Double slit experiment, Quantum consciousness

Hi boneheaded,

The basis of the double slit experiment is very well known as a wave theory of light. At that level of understanding we understand entirely what is going on. Any elementary physics text tells us a great deal about this phenomenon. The wavelength of the illuminating light source, the slit width and the distance between the slits are part of an "exact" theory of the behavior of the phenomenon. As to the "movement" of the experiment .... I can only comment that as part of Special Relativity the velocity of the source or the experiment would not unduly influence the result. If coherent monochromatic light from a quasar approaching the earth at a significant fraction of the velocity of light... was used... then we are able to determine the way in which the frequency of the source will be affected due to Doppler shift. Passing this illumination through a single slit could be accomplished and the experiment carried out as before. We know that in every other respect the light still propagates on the surface of a sphere through the slit as the source. The different "apparent" propagation frequency does not change the physics of the experiment but it would change the relationships between the maxima and minima because the interference phenomena is now working with a different source frequency and the same slit width and distance between slits. From the point of view of "physics" the experiment is still the same, the result is different.

As to turning the detectors are turned on and off... this also should not change the outcome of the experiment. This goes back to your original questions to the "conscious observation" affecting the result of the experiment. What I could say here is consider the entire experiment being performed inside a sealed box from which no real time observations were being made. This can be accomplished the old fashioned way of using not "sensitive optical scintillation detectors" inside the sealed lightbox leading to an external recording device but simple photographic paper placed in the back of the box replacing the screen. This is then an unusual example of the camera obscura with a more complex "pinhole". Nevertheless the intensity of the light can be made as weak as you like and no external observations will be made at all and under no conscious observation. After this individual photon source sufficiently exposes the plates they can be developed to reveal the "unobserved" result that coincides with the "consciously observed" result using sophisticated light sensors. Blocking the light with an opaque panel or switching the detectors on and off will make no difference to the final outcome. The interference pattern will be built up over time.

To make this concept work "for me", I examine the light in its two modes of interaction... travel as a wave phenomena as undetected quanta from source to destination and the other mode as a particle interaction when it strikes the screen at the back of the experiment. The wave nature of light may be detected without actually disrupting the effect on the screen. Unfortunately to do this we need to create some interactions so this disrupts the final pattern on the screen. It is fine to realize that this wave propagation is actually occurring "unobserved". If you use strong illumination then it is easy to see the phenomenon. The recording of this will "damage" those photons used to make the determination. Of course if you perform this experiment correctly there are plenty of other photons that show the result and you can minimize the disruption on the bulk of the experiment. The way to do this would be to record the pattern on the screen for different screen distances and for different screen widths. This may be tedious but it is "routine" physics. It is clear that the experiment will agree with the theory as far as it goes. For light we have the spreading phenomenon yet when we detect the light as "corpuscles" they fall on the various screen positions "statistically" related to the "intensity" of the diffraction pattern. Since we are dealing with only one frequency of light the intensity of the illumination is simply the number of these individual "corpuscles" that fall on the screen per unit area. There is a discrepancy when we consider "weak sources of illumination", the problem of one photon at a time. In large numbers the "corpuscles" appear to spread like water waves but they "interact" as very tiny localized "corpuscular" interactions. Translated... if the screen was made of Zinc Sulphide this would translate to tiny flashes of points of light where the photons individually struck the Zinc Sulphide Screen.

I will digress but I hope I will keep this topic very simple and understandable so that you can visualize these processes.... In the end you will be able to see what is really happening with those electrons and photons that are executing "quantum jumps" in "space".

A lot is made of this apparent discrepancy between the way photons "individually" travel through space and the way they finally interact. We know that from elementary theory the photons are usually a lot larger than what you may think. The emission of the individual photon by an atom occurs in many ways, the most commonly used explanation is that the photons are transitions between the bound state of the electron in a higher energy level in an atom to a lower energy level in an atom with the emission of the photon of energy.
E = hf
E is the energy, h is Planck's Constant (a unit of impulse) and f is the frequency. Of course most of the useful monochromatic sources of radiation have been traditionally been produced using radio transmitters where vast quantities of energy are emitted as waves from a dipole transmitting antenna. Lasers and other coherent emitters are more sophisticated sources working at shorter wavelengths but essentially they are working the same as the radio antenna. They are a form of stimulated emission. The are coherent in phase and all have a central tending frequency. The narrower the band of these central tending frequencies the more monochromatic it is. Lasers with their optical frequencies appear as a central line with broadening. The broadening is the interesting part. Radio Frequency excitation using large dipole radiators are effectively huge "synthetic atomic oscillators" providing wavelengths that you can measure with a ruler or even in some extreme cases, the odometers of motor cars. The radiation patterns are similar in origin (though not exactly the same) as those produced by the tiny optical emitters such as a laser using a single transition in an atom species. The differences are we can synthetically manufacture our "super atoms" to suit the need. We do this using resonant cavity resonators and specially constructed antennae "wires" or beams, specifically designed geometrically to transmit vast quantities of "corpuscular" radiation at whatever frequency we may choose. The corpuscles are similar in size to the size of the antenna (as per the design). The same as in our atomic radiators in lasers... the main difference is only scale and mode of "launching the wave".

In respect to radio transmitters the waves are emitted from our "single synthetic atomic oscillator" in vast numbers all originating from the one source... the single antenna (the equivalent to a single "atom" source of excitation).... one "atom" (antenna) many photons (created from a driven resonant cavity). The laser is different in that the device contains many "atoms" usually within a laser tube and a "wave" passes through the crystal, gas or liquid medium, the way a wave travels across the ocean. Lasers usually have reflecting or semi-reflecting dielectric mirrors at either end of the cavity. Each tiny transmitter (atom = oscillator and radiator) being stimulated by this wave to release the photons in the one direction and in sympathy to the phase and amplitude of the passing wave. This is a property known to a class of sub-atomic particles known as bosons. The photon is a boson and they have the property of many of them sharing the same quantum state in the same place at the same time. This principle is well known and is called Bose-Einstein Statistics. An alternative property of "solid matter" such as the antenna material itself or the "solid" sub-atomic particles such as electrons or the sub-atomic constituents of protons or neutrons (quarks) in atoms obey the opposite property of Fermi-Dirac Statistics where the particles cannot occupy the same space at the same time... the property we are usually more familiar with (only one thing at the one place in space). However the boson wave is a principle that is well known in hybrid quantum materials such as Bose-Einstein Condensates where the particles (fermions) can all share this property of existence in the single state with bosons (this is because being a boson is really only a group property of total spin, a single particle such as an electron has spin of say 1/2 but two electrons have a spin of 1/2 + 1/2 = 1 which is integer and therefore the combined particles are a "boson"... the cooper pairs of superconductivity). A coherent wave is passing through the material in which all the internal particles share a common quantum state. This is similar to the case of the radio transmitter and of the laser. The photons (difficult to deal with only because they travel at the speed of light... never more or less) exhibit waves of photons all having the same constituent photons with the energy equal to hf, but on the surface of each and every wavefront of emitted radiation all share a common bosonic state as well as "overlapping position". This is a quantum phenomenon and is not able to be directly observed. We can make some general measurements at the expense of "destroying" some of this coherence. The individual photons have temporarily lost their individual particle-like nature and are traveling in quantum mode all waves in a single coherent state.

Here is an animation indicating the nature of propagating light from a dipole. This is a form of "coherent radiation".

The "dipole" source is in the center of this image and we are seeing a slice through the axis of the dipole. The bosonic character of the "wave" is such that all photons are launched in phase to the internal wave-like disturbance spreading internal to the dipole itself. In practice this is driven using a resonant circuit that is usually physically tuned to the frequency of the mechanical system minimizing the radiation impedance of the system. A LASER is very similar except the individual radiators are actual single atoms and their shells but in many respects are nearly identical but for the scale to the radio mast. In this case the "disturbance" is a longitudinal one in the "lasing source". The disturbance is traveling end to end along the LASER Tube "sucking" photons out of the system into the wave. At either end of this cavity are dielectric mirrors that partially reflect the waves until the barrier is overcome by the sheer energy due to "weight of numbers". I guess you have all witnessed "coherence" in laser light as a speckle pattern on the surface of your eye? Some interesting information about "speckle" I am sure most people have no idea about.

This "coherent" property of LASER Light is a bosonic property of light as it interferes with itself in free space forming a grid of "specks". To a lesser extent any monochromatic source can exhibit this phenomenon since monochromatic light "tends" toward coherence in a light source. The Young's Interference Experiment was able to be performed before lasers were invented for just this reason. These speckle patches can be increased in size using appropriate optics an for perfectly collimated and coherent sources the "specks" can be reduced to a just a few single large "specks" as indicated in the animated Gif. Of course with radio frequency photons you are not able to see "specks" since they are below the visible region of the spectrum ... but theory are still there as a "phenomenon".

Each individual photon is a packet and this packet is able to apparently "propagate" in space as a spreading wave. Now I will digress into the phenomenon of matter waves. This is the concept expounded by de Broglie and is the basis of all quantum phenomena, it applies to photons but applies even more to "particles" of matter... the matter waves. The individual packets for particles have additional frequencies due to the truncation "spatially" of each packet. Here is a Java applet showing how this phenomena occurs...
http://ist-socrates.berkeley.edu/~cywon/Quantum.html
Experiment to see how changing the frequency and amplitude affects the propagation properties. Notice that for particles the increase in momentum increases the velocity of the particle and the width of the packet is representative of the "size" or the "mass" of the particle. You can fix the momentum in this applet and see how this affects the propagation. The greater the momentum and the narrower the packet the velocity approaches the speed of light. The limiting case are photons themselves which only travel at one speed ... the speed of light. You should also notice that the internal phase velocities of the component frequencies indicate the internal phase velocities to be greater than the group velocity. The 'energy" of the packet travels with the group velocity but this is the sum of the component phase velocities so it is possible to have this "internal" phase velocity travel many times the speed of light or in special cases even negative velocity... the particle travel one way while the component phase waves travel the other direction. Careful examination of the "background" zero level indicates a wavelike phase disturbance spreading much faster than the speed of light itself. This reaches all through space fairly quickly.

The de Broglie relationships are given by this equation from Wikipedia...

Where V = velocity of the particle, C = Speed of light, Lambda = wavelength, m = particle mass, p = momentum and h = Planck's Constant
Wikipedia: De Broglie's Hypothesis
This is just one end of a continuum of velocity related properties which is Einstein's Special Relativity. Around the velocity of V -> 0, or m -> 0 it would seem that we would have an infinite wavelength. Obviously a "drover's dog" would realize that the wavelength cannot go to absolute zero since this implies the Universe would be infinite. This dimension (wavelength) is limited to the size of the 'brane" of our Universe and to "external windings" on this basic structure.... an integer of standing waves on the external brane of the Universe. You may have noticed the measuring rods of time and space have change to reciprocal measuring rods of reciprocal time (frequency) and reciprocal space while still sharing the same space and time with us. This is on the surface of our Universe or if you like on the surface of an equivalent sub-atomic particle. Oops you say, the Universe is very big and a sub-atomic particle is very small. Well that depends on the measuring rods. This Universe solves this connection by having different scales internal to particles compared with the dimensions external to the particles. Pebble Universes "spin" in an additional six dimensional space (plus one for connectivity) according to String Theory. This means a total of 11 dimensions. Our 4 dimensions plus an additional six (seven) dimensions and the reciprocal equivalent of time. Just don't count the time twice in reciprocal space they are not part of the temporal manifold. IMHO the connection to these additional dimensions is purely "harmonic" not "spatial" and this is where current theories in String Theory fall down. The problem is this will mean that you cannot naturally connect "space" with "reciprocal space" at the same time using linear techniques.If you look around this site in my posts you will find my attempts to reconcile this obvious "conundrum".

To illustrate this point consider the De Broglie Relationship above for a particle. Lets make the most elementary assumption (and mistake) that space and higher dimensions are connected "linearly". Then now lets say that a particle executes transverse simple harmonic motion due to trapping of this particle (confinement) in higher dimensions. Put another way lets say it "bobs up and down on the spot with a regular frequency". Now lets "translate" this particle in space from one point to another. This bobbing up and down now becomes a truncated wave motion. The faster the particle moves the longer the apparent wavelength of the particle. Woops you say... De Broglie insists (and experiment) that the wavelength shortens not lengthens. OK... lets say the internal space is non-linear but a reciprocal space where distances are 1/distance yet remaining connected with our spacetime of distance and time in 10 (or 11) dimensions. We substitute these internal dimensions into the formula and we immediately see the relationship now works. The faster the particle moves the wavelength in our space is shortened. This is simply because the internal space "tunnels" into our space in the "near field".

Now lets look carefully at this point regarding the inverse nature of mass and velocity. The larger the mass of the velocity the shorter the wavelength and when the velocity approaches the speed of light, Einstein's Special Theory of Relativity slowly predominates. We have the equation for photons and other quanta of
E = hf
Where E = energy, h = Planck's Constant and is in units of impulse and f = frequency which represents the way energy relates to the two separate domains of Fourier Theory the particle and the wave... h represents the particle nature (impulse response) and f is the wave nature of the particle (harmonic response). The simple product is "energy" for particulate phenomena. I will call your attention to how we derive these Fourier Transforms between the two complementary domains of time and frequency (respectively). I will put an image and a link here and a reference...

See section 4.4 of below....
Digital Geophysical Analysis
These complementary domains of frequency and time are totally reversible and they represent "quantum states" in atoms. The relationship to the reciprocal spaces is also "natural" and forms a real connected realm in those higher dimensions. Atoms are hybridized states of individual branes formed by the T-Dual influence of particles in the nucleus.

This is the Ed Witten 11 dimensional manifold and the way strings "connect" in higher dimensions. What is not shown is the common 4 dimensional manifold and the way six of the extra dimensions actually connect. Presently the connections are assumed to be "linear", naturally I believe that experimental evidence shows the connection is "harmonic" and these branes are the atomic shells and they have a sort of life of their own which emanates from the fermion dual.

I am reminded of a statement made by Leonard Susskind, the "father" of String Theory, which I paraphrase here as "If anything in the Universe are strings, then everything are strings"....
Wikipedia: Leonard Susskind
To be totally consistent then this is the only way to connect the dots. Unfortunately the "language" of mathematics can confuse even the very 'elect' and they prefer to think only in terms of chancing on answers to the big problems of the universe. Once in a while this happy accident does occur but it would be nicer if the maths was couched in appropriate physical ways to allow ordinary people to understand the concepts that are totally abstract and unrelated to the physical world not by accident but by deliberate "design". The old physicist adage "Shut up... don't think, calculate!".

It should therefore be clear that this inverse dependency on mass and velocity leads naturally to Mach's Principle, since De Broglie's Hypothesis leads to a singularity around m = 0 or V = 0, the Universe itself places dimensional constraints on this division to limit the size of the Wavelength to the dimensional size of the Universe with a potential "winding number" on the outside of this "brane" as a standing wave number. This will be the integer N or a principal quantum number and is one of the many postulates in quantum theory. The other quantum numbers are the spherical harmonics described using the Legendre Polynomials on the surface of this particle "sphere" which exists in those additional six dimensions. These are all the various eigen values of the system and the harmonic properties of energy transitions within that realm. Mach's Principle can be stated as...

or alternatively as ....

Wikipedia: Mach's principle
Once the mass is truly included into the scheme of things a concession must be made for inclusion of Special Relativity into the scheme since this has now "broken the symmetry" of space with the introduction of primary mass. SR now changes from Global Symmetry to Local Symmetry. The other point is that at high velocity the coordinate system of Special Relativity has a preferred direction which is the relative direction of motion in the coordinate system of the observer inertial frame and the inertial frame in relative motion. This means the generalized coordinates of General Relativity must be reduced in symmetry to include only orthogonal spatially limited coordinate frames where the X-axis is "special", the relative direction of motion, and is specifically chosen as the primary axis. Space now has "direction". For a sufficiently extensible inertial coordinate frame the size of the frame is now "restricted" regards time and spatial coordinates. The Universe is "confined" by relativistic spin on the light cone wall. This is a surface of spin in six dimensions whose circumference is not related by Euclid's circle. The space is actually bigger on the inside than on the outside and the relationship to these two realms is through the conformal mapping of the rotated spacetime on the surface of the light cone we identify with "Length Contraction". These physical and optical influences can be seen in these supercomputer simulations at this site...
Relativistic Optics at the ANU


These ideas come the full circle in the Holographic Principle where we embed "Universes" into our Universe "almost recursively", and presumably visa versa...

Wikipedia: Holographic Principle

Well one more thing "boneheaded", these Holographic Universes reside on the surfaces of the pebble universes as "strings" which are temporal "holograms" occupying the surface of these "particle universes". You have seen Holograms which are surface "strings" or interference patterns on flat film that give the appearance of a higher dimensional surface "within". This is the Spatial Fourier Transform pair as mentioned earlier taken that extra step to generate "everything" through "imaging" utilizing the process of Kondo Phantoms. These are like reflections in the light cone mirrors of our Universe as matter wave internal realities in a similar fashion to the way in which there is our world and an apparent mirror Universe on the other side of a mirror that is very similar to our world yet is only a surface phenomenon of the mirror. It has apparent depth and "life"... it is just mirroring our Universe "locally". The holographic Universe uses higher dimensional principle identical to optical Fourier spatial filtering systems acting in "reciprocal space" just like this system seen here only in higher dimensions through a "natural" process.
Optical Fourier Transform Demonstration
Fourier Optical Processing
An Intuitive Explanation of Fourier Theory
See... an analog analogy.

Cheers

This post has been edited by Good Elf on Jul 28 2006, 05:18 AM

No photons are damaged, GoodElf. The true is, if you don't understand the principle, the article of any size won't help you in explanation of phenomena, which is quite simple, in fact.

Everybody know, how the waves are spreading. The wave prefers the more dense volume areas for it's spreading, such volumes are serving as the virtual lens for such wave. These random fluctuations of vacuum are making a virtual more dense paths, preferred for particle wave spreading, which are changing over time by such way, the resulting path of particle wave pocket is unpredictable. But such particle can be observed using by light, i.e. by path of reflected photons. Whole the trick is, the path of photons is unpredictable too, but the photons are using the same virtual path configuration, as the particle. With respect of this, the observation of particle by photons will give the picture, which is independent to the momentary distribution of vacuum density - that's all. We don't know, how the fluctuation of vacuum are distributed, but we know for given moment, they're distributed by the same way both for the particle being observed, both for the reflected photons. At this point the influence of density fluctuation of environment compensates itself and the resulting picture of experiment remains very classical and predictable.

Hi Zephir,

The "damage" referred to is the loss of a qubit.

The quantum particle's path is "unpredictable" but after the fact "when the particle has been damaged" through an interaction, the particles can be shown to have followed a path that is consistent with the dynamics of the system. This you already know is the Bohmian Mechanics of the system. This means that the path is not inconsistent with the standard dynamics of the particles be they photons or other quantum particles. I imagine this is what you mean when you say "At this point the influence of density fluctuation of environment compensates itself and the resulting picture of experiment remains very classical and predictable."

I do not accept that any "density fluctuation" is able to be predicted either... or if it can be demonstrated or not. Density to my way of thinking is mass per unit volume and this should not vary in "free space" unless you have a particle there. Virtual particles are another matter.

As to the maths behind the suggestions I have made I would look to Canonical Analysis and to the Computational Methods and Results as shown in this page on the Internet...
Canonical Analysis
... and
Canonical Typicality: Sheldon Goldstein, Joel L. Lebowitz,,Roderich Tumulka,and Nino Zanghı`
.. you would also be rewarded to look here...
Proof of Randomness

Cheers

This post has been edited by Good Elf on Jul 28 2006, 10:03 AM

Absolutely. The result of the two slit experiment is simply 'ridiculous' .. it simply shouldn't happen the way it does. Any attempt to explain the ridiculous is destined to become ridiculous at some point... the fun comes from watching it happen.

Let us imagine we have one of those really expensive oscilloscopes that does everything and has more buttons on it than the flight deck of a Boeing 747.
We take the signal from a signal generator set to 'sinewave' and feed it into the 'scope. Nice sinewave. No problem. Gradually we turn the output of the signal generator down and turn the gain of the oscilloscope up to compensate. The first thing we notice is that the signal becomes noisy .. we can still see the sinewave but there's a lot of cr*p as well. This comes from the oscilloscope amplifiers .. even our vastly expensive scope makes its own thermal and other types of noise. At about this stage we notice the signal generator has an output marked 'sync' and the scope has an input marked 'ext trig' .. the time spent finding a lead to connect the one to the other will not be wasted. Our first step into LaLa land is to pretend the scope is perfect and the noise doesn't exist. We turn the signal generator down a bit more. Eventually we're looking at what appears to noise even with a perfect scope. Now we hunt about on the scope panel for the button marked 'integrate'. We press 'integrate' and fiddle about for a few hours with the other knobs to make the scope do what we really want it to do rather than what the last person who used it wanted it to do. In the unlikely event that you can find the instruction manual it is perfectly acceptable to ignore it.

By now you probably have a small crowd gathered round you .. muttering "he doesn't know what he's doing". You can distract the crowd by giving them the manual for the scope or signal generator and have their spokesman read out irrelevent randomly chosen extracts from the manual. If the screen goes blank for more than a few seconds be prepared for the wit who will ask whether you actually know how to turn the thing on.

The reason for all this is that we're going to look at a single photon (in the time domain) .. once we know how it behaves the whole two slit thing should become a lot clearer.

OK .. I'm going too slowly .. we have a perfect oscilloscope with enough gain to detect an individual photons .. all you knowledgeable guys .. what do we see?

-C2.

Can anyone see how to use this electrical stuff to make a two slit experiment?

Thanks Good Elf
Naturally I will have to reread this to get the whole picture, but this helps.
I have been working 15 hr. days lately, so I will have to get another read of it
in over the week end.
Thank you

Boneheaded

OK so you want to know what frequency is coming out our signal generator. Let's say 1GHz .. modern scopes can just about handle this and still give sensible results.

It would be nice to use the 'pulse' output of the signal generator at some stage. This will enable us to observe the Heisenberg Uncertainty Principle in action .. if that hasn't already become clear from the explanation of what we see when we're looking at individual photons.

-C2.

Carpe diem.

By Aether Wave Theory (AWT) the density of space corresponds the energy density despite the fact, if you consider the virtual particles as a real entities or not (they're real, but not directly observable by photons, because they're just serving as a photon spreading environment).

The Aether concept just enables to understand the mechanism from real physic perspective, the math background of such concept is contained in mass-energy equivalence principle and wave equation, so it's as hard as nails from math formalism perspective.

Hi Confused2, boneheaded, Zephir et al,

I understand as much as anyone that the level of the signal is too small to be undisturbed by any measurement of that tiny signal by a test probe. This is not the issue at question here. The flash from each photon impacting the Zinc Sulfide Screen "locates" the photon finally. In certain cases we can localize the photon without interference. An example of this is a pinhole in a card instead of the double slit. Once the flash is recorded and the speed of light is a known we can say with a fair degree of certainty where the photon was between the pinhole and the screen at all points in the intervening time. The fact that we cannot "predict" this event does not alter the fact that the individual event is perfectly behaving as a dynamic particle with position and momentum and with a certain vector. This is "locality" that was not admitted to in years gone bye. The particles passing through the dual slit still have locality and will satisfy the dynamic relationships for locality "a posteriori". The quantum postulates apply only to group behavior and according to that "ridiculous" claim is indeed "quite ridiculous" in that no single event can be predicted by "group behavior" because individual photons possess the values that we are unable to measure without the introduction of a gross error in at least one of the variables of position or momentum. This is why Schrodinger's Wave Equation which applies only for statistical density functions of particles can be mirrored by another wave equation for electromagnetism.
Schrodinger's Wave Equation
The Electromagnetic Wave Equation
This principle is used in Circuit Quantum Electrodynamics "all the time" where measurables of the system such as the position and electric field strengths can be made using a test probe on a single trapped photon in a specially constructed artificial "atom".
Cavity Circuit QED
De Broglie-Bohm Home Page
More Bohmian Mechanics References can be demonstrated to show that this is highly credible line of approach and that this is consistent with the analysis above in
Canonical Typicality
No laws are broken nor any precious theory destroyed other than some quantum interpretations that have been "sacred cows" in the past. Check out these references at the bottom of this Web Page on Bohmian Mechanics...
Bhomian Mechanics

I would also like to call everyones attention to the Aharanov-Bohm Effect (also the Aharanov-Cashir Effect and several other verified variants of the dual slit experiment that indicate these phenomena are related to global defects in spacetime that could be exploited since they represent a propagation instantly of the Scalar or Vector Field once thought to be a derivative is now a primary field. This has led to a number of novel application in Photonics such as negative refractive index, negative velocity for light and Electromagnetically Induced Transparency, Optical Anti-matter and a host of other useful technologies.

Cheers

This post has been edited by Good Elf on Jul 28 2006, 11:39 AM

That sounds like the start of a good answer. A REAL answer that doesn't rely on smoke and mirrors.

We know that the number of photons from our signal generator varies sinusoidally .. most of the photons will be at the + and - maxima. So the probability of our scope detecting a photon is likely to be greatest at that time. There's more to it .. but that will do for the present. An odd problem appears .. what is the significance of a 'negative' photon?
-C2.

Hi Confuesd2,

No smoke and mirrors since I can give many new applications already in the literature that involve these quantum phenomena. I doubt very much that you can actually determine the finer internal points of individual photons using any kind of CRO. Any artifact will be because your instrument is "ringing" wth an alias signal.

Cheers

Hi Good_Elf,

I hope this level of examination is OK with you.

At some point we had to switch our scope to 'Count' mode .. which, as you suggest .. loses the internal structure of the photon.

Any insight into what is happening at the borderline of noisy sinewave and the point when we have to go to count mode?

For present purposes I think we can allow that our scope can resolve the instant of detection with a fair degree of accuracy .. we still see a waveform building up in 'count' mode .. but what and why?

-C2.

The point I/we am attempting to examine here is..

Good_Elf's assertion
There is a structure to a photon .. and such a structure can pass through two slits and re-emerge at the other side unchanged

GE.. please clarify if I have misunderstood.

My assertion (also known as Quantum Theory)
The photon only exists as a probability distribution, it is the probability distribution that is influenced by the presence of the two slits.. the photon has no 'structure' that can be found except in terms of the probability distribution that describes it.

To support my assertion (and quantum theory) I can't really avoid the claim that the 'intensity' is at all times a photon count. Which leaves me to explain (either) the negative (or positive) excursion of the sinewave in the region before the scope must inevitably be switched to 'count' to make any sense of the waveform.

Hopefully at the same time Good_Elf will be able to explain the effects seen after the scope is switched to count mode.

-C2.

Carpe diem.

Just to clarify the setting for single photon counting..

The scan is locked to the frequency generator and the screen effectively gives a bargraph display (say 30 bars with current technology) showing the number of photons and time during the cycle when photons are detected.

Any guesses as to what it looks like?

-C2.

Hi Confused2,

If I said that people exist as a probability distribution I would be right. All you do is count people and their distribution. The density of "objects" is per unit volume a kind of psi^2 . dv. There is nothing mysterious about the value of psi and its inability to measure anything in particular. It is a fully statistical property and does not attempt to model any physics. This is why there are so many so called quantum postulates for which there are no physics based justification. I have stated elsewhere...

OK... I also claim that a requirement for prediction drives the Physics. As you point out this pursuit is ultimately hopeless. The reason for this is the processes are of such a feeble nature that any methods of measurement to determine the measurables of any quantum system, will disturb the system to the extent that at least one of the position or the momentum become very disturbed. What can be said though is there is no evidence to show that the dynamics of the system are inconsistent with the quantum theory as far as that theory goes. The analogous problem occurs when we deal with relativistic particles, their position and momentum cannot be accurately known as well since inference from a single point of reference is an incomplete problem with unresolved parameters. The prediction of the trajectory of a particle depends on the ability to measure a number of measurables of the system for which there are always a level of imprecision. With our systems this will always be the level of the quantum. There are some minor but significant exceptions.

I have discussed this problem in the thread Quantum Superposition...
Quantum Superposition: Good Elf
where I mention this phenomenon...
Measuring single qubits - "quantum back action"
It is worthwhile Googling a few more references to assure yourself that we are not talking "smoke and mirrors"... but current "best practice". This phenomenon shows that provided that a number of "soft" readings of the measurables of a single quantum state are made the state itself can sometimes restore itself and be read again without quantum demolition. No single pair of readings of position and momentum will result in a good value but repeated statistical measurements with a suitable relaxation period between the readings will supply a significant number of pairs that center on the true value and the statistical mean of the parameters, where the square in the product of this expectation value can be evaluated to a minimum. This is not elfen theory but is curent experimental fact.

Some further reading on Quantum Back Action...

Quantum back-action of optical observations on Bose condensates
Quantum Computing: Backaction Conference : 6 - 12 March, 2006 IIT Kanpur
What is back-reaction? Jack Sarfatti

Cheers

Hi Confused2,

Photons do have structure. They carry the property of integer spin, they are its own anti-particle, the influence of the passage of these "particles" result in transient electric and magnetic field stresses in the continuum. Crude imaging of this property has been recently accomplished. While conservative the fields do not come from any internal property of charge carried by a photon (photons do not carry charge), but the wave is polarized exhibiting transient electric and magnetic field properties. This is how radio works for instance. The theory of wave packets is well understood and entanglement of individual photons is also a common property that is exploited with some new Encryption Devices and Quantum Computing Devices. This is traceable to the electric field polarization angles of the entangled photons emitted in specially designed parametric crystal down-converters. The blue gif animation shows what swarms of individual photons produce and if you do your sums this tallies with the animation above for individual bosons (wavelength of photons matches the wavelength of the light or radio wave). This can be verified using Youngs Experiment if you wished. All photons of the same phase (on the same wavefront) travel in the one boson state, they all occupy the same spatial volume as well and are non-interfering with each other and do not have any influence on the final destination of each photon leading to those crisp Hubble Deep Field Images. This is the property of Bose Einstein Statistics. Photons do not "destructively" interfere they can occupy the same volume of space without numerical limit. This is standard theory.
Here is a model wave packet as designed by Berkley University...
http://ist-socrates.berkeley.edu/~cywon/Quantum.html
Have a play with it and discover why things work the way they do. The only limitation is that the limiting case is the photon and other particles are better modeled here. Photons can tunnel through certain amounts of matter provided they are smaller than a wavelength in size... unharmed. The single photon does not need to pass through both slits and I do not think you can show that it does. What you do need to have is the two slits "open" so that the interference can occur. This is simple cavity resonance phenomena since the two slits form part of the one system... you know the sort of thing you have when you play a flute.

Cheers

This post has been edited by Good Elf on Jul 28 2006, 05:15 PM