Problem with the two slit experiment, Observing later

TRoc, et al,

http://lectureonline.cl.msu.edu/~mmp/kap27...TwoSlit/app.htm

Play with this applet by varying the top slider all the way to the right.

Interference patterns emerge.

LL

Hi all,



LL, if words were all that were required, this conversation wouldn't be happening (still). Science demands more, ie. math and/or geometry, etc.


Even then, your words are NOT adequate. You are falling back to "square one" here, by thinking you can "simply" describe the ENTIRE "set" of experiments that define this phenomenon. If this were possible, QM would not have had been developed to "explain" this.

Do you mean the Sun, or the laser? (rhetoric)

No, you do not.


Tell me then, in words, why we can treat the slit as a "new source". Don't use geometry, or math.


Ok, don't tell me, I already know that "words" aren't going to "cut it".

Why?


Because, as C2 has pointed out, you are ignoring the facts:

(1) With one slit, we get ONE peak, with two slits, we get THREE. (essentially)


So, your "photocopy of the bunny" doesn't hold water. The bunnies might have had sex on the way, I'm not sure.


(2) Not only that, but the center peak, is NOT a copy of EITHER slit, as far as intensity is concerned. (copy = same)


(3) NOR is it a copy of the single slit version. (4x intensity)


(4) To delineate the difference between 1 or 2+ slits, we try to "peek" at the process, to see what is happening "in mid stream". Of course, we "peek" with an absorber, and guess what? One of the Talbot revivals gets absorbed, and we lose the interference: from a "photocopy" of 2 slits, we get a picture of ONE slit, just by "lifting the lid on the copier", so to speak.


This means that the Talbot revivals play an integral role in the final result. In analogous form, the Talbot carpet is woven with ONE thread. Pull the thread anywhere in the carpet, and the whole thing unravels. (back to a copy of one slit, even though the image that we input was of 2 slits)


Do I make sense?


regards,

T.Roc


This post has been edited by TRoc on Sep 9 2007, 07:34 PM

Size to density ratio of the source.

Guest,



Ahhh! You mean the density of the "imaginary slit", that is in between the other 2 real slits. That is where the extra intensity comes from?

TRoc,

Contrary to your emotional protest, DENIAL is not a river in Egypt.

Count the peaks from one slit.....how many do you see...come on you can do
it!

Double slit vs. single slit intensity patterns:

Wasn't the discussion about "Talbot carpets", which are basically ENERGY PATTERNS caused
by superposition of wavefronts? FWIW, your single thread approach is incorrect,
it takes AT LEAST 2 signals (threads) to produce repeating energy patterns.
Remove 1 thread and the patterns disappear but there is still the energy available
from the remaining "thread".

Even you must concede that resonance requires at least 2 separate signals (threads),
one being a physical mixing point for resonance to occur. It is the basis
of resonance. Resonance, cannot spontaneously occur in space without the benefit
of a physical point of mixing, so effectively there are a minimum of
3 components necessary for signal mixing to occur...2 signals plus a
physical point of mixing/summation.

Is this "direct" enough?

Comments,
LL

This post has been edited by Laserlight on Sep 9 2007, 09:10 PM

Hi all,

There was no emotion in that post, sorry.

No, its playing games with words and pictures.


Let's look at all the facts, and not select just the ones that will support an isolated statement.





One picture, showing both results (SSE, DSE), with intensity, and diffraction included.


I see: one peak for the SSE, with 2 very minor sidelobes.

I see: three peaks for the DSE, with 2 minor sidelobes, and a few more very minor sidelobes.


We could probably play this game some more, but let's not, OK?


My simple point is that a simple "photocopy", or direct (but proportional) reproduction of the "image of a slit" does not answer all the questions.

No, there is nothing for me to concede. I have been saying we need 3 sources for a "new definition" of resonance all along, including prior to this thread (by years).


An analogy is an analogy. Do not attempt to further misconstrue what I said. "What goes up, must come down" is very true, but does not result in a good "theory of gravity".


The "single thread" analogy of the Talbot carpet refers to the "wavefunction". The inclusion of the rest of the analogy (TWO slits, ONE carpet) already implies "more than one" component. If you "pull the thread" (collapse the wavefunction of ONE of the sources), the "carpet" (interference) is destroyed, and you go back to the SSE result. (note: this is AFTER the slits, we go from 2, to 1 slit results)


As for the "physical point of mixing", we have already covered that. Since we are not in a "perfect-vacuum", the MEDIUM that the experiment takes place in IS that point of mixing. Nothing more is required.


Just like the term "black and white interference fringes" is a misnomer, so is "interference in a vacuum": nothing is there to interfere with. Period. That is, of course, imagining that a perfect vacuum exists, which it does not. So, as long as there are ALWAYS wavefunctions in the medium, then interference in that medium is possible.


If you start from imaginary assumptions, you can only arrive at an imaginary theory. I'm not going to vote for that.


Now do I make sense?





T.Roc


ps.

No, the question at hand was to C2, and what his distinction between linear and non-linear was, and in which category he would place a "slit wall in a medium", and "a crystal with a periodic/symmetric lattice" in.


Not that you are not free to discuss what you'd like, but I am interested in what you (and anyone else) think about that. I'm not so interested in having general analogies taken apart as if they were Science. They are used to help further understanding of the underlying Physics, and that's it.


This post has been edited by TRoc on Sep 9 2007, 09:50 PM

TRoc,

Perhaps, a bunny is too confusing, I should have used something that you could relate to:




An energy pattern is created because of the geometry originating from
a source...a stencil....a mask.... slits, and how energy interacts with those
pattern originating "sources".


Did you adjust the sliders to derive superposition energy patterns that can
be observed in the waveforms? Of course this is only a simulation viewing
one cross-sectional "projection" plane arising from two slits, where the
geometry can be changed, to change the pattern generated.


LL

This post has been edited by Laserlight on Sep 9 2007, 09:45 PM

LL,





Well, for C2 and GE, you are correct.


Can you make a Condor, or a Llama?


(wrong southern continent)



ciao,


T.Roc


ps. Yes, I see what you mean in that java model.

another ps. I noticed that M Berry refered to one of the interference patterns in his paper a "hedgehog". I don't know that one!


This post has been edited by TRoc on Sep 9 2007, 10:00 PM

TRoc,

Sorry 'bout that? A pleasant surprise. Your mastery of English is very good.

C2 is in England. GE is Aussie.



Peru? Bolivia? Equador? Colombia? What country?

LL

This post has been edited by Laserlight on Sep 9 2007, 11:48 PM

LL,


Do you have the whole ark in there?




Chile.


Don't be too impressed with my english, it is my "first" language (or more than 1/2). Mixed family; dual citizen, etc.


I am in the US now (just for a few more weeks), too.


I'm not sure why I thought C2 was also from australia? Same accent as GE?



OK, a technical question (because I forgot to mention this difference in my "list".)


Do those "puppet shadows" get bigger, if you use smaller source (slit)? (like the DSE)


The DSE has too many "surprises" to be explained by the "classic" method, as they say, and the QM explanation just leaves logic by the wayside.


regards,

T.Roc

Hi Laserlight, janrinze, TRoc, Jal, Montec, Confused2, yquantum, StevenA, "Why Not?", Siau, Neil Farbstein, Terry Giblin, "THEY" and "THEY2" et al,

it is not so much arrogance (though I admit to some) but it is related to my frustration having to repeat myself endlessly. From what is transpiring it would appear that this entire discussion is traveling in circles.

On to more interesting parts of the discussion... Thanks TRoc for your points about Talbot carpets... Unfortunately it is very difficult to analyze the fine points regarding them. The issue about Airy Packets being non-spreading... that is interesting and could be very important. Another interesting packet is from Bessel Beams and are produced and investigated in a single interfering photons regime. Bessel beams are collections of individual bessel photons in the strong source situation but individual photons one at a time behave in the same self-interfering (actually non-interfering) way as the beam ... in the weak source limit. This is shown in this paper (Application Note).
Bessel-type interference patterns detected in single photon regime
R. Grunwald and M. Bock
Bessel-type interference patterns detected in single photon regime (App Note)

In this case you can all see the differences between spatial and temporal correlation. Here we see that the "diffraction" leads to single photon correlation to the single pattern... all around it as shown by the detail in the "Setup" image detail of the frontpage of this application note. I would have got better examples of Bessel Beams but I wanted to emphasize the single packet response of this system to the ensembles of photons.

These are very special shaped wavepackets produced by 'wedge shaped"... in this case "gaussian shaped" optical elements through which conventional photons have been propagated. The other interesting feature is the ability of the Bessel Beam to penetrate dispersing media without any diffraction (up to a point)... depends on the quality of the beam.

I suggest this has a very great bearing on the interpretation of the quantum phenomena and to features of these special "shaped" photons. Note that these patterns represent single photon interference patterns for single wavepackets 'constricted" to a finite size by the Bessel Function "shaping". Individual photons are still required to build up a picture over time but the packet that the image is building on is the same shape for all the single correlated photons. This is limited specifically by the nature of the non-spreading Bessel packet. other ordinary photons have a spreading wave packet and that would normally lead to mutual interferences between the packets. IMHO the entire DSE interference pattern which is due to spreading and mixing of single wavepackets ... one at a time to produce the whole pattern is the "norm" and this is the "exception condition" by taking the norm and passing it through a wedge shaped lens resulting in the non-dispersive Bessel reshaped wavepacket from each of the seven 'separated sources".

Does everyone see this as evidence for "spreading" wavepackets that would converge through successive 'morphing" of the "wedge shaped" lens into the normal multi-pinholed DSE... especially if these were arrayed in a line? These are also a kind of soliton packet... there are several examples of soliton producing wavepackets in the literature beside bessel and airy Packets.

Cheers

This post has been edited by Good Elf on Sep 10 2007, 02:48 AM

Hi TRoc,

Chile, I eat it all the time....oh, sorry, that's chili.

The size of the "projected" image varies according to the ISL, It depends upon
how far the source is from the screen, but you know this. Ever go to a movie
theater?....small 35mm film image.....HUGE expanded image on screen.
It depends upon the image focal point from the source.

If you really think about the interference process, every object image that we see
is an interference pattern that replicates the details of the image.

The viewed object is the "secondary emission source", and the interference pattern
is imaged on our retina. We have discussed the physiology of the process
at length previously.

LL

This post has been edited by Laserlight on Sep 10 2007, 02:21 AM

Hi Laserlight, janrinze, TRoc, Jal, Montec, Confused2, yquantum, StevenA, "Why Not?", Siau, Neil Farbstein, Terry Giblin, "THEY" and "THEY2" et al,

Referring to the entry above..

Some slight corrections... I mentioned "wedge shaped" lenses when in fact they should be an "Axicon" cone shaped lenses.

These little cones produce images of the packet on small footprint areas beneath them. The argument about how many nodes are to be found in an airy Disk should be understood as a question as to what level of the field where the ripples are too small in amplitude to be detectable. In actual fact the ability to detect these smaller ripples would be highly dependent on the signal to noise ratio of signal photons to noise photons and the period of exposure. The 'count" is simply you arbitrarily determining the limit. The trailing and leading edge of these packets depends on your belief/understanding of Wheeler Feynman Absorber Theory and the possibility of parasitic emergent behavior in the far field. This cannot be ruled out simply because experiments have not been performed to test when and where this emergent behavior occurs... Just like Talbot Carpets. It is possible to restore the entire packet no matter how small these amplitudes become "attenuated" through distance simply because this is a quantum event so even the slightest "response" could result in the full "revival" of the entire packet .... do not write packets off just because you cannot individually see then because of "distance". Photons never die.

The other types of beam that we have spoken of before are "Orbital Angular Momentum" (OAM) enhanced packets. These lead to "twisted light" and this carries additional orbital spin quanta which are used to confine the packet and prevent spreading. This can only be "demonstrated" up to a point but it is an apparently very successful technique (optical tweezers etc.). You can all remember these objects from which result from topological charge and optical vortices and instantons as discussed by Dr. Taco Visser way earlier in this thread. OAM is an infinite level quantum number that could be used to encode an infinite amount of information on a single monochromatic photon. We have previously discussed how this information could be read using an optically resonant "tree" structure that 'sorts" the photon among the resonant states of OAM until it is finally detected along a uniquely resonant path that resonant to that specific mode of OAM where a light sensor 'confirms" the data encoded on the single photon. In theory you could write the Bible on a single photon and then read it by providing a resonant tree that responds uniquely to that one 'resonance".

Cheers

This post has been edited by Good Elf on Sep 10 2007, 06:12 AM

i have an answer which takes into account several observations in duality...the study is about a 'singular particle universe'.

"singular particle Universe"

This defines 'quantum' as being the only 'real' particle , and then there being only one of them. Though this may seem bizzare , the problem of causality is resolved in this fashion.
the "particle" behaviors according to duality. Meaning it has only two states. One occupies all space as a volumed particle. (The even distribution of itself).In the other state it becomes a quanta of energy>
Looking at it this way , it takes no longer to compress to any point in space than to any other.Because only one particle is doing this , it does not create causality and can never meet or interact with itself in either of the two states.....hence causality is preserved...there is only ever one..

the important difference in this is that whatever theory you use , you must go from a zero energy state (before causality) to an increased energy state (after something is caused). Unless you start with a state where all the energy is already present and distributed and compressed, (such as the big bang)..Unfortunately , it's the chicken and the egg. Where did the energy come from...

Which singular particle theory, The same level is repeated by the same particle. There is a type of causality which always remains as one when the particle has repeated the contraction to quanta and expansion to universal volume .

it must never occupy two "pixels" of space at the same time. This breaks causality and calls for twice the energy to be created.Further, It cannot take up a position that it has already occupied.It seeks opposing positions in a uniform fashion to create a balanced distribution.
However , this distribution is not limited by space alone but time as well. if this were not so the light created and received from a star would not be able to exist in our future.So the quanta particle places or "occurs in an even distribution."The alpha and the omega"

Only when ALL the universe has been occupied by quanta can time be seen to operate.Even at this point Chaos is more relevant than intelligence, structure and design.

We need to remember that throughout all of this the quanta states have not been able to interact with each other,But once the universe has been totally mapped the cycle continues to operate.for the first time causality can be created.Unfortunately we are a long way from increasing energy.
the interim states between quanta and volumization can add up to a quanta,And there are as many of these occupying the universe as quanta itself.Because each time the cycle was run it made the transition through volumes.This means that :

1/2 cycles + 1/2 cycles can equal a quanta.
1/10 cycles + 9/10Th's of a cycle can equal a quanta

Because in retrospect (after space has been filled) , There are many new possibilities

Diversity has been created for the first time. Still only one quanta at a time but using a very different method of volumisation and reduction to quanta.once the diversity cycle completed.
Time now becomes a factor since the new cycle does not rely on the reduction from one point to another point only. But the interaction between two or several points.
localization occurs where High combination cause voids in the system which and motion becomes necessary (as we see it today. Since the Quanta is still responsible for all this it needs to repairs it's clusters of occurrences which are occurring.

Planetary motion keeps the quanta from occupying the same space again while still being able to maintain the reality of an object.Since the object is made up of occurrences , These must be replaced at the same rate as the quanta originally created it's cycle.

In all this Causality is preserved by ONE. No energy is added nor subtracted by any thing that occurs in the universe since it only has one source and that source gave nothing more that it's occurrence.

cheers
iseason
:rolleyes: iseason@igrin.co.nz

Hi Guest_iseason,

Firstly it is customary to register with the Forum so that we can know that we are speaking with a single person and that the identity is not an alias for an existing board member. You would not want others to make problems for you here on the Forum. In the past I have had some "awkward" experiences with individuals that refuse to properly identify themselves and want their identity to be mistaken for someone else.

Secondly I really cannot relate to that theory of a single particle Universe. Too weird even for me... Science requires experimental proof... You need to provide this theory with "substance" through existing experiment or through a Gedanken Experiment based on known physical principles with predictions that indicate outcomes that match with our reality. Otherwise it is an unsupported "belief" sounding more like something out of Genesis than from a physics book.

The next point is you have decided to abandon the whole of current physics that has worked so well without any justification. Remember that existing physics does have merit since it has demonstrated a mastery over certain processes that lead to knowable and reproducible outcomes. This is something belief cannot do regardless of how earnestly we might like these theories. Your theory offers no immediate promise of any similar capabilities and seems to be the basis of a religious belief rather than thoughtful science.

It is not good to directly publish your email address and it is usually better to deal in the way the Forum operates with Personal Messages and Forum email which is "effectively" the same since the limited anonymity and available communication channels are ways to protect our privacy and to stop any obsessive behavior by those who may become agitated by some of the ideas expressed here.

Please feel free to join in but also think deeply about those ideas in constructive and arguably scientific ways... Nobody needs to be be a scientist but it sure helps here to talk about the same things in the same way.

Thank you for quoting me but my ideas are not for everyone so I do not expect that everyone should try to follow them without thinking carefully about exactly what they mean as a collection of concepts. The Delayed Choice Quantum Eraser Experiment is a very interesting experiment and it demonstrates a very subtle point about the underlying nature of time. Propagating photons do not experience the passage of time, similarly they cannot distinguish between spatial events. This is because photons are subject to the most extreme form of time dilation and length contraction possible. From the reference frame of the photon the emission and absorption of a photon are simultaneous even though in our observer frame of reference any amount of time may separate these events. So from the rest frame of the two entangled photon it is possible to consider that the events of emission and absorption are simultaneous even though we "observe" them separated in time. This is no mystery since this happens all the time even in our rooms where light must travel some distance to reach us, and this is interpretable as spatial distance. Everything we can see is in the past... It remains to be seen how much in the past these photon events in the Delayed Choice Quantum Eraser Experiment are relative to each other and that is the only thing that is really surprising to us.

Cheers

This post has been edited by Good Elf on Sep 10 2007, 02:42 PM