Problem with the two slit experiment, Observing later

Thanks Ron. Yes.

The real test of character comes when you have an odd legs device and feed an electron into it. Rather more difficult to actually build the thing .. but it should work the same way as a photon version.

Since I've found it .. this includes nice photos of single electron interference

http://physicsweb.org/articles/world/15/9/1

The number of maxima indicate (to me) that a single electron is effectively in more than one 'wave' of de Broglie wavelength... the same as with a photon, just how far this goes is unclear to me. Comments most welcome.

-C2.

Good Elf, C2

It took a few tea times but I was able to read the information given. Please help me on this when I read what you have stated there is a flavor of D. Bohm which I believe if it had not been for the trials that he refused to participate in, many scientist of today might have seen the light © in a different perspective today as of today in 2006.

You have certainly brought up some interesting questions that should and I believe is being researched in many labs around the world because the papers that are now coming out on the subject.

I will stay in touch and Best to you both.

ciao_
yquantum

Excellent link, C2!
The photos are particularly amazing. I remember my first light double-slit experiment I did in college that blew me away, but seeing the same pattern with electrons, even learning the principles since, is just incredible. Your link also talked about experiments with nucleons much larger than electrons. To think, if we had the right equiptment, we could probably do the same experiment with baseballs!
Thanks again, man.
You should probably bring that credibility factor up a few hundreths!
Later,
Ron

Hi Ron, Yquantum, Confused2 et al,

He he he… you see through me like a pane of glass... a "Looking Glass". I think there would have been a lot of problems a couple of decades ago about actual testing of these ideas of David Bohm. Unlike David, I am no “mystic” on these matters and I am a very interested in Bhomian Mechanics and to interpretations of physics in terms that also remove the “observer” as "creator" from a central role in events occurring in the sub-atomic realm. Or even to the concept of the idea of the Anthropic Principle. Physics is not about a quest to "discover God" or to substitute "us" into the place, if one exists, that only a "god" would hold.

There are just so many different practical experiments that reinforce these views and play down the “other mystical” interpretations of Quantum Mechanics, one based on a flattened version of Physics forced to work in only three dimensions plus time. What remains is a melding of a “semi-classical” interpretation of Quantum Mechanics that involves an interpretation of dimensional space that will not conform to Einstein’s Spacetime, yet Einstein’s Spacetime forms a subset of a greater dimensional interpretation.

I believe that David Bohm’s idea of a "guiding wave" is also not the true picture (I have said this previously in this thread) since the “hidden variables” of Bohm’s Configuration Space simply confine the particle to follow an undulating path in spacetime. To me the only acceptable “physics” is that “particles” behave according to long established patterns of very conventional dynamics except in an unconventional space of additional dimensions. The view I am proposing is a purely geometrodynamic interpretation where “particle” is just what we measure when an "particle interaction" occurs. The quantum “realm” is truly a different space that is additional to the common dimensions we experience. The additional dimensions must be whatever we mean as "ordinary space" since they are conforming to the "ordinary physics" that we use within "spacetime".

In this respect the quantum “particle” travels in a “hidden” space where the effects we are able to determine are all wavelike as projections into normal “spacetime”. This is this “harmonic” connection I am always trying to stress. These “waves”, we have them discussed before and for particles, are the de Broglie Matter Waves. For light the waves are actually traveling or propagating within our space yet confined to our Universe as mentioned by a strict interpretation of Feynman’s “explore all paths” dictate. Light travels at a finite velocity in our space but we also know that when we are considering entangled photons this influence can be instantaneous across any distances. The Delayed Choice Quantum Eraser Experiment reinforces the fact that the photons seem to know the answer to the physical question “explore all paths” the instant the photon is launched and seems to know, even in our dynamic Universe, the position of all particles and objects everywhere and everywhen inside of that "extended space". This suggests the space this “signal” is traveling in does not have the same significance for distance as the space we live in. It just takes time for this temporal “painting” to propagate through the entire Universe, at the speed of light. What it is saying about that event is it is unable to be changed and it “knows”, using a “shortcut”, where everything was, is, and going to be… even in the distant future.

The “vision” it has created for me is the “outside” of our Universe (the surface of a light cone), could be a tiny pebble the size of an atomic particle in which this "where and when" information about the internal physical and temporal landscape of our "internal" Universe is always present. All the while the inside of this “particle” is our Universe… at the very least three spatial dimensions and time of it. How does this trick with a “Russian Doll” that is bigger on the inside than on the outside work? IMHO it is David Bohm’s “Holographic Universe” where the internal dimensional space is defined on a lower dimensional “hypersurface”, a flatspace very similar to the flatspace of a hologram where “strings” define a frequency reciprocal space… an anti-de Sitter space. Of course if a Universe is defined by a comparatively flat “hologram”, this flat “screen” of this surface reveals an inner portal to a much larger "virtual" space.

A low dimensional analogy would be those large holographic plates you can see in certain Science Displays showing the interior of a full scale room. Of course this hologram is simply a two dimensional surface of acetate film or glass plate recording what appears on close examination to be "harmonic strings" caught at a single instant in time in that surface. It behaves and looks like a complete three dimensional room with all the perspective and depth similar to Alice’s “Looking Glass World”… Yet this is just a heap of dynamic “surface” frequencies which are “decoded” using a laser reference beam. There is apparently nothing “in” there. This idea has physical relevance since Stephen Hawking, Carlo Rovelli, Juan Maldacena and Ed Witten have separately worked on this idea and shown that the information contained in Black Holes is contained on a surface. One of the great breakthroughs of current string theory was a proof that showed that the information inside a "Black Hole" is a simple function of the "informational string" found on the surface of that Black Hole and that this was found by using the T-Duality Principle of String Theory that relate "dimensions" to the "reciprocal dimensions". See this reference for String Theory...
Wikipedia: T-Duality
Please look at this interpretation of the Weak Holographic Principle in this Wikipedia reference where the contents of the “Black Hole” actually is the surface “hologram”.
http://en.wikipedia.org/wiki/Holographic_principle
I am simply extending this idea to “optical” Black Holes not just “gravitational” Black Holes. I will quote…

Thus a kind of Hologram. One success of String Theory was to show that it could be used to determine that this principle was indeed upheld.

Please look at this reference here...
Wikipedia: AdS/CFT correspondence - anti-De-Sitter space/conformal field theory correspondence

These principles are sweeping behind the scenes of the more popular theories of Quantum Theory which are confined to the much "flatter space" of spacetime. For background discussion here is a reference about "interpretation"...
Black hole entropy: inside or out? Authors: Ted Jacobson, Donald Marolf, Carlo Rovelli

I have stressed the relationships between Special Relativity and de Broglie Matter Waves (I have explained this relationship here)...
Perpetual motion?, Cyclic photon reflections: Good Elf

The reciprocal relationship "connects" with the spatial relationships through the evanescent region and the property of quantum tunneling. This behaves like a very small zone in which the different "Universes" mingle. The speed of processes there are supraluminal but fade rapidly with distance from the zone as does those "matter waves". The low speed end of particles that lead to this relationship for de Broglie's theory and an ultimate "delocalization" of the particles world line lead with increasing speed to the high velocity end of Special Relativity and a rapidly thinning world line of high energy particles. These properties wrap in reciprocal space and are the one physics. This process occurs in the limit as relative velocity approaches zero or the mass approaches zero. The "conjecture" is this process can be encapsulated "holographically" any number of times leading successively to Quantum Electrodynamics of Atoms and then immediately to Quantum Chromodynamics at the next "twist".

There is tremendous experimental support for a physical interpretation for "all of this". Kondo Phantom Particles even "Kondo Atoms and molecules", some part phantom and part actual atom with all the properties of a source atom do really exist and have been experimented on in the NIST Laboratories under the topic of Quantum Corrals. What is interesting about these experiments is the behavior of these quantum images exactly mimic the "real McCoy". These "signals" are an entangled connection between the "object" and its "image" at the level of the de Broglie Matter Wave. The matter wave defines actual physics (virtual photons) in the same way optics define "image". The difference is only in "degree". All the more if nature actually provides "perfect quantum corrals" where we identify sub-atomic particles. Therefore what we are looking at are the "Many Worlds" we know theoretically exist but never dared think really did exist and are able to witness them almost with our own eyes since what we are seeing right now are "reflections" in our own personal "Looking Glass World"!

Arthur Conan Doyle's fictional character Sherlock Holmes once remarked to Watson... "How often have I said to you that when you have eliminated the impossible whatever remains, however improbable, must be the truth?"

Cheers

This post has been edited by Good Elf on Oct 20 2006, 12:40 AM

yquantum, Good_Elf, Ron et al,

Good Elf .. not an attempt to supercede your post .. hopefully both stand.

On another thread yquantum has kindly offered to look at my problem with 'the speed of light'.

Clarification of the problem ..

For simplicity we re-use 'old' equipment but on this occasion we are looking at the speed of light itself .. detection of Aether drift is not what is being analysed.



Full image here : http://upload.wikimedia.org/wikipedia/en/9...lson-morley.png (thanks Wiki)

The semi-silvered mirror has many of the properties of a double slit in that it allows (forces) the light into two paths. The light detector is normally a screen, this will suffice for a start. By moving the mirrors we make the total blue path length one metre and the total green path length 1000 metres. Classical analysis assures us that we still see interference at the screen. Quantum analysis (Dirac?) assures us that a photon can only interfere with itself .. so does the photon 'probability pattern' arrive at the screen after 1/c, 1000/c or something else? To me it seems that the 'speed of light' cannot be consistent over both paths.

If we use a laser and reduce the light intensity it should be possible to scan a detector over the interference pattern and actually measure the time delay between the photon emission and detection. I feel this should be a 'classic' QM demonstration experiment .. but I can't find anything like it.

This might or might not shed some light on the 'instant' nature of solutions which Good Elf has described in his last post.

Best wishes,

-C2.

Hi GE, C2, YQ, Ron ..



I have thought of a better way to ask about a specific detail of this process, that will still lead to my point (which I have never been able to get to, because of the "debates" that ensue from my question).


So, rather than ask about how to know if we ever have "just one photon", let me ask this:

Does a single "photon" constitute only ONE frequency? IE. is 1 "photon" monochromatic. Here I mean, as usual, ABSOLUTELY monochromatic, not the kind of monochromatic thrown around in the labs, that are derived from statistics & probabilities.


Secondly, and also very important to understanding this "phenomenon", (IMHO) I will ask this:

Is the "half-silvered" mirror an observer? Is it composed of electrons, like all other matter? I'm certain that it is, but I could be wrong.

If the mirror is an observer, what does this say about the round-trip measurement done on the "photon's" journey? Is the second "gate", or re-emission point any different from the first? All journeys of light will be measured @ c regardless of changing parameters like distance and speed.

I would prefer a measurement of the ONE-WAY journey of light over distances greater than 299,792,458 meters, compared to another similar set up (orthogonal).

And, in order to rule out self-interference, it MUST be absolutely monochromatic.
(at least for the DSE)


yours,

T.Roc

Hey C2, Good Elf, yq, et al.

C2 - I think you may be talking about a version of a Franson Interferometer. Maybe this will help, at least with the background. GE and yq will need to discuss the implications.

http://www.pas.rochester.edu/~howell/mysit...nterference.pdf

Also, you might find this interesting...

Cancellation of laser noise in an unequal-arm interferometer detector of gravitational radiation

Best!

Hi Good_Elf, Troc, Ron, Why Not, yquantum et al,

As already mentioned .. I don't feel we've got a good analysis of even the basics of the DSE .. if one peak is 'equal length paths' then clearly any other peak is the result of unequal path lengths .. does light (photons) 'hang about' to make these other peaks or something else?

With particular reference to the modified MM experiment I have outlined above (bear in mind that there may be no interference when the path lengths are radically different .. the case is not proven)

1/ This looks like the Kennedy Thorndike ( experiment.http://en.wikipedia.org/wiki/Kennedy-Thorndike_experiment ) but without a photon by photon accouny of the KT I am no further forward. To say "A modified MM (ModifiedMM) experiment" takes us back to the essential elegance of the original experiment.

2/

Can this be used to predict the result of the simple ModifiedMM experiment?

3/ Troc..
Does a single "photon" constitute only ONE frequency? IE. is 1 "photon" monochromatic. Here I mean, as usual, ABSOLUTELY monochromatic, not the kind of monochromatic thrown around in the labs, that are derived from statistics & probabilities.

Assuming no relative movement (it's complicated enough already without it) -as far as I know a photon always arrives with the same momentum that it left the source ..
since E^2 = p^2c^2 + m^2c^4 (and m=0 for a photon)
E= pc
and unless the photon gains or loses energy
we get f = E/h = k from source to detection.
The real object of the experiment is to test our assumptions about 'c', f and lambda.

3/ Why Not .. many thanks ..
The Franson Interferometer - EPR - overly complicated ?.. Just the speed of light would keep me happy for the present and help us to get a 'proper' analysis of the DSE in the region between the slits and the screen.

http://elmer.caltech.edu/ph237/week18/AET1.pdf

These EM analysises (?) do not adddress EM as photons or the single photon case.

-C2.

C2 & all,



It's hard to have faith in the equation if you don't have faith in the lab equipment that you've been told is "A", when it is not.


So, I'm probably in a one-man parade, when I say that we are NOT producing absolute monochromatic light in the equipment, therefore, our simple and absolute equation, one like E=hf , is not giving us an answer that holds an absolute truth.


There is no duality in a wave, and a particle. That is a misnomer; incorrect of the definition.

There IS a dualistic result in the DSE: it's called interference, and shows up as fringes/bands of light & dark. In this context, perhaps I should say self-interference, since we are ASSUMING that there is a monochromatic "photon" going through the slits.


Does anyone agree that the correct definition of single "photon" should be that it has just ONE frequency?


Can anyone imagine the "shape" of a small group of incoherent photons would have? If not, would you at least say that the chances are, that the shape is NOT symmetrical?


Can you imagine the results of a non-symmetric shape, slowed down so that not more than one "part of the shape" went through the slits at a time, would have on the trajectories of the impact locations?

Wouldn't it "seem" random, that is, until the non-symmetrical parts are "whittled" down, and the pattern then becomes the predictably symmetric dualistic light/dark bands?

Can anyone see that this is the reverse of the process that is supposed to be making monochromatic light? Both are being misunderstood.


This is why I have said so often, that "slowing down" the wave, that is, lessening the INTENSITY, can not effect the underlying pattern that is inherent in the "not-so-monochromatic" light that is being produced. It does, however, allow us to see the "whittling down" process of resonance in the act, which is actually pretty cool.

How does "Science" forget its' own rules??

In several other key experiments, it has been established that the NUMBER of photons does not effect the ENERGY of the interaction. HOW, then, can we trust the DSE mantra, when they are telling us the the CHANGE in ENERGY is regulating the NUMBER of "photons" present in the experiment??

How does any Scientist give in to the "lab equipment salesman", and believe that monochromatic light is being produced when ALL the evidence proves otherwise???




Soon, this will change!


ciao!

T.Roc

Hey C2, TRoc, GE, yq, at al,

I think this may all come down to the problem of defining uncertainty with respect to a single photon. Since time and frequency are conjugate variables, there is a limit to defining the monochromatic nature of a single photon. As a result, I do not think you can look at a photon in an environment with "no movement." A photon must move and one cannot define the frequency of a single photon in any time-frame less than the time-frame which defines that frequency.

C2 - An interpretation of your experiment (possibly incorrect, but what the hell), A single photon would either travel through the half-silvered mirror or be reflected by it. By setting the detector to measure the delta t between emission of a photon and detection at the detector, we can determine the "which path" information the photon took (either 1/c or 1000/c). If we collect the results from a large number of single photon runs through the experiment, we have detailed "which path" data from each event and "noise" (read - no interference) when combining the data at the detector. But if we then run the "noise cancellation" equation (from the second link in my previous post) across all photon measurements, we lose the "which path" information for each event and generate an interference pattern.

As a final thought, what would happen if the distance between the slits and the screen were less than the minimal wavelength of the photons being sent through the slits?

Hi Ron, Yquantum, Confused2, TRoc, Why Not? et al,

Please look at the images I have included... I have linked to them diectly rather than shown them embedded here, this is because the Forum crushes the images soo small they are usually no benefit. Others may not be able to understand that these can be viewed full size using a right click and choosing to view it full size... so bear with me please...

I agree totally, it will shed some light on the problem. This reference may assist in dealing with your particular question...
Wolfram Research:Fourier Transform Spectrometer
The speed of light is indeed constant but the paths differ in length. This should not pose a conceptual block to understanding the nature of propagation. You can see these effects when you are in a TV reception area where it is subject to two different paths at the same time. You end up with a "ghost" image that may be delayed or advance of the stronger main beam image. With digital signals of course ghosts are a thing of the past but this phenomena is explained by having two separate paths to the receiver. In the Michelson-Morely Experiment (with unequal arms), the important factor is the resonant nature of "empty space". Now how many photons actually are used is important to the original concept of the quanta. You seem unable to resolve the idea that these waves are spreading for photons, or at least for most cases of radiation. This is the nature of this basic bosonic field within our Universe. I did answer this question here...
Problem with the two slit experiment, Observing later: Good Elf
this was a follow on from here...
Problem with the two slit experiment, Observing later: Good Elf... earlier
I try and think of this "spreading effect" in a similar way to the way we think of our shadows cast by a "lonely" street lamp as we walk away from it into the darkling gloom. There is a distortion of perspective. That which is casting the shadow remains small and intact... me... while the shadow lengthens grossly and dramatically across the flat landscape as the angle between the streetlight and my head reduces to ever lower angles.... Eventually my shadow covers everything in front of me out to "infinity", my feet are normal but the distortion of my head is "extreme". However when I arrive home and pass into my house through my door that "big" shadow does not need to fit... My presence in the house means that the shadow outside is now "gone".
Mobius Transformation Stereographic projection of a Riemann Sphere

Of course this is a low dimensional representation and the reality is far more complex involving the quantum harmonics that dance on the Riemann sphere as the principal quantum numbers... at least for particle domains. What these "superpositions " are should be left for another discussion. We will stay with the geometry of the Michelson-Morley Experiment and the original question which is only the projection onto our flatspace in spacetime.

You had a question about the quote you have there.

That does help when you are considering other kinds of particles and their de Broglie Matter Waves. If you see what I mean it is the de Broglie Matter Waves that are the same "essence", that is electromagnetism, of the quantum penetrating from within the electron or other particle. Naturally that is a reciprocal space noted there ... at least relative to our space. The fermion tries to penetrate our space through tunneling... it cannot because it is "causally knotted" via CPT. The internal radiation can leak marginally from the space as waves but cannot dissipate in particle interactions, the advanced and retarded potentials are dynamically balanced. A more instructive quote was the one on virtual photons I made above.
"Virtual Photons" quote from above... near end
The origin of all known forces except for a tiny contribution from the weak force as radioactivity. Of course I think that "gravity" is only a pseudo-force and that leaves the other three "forces" to pick up the tab for everything else.

I can't indicate here an entire course in Fourier Transforms and their uses (I wish I could) but I will try and get you up to speed on just some aspects of it, the rest you may be able to "Google". Nothing in the Universe can exist as one frequency unless it extends to + and - infinity in time (consider this as a convergence at T = 0 of two waves one moving forward in time and the other time reversed (advanced and retarded waveforms shown above when discussing Wheeler and Feynman's Emitter-Absorber Theory (see diagram a few posts ago). If you truncate this "perfect sinusoid" by emitting and absorbing you have automatically introduced the extra frequencies. Every event in time must have a finite duration, this is the natural way to express this. Photons experimentally can be considered to exist in approximately 1/2 a wavelength of distance in the direction of propagation, a narrow "packet". Classically the packet is an impulse function (the response of a system to an event of finite duration) which is a single rectangular "pulse" of almost infinite height and extremely narrow extension (like a blow from a hammer) in time with conventionally unit area when integrated + to - infinity in time... the Dirac delta function. This is in the time domain... the same function can also be expressed as a "sync function" in the frequency domain, a harmonic packet that contains an infinite number of frequencies in the frequency domain (please note that the diagrams are "complex" and have "complex" sign). Usually instruments cannot record this "complex" part and displays something like the energy density... the normalized square of the amplitude. The same "impulse" in the frequency domain is a single frequency (as TRoc suggested) of near infinite amplitude and also nearly absolute zero frequency bandwidth. If we then express this in the time domain it is a "sync function" only this instance in the time domain... a sinusoid (mechanical oscillation) that is attenuated in the time domain but extends to + or - infinity running forward and back along the time axis. You cannot get around that. These are not theoretical idealizations they are used in practical signal processing and image reconstruction as well as the principle behind so many instruments I could not begin to describe. You can closely simulate a perfectly sinusoidal waveform in the time domain.... this is an undulation that starts slowly at first at some time and continues for a period of time at constant amplitude then stops by tapering off in time. the wider you make this "oscillation" in time the representation in the frequency domain looks more and more like that single line TRocs ideal single frequency "spectra". The more you try and simulate a single harmonic frequency... The longer the duration in time that you will need to "purify the frequency". A "pure" frequency which is a single line in the spectrum of infinite narrowness correctly extends from + infinity to - infinity in time. The nearest we can approach this is the Continuous Wave LASER. To be a "continuous" wave you must leave it "stimulate" forever, to + and - T = infinity, only then will it be a true single line.
Transform Pair
This image shows the "pair" in the frequency and the time domain of the way a boxcar (truncation) of a perfect sine wave results in extra frequencies. I have shown this before. Here is a new image that I have not shown before... transform pairs.
Fourier Transform Pairs See this link for detail...

On the left side is the "Time" Domain and on the right side is the "Frequency" domain. The left side is a "time series" with time increasing to the right and T = 0 in the middle and the right side is a frequency spectrum (including the phase and frequency) with frequency increasing to the right and f = 0 in the middle. Note the negative frequencies.... There is a double arrow in the center between the two representations. This indicates absolute equivalence (they are the same in different domains... what I mean by saying this is you could choose to show the same events either as a time series or as a complex frequency spectrum... the same). I should also point out that except for the naming conventions the left and right hand sides could be seamlessly exchanged without any change in "graphs". This means a "sync function" in the 'time" domain is identical to an "impulse" in the frequency domain (delta function or Dirac function of infinite narrow width but area under of the curve noralized to one). Perfect "reciprocity". The top diagram is your function TRoc... a single line (impulse) in the time domain is equivalent to an infinite continuum of frequencies in the frequency domain. But more importantly you can also reverse this picture such that a single line in the frequency domain is equivalent to to a DC offset in the time domain. So if you want to have a single "real" frequency this consists of two DC offsets in time... one up followed by one down. with as near to zero interval between them as possible. The third series shows a single truncated sine wave which stops where it is shown at + and - T. This is equivalent to two impulses in the frequency domain at the positive and negative frequencies shown. These may also be represented by Euler's Equation as well using the functions i = square root of minus 1 and pi. One of these "starts" the oscillation in time and the other stops the oscillation in time in harmonic systems. This is the function shown in the previous image above. Now consider that the sync function in time is a packet where if you were considering photons... that central 1/2 wavelength "hat" sits squarely at the center of the propagating wavefront around a 1/2 wavelength period. The next 1/2 wavelength "bump" differs in phase by 180 degrees and sits 1/2 a wavelength away from the first. The trailing bits to + and - infinity overlay and "cancel" in amplitude and phase where they coincide. Being on different wavefronts they cannot exchange any energy with each other being "causally" disconnected in time but they do contribute to the wave "picture". Thus ends the elven view of Fourier Transform Pairs and their relation to the entire universe. What I have omitted to say is that this time vs frequency "picture" is equally disposed to the space and spatial frequency picture... it is absolutely idential (all maps and pictures are the same)... these spatial frequencies are reciprocal space in the same way as reciprocal time is the frequency. This leads to holographic imagery not only in time but through all space. Thus all the Universe is "Holographic" in all dimensions and for all space and time coordinates ... the link is to reciprocal space and reciprocal time through resonances and spatial and temporal cavities. We have always been dealing with these "indirectly" though primitively as Radio Frequency Technology and to Optics.

We know that light is made up of "packets"... immediately this tells us that the photons "individually" though predominantly of a single frequency MUST be composed of a spectra to exist with those sidebands in space and in time. It so happens that the energy of the bosonic state can be reduced to a least action if in general a number of these photons share the same state and allow those "sidebands" to mutually cancel through overlap since the main frequency cannot cancel. These extra frequencies that the packet contains "kicks" the particle (photon) from the orbitals during "stimulated emission". Think of the packets "merging" in the one boson state on the one wavefront pairing up to minimize those sidebands by choosing to allow them to be "conjugate phases".... just in those additional frequencies. These effects are like "Cooper Pairs" for the electron (fermion)... there is a strong correlation but that is another story.. we will stick with bosons for now.

Now TRoc's last question... does the beam splitter act as an observer... not really. Observer's collapse superimposed states. This refers back to when does the wave-function collapse (just ignore any photons that do not contribute to the final interference pattern). The contributing photons all carry a qubit, when they lose the qubit through any process they no longer contribute to the picture It collapses (in our time) when a particular photon is involved in an absorption or scattering event. This does not occur (in this case) in the beam-splitter but on the screen. A photon ideally can reflect, diffract, interfere, tunnel any number of times without penalty (sure some of them will be destroyed but they will not take part in the final interference pattern). Only particle interactions detect the photon and "localize" it. Otherwise it is off "exploring all paths" way out to infinity as "waves"... all these functions extend to infinity in both the positive and negative frequency directions completely enveloping our Universe wherever it can go. This is the events "foreknowledge" of future things and also describes all that went before the event reaching even to the end of time and back to the big bang. The photon is freed from the temporal restrictions we all experience as Time but the penalty is that it cannot experience time either. This is conventional Wheeler Feynman Theory (as explained by elves of course). So what part does an observer really play in Wheeler Feynman Theory... nothing at all... it is a classical theory of causality in a non-local Universe.

Cheers

This post has been edited by Good Elf on Oct 22 2006, 02:17 AM

Hi Good Elf, Ron, Yquantum, TRoc, Why Not? et al,


I think what you are suggesting is that you take the frequency response H(w) of the DSE considered (somehow) as a network.. If we could model a photon as a function of frequency to get F1(w) we can say that that the output should be
Eq (1) F2(w) = F1(w) x H(w).

Looking at a real analysis of a somewhat similar situation ( http://elmer.caltech.edu/ph237/week18/AET1.pdf [thanks Why Not] ) either these JPL guys have got it wrong or what turns up at the receiver is simply the FT of laser signal noise delayed by the path length.

From Eq 3.1 is a time domain analysis and from Eq A1 is a frequency domain analysis .. both with the same result.

Clearly their 'arms' are very much longer than the wavelength of interest whereas our arms are relatively short compared to the wavelength .. even so, I think caution is appropriate here. To confirm or refute the validity of my Eq(1) I see no reason to avoid expressing the intensity at a particular point on the screen as a function of frequency (using classical EM analysis) to get H(w). We know the F2(t) at the screen so we can get the F2(w) from that .. we then look at the implied F(w) of a photon and see if it's plausible. Does that seem fair and reasonable?

If you are happy with the process (or can suggest a better one).. state your assumptions clearly and we can try to zap it with some maths.


-C2

This post has been edited by Confused2 on Oct 22 2006, 10:22 AM

Hi Confused2, Ron, Yquantum, TRoc, Why Not? et al,

The simplest form of photon is the atomic system response to a "primitive" impulse and that is it. The foregoing was all about that kind of description. More complex phenomena such as OAM may be "added" as we have discussed in the past. Intrinsic spin is essentially part of all photons. There is no simple way to model a complete real MM Interferometer. Simple mathematics using optical construction give a very good practical picture though wrong in the level of detail we are discussing here (as we both know). The DSE can be modeled with the standard Feynman Approach to Quantum Electrodynamics (without the Emitter Absorber Theory) that I pointed you to since that instrument is "linear" and does not retrace any paths. I am sure that a similar piece of software "could" be constructed for a MM Interferometer but not everything is readily available.

The article you have placed here on Gravity Wave Detectors bears no import on the matters under discussion. JPL have presented a classical description of an interferometer that would have been perfectly understood by Huygens in his day. It does not discuss the shape or nature of the quantum phenomena since it is not required for this analysis. It deals with signal noise in a more sophisticated manner though. Unequal arms in MM Interferometer does influence the ability to invoke noise cancellation in GW detectors (noise is just noise) but it is just a side issue which is only of interest to those who need to measure such things. A little system noise does not cause any problems with the standard MM Interferometer nor will it be any deciding factor in the Double Slit Interference Experiment or Delayed Choice Quantum Eraser Experiment. Interference will still occur within single photons regardless of the lengths of the arms in the MM Interferometer... the noise mentioned will always be there with electronics but the systems we are discussing are not that sensitive to that level of influence. What we are supposed to be debating is the shape of the extended wavefronts of single packets in (and about) the MM Interferometer for single spreading photons. You must keep on the subject matter I am not about to discuss the state of pixidust in Neverland.

As to assumptions, I do not make any, I rely on mostly existing experiments and their results for evidence, and I have researched what I am discussing as well as I can without any research materials other than the Internet and my own "ingenuity". I am not about to simply waste time on irrelevant papers without some real justification ... I see absolutely no connection with the experiments we are discussing or any need to reduce the noise by such a factor required to measure distortions in spacetime of the order of 1/1000 the width of an atomic nucleus over several kilometers. Gravity Waves represent one of the most feeble influences that man could possibly measure ... if we ever finally do.

I have shown that my statement is standard theory that photons only interfere within themselves and not with other photons... they are bosons. That is essentially why pictures from Hubble deep space can travel those vast distances without any distortions at all and still produce crisp and bright images after 13 billion years of travel. If they were able to be interfered with by other photons you think they could get here with so much clarity if they picked up "noise" along the way? Now if this interference can be accounted for by semi-classical non-local methods or that only a local quantum explanation derived through some throw of the dice is required... is the subject I think. There are excellent experimental grounds for the former and I have previously presented the information in this thread. There is no significant noise in the results of any of these interference experiments... the results are the same regardless of the photon flux. Every photon through an interferometer that undergoes interference and is detected results in a flash on the screen. All other inadvertent flashes throughout the instrument can be reduced to as low a level as you like with correct design. All flashes on the screen can be arranged to be the result of the laser source. All flashes not on the screen are not recorded.

Obviously you do not see what the significance of the article on Fourier Transform Spectrometer has to this discussion and why the scanning of that arm length actually performs the transform required to visualize a "packet" filtered by the response function of an instrument if you use a "pure" CW Laser. The numerical value of the response function is not required. Go work it out with a pencil if you like but these devices sit on workbenchs as diagnostic instruments.

By your reckoning the unequal arm MM Interferometer could not work if the photon flux was reduced to single photon events as shown in other experiments like the DSQE or the DSE. Why would the Universe have a different answer for the same kind of problem? Purely "classical" interpretations of reflections will not work in the real world as you already know.

If you have some theoretical objections to this proposition, you put your case and I will consider it. Please stay on the subject at least a little... No criticism intended just testing to my patience. I do not "like" to use maths as you probably realize, I prefer visual and physical understanding with references from relevant papers (by authors who incidently have done all the "mathematical legwork" for me, I am not about to simply "copy" their work but I am happy to quote it), but that does not mean that I do not understand mathematics and recognize a "red herring" when I see it. Not only that I have very limited server space to "publish" and make generally available.

Cheers

This post has been edited by Good Elf on Oct 22 2006, 04:48 PM

All,



I feel I should reiterate my main question:


"Does anyone agree that the correct definition of single "photon" should be that it has just ONE frequency?"


Why Not? - "what would happen if the distance between the slits and the screen were less than the minimal wavelength of the photons being sent through the slits?"

Nothing, or at least, not the results of the experiment.

That is why, given that the wave going through the slit is NOT one frequency, it vibrates differently at each meeting with the slit. This results in the pattern being "random" at first, and then, as the "noise" (meaning the UNACCOUNTED FOR parts of the wave) is reduced, through beat frequency reductions, to its' ground resonance, which is derived simply by the resonant ratio of the wave to the slit.

This is exactly the opposite of the way that the wave is created in the laser. Essentially, we are limited in the energies that we can produce/control, so there is always "leftovers" from the quantum transition. These are reduced through Bf reductions in the cavity, and then filters, to get the beam "focused". The almost-monochromatic light has a definite PHASE, which is what, in the end, is being translated onto the screen.


GE,

I think, given your tendency toward the wave approach, that you should consider the "switch". I felt much better after having done so. From Fourier to Wavelet Transforms. You must remember always: the rule does not define the phenomenon, it explains it. You can not offer the limitations of Fourier Transforms, and the "sine-wave" model, as an argument against the experiment.

This is exactly what I mean about Science over-focusing on the shape of the wave, when we have no good, hard evidence (in the books) of what shape it is. We all (here) seem to agree that the spiral/helical shape is, at least better, than the sine.

The part they never took a good enough look at is the interactions of resonance. There are no real rules, or clear definition. Think about the color wheel for visible light, and the chord in music. They never (had) any mathematical derivation; what a shame! I have shown these before.

So, I will also add, that I disagree about ONLY self interaction of the photons. That contradicts the visible light color mixing experiments, that are accepted, and "in the book".


regards,

T.Roc

Hi TRoc,

Color addition is actually a psychological phenomenon. The Universe does not care what we individually "see". The single frequency is only realized in totally "coherent" radiation. This is when all photons can "inhabit" the one state in the one place at the one time as a bosonic wave... Bose-Einstein Statistics. LASER's also have a natural tendency toward "coherency" as does monochromatic light from a metal halide lamp. For interference to work the light waves have a phase organizing capacity for each frequency of light from a source. Better to be a LASER source but not "absolutely" essential. Coherency does not automatically mean parallelism either.

While there is plenty of random "noise" in the Universe photons retain their "eternal youth" forever or they "die" instantly. There is no evidence in the practical universe that photons pick up noise as they travel through space as I have said above. I have always thought that there is no ceaseless disturbance at the quantum limit. That would necessarily disturb this calm medium of the vacuum to transmit all that phase information about distant stars without any break-up or blurring of the source image. My view is the smaller we look the greater the energy needs to disturb the "surface" of the Universe's "pool". The noise is totally reduced to events in that "pools" surface which embed in a surface that is "eternally calm" due to the energy that is needed to disturb it. I may not be right about that and it flies in the face of conventional wisdom. So this seems to be strong evidence for interference only being able to disturb the one photon. All photons in the one boson state will undergo the same self interference. What I would add is "conventional wisdom" has no proof that their view is correct either. The absence of evidence is evidence of absence... he he he!

Sorry I am not arguing against any experiment... you must have me wrong there? The Fourier series is the only "natural" process used by our Universe as evidenced by electromagnetism and by circuit theory and also Electrodynamic Quantum Theory are spherical harmonics... Fourier on the surface of a sphere. The existence of the dual nature of particles are only truly symmetric using Fourier theory and the Wheeler-Feynman Emitter-Absorber Theory works only with the existence of that interpretation of time and frequency in a complex domain. Wavelet Transforms are only 1/2 the picture (real transforms... using only 1/2 plane in time)... a useful tool but is an underachiever in this regard. It lacks the full symmetry.

Cheers