made it very clear that I was interested in getting
references to ANY experiments that clearly show what the time
delay is between a cause and an effect involving "photons"
and "electrons", and was not restricting this to any particular effect.
Unfortunately, I made the assumption that intelligent people
would respond to the essence of post, and not nit pick about wording.
> >> [...]
> >> >I put quotes around "photon" because as I have asserted before,
> >> >"photons" are imaginary objects. One could just as correctly
> >> >assert that angels conveyed a change between a cause and an
> >> >effect, as the only thing that can be measured is an
> >> >interaction time.
> >> >
> >> >I have zero interest in any particular "effect".
> >>
> >> Of course not. Those would ruin your notion that photons are imaginary
> >> constructs.
> >
> >How would you set up an experiment to determine whether a change
> >is conveyed between a cause and an effect by a photon or an angel?
>
> Because I've done \beta-\gamma coincidemce measurements in which
> the decay of a nucleus by positron emission left the daughter in an
> one of several low-lying states which subsequently decayed by emission
> of a gamma ray. Furthermore, the gamma ray detectors were compton
> supressed HPGe. A large fraction of the gammas that compton scatter
> and don't deposit all of their energy in the Ge, end up in the compton
> shields and you can easily tag the compton scatters and see it in the
> spectra.
Explain how you can eliminate angels as a carrier,
and prove that photons exists between a cause and an effect.
> >> >These are side issues that obscure the issue and generate noise.
> >> >I want to know something more basic and general.
> >>
> >> Go study the lamb shift.
> >>
> >> >I want to know where "space" resides.
> >>
> >> It resides between "things".
> >
> >What is the density of space?
>
> I believe you can find that data at nasa or jpl. For intergalactic
> space it's something like 1 hydrogen atom in a cubic meter.
I didn't ask for the density of space plus matter,
I asked for the density of space.
> >How do you differentiate between a space, an aether, and a field?
>
> What do you mean how do I differentiate between them? That's
> like asking how does one differentiate between a car, santa clause
> and a shoe.
In other words, you can't?
> >Does it move around between "things" or just sit there?
>
> Does what move? Space? No. That's why it's space. Things move.
So space just sits there?
> >Is there one or two spaces between a pair of things,
> >or do all "things" share the same space?
>
> If "things" didn't have the space between them in common, "things"
> could not interact with each other. You seem to take this space bit
> too seriously. Give objects a label with numbers on them. The
> distance between them is the difference in the numbers on the label.
So I have to put space labels, like x, y and z on objects?
Does this mean that the space is in the object?
In other words, every object has its' own space, right?
> >What kind of experiment would you use to determine
> >if space was between "things", or in "things"?
>
> I stand up and notice that my face isn't staring point blank into
> the wall. I decide to define that experience as an observation of
> space.
It seems that we are still back at the x,y and z space
is with the objects.
> Look. The reality is that what you can measure is reality. I
> suggest making the most of it, since anything you can't measure
> can't affect the outcome of anything, nor can you ever hope to
> deduce such an unmearsurable quantity, since it would have a
> non-effect on everything, which would be a serious handicap as
> far as hints go.
It seems to me,
that the only thing that exists between a cause and an effect,
is an interaction time.
If this is the case, where does photons and space comein?
In other words, we can measure interaction times.
We can't measure spaces, without introducing unnecessary
things like "rigid measuring rods", "c" and angels.
Tom Potter
Martin Green
> > And later in the same later, Steve appears to justify the
> > shoddy arguments found everywhere in textbooks to
> > debunk the wave theory of light with the following
(snip for brevity)
> >.........how can he say there is nothing wrong with deliberately
> > "padding" that evidence through false and misleading
> > arguments?
Steve replied:
> You've never taught an undergraduate quantum mechanic
> course, have you?
And you're not going to answer my question, are you?
> Here at UC Davis, we have about 23 hours of class time,
> including a midterm, after which students are supposed
> to know how to solve the Schrodinger equation for a free
> particle, a finite square well, barrier penetration
(impressive list of topics snipped for brevity)
> ...................and be able to compute
> scattering cross-sections and lifetimes.
>
> This, like most courses in quantum theory, is not a course for
> dilettantes. The assumption is that our students are going to
> be *using* quantum mechanics, and that they have to learn
> the concrete, nitty-gritty details.
>
> You are proposing a redesign of this and similar courses that
> would, as far as I can tell, require that I spend about a third
> of the course on ``experimental evidence for photons.''
Listen to yourself, Steve! I started off this discussion by
claiming that contrary to the impression given by most
first-year physics textbooks, there is no honest way to
debunk the wave theory of light at the undergraduate
level. Now you've just admitted that the only way you
could actually do this would be to totally re-design
the undergraduate curriculum. So where do we disagree???
> I certainly agree that one shouldn't lie to students. One should
> not claim, for instance, that the photoelectric effect by itself
> conclusively disproves a wave theory of light. If you point to
> specific instances where textbooks make such false claims, I
> will happily join you in your objection.
But you seem happy to use misleading arguments about the
photo-electric effect to help build up your "preponderance
of evidence from different sources"....as long as you don't
claim the photo-electric effect is enough "by itself".
> I also think many texts and courses could be made better by
> focusing less on the rather uneven historical development of
> quantum mechanics, and more on modern experiments
> (single photon in a beam splitter, cavity QED, etc.) that, by
> virtue of improved technology, allow for much more clear-cut
> demonstrations of inherently quantum phenomena. But when
> I've given examples of such experiments, you've consistently
> objected, for no clear reason that I can see.
In my opinion, this would most definitely not be an improvement.
If photons exist, you can be sure that there are powerful theoretical
reasons that the theory demands them...reasons at least glimpsed if
not fully developed by the "old masters" of the early twentieth century.
I find it incomprehensible that rather than exploring and understanding
these profound concepts, you would rather set up a geiger counter,
listen to the clicks, and say "see...there are your photons!".
And by the way, just because you cannot understand my reasons
for holding these opinions, it doesn't mean that they are "silly", as you
called them.
Franz Heymann
"Tom Potter" <t...@earthlink.net> wrote in message
news:f76e0bb3.02081...@posting.google.com...
> I suggest that I made it very clear that I was interested in getting
> references to ANY experiments that clearly show what the time
> delay is between a cause and an effect involving "photons"
> and "electrons", and was not restricting this to any particular
effect.
Your suggestion is at variance with history. This has been pointed out
many times, so quit bullshitting.
Franz Heymann
Steve Carlip
> Martin Green wrote: (describing possible arguments
> that can be made against the wave theory of light:)
>> > 4. Prompt electrons cannot be explained by
>> > classical e-m because of the total energy
>> > flux over the area of the cathode.
> Steve Carlip replied:
>> I've never seen this one.
OK. I have now. The definitive experiment is Davis and Mandel,
``Time Delay of Photoelectric Emissions: An Experimental Test
of Classical Radiation Theory,'' in _Coherence and Quantum Optics_
(ed. Mandel and Wolf, 1973). It's a very careful experiment, which
shows conclusively that photoelectrons are emitted long before the
``accumulation time'' needed for enough classical wave energy to
be collected over the entire cathode. They also show that there is
no change in the statistics of photoelectrons before and after the
``accumulation time'' is reached, and that the number of electrons
emitted in any time interval very nearly follows a Poisson distribution.
In cidentally, there is also now a version of the ``single photon in a
beam-splitter'' experiment designed for undergraduate labs. See
Holbrow et al., Amer. J. Phys. 70 (2002) 260.
If you want a nice, though slightly outdated, review of the successes
and failures of semiclassical electrodynamics, try Mandel, Prog. in
Optics 13 (1976) 29. (It's slightly outdated because it came before
the beautiful recent experiments in photon antibunching, which
further rule out any semiclassical radiation theory.)
Steve Carlip
Steve Carlip
> Martin Green wrote:
>> > [...] how can he say there is nothing wrong with
>> > deliberately "padding" that evidence through false
>> > and misleading arguments?
> Steve replied:
>> You've never taught an undergraduate quantum
>> mechanic course, have you?
> And you're not going to answer my question, are you?
I thought I had. One clearly shouldn't present false
arguments. (``Misleading'' is a bit in the eye of the
beholder. It's quite possible that you were ``misled''
in a quantum mechanics course without having had
anyone ``mislead'' you. Clearly, a good teacher should
start out by saying, ``This is an oversimplification,''
but a good student should also know by the time he
or she gets to college that introductory courses are
going to be full of oversimplifications.)
> Listen to yourself, Steve! I started off this discussion by
> claiming that contrary to the impression given by most
> first-year physics textbooks, there is no honest way to
> debunk the wave theory of light at the undergraduate
> level.
Is that what you said? Then in a sense I agree---to fully
``debunk'' the wave theory of light is a very long and
complicated process, if you define ``wave theory'' broadly
enough and allow enough fiddling around with matter
interactions. Nor should that be what an undergraduate
course is about, any more than a course in relativity should
have to ``debunk'' Newcomb's explanation of Mercury's
perihelion advance. (Newcomb proposed changing the
exponent in Newton's gravitational law to 2.0000001574.
It works for Mercury. Should anyone care?)
On the other hand, it certainly *is* possible, and not too
hard, to give compelling evidence that the classical wave
theory has serious problems. Three strong arguments are
prompt electrons in the photoelectric effect, the behavior
of a single photon in a beam-splitter, and (slightly more
complicated, but not by much) photon antibunching.
> But you seem happy to use misleading arguments about the
> photo-electric effect to help build up your "preponderance
> of evidence from different sources"....as long as you don't
> claim the photo-electric effect is enough "by itself".
What *specific* ``misleading arguments'' are you accusing
me of?
> And by the way, just because you cannot understand my
> reasons for holding these opinions, it doesn't mean that they
> are "silly", as you called them.
I used the word ``silly'' in one instance. It had virtually nothing
to do with your ``reasons for holding these opinions''; it had
to do with your instant and apparently reflexive dismissal of
an example of a conceptually simple experiment that showed
the existence of photons.
Let me repeat it, and perhaps you can tell me specifically why
you don't think it's suitable for undergraduates. The idea is
simple: trap what should be one photon's worth of light on an
optical table, send it through a beam-splitter, and see if you
can divide it in half. If a semiclassical wave theory is right, the
beam-splitter should split the wave in half, and if one half has a
probability p of triggering a detector, there will be a probability
p^2 that both detectors will be triggered. If quantum theory is
right, the single photon will trigger one detector or the other,
but never both.
How do you get ``what should be one photon's worth of light''?
Easy: you gather the light from a single atomic transition. There
are various ways of doing this (atomic cascades to trigger a shutter,
using a parametric downconverter, etc.), but the details don't
really matter much---if you get the quantum result, you know
that your triggering mechanism succeeded in capturng a single
photon. There are some technical details in the analysis, having
to do with accidental coincidences when your shutter isn't fast
enough, but it only takes a few lines of simple math to show that
the quantum result is still drastically different from the classical
one.
What's so hard about that?
Steve Carlip
greywolf42
{snip}
The
> discussion of the photoelectric effect usually takes
> place in a ``historical introduction'' section, whose
> purpose is to motivate quantum mechanics, not to
> ``prove'' it or to discuss all other possible theories.
> In particular, semiclassical theories are clearly wrong
> ---they're not going to give you the Lamb shift, or
> the photon-photon scattering cross section, or
> antibunching of photons in resonance flourescence
> ---and I don't see much point in distracting students
> who are just beginning to learn the subject.
>
> By analogy, the problem of Mercury's anomalous
> precession was known for decades before general
> relativity, and lots of elaborate explanations were
> concocted, almost all of which failed for reasons
> unrelated to Mercury's orbit. Reading about them
> is entertaining. But I don't think there's anything
> wrong with giving the precession of Mercury as a
> piece of evidence for general relativity, without
> spending a week explaining why ``Zodiacal light''
> doesn't work or giving evidence against Vulcan.
>
That is the classic "spin" given in modern texts.
As pointed out in "The Perihelion Advance of Mercury" by Roseveare (and
several times on this newsgroup), that cute little story on Mercury is as
much a fraud as the photoelectric effect proving the existence of photons.
Mercury's precession 1) was not considered an anomaly by the astronomical
community, 2) there were simple explanations for the whole amount by Gerber
17 years before Einstein (to determine that gravity moves at the speed of
light) 3) No single solution has to apply to the entire amount.
But even though it was you who recommended Roseveare to me, you continue to
be set in the carefully directed thought processes in which you were
"motivated" as a young student. You remember the lie (and repeat the
catechism) that there was no explanation of this prior to GR.
So you have just confirmed Martin's hypothesis by ironic demonstration. The
purpose of these deliberate misrepresentations of history and theory is to
indoctrinate ("motivate") students into accepting their teacher's
worldview*, not to teach reality or the scientific process. Proscribing
thought is a horrible way to train people to think. Then everybody just
chants "But all the texts say.... And we know the texts wouldn't lie." (As
commonly repeated by SRists in the relativity newsgroup.) There's nothing
wrong with admitting to imperfection!
* To make them more willing to undertake the complex mental gymnastics
required by the worldview -- thus saving the teacher hassle, and allowing
them to look omnipotent and unquestionable.
Every one of your "clearly wrong" examples of photon proof is -- at best --
a point of contention. But they're really only believed to be "wrong"
because no one will look outside of the paradigm in which they've been
"motivated" -- even when they know better.
You, for example in your parallel response: "But when I've given examples of
such experiments, you've consistently objected, for no clear reason that I
can see." The reason you can't "see" is that your thoughts have been
successfully proscribed. So you can't take the "classical" worldview
seriously. Because you feel that it is appropriate that a "simplification"
will do to end a discussion, every time a single "simplification" is
shattered (and you admit that it's not the defining case that you
represented it to be), you then drag out another simplification! This is
not a rational discourse on the evidence. It is a debating trick to defend
a worldview.
And attempting to use your "motivational" approach on this newsgroup is way
out of line. We are not attempting to "motivate" brand new students, but
discuss the true nature of the universe (whatever we belive that to be). Or
is it still your intent to proscribe thought?
greywolf42
ubi dubium ibi libertas
Martin Green
> It's quite possible that you were ``misled''
> in a quantum mechanics course without having had
> anyone ``mislead'' you. Clearly, a good teacher should
> start out by saying, ``This is an oversimplification,''
> but a good student should also know by the time he
> or she gets to college that introductory courses are
> going to be full of oversimplifications.
So now it's my fault because I was a bad student?
OK, how do _you_ handle a student who questions
one of your arguments because he suspects it
might be an "oversimplication"? Oh, yeah...you
tell him he's being silly.
> I used the word ``silly'' in one instance. It had virtually nothing
> to do with your ``reasons for holding these opinions''; it had
> to do with your instant and apparently reflexive dismissal of
> an example of a conceptually simple experiment that showed
> the existence of photons.
Instant and reflexive? I checked Google's records and there
was apparently a time lapse of almost 21 hours between
your post and my response.
> Let me repeat it, and perhaps you can tell me specifically why
> you don't think it's suitable for undergraduates. The idea is
> simple.....
Should I be on the alert for one of those "oversimplifications"
you say your courses are full of? Or would that be "silly" of me?
> trap what should be one photon's worth of light on an
> optical table, send it through a beam-splitter, and see if you
> can divide it in half........(snip argument)..................that
> the quantum result is still drastically different from the classical
> one.
>
> What's so hard about that?
I'm very sorry but I have two serious problems with this argument,
which I have stated as best I can in previous posts, and which
you do not seem to follow. The first argument is the less important
one, and the one that you keep focusing on, to my dismay: basically,
that all these modern experiments require me to "take your word"
for the fact that the technical/theoretical details have been ironed out
and the experiment actually does show what it claims to show. With
all due respect, Mr. Carlip, I do _not_ take your word for it. Why
should I, when you condone the use of arguments that you and I
both know to be false, and when you invoke papers like Meyers-Gerlach
(granted, on a second-hand recommendation) that I have read
personally and found to not support what you say it establishes?
This is my "less important" reason for not engaging you in an argument
over this particualr "photon-splitting" experiment. Here is my
"more important" reason: If photons exist, then they exist for
good reason....not simply because you find them when you turn
on a photon-counter. The photon theory was deeply entrenched
decades before the appearance of these experiments you like
to cite, and I find it hard to believe that was entrenched because of the
"silly" arguments presented in Tipler, or Halliday and Resnick.
Einstein, for example, had a definite conviction that an photon
emission from an atom was directional, and that there was recoil.
I have no idea where this idea comes from. I can see it in the
case of "stimulated" emission...the semi-classical case also has
recoil. But in the case of spontaneous emission, the semi-classical
wave is spherical. Why does Einstein say there has to be recoil?
Tom Potter
"Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:ajjrjs$h8m$5...@knossos.btinternet.com...
Please provide references to some historical experiments
that demonstrate what the time delays are
between causes and effects
over a wide range of frequencies.
I am interested in seeing if frequency
enters into the time delay between a cause and an effect,
I am not interested in nitpicking about spelling, phrasing,
showing off one's limited knowledge which doesn't address
the question raised, flaming, childish remarks, etc.
For example, if there is an energy level transition at a source,
and another at a sink, and these correlate highly in time
and are considered to be related causes and effects,
where are the historical time interval measurements
made from? The start of each energy level transition,
the end, indeterminate, in some average middle, etc?
I would prefer to see references to experiments where a
block diagram is provided, so I can see what errors might
creep into the measurements.
Hopefully, I have not left a door open for some
nitpicker to post common knowledge, and
avoid answering my question, and hopefully,
some capable physicist will know the answer this question.
--
Tom Potter http://home.earthlink.net/~tdp
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Franz Heymann
> *** post for FREE via your newsreader at post.newsfeed.com ***
>
>
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> news:ajjrjs$h8m$5...@knossos.btinternet.com...
> >
> > "Tom Potter" <t...@earthlink.net> wrote in message
> > news:f76e0bb3.02081...@posting.google.com...
> >
> > > I suggest that I made it very clear that I was interested in
getting
> > > references to ANY experiments that clearly show what the time
> > > delay is between a cause and an effect involving "photons"
> > > and "electrons", and was not restricting this to any particular
> > effect.
> >
> > Your suggestion is at variance with history. This has been pointed
out
> > many times, so quit bullshitting.
>
> Please provide references to some historical experiments
> that demonstrate what the time delays are
> between causes and effects
> over a wide range of frequencies.
This is not what you originally asked about. You were specifically
asking aboout 1 Mz EM waves participating in the photoelectric effect.
Now take a running jump at yourself.
Franz Heymann
Bilge
Re: What evidence for photons? to usenet:
>
>
>"Franz Heymann" <Franz....@btopenworld.com> wrote in message
>news:ajjrjs$h8m$5...@knossos.btinternet.com...
>>
>> "Tom Potter" <t...@earthlink.net> wrote in message
>> news:f76e0bb3.02081...@posting.google.com...
>>
>> > I suggest that I made it very clear that I was interested in getting
>> > references to ANY experiments that clearly show what the time
>> > delay is between a cause and an effect involving "photons"
>> > and "electrons", and was not restricting this to any particular
>> effect.
>>
>> Your suggestion is at variance with history. This has been pointed out
>> many times, so quit bullshitting.
>
>Please provide references to some historical experiments that demonstrate
>what the time delays are between causes and effects over a wide range of
>frequencies.
>I am interested in seeing if frequency enters into the time delay between
>a cause and an effect, I am not interested in nitpicking about spelling,
>phrasing, showing off one's limited knowledge which doesn't address
>the question raised, flaming, childish remarks, etc.
opportunity to misconstrue the responses you're given.
>For example, if there is an energy level transition at a source, and
>another at a sink, and these correlate highly in time and are considered
>to be related causes and effects, where are the historical time interval
>measurements made from? The start of each energy level transition, the
>end, indeterminate, in some average middle, etc?
>I would prefer to see references to experiments where a block diagram
>is provided, so I can see what errors might creep into the measurements.
Then, by looking up some of the reference posted throught this thread,
you should get what you are after. In general, experimental papers will
have that sort of thing and equipmemt which is designed specifically
for a special purpose will often be found in NIM, complete with schematics
and test data.
>Hopefully, I have not left a door open for some nitpicker to post common
>knowledge, and avoid answering my question, and hopefully, some capable
>physicist will know the answer this question.
You aren't interested in an answer and I wouldn't say that what you've
been given is too "common", since you've managed to miss the point to
most of it.
Carlos L
> In sci.astro Martin Green <btes...@home.com> wrote:
>
> > Listen to yourself, Steve! I started off this discussion by
> > claiming that contrary to the impression given by most
> > first-year physics textbooks, there is no honest way to
> > debunk the wave theory of light at the undergraduate
> > level.
>
> Is that what you said? Then in a sense I agree---to fully
> ``debunk'' the wave theory of light is a very long and
> complicated process, if you define ``wave theory'' broadly
> enough and allow enough fiddling around with matter
> interactions. Nor should that be what an undergraduate
> course is about, any more than a course in relativity should
> have to ``debunk'' Newcomb's explanation of Mercury's
> perihelion advance. (Newcomb proposed changing the
> exponent in Newton's gravitational law to 2.0000001574.
> It works for Mercury. Should anyone care?)
>
> On the other hand, it certainly *is* possible, and not too
> hard, to give compelling evidence that the classical wave
> theory has serious problems. Three strong arguments are
> prompt electrons in the photoelectric effect, the behavior
> of a single photon in a beam-splitter, and (slightly more
> complicated, but not by much) photon antibunching.
>
>...
>>...
>
> Let me repeat it, and perhaps you can tell me specifically why
> you don't think it's suitable for undergraduates. The idea is
> simple: trap what should be one photon's worth of light on an
> optical table, send it through a beam-splitter, and see if you
> can divide it in half. If a semiclassical wave theory is right, the
> beam-splitter should split the wave in half, and if one half has a
> probability p of triggering a detector, there will be a probability
> p^2 that both detectors will be triggered. If quantum theory is
> right, the single photon will trigger one detector or the other,
> but never both.
>
> How do you get ``what should be one photon's worth of light''?
> Easy: you gather the light from a single atomic transition. There
> are various ways of doing this (atomic cascades to trigger a shutter,
> using a parametric downconverter, etc.), but the details don't
> really matter much---if you get the quantum result, you know
> that your triggering mechanism succeeded in capturng a single
> photon. There are some technical details in the analysis, having
> to do with accidental coincidences when your shutter isn't fast
> enough, but it only takes a few lines of simple math to show that
> the quantum result is still drastically different from the classical
> one.
>
> What's so hard about that?
>
> Steve Carlip
Is there not the possibility that the analysis of those type of
experiments is biased? An experimenter conditioned by his belief in
the corpuscular character of light (i.e. in the existence of photons
as opposed to a spread-type disturbance) will have the tendency to
acknowledge that a "photon's worth of light" has passed through the
beam-splitter only when one of his detectors (placed behind the
beam-splitter) is triggered. Based on this belief and on his
calibrations he will indeed assign a probability p that a detector is
triggered when (according to the semi-classical point of view) a half
"photon's worth of light" reaches it. But the "semi-classical
physicist" will argue:
Wrong. Such probability is not p but q (such that q<p) because you
have omitted all those many events in which (according to my belief) a
"photon's worth of light" has passed through the beam-splitter but has
not triggered any of the detectors. You say that it has not passed
because "your" photons "should" always trigger one of the detectors if
they pass through the splitter. I say that it has passed because "my"
spread wave-like light has "in theory" the possibility and a good
probability to reach a detector and not trigger it. But now the right
probability that both detectors are triggered (simultaneously) by a
given "photon's worth of light" passing the beam-splitter is q^2
instead of p^2. More precisely, according to my analysis of the
experiment, q is not known but my predicted number of events in which
both detectors will be simultaneously triggered compared with the
number of events in which one of the detectors is triggered is q^2/q
while your prediction was p^2/p. Making a guess say q=0.1p, the right
semi-classical prediction is that the double triggering should occur
10 times less than what the photon-biased physicist had assumed. (That
is just an example guess. A better guess can perhaps be made (without
contradicting other facts) that fits the experimental result that, by
the way, as Steve has admitted calling them "accidental coincidences",
is known to have some cases of double triggering).
Note: I haven't read any detailed paper on these experiments nor their
analysis. I am not a professional physicist and have no easy access to
them. Furthermore I hate to pay for papers and find most of the times
that they are written in a highly specialized condensed obtuse jargon.
So I of course admit that I may be wrong in my above analysis and the
intention of my post is to ask Steve or someone familiar with these
experiments to enlighten me a bit on these issues.
Carlos L.
Tom Potter
"Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:ajm55p$k6g$3...@knossos.btinternet.com...
>
> "Tom Potter" <t...@earthlink.net> wrote in message
> news:3d5d...@post.newsfeed.com...
> > *** post for FREE via your newsreader at post.newsfeed.com ***
> >
> >
> > "Franz Heymann" <Franz....@btopenworld.com> wrote in message
> > news:ajjrjs$h8m$5...@knossos.btinternet.com...
> > >
> > Please provide references to some historical experiments
> > that demonstrate what the time delays are
> > between causes and effects
> > over a wide range of frequencies.
>
> This is not what you originally asked about. You were specifically
> asking aboout 1 Mz EM waves participating in the photoelectric effect.
>
> Now take a running jump at yourself.
>
> Franz Heymann
Although Franz Heymann is unable to provide me
with the references I seek, I would appreciate it
if anyone knowledgable in physics, could.
See below for a clearer picture of what I seek.
--
Tom Potter http://home.earthlink.net/~tdp
> > I am interested in seeing if frequency
> > enters into the time delay between a cause and an effect,
> > I am not interested in nitpicking about spelling, phrasing,
> > showing off one's limited knowledge which doesn't address
> > the question raised, flaming, childish remarks, etc.
> >
> > For example, if there is an energy level transition at a source,
> > and another at a sink, and these correlate highly in time
> > and are considered to be related causes and effects,
> > where are the historical time interval measurements
> > made from? The start of each energy level transition,
> > the end, indeterminate, in some average middle, etc?
> >
> > I would prefer to see references to experiments where a
> > block diagram is provided, so I can see what errors might
> > creep into the measurements.
> >
> > Hopefully, I have not left a door open for some
> > nitpicker to post common knowledge, and
> > avoid answering my question, and hopefully,
> > some capable physicist will know the answer this question.
> >
Tom Potter
"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
news:slrnalt6a...@radioactivex.lebesque-al.net...
> Tom Potter said some stuff about
> Re: What evidence for photons? to usenet:
> >*** post for FREE via your newsreader at post.newsfeed.com ***
> >
> >
> >"Franz Heymann" <Franz....@btopenworld.com> wrote in message
> >news:ajjrjs$h8m$5...@knossos.btinternet.com...
> >>
> >Please provide references to some historical experiments that
demonstrate
> >what the time delays are between causes and effects over a wide range of
> >frequencies.
>
> Many references have already been provided.
I have seen only one.
All the other references are to commonly known effects,
such as the photo-electric effect, etc.
I did get one useful reference to NA22 experiments
involving photons and electrons, and I am analyzing this information.
Please list the URL's you refer to in your response to this post.
> >I am interested in seeing if frequency enters into the time delay
between
> >a cause and an effect, I am not interested in nitpicking about spelling,
> >phrasing, showing off one's limited knowledge which doesn't address
> >the question raised, flaming, childish remarks, etc.
>
> Then try to stick to what you are interseted in rather than taking every
> opportunity to misconstrue the responses you're given.
>
> >For example, if there is an energy level transition at a source, and
> >another at a sink, and these correlate highly in time and are considered
> >to be related causes and effects, where are the historical time interval
> >measurements made from? The start of each energy level transition, the
> >end, indeterminate, in some average middle, etc?
>
> >I would prefer to see references to experiments where a block diagram
> >is provided, so I can see what errors might creep into the measurements.
>
> Then, by looking up some of the reference posted throught this thread,
> you should get what you are after. In general, experimental papers will
> have that sort of thing and equipmemt which is designed specifically
> for a special purpose will often be found in NIM, complete with schematics
> and test data.
>
> >Hopefully, I have not left a door open for some nitpicker to post common
> >knowledge, and avoid answering my question, and hopefully, some capable
> >physicist will know the answer this question.
>
> You aren't interested in an answer and I wouldn't say that what you've
> been given is too "common", since you've managed to miss the point to
> most of it.
Thanks for all the time you took to provide me with references.
Edward Green
> "Edward Green" <null...@aol.com> wrote in message
> news:2a0cceff.02081...@posting.google.com...
> > BTW your comment on the photoelectric effect in metals is interesting:
> > since we know the electrons are distributed in delocalized bands, why
> > should we expect that the absorbtion cross-section is on the order of
> > an atomic cross-section?
>
> The fact that the electronic wavefunction is spread over the whole
> crystal does not mean that that is the size of the electron. The
> wavefunction simply tells us someting about the likelihood of finding an
> electron somewhere. (It tells us other things as well, of course!)
Well, I like to think of delocalized electrons as actually being
spread through space in a kind of smeared out defect; like a bump in a
rug you can't quite flatten: but who the hell cares what I think.
Even my Laphroig supply is depleted.
Pmb
> > Actually Einstein never really liked the idea of photons.
>
> How about some references for this claim of yours?
Okay. I was able to locate a comment regarding Einstein's thoughts on
photons. Stachel writes:
John Stachel, "Einstein and the quantum : fifty years of struggle, in
From quarks to quasars (Pittsburgh, PA, 1986)," 349-385.
"I do not believe that the light quanta have reality in the same
immediate sense as the corpuscules of electricity. Likewise I do not
believe that the particle-waves have reality in the same sense as the
particles themselves. The wave-character of particles and
particle-character of light will -- in my opinion -- be understood in
a more indirect way, not as an immediate physical reality."
Pmb
Franz Heymann
"Edward Green" <null...@aol.com> wrote in message
news:2a0cceff.02081...@posting.google.com...
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:<ajh1h4$7pf$2...@paris.btinternet.com>...
>
> > "Edward Green" <null...@aol.com> wrote in message
> > news:2a0cceff.02081...@posting.google.com...
>
> > > BTW your comment on the photoelectric effect in metals is
interesting:
> > > since we know the electrons are distributed in delocalized bands,
why
> > > should we expect that the absorbtion cross-section is on the order
of
> > > an atomic cross-section?
> >
> > The fact that the electronic wavefunction is spread over the whole
> > crystal does not mean that that is the size of the electron. The
> > wavefunction simply tells us someting about the likelihood of
finding an
> > electron somewhere. (It tells us other things as well, of course!)
>
> Well, I like to think of delocalized electrons as actually being
> spread through space in a kind of smeared out defect; like a bump in a
> rug you can't quite flatten: but who the hell cares what I think.
> Even my Laphroig supply is depleted.
You are in a bad way. Try Lagavulin when you restock. I got 3 for the
price of 2 at my favourite bottleshop a little while ago.
Franz Heymann
Patrick Reany
Pmb wrote:
And what is it that you conclude about this
quotation from Einstein, assuming that it really is?
What is the original source of this alleged
quotation of Einstein's?
Einstein said that physical concepts are free
creations of the human mind, so I am NOT
surprised that he would warn people against
taking models of photons a literal truths. Very
obvious and consistent of him! It's very clear,
though, that Einstein was NOT denigrating
the use of the photon MODEL, just perhaps
its metaphysical meaning.
If people could only learn that
physics != metaphysics
things would be so much clearer to you people!
Einstein was allowed to make metaphysical statements
along with his physical (free creation) statements.
One could equally say that the continuous model
of macroscopic matter is not proved to be true
based on the fact that the model is proved useful
for certain purposes.
Patrick
tj Frazir
tj Frazir
It colides with nothing so some energy condences and dont expand at te
same rate as space. Te condenced energy is just an eddie of space in
motion causing a low energy presure with out resistance to spin other
than wave interaction from te waves made in space time by its motion .
James Hunter
Patrick Reany wrote:
> Pmb wrote:
>
>
> And what is it that you conclude about this
> quotation from Einstein, assuming that it really is?
> What is the original source of this alleged
> quotation of Einstein's?
>
> Einstein said that physical concepts are free
> creations of the human mind, so I am NOT
> surprised that he would warn people against
> taking models of photons a literal truths. Very
> obvious and consistent of him! It's very clear,
> though, that Einstein was NOT denigrating
> the use of the photon MODEL, just perhaps
> its metaphysical meaning.
Einstone only said that though since he was even more
energy challenged that fuck-head chemists.
And also for the better reason that he was
an integral MORON, as every
spew-churning, dipshit,
creationist, born-again, geometric stooge,
science-ignorami, Latin-belching, mathemamoron is.
Steve Carlip
> Steve Carlip <car...@dirac.ucdavis.edu> wrote in message news:<ajk2s9$qd3$3...@woodrow.ucdavis.edu>...
>> you don't think it's suitable for undergraduates. The idea is
>> simple: trap what should be one photon's worth of light on an
>> optical table, send it through a beam-splitter, and see if you
>> can divide it in half. If a semiclassical wave theory is right, the
>> beam-splitter should split the wave in half, and if one half has a
>> probability p of triggering a detector, there will be a probability
>> p^2 that both detectors will be triggered. If quantum theory is
>> right, the single photon will trigger one detector or the other,
>> but never both.
> Is there not the possibility that the analysis of those type of
> experiments is biased? An experimenter conditioned by his belief in
> the corpuscular character of light (i.e. in the existence of photons
> as opposed to a spread-type disturbance) will have the tendency to
> acknowledge that a "photon's worth of light" has passed through the
> beam-splitter only when one of his detectors (placed behind the
> beam-splitter) is triggered.
No, not at all. Any good experimenter knows that the detectors are
not completely efficient, and that sometimes a photon won't register.
> But the "semi-classical physicist" will argue:
> Wrong. Such probability is not p but q (such that q<p) because you
> have omitted all those many events in which (according to my belief) a
> "photon's worth of light" has passed through the beam-splitter but has
> not triggered any of the detectors.
My p is the same as your q. It's an experimentally observed quantity.
I give you a black box that I claim releases one photon through a
narrow shutter each time you push a button. You set it up on your
optical table, pointed toward a beam-splitter, and observe that a
detector registers at one side of the beam-splitter with a probability
q, which you *measure*. (It's easy---you push the button N times,
and register n events at your detector. Then q=n/N. This is pure
observation; no assuptions about the light have yet been made.
Now, what's the probability that both detectors will register? If the
light is a wave, and is in half split by the beam-splitter, the anwer
is q^2, right? So now you test your model by observing this, as well:
you count both the number of times each detector registers, and
the number of times they register simultaneously.
> More precisely, according to my analysis of the experiment, q is
> not known but my predicted number of events in which
> both detectors will be simultaneously triggered compared with the
> number of events in which one of the detectors is triggered is q^2/q
Right. Now *measure* q, with the same apparatus. That's what the
experiment of Grangier et al. did. They made no a priori assumption
about q; rather, they compared the observed probability of both
detectors firing to the observed probability of a single detector firing.
In your analysis above, which is perfectly sensible, look at the ratio
(simultaneous events)/(events in detector 1)x(events in detector 2),
which should be q^2/qxq = 1. Grangier et al. measure this ratio,
and find that it's only .18. To check, they redid the experiment
with a weak ``multiphoton'' source, and confirmed that for such
a source, the ratio was indeed 1.
Steve Carlip
Martin Green
Steve Carlip wrote:
> Now, what's the probability that both detectors will register? If the
> light is a wave, and is in half split by the beam-splitter, the anwer
> is q^2, right?
Maybe light is a wave, but the nuts-and-bolts beam splitter has
trouble splitting it in half when you get down to the microscopic
level. What if it's the nature of the beam splitter that causes
it to take a continuous wave and break it up into lumpy packets?
me...@cars3.uchicago.edu
>
>Steve Carlip wrote:
>
>> Now, what's the probability that both detectors will register? If the
>> light is a wave, and is in half split by the beam-splitter, the anwer
>> is q^2, right?
>
>trouble splitting it in half when you get down to the microscopic
>level. What if it's the nature of the beam splitter that causes
>it to take a continuous wave and break it up into lumpy packets?
>
accounts for this (as well as any other) phenomenon, then come back.
"Maybe" is not a physical theory (especially not when you keep coming
with a new "maybe" for every new phenomenon you encounter. And, in
case this is not clear to you, an argument along the lines of "it is
not conclusively proven that this is the only theory that fits all
available facts" is of no interest since nothing like this this is
ever conclusively proven.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Martin Green
> Good. Develop a new, comprehensive ant self consistent, theory that
> accounts for this (as well as any other) phenomenon, then come back.
> "Maybe" is not a physical theory (especially not when you keep coming
> with a new "maybe" for every new phenomenon you encounter. And, in
> case this is not clear to you, an argument along the lines of "it is
> not conclusively proven that this is the only theory that fits all
> available facts" is of no interest since nothing like this this is
> ever conclusively proven.
I did not make the argument which you attribute to me. The
argument at issue is made by Steve Carlip when he says
that (paraphrasing) "the details of this particular experiment prove
conclusively that light cannot be explained by the wave theory."
I have simply shown that his argument is based on certain
unproven assumptions.
me...@cars3.uchicago.edu
>Mati Meron:
>> Good. Develop a new, comprehensive ant self consistent, theory that
>> accounts for this (as well as any other) phenomenon, then come back.
>> "Maybe" is not a physical theory (especially not when you keep coming
>> with a new "maybe" for every new phenomenon you encounter. And, in
>> case this is not clear to you, an argument along the lines of "it is
>> not conclusively proven that this is the only theory that fits all
>> available facts" is of no interest since nothing like this this is
>> ever conclusively proven.
>
You did, and I'll continue to attribute it to you.
> The argument at issue is made by Steve Carlip when he says
>that (paraphrasing) "the details of this particular experiment prove
>conclusively that light cannot be explained by the wave theory."
>I have simply shown that his argument is based on certain
>unproven assumptions.
>
You have shown *absolutely* nothing of value (as usual). His argument
is not based on unproven assumptions. Your response is. And, to
boot, you're boring.
Aleksandr Timofeev
See disproof of "the behavior of a single photon in a
beam-splitter " located below.
Just in the given place of your physical interpretation "the behavior
of a single photon in a beam-splitter" there is a methodological
error.
This methodological error is mixing of two insulated physical
processes
in one whole:
1. Process of transiting of electromagnetic radiation through
slots of an interferometer.
2. Process of shaping of an interference pattern.
Now there is a rather new type of an interferometer - VLBI,
in which one this methodological error is demonstrated in the bright
and decisive form:
The interference picture in VLBI (interferometer) is pure
mathematical abstraction, since the construction of an interference
pattern is carried out in the computer.
In VLBI there is no direct physical process of addition
" of waves " passing through slots!
Whether you can give physical interpretation of principles of
operation for an VLBI (interferometer) from the photon point of view?
There are two graphic schemes illustrating the description:
Step 1.
The microwave interferometer with superlong basis. Part 1.
----------------------------------------------------------
Block scheme.
. [videotape 1] [videotape 2]
. ^ ^
. | |
. radio-receiver 1 radio-receiver 2
. | |
. | Length of VLBI basis >= Earth diametr |
. |<--------------------- {snip} ------------------>|
. /^\ antenna 1 antenna 2 /^\
.^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ {snip} ^ ^ ^ ^ ^ ^ ^ ^
.| | | | | | | | | | | | | | | | | | | | | | |
. Noise microwave radiation
VLBI (interferometer) simultaneously record the information
reflecting a state of an electromagnetic field in space of each
slot (from the antenna) on a magnetic tape, it is natural that
for each slot/antenna we use a separate magnetic tape.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Step 2.
. The microwave interferometer with superlong basis. Part 2.
. ----------------------------------------------------------
. "Interference pattern"
. ^
. |
. [videotape 1] ------> [ COMPUTER ] <---------- [videotape 2]
The VLBI interference is a new kind of an interference -
so-called postponed in time or virtual interference, i.e.
abstractly or mathematically realizabled interference in the
computer.
In any time, convenient for us, we input the information from
macroscopic magnetic tapes in the computer and mathematically
on any required (demanded) algorithm (which can be changed at any
time) we obtain an interference in representation, necessary for us.
The physical principles of operation of an VLBI (interferometer)
enable physically to divide two physical processes:
Step 1. Process of transiting of electromagnetic radiation through
slots of an interferometer.
Step 2. Process of shaping of an interference pattern.
Note 1. The interference pattern in VLBI (interferometer) is pure
mathematical abstraction, since the construction of an interference
pattern is carried out in the computer.
Note 2. Here there is no direct physical process of addition "
of waves " passing through slots!
How does the possibility of addition
" of parts of a single photon " from two magnetic tapes?
Is it possible? Or is it impossible?
What's so hard about that?
>
> How do you get ``what should be one photon's worth of light''?
> Easy: you gather the light from a single atomic transition. There
> are various ways of doing this (atomic cascades to trigger a shutter,
> using a parametric downconverter, etc.), but the details don't
> really matter much---if you get the quantum result, you know
> that your triggering mechanism succeeded in capturng a single
> photon. There are some technical details in the analysis, having
> to do with accidental coincidences when your shutter isn't fast
> enough, but it only takes a few lines of simple math to show that
> the quantum result is still drastically different from the classical
> one.
>
> What's so hard about that?
>
> Steve Carlip
http://groups.google.com/groups?selm=e16a4a22.0205290718.4a5d6982%40posting.google.com
Regards
Aleksandr Timofeev
Bruce Scott TOK
Steve Carlip <car...@dirac.ucdavis.edu> wrote:
[replying to Martin Green]
>This, by the way, is what I meant by a ``reflexive'' response: you
>didn't look up the references, but immediately assumed that there
>was a problem.
Warning to Martin: Steve has *orders* *of* *magnitude* more patience on
points like this than most physicits. You really should appreciate his
efforts here. Most of us, myself included, will immediately drop anyone
who (1) transparently doesn't know the physics, and (2) starts arguing
that it's fundamentals (be it all of physics or just a particular point)
is all wrong.
[how did the idea of photons come about]
>This is a tangled mixture of physics and history, which I don't know
>very well. Jauch has written several books about the history of quantum
>mechanics; you might start there. My limited understanding is that the
>photon picture did not become widely accepted until observations of
>Compton scattering, including measurements of electron recoil that
>confirmed conservation of momentum. It's worth remembering that
>a satisfactory theory of quantum electrdynamics didn't really appear
>until some twenty years after the Schrodinger equation; by that time,
>the idea that one should quantize some things (atoms) and not others
>(electromagnetic fields) must surely have seemed perverse.
To really get to the bottom of this, one would have to research the
16th-18th Centuries, in which more people actually believed in the
"corpuscular" picture. I don't know the details of that, but...
[Einstein]
>I don't know, but at a guess, simply from conservation of momentum.
>In any case, while these are interesting historical questions, I don't
>see why a course on quantum theory should be expected to retrace
>the history.
Einstein's views and motivations are pretty well documented in _Subtle
is the Lord_ by Abraham Pais. He convinced himself even before the
photoelectric effect... something in the details of the blackbody
calculations convinced him, and, so convinced, he simply walked away
from the debate circa 1909. He didn't really return until quantum
mechanics got going after Bohr put up his model of the atom. (Yes, that
wasn't too long after, and the war got in the way, etc, but Einstein got
back to all that circa 1920)
--
cu,
Bruce
drift wave turbulence: http://www.rzg.mpg.de/~bds/