Problem with the two slit experiment, Observing later

Hi GE,

Interesting, kind of like the photonic analog of the Coriolis effect where the
spin of the earth affects water and weather pattern rotation depending upon
which hemisphere is observed.

EM retardation, is basically EM field "recoil" that opposes the acceleration of
a mass. In electric motors it is a counter torque phenomenon. I guess the
point being that this occurs at every size geometry where forces interact. There
will always be an opposing force proportional to the size of the masses involved
and the acceleration component that exists between them.

.

Elegantly simple and "unified", IMO.

Regards,
LL

Hi Laserlight

NO... its over a precise specific distance. Each unit must be the same "size" or there will be fluctuations in the time taken to travel from point A to point B.
If you don't start with the right model you will not get the right answers.
Refresh ...
http://math.ucr.edu/home/baez/planck/node2.html

Hopefully.... everyone will see the relevance of this to this thread and where we go from here.
jal
I don't understand Neil Farbstein

Neil,

ROTFLMAO! Nerd-tronium! Priceless!

LL

Neil,
To answer your quark bag question....LOL!

THis short article on quark stars should help.

http://www.news.harvard.edu/gazette/2002/0...quarkstars.html

Hi Aerohead,TRoc,Laserlight, Good Elf,yquantum,Niel Farbstein et al,

Edit .. and jal of course! sorry (age).

For a given frequency it is generally agreed that a photon has an energy given by E=hf, ( eg http://en.wikipedia.org/wiki/Photoelectric_effect ) and it seems photons are absorbed 'whole' or not at all so if two antenna picked up one photon then there would be a serious energy conservation violation which would probably have been noticed by now. I'm pretty sure that one photon transmitted will (at best) give you one photon received.
In the experiment we've been looking at ( http://www.teachspin.com/instruments/two_s...periments.shtml ) the results show that the number of photons counted with both slits open is the same (within 5%) as the sum of the counts for each slit individually ( http://www.teachspin.com/instruments/two_s..._combiplot2.gif ) while this result doesn't actually prove anything .. it would have been worrying if it had not been the case.
A possible explanation of the 'one in one out' rule might be that the field is quantised at the point of origin and detection but not at the points in between. Clearly this raises more questions than it answers but I thought it might be worth mentioning it.
http://en.wikipedia.org/wiki/Quantization_(physics)
http://en.wikipedia.org/wiki/Path_integral_formulation
Best wishes,
-C2.

This post has been edited by Confused2 on Jan 17 2007, 12:06 PM

Good Day All!
Good Elf
You are putting up strawmen to refuse to accept the validity of my approach. (Particle-like) There is a large body of work that has been done and is being done by respected people in String Theory, Loop Quantum Gravity and Quantum Geometry. There is even a new math approach being investigated. (See the last link in my summary thread. http://modelingnts.la.asu.edu/pdf/Spacetim...y.w.GC.proc.pdf )
I have only added just one tiny little piece …. A model which is derived from 2d and 3d packing.
I believe that the review/link to J. Baez should have cleared the air. If not then anyone who has the inclination can read the links provided in my summary thread. (http://forum.physorg.com/index.php?showtopic=5203&st=45&#entry166956 )
It is not that my explanation is too hard to understand. Rather, the problem resides in the unwillingness of the brain to accept the particle-like and quantum geometry approach because it overthrow the establish concepts that have been proposed of how the universe is made and operate.

The last two links which you have just provided on your post should help to clarify the validity of a particle-like and quantum geometry approach.
jal

YOU HAVE A GOOD DEFINITION OF A GOOD THEORY. Now i understand where you were coming from and hwere you are leading

This post has been edited by Neil Farbstein on Jan 17 2007, 04:48 PM

Hi TRoc,
http://socrates.berkeley.edu/~phy7c/huygens.html
The argument suggests why a wave spreads at an opening by using an argument based on the source(s) that would cancel out the wave at the opening .. which (clearly?) represent spreading sources.
I can see you don't like it... it is a 'construction' not 'new photons'.
My post suggesting the EM wave might be quantised at emission and detection may help to sort out the number of photons required .. probably (?) just the one will suffice.
Please bear in mind I am just prodding the swamp with a stick at this point . I suspect your posts have far more influence on me than vice-versa.
Best wishes,
-C2.

What now?
How about..

Edit .. sorry, I meant this link really..
http://www.lepp.cornell.edu/spr/1999-02/msg0014938.html

Baez points out .. you need an ensemble of photons .. I suspect that's exactly what we've got.
Baez who?
http://www.edge.org/3rd_culture/bios/baez.html
Wavefunction?
http://en.wikipedia.org/wiki/Wavefunction
Please bear in mind that (as stated in my last post) .. I am just prodding the swamp with a stick to see if the path ahead is safe.
Best wishes,
-C2.

This post has been edited by Confused2 on Jan 18 2007, 12:11 AM

Good Day All!
Thanks Neil Farbstein.
Some links, for the students, that show you how to do the calculation. No theory (well very little.)
http://electron9.phys.utk.edu/optics421/mo...nterference.htm
http://electron9.phys.utk.edu/optics421/mo...Diffraction.htm
http://electron9.phys.utk.edu/optics421/mo...5/Coherence.htm
jal

Hi all,


C2,

Thanks for 'staying on target', and the links. I think we agree now that, basically, the HF method is 'classical', and we (GE, LL, I) are trying to 'tweak' QM here or there. The HF method describes and maps out the DSE very well, and in a simple way. In the process, however, it breaks a commandment of QM, and 'creates' "photons" (QM's baby) from an 'area' with no electrons.

I often take up the 'devils' advocate' position, in order to show where I think a problem, inconsistency, or redundancy exists.

The "in between" argument that I have thrown out so many times, is directed at the WHOLE "photon" method (QM). The "photon" is the field, or, the electrons (emitter and receiver) are the field. When you 'adopt' the QM baby (the "photon"), you take the baggage too!

If your model describes a 'communication' between 2 electrons with the "photon" being the mediator, then the "photon" IS what is interacting, because what is SENT is not the same as what is RECEIVED (in interferometry).

If your model describes the 'communication' as just 'energy' waves, then the properties of sender and receiver can interact directly, through resonance.

The problem with the latter model is, that this 'violates' our causal mindset. They WANT the problem to be described as an 'in between' explanation, so it is 'causal'. The problem then, becomes MEASURING: you can't measure a "photon" while it is 'in flight'. The method for measuring is AT the screen, so our answers are only about "what happened" at the screen. They can not answer what happens 'on the way'.

We have talked a little about some of these 'other' methods, that use new 'virtual particles', and can completely describe the phenomenon from THE SCREEN. The different frequencies that hit the electrons in the screen act in unison to produce the pattern, and intensity of 'diffraction'.

This 'back door' approach is too good to overlook, and is supported by more and more experiments. I say 'back door' because they have (again), arbitrarily added some 'new toys' to the box, without prior prediction. They are speaking of 'electron to electron' interactions, and NOT mentioning "photons". They 'get away with it' because its' happening in the 'lattice', and never becomes 'free radiation'.

To me, I have no problem with the idea of 'action at a distance'; if they want to develop the full theory of 'electron to electron' interactions, and 'do away' with the "photon", that's fine.

Either way, I have a "virtual model", that lets the energy ("photons") superimpose, and interact (while superposed) in certain ways, that become causal for the measured differences between emitter and receiver.

I said, quite a ways back, that this (the DSE) is a 'side show' for me, meaning that it was not my intention to come and throw out the 'perfect answer', but rather, to point out what I consider the "problems" with the DSE interpretations.

A quote from the link in C2's last post:

could have been said by any of us !!


..Onwards!!


ciao,

T.Roc

Hi Aerohead, Confused2, Laserlight, Jal, Montec, TRoc, Duality, yquantum, Neil Farbstein et al,

Aerohead's Reference with "question"
Aerohead has struck a very important question. We all think we know what a photon 'looks" like but do we really agree on this concept. I will post a two part answer to what I think a photon looks like and I am pretty sure that most people will not be able to find any common ground ... yet I base most of what I say on sound research that seems never to trickle down to "Joe Public". So at the end so we can all agree on a common "idea" about just what photons are and how much makes up a photon please respond constructively....

Any question can be asked it is just that not any answer is acceptable. I just do not think that "answer" is acceptable... he he he! The standard answer for this because it is a quantum process the question is that it is irrelevant... end of story. See... You did indeed ask the wrong question.

It is an interesting question and gets to the heart of what people believe about photons. You are correct to consider the size of the receiving antenna (or even the transmitting antenna) to determine a couple of things right off about photons. Antennas are "tuned" to capture photons. Their size is related to some property of the photon since it is related to the wavelength of the "particle". We know that a wavelength of the photon does not change in the far field. This is during propagation successive crests and troughs in the electromagnetic intensity of a monochromatic beam retain this dimension. The other important property of light is it spreads. While it is propagating it is also spreading and the intensity of the beam for a standard 1/2 wavelength dipole radiator falls "effectively" on the surface of a sphere... actually in the case of a dipole this is the surface of an expanding irregular shaped torus.

This shows a cross section.

There are a couple of factors that many educators gloss over along the way and these are that photons are bosons and an infinite number of them can occupy the same state. The next point is when they travel they travel as waves and when they interact they interact as particles. They do not do both at the same time. The next point is as far as can be known the group velocity of light is equal to the phase velocity of light... this is an important consideration since everything that moves slower than light has a group velocity less than light and a phase velocity greater than light.

Incoherent light is a situation where photons are emitted one at a time without any organizing principle. There are two ways to "organize" the emission of photons one is through LASER population inversion and the other is through amplifying resonance in either an optical or electronic cavity or "resonator". Obviously there are certain problems in producing coherent radiations that are solved by techniques that work in other frequencies. We have several basic techniques. We still do not have reasonably powerful radiators of coherent radiation in the Tera hertz range and because of the great usefulness, research is still underway in that region. Some LASERS require the detonation of a small atomic bomb to work effectively.

In all cases light is primarily a force carrier. Light is also a transverse wave when sufficiently far from the source. While the wavelength of the wave is "fixed" the amplitude can be "modulated" and this is done at a certain frequency by simply increasing the number of coherent photons "in the wave". Each individual "packet" of light could be considered as the result of a fundamental process. An energetic Electron in a high energy quantum state "falls" to a lower energy state releasing a single photon. This is similar to a a hammer striking a nail. It is "unidirectional and polarized" impulse... a sync function like sin(x)/x...

Click to enlarge...
This is the simplest case possible. In some practical cases the photon will be formed by a more complex wave function. If you consider this process as that electron "shifting shells" it goes from a higher energy shell to a smaller lower energy one.

In the "cavity" it creates an impulse (this cavity is a cylinder)... more typically in an atom it is often a sphere or other regular cavity shape. here is a reference to cavity resonators...
Cavity Resonators
Here is the cavity resonator simulated from a series of "tank circuits"... made from 1/4 wave sections...

each one the equivalent of this one...

In the spherical case the sections are "C" shaped, the "bit" on the left a rudimentary inductor (a short) and the bit on the right a rudimentary capacitor (open circuit). Two "C" shapes make up a single section of a spherical cavity.

In the case of radio transmitters continuous waves are produced as shown in the top blue animation (produced by Zephir from an original by Dr 'Bas' Lago). IMHO a process of wave construction occurs through the summation of sync pulses in this fashion...

Click to enlarge...
We see that the higher frequency content of the sync pulses are constructively interfered with in the temporal direction of propagation to suppress the higher frequencies and only the primary 1/2 wavelength "pulse" remains in a construction.

So in one sense of the description a classical view would have photons all being produced in step from a source which is "periodic" or "resonant". Individually the photons are sync packets but they propagate on a wave and then finally interact with the "sink". I have exhausted my access to images so to access more images I will now carry on into the next post... keep reading ... this is the best part.

Cheers

Hi Aerohead, Confused2, Laserlight, Jal, Montec, TRoc, Duality, yquantum, Neil Farbstein et al,

Continued from my previous post...

Annotated explanation of photon propagation in free space with MIT Animations

Below are a number of professionally developed animations that should be set to "loop" to show how these features develop. It is "amazing" to me that there are few sites that take accurate representations with any seriousness. In almost all cases there is a tendency to "guild the lily" as to processes. I could show some of these incorrect representations but you would learn nothing from them since they are dead wrong. I have selected these animations from a MIT site. First some explanation about how atomic oscillators work... Please focus on the emitted photon moving off into the far field and do not be distracted by the inductive fields in the near (evanescent) region...

The dipole that "turns on" releases a photon into the far field (just one photon... a single impulse) The "far field" extends only as far as the external geometry permits (stays within a dimensional cavity). With atoms this could be limited to the next "shell" where the photon is then "re-absorbed", or in some instances, a higher energy transition could create a free photon that may pass beyond the bounds of the atom into the external spaces as a "single free photon". Notice that the "far field single photon" has only one major maxima in the "packet" (a sync pulse). In this process shown the electric field rises from a zero to a maxima "inside the shell". This is now an "excited high energy state".

The dipole that "turns off" also releases a photon into the far field (just one photon... a single impulse) The "far field" extends only as far as the external geometry permits (stays within a dimensional cavity). With atoms this could be limited to the next "shell" where the photon is then "re-absorbed", or in some instances, a higher energy transition, could create a free photon that may pass beyond the bounds of the atom into the external spaces as a single free photon. Notice that the single photon has only one major maxima in the "packet" (a sync pulse). In this process shown the electric field falls from a maxima "inside the shell". This is now a "un-excited low energy state"..

Each of these photons are opposite in phase in relationship to each other. Below... a succession of accurate computer generated animations show each of these conditions as seen from within the appropriate frame of reference. No animation can show accurately both processes since the rest frames are quite different. As long as you can understand that you will begin to get the gist of how this all happens.

The entire process involves both stages of "turning on" of the field followed by also "turning off" of the field... these processes occur within different shells usually where we have electron "transitions" from one low level to the next higher level (by absorbing a photon... a "turning on" process). This is then followed by a "turning off" process from a totally different shell which releases the electron to "fall" to a lower energy state through a conversion of its excited energy and liberates the photon. Each separate process is seen from different shells when they are usually "internal" transitions. The transitions can be "free" or "forced". In "free" transitions the photons are excited by absorption of an external photon and win lose the excited state at some arbitrary time period later. A "forced" transition is one driven by some periodic process and sometimes this periodic process even "forces" the direction in which the photon may propagate. In a forced system the energy that drives the system "fills" the states and so absorption and emissions occur simultaneously as oppositely phased photons rather than "internal" processes hiding the transitions from external observers.

In the case of where one of these transitions becomes an "external" process and the photon totally escapes from the shell structure of an atom, there is no "closure" for the atom. The photon is usually in an "excited" state or higher shell or cavity and then "turns off" allowing the electron to fall to a lower "unobserved" shell releasing the far field photon which escapes the atom shells altogether becoming a free photon.

The animations below do not show the fact that the direction of the photon emission from one atom is not totally spherical and in a particular case will always emit in a certain "random" direction depending on unknown initial parameters. In coherent systems this random factor is removed by an external process such as in the case of LASERS is "stimulated emission" which ensures that this direction is not random but directed.what this means is the photon phases are "aligned" with an external boson field of co-moving photons. Liken this to a "transverse wave" at the beach in deepish water "plucking" you "up" from the bottom and moving you forward with it as it passes (unlike photons you are left behind after being "plucked" but photons travel always at the speed of light and so ... "off they go"... all in the one direction). In the case of radio wave transmitters this is an EM Resonator that causes free electrons to move in sympathy to an impressed electric field which is generated from a "resonant tank circuit" fed with electrical energy.. In this case the transverse wave is launched from a wire in which charge centers in the wire are displaced from one end to the other end sympathetically in oscillation. As the charge centers on the wire "cross" the field drops to zero and if you have gotten it right (not doing this too slow so it will be reabsorbed entirely) some of the energy will be "launched" as photons of the appropriate frequency... the rest of the energy oscellates in the inner near field and remains behind as electric and magnetic fields "pulsing back and forth". In dipole systems where currents move along wires to launch photons the field loops develop from instantaneous nett charges are "pushed" to either end of the antenna and with a suitable regenerative energy feed are allowed to rush back and forth under simple harmonic motion "nipping off electric field loops" as the respective positive and negative centers cross each other near the geometric middle of this "bouncing motion". These electric field "loops" contain energy since they can be used to drive charges in circuits, but in "free space" these complete propagating loops cannot "earth themselves" on any suitable material to dissipate their stored energy. Therefore the radiation patterns which are "atomically" the traveling photons "carry" energy from "source" to the "sinks". When the "loops" reach a suitable destination they "touch" the surface of a suitable "conductor" and snap into a open loop with both ends "grounded" on the conductive medium. These loops then shrink in virtual photon processes dissapating their energy in driving electrons in an external circuit in a process similar to the original creation process in the near field. An analogous process occurs inside the individual atoms for atomically derived processes like visible light but accounting for scale and for available "systems".

Here is the Main site...
Visualizing Electricity and Magnetism at MIT
http://web.mit.edu/8.02t/www/802TEAL3D/teal_tour.htm

Magnetic Dipole Radiation From a Dipole That Turns Off

The field lines of a magnetic dipole for the case where the dipole moment falls to zero over a time scale T. The specific time dependence of the dipole moment is proportional to (Pi/2-arctan(t/T))/Pi, which is a function which is 1 at t = -infinity and zero at t = + infinity, and falls to zero in a characteristic time T.

http://web.mit.edu/jbelcher/www/off.html
(image shown above)... please run animation in Loop to show the full process.
Two dimensional Slice


Magnetic Dipole Radiation From a Dipole That Turns On

The field lines of a magnetic dipole for the case where the dipole moment rises from zero to a constant over a time scale T. The specific time dependence of the dipole moment is proportional to (Pi/2+arctan(t/T))/Pi, which is a function which is 0 at t = -infinity and 1 at t = + infinity, and increases in a characteristic time T.

http://web.mit.edu/jbelcher/www/on.html
(image shown above)... please run animation in Loop to show the full process.
Two dimensional Slice

Magnetic Dipole Radiation From A Sinusoidally Varying Dipole--The Near/Transition Zone

The field lines of a magnetic dipole for the case where the dipole varies sinusoidally in time by 10% in amplitude (20% peak to peak). That is, the dipole is always oriented along the vertical axis, and its dipole moment varies in time in a manner proportional to (1.0 + 0.1 sin(2 Pi t/T) ).

The animation runs over one period of the oscillation. The radiation terms begin to dominate at about cT. Well inside that distance, the field is quasi-static.

The motion of the field lines is given by the ExB drift motion, which is also the direction (but not the magnitude!) of the Poynting flux. By looking at the motion of the field lines one can see that the energy flow in the quasi-static region is first away from and then toward the origin, as energy is first put into and recovered from the magnetic field. However, in the radiation zone, the energy flow (and field line motion) is consistently away from the origin, representing the irreversible energy loss to radiation.

http://web.mit.edu/jbelcher/www/sin.html


Two dimensional Slice... please run animation in Loop to show the full process.


Three Dimensional View (one electric field line view)... please run animation in Loop to show the full process.
A 3D representation of this same radiation, but choosing only one field line per loop and replicating it every 15 degrees in azimuth, to give a field for the 3D structure of the field. In general this may be split into many individual photon "zones" depending on geometry of the antenna.


Three Dimensional View ( Sited inside a room to give some perspective ... actual frequency. 70 MHz Dipole Radiation, shown to show physical scale relative to desks)... ... please run animation in Loop to show the full process.

Magnetic Dipole Radiation From A Sinusoidally Varying Dipole--The Transition/Far Zone

The field lines of a magnetic dipole for the case where the dipole varies sinusoidally in time by 10% in amplitude (20% peak to peak). That is, the dipole is always oriented along the vertical axis, and its dipole moment varies in time in a manner proportional to (1.0 + 0.1 sin(2 Pi t/T) ). The animation runs over one period of the oscillation.

http://web.mit.edu/jbelcher/www/sin_far.html


Two dimensional Slice... please run animation in Loop to show the full process.

Together these "sync pulses" construct as shown in my illustration previously. Annually these "photons" expanding on an irregular torus, will be "segmented" into single photon "spatial zones" or nodal boundaries depending on the way the photons have been generated. Some "lobes" of the radiation pattern are suppressed and others are accentuated as indicated in regular antenna theory. Remember also that bosons can all occupy the one state so what you see for one photon actually apply to all photons from the one source. This means they all occupy the same apparent space. Some energy is radiated and some energy is "stored" inductively within the evanescent zone as seen in the near field animation. In the near field the photons remain "virtual" and connected to their sources by their field lines and are involved in doing work when they are allowed to discharge into their surrounds.

Note: I have an interesting story to tell about magnetic fields and static fields that also makes sense ... but not here.

Other points to watch is that these "patterns" are wave patterns and they cannot be observed without damaging the overall photon structure and information each photon carries about the source. That would be an entirely different story.

Comment welcome and any ideas people have other than really difficult ones that are so far from standard theory they cannot be accommodated are welcome. Remember the "devil" is in the detail and both the near and the far field need to be understood to truly grasp what geometry and phenomena we are dealing with here but you should now be able to understand a little about the actual "shape" of propagating photons. The shape is "based" on the single sync pulse and because the field "nips" off between cycles the quantum are not continuous between cycles. Once "nipped" off the energy of the loops is fixed. As discussed previously individual photons interfere with themselves and not with any other photons. The "temporal" mixing is not "joining" the photons in any permanent way but simply minimizing the spatial distribution of energy.

Cheers

PS: If you do not look at the animations carefully you probably will not understand a single word I am saying.

This post has been edited by Good Elf on Jan 18 2007, 05:12 AM

Hi GE,

Good post! I have seen those animations before.

Would you say that the advancing wavefront of the toroidal impulse "bubble"
(which I consider an energy pulse) becomes "conformal" to objects
in its path as it advances/propagates? This is an alternative way of stating
that the wave "seeks all paths" or seeks the path of least resistance (like an
advancing wave) to topography in its path.

The reason that I phrased my question this way is that, I have been trying to
make a point that you have either disagreed with, or not understood, in trying
to explain how a photon advances thru the separate slits of the DSE. This actually
somewhat supports C2's advancing water wave scenario and Feynman's seeks
all paths statement.

If we agree that a photon wavefront "seeks all paths" by becoming conformal
to obstructions and openings that are in its path, then it seems logical that
a portion of the advancing wavefront must deform and pass thru each open slit
in its path.

You have fought this concept by believing that the energy of a photon cannot
be divided. I contend that the if the amplitude or power of an advancing wavefront
becomes spacially "uncoupled" (but it still retains its temporal phase relationship)
and that it can travel thru both slits simultaneously, like any advancing wavefront.

The openings of the slits become new sources for the 2 advancing and expanding
wavefronts that are still phase matched (coherent) but they are separated spatially
and have some delay (or phase shift) from negotiating the slits.

For the sake of discussion, an example with a slight twist:
In this "model" we use a fair sized blob of mercury
to represent the closed energy system of a conformal advancing wavefront.
We also have an enlarged DSE configuration with a very slightly inclined
baseboard to provide momentum for the mercury as it moves downhill toward the
slits.

The mercury "wavefront" will strike the slit wall and will go thru both slits, similar
to the water wave. The wavefront will become conformal to the slits
and will "compress" to pass thru each of the slits. The individual mercury blobs will
attempt to expand and recombine as they pass thru the 2 slits toward the screen.

The process of "compression" while passing thru the slits will induce some timing
delays to each mercury "wavefront" energy system, but the total closed energy
system of the original mercury blob is still "intact" and it will attempt to reform
into a single blob again.... I know that it doesn't illustrate the interference aspects
of the DSE, but my intention was to describe how a conformal wavefront
could "divide" as it seeks all paths and would incur timing delays that set up the
mechanics/physics of the interference phenomenon.

Constructive comments, opinions, discusson welcomed.

LL

This post has been edited by Laserlight on Jan 18 2007, 08:01 AM

Hi Good Elf, Laserlight et al,

I have seen these animations many times.

Is what follows a reasonable analagy for a GE photon?

You fire off a small explosive charge ... the result is a sudden increase in pressure .. either side of the pressure wave the pressure is normal. The pressure wave expands 'seeking all paths' .. let us say it grows to become a sphere 1 mile in radius. OK so far? BUT .. if the pressure wave is detected .. eg somebody 'hears it' .. the pressure wave is instantly removed from everywhere else to ensure the wave is never detected twice. If the pressure wave were to meet two slits the pressure would expand on the other side of the slits .. there would be a meeting of the two expanding wavefronts from which it would seem to be extremely difficult to extract the observed DSE effect .. and the conceptual problem remains that detection of the pressure wave after the two slits apparently causes a cancelling wave to pass back through the slits to ensure the pressure wave isn't detected anywhere else.

Comparison with a QM photon (hopefully reasonably accurate0 ..

In fairness the main difference between GE and QM analysis is that QM tackles the problem head on.. this leaves..

The applets are substantially OK except they don't claim to represent anything other than the probability of detection (the psi-wavefunction ).. this means there is no need to 'nip off' the wavefront .. the probability of detection behind the wavefront simply reduces as the wavefront expands. On encountering the slits the wavefunction expands from the slits as before but because the probability of detection doesn't fall to zero behind the wavefront we just need a simple vector addition to get the interference pattern. If the photon is detected at any point then that is simply the end of the game .. the wavefunction has no purpose or physical existence (arguably) beyond its ability to predict the probability of detection.

The psi wavefunction and the classical EM waveforms look pretty much the same because a psi-wavefunction IS an EM wave except that the EM wave assumes many 'photons' and shows the distribution of photon counts (or intensity) and a psi-wavefunction shows the probability of finding a single photon at the same point. With enough photons .. they should look the same.

Hopefully this has highlighted one or two problems.

Best wishes,

-C2.