Problem with the two slit experiment, Observing later

Hi Good Elf,

Thanks for that .. no time to read it in detail but what we are looking at is a quantum of (say) electromagnetism. The input isn't a continuous function (in time) and nor is the output. I don't see how you reclaim your photon to allow it to perform a 'quantum action' from the equations and graphs so far presented. For simplicity we might imagine an electron in a hydrogen atom drops to a lower energy level .. the resultant photon excites a similar hydrogen atom .. this time from the lower energy level back to the one the first electron started from. 1 transition.. 1 photon .. 1 (cancelling) transition. What are the chances of that happening (literally!). We might have a hydrogen line source and a photographic film .. the film responds to photons (?) .. how do they get relocalized at the detection end of things. Sorry .. work calls..

Best wishes,

-C2.

C2,

If I may interject....

You are assuming a photon is a singular (particle) entity with that scenario.
If, however, a photon is a toroidal EM wave emission from a radiating source
(like a dipole antenna) then the single H atom that has been stimulated by an external energy
field, will release its own toroidal photon field of the specific wavelength for hydrogen

The originating external EM energy wave will stimulate all surrounding atoms in 3 dimensions;
to a higher energy level in a donut shaped toroidal effect as it propagates thru them, and they will
in turn radiate photonic EM toroidal waves at their specific atomic harmonic frequency.

An example: have you seen the TV commercial of the guy dropping a single ping-pong ball into
a gymnasium filled with closely spaced mouse traps, each fitted with a single ping-pong ball?
One initial pp ball sets off an exponential chain reaction until eventually all the mousetraps have
been triggered and there are thousands of balls bouncing around. Maybe not the best analogy,
but gives an example of a simple cascade propagation effect. 1 source event stimulates other
event reactions to release their potential energy. Keep in mind that there is a time propagation
delay in this whole process which is analogous to the wave function.

Now imagine if this toroidal EM propagating energy front is the wave mechanism as it travels
thru a medium of identical matter, you build a wave front building in harmonic intensity and
duration until a peak level is achieved and the wave front passes a specific point in space.

Any comments, or opposing opinions welcome.

We can expand on this concept in 3 dimensions and the complex inverse propagation timing
delay interactions that occur in a medium as they generate inverse harmonic wave functions,
but that is off topic for this discussion.

LL

This post has been edited by Laserlight on Nov 20 2006, 08:32 PM

Hi LL,

The original evidence of quantization of light didn't come from the DSE but it does give rather nice evidence of it . Good Elf has kindly taken us through nineteeenth century geometric optics and you would like us to go through nineteenth century EM theory .. I'm not suggesting there is anything wrong with any of it as far as it goes.

BUT

Looking at yet another single photon DSE (they all give the same result)
http://www.physics.brown.edu/physics/demop...demo/7a5520.htm
Please see the dots, please see that these build up over time into regions of high and low intensity. The maxima are predicted by nineteenth century physics ** .. it is the dots that are the problem .. it is the dots that help to make the DSE is 'The beautiful experiment'.
Please LL , look at the dots .. they are there for the same reason that electrons don't spiral into the nucleus, lasers 'lase' and sooooooooooo many other things.
Best wishes,
-C2.
** see http://schools.matter.org.uk/Content/Inter...ce/formula.html

Hi .. all?
I think GE's misunderstanding of my understanding of wavelength might help .. or not! The DSE is effectively 'spreading out' the wavelength of the light by using the very small path difference between the two slits .. with a single photon DSE we see where the photon is located within the classical wavelength (this is the imprtance of the 'Young's slit equation' http://schools.matter.org.uk/Content/Inter...ce/formula.html
) .. and we see that it can be just about anywhere .. (except at the points where the paths cancel) and only statistically do we get the maxima and minima associated with classical analysis. I think GE feels the dots are the size of a photon whereas I would suggest only that they represent the point where a photon has interacted with an electron to precipitate the chemistry which follows.

Single photon detection by photographic film

from http://www.cheresources.com/photochem.shtml

Same source..

-C2.

This post has been edited by Confused2 on Nov 21 2006, 02:40 PM

Hi Confused2, Laserlight, Jal, Yquantum, TRoc, Jal, bee, StevenA, AlphaNumeric, Laidback, zephir et al,

Alright... a lot of this is indeed 19th Century Physics.... but it is not the Physics of the 19th Century. We have come nearly one hundred years into the future and that is nearly the current age of Quantum Theory now... It has its origins in a theory that is nearly 100 years old. Nobody alive today is associated with the beginnings of QT it is so old. What the "so called" 19th Century Physics has going for it is that it has not advanced since the 19th Century while a massive effort has been expended in quantum theories. It is just "bangs for bucks"... It is natural with advances in technical calculation means that quantum theory would have advanced in those 100 years but using hindsight we can "revisit" the now aged quantum theory seeing that we went down this course when the most sophisticated computational tool available was two articulated wooden sticks known as a slide rule capable of a maximum of 1% "resolution".

The actual "point" where photons actually end up is just a convergence of the fields to a near point after the initial divergence from a near point. Now QM can't predict where individual photons go and neither can Classical Theory but Bohmian Mechanics says "After the event... you started here and you ended there and we draw a line between the two points in configuration space". It is no worse and it predicts the same results. Actually it is better than that. What I am saying about photons are they are "de Broglie" particles "spreading" as events in an orthogonal space to a "quantum space" (our space) in which every particle in our Universe is "apparently" at rest relative to light since everything is moving "perpendicular" to the photon.. light spreading as waves is then simply the result of the geometry of the space...

The "other end" of Special Relativity.

What I am saying is it is possible to think that since "19th Century Physics" can actually now accommodate quantum mechanics as a theory of a continuum and since it has been shown conclusively that without string theories current QM cannot unify "Gravity" and the other forces in the Universe.... Maybe there is another way to go and that is instead of quantizing the manifold of General Relativity to accommodate Quantum Mechanics (Quantum Gravity), we convert Quantum Mechanics to a continuum theory to accommodate General Relativity.

IMHO Blind Freddy could understand that quantum theory is a theory of eigen values of superimposed "resonant states" on a sphere. The eigen states are swell but they are a simplification of the actual standing waves on the sphere that generated the states in the first place.
Spherical Harmonics

Here is a real good Fresnel Simulation. Fiddle with the aperature scale and see how spread out things actully become when you try narrow slit/ aperatures or whatever.

Frenel Diffraction Simulation

And consider just where this simulation goes wrong when it arrives at quarks...
http://micro.magnet.fsu.edu/primer/java/sc...of10/index.html

Cheers

This post has been edited by Good Elf on Nov 21 2006, 02:47 PM

Hi Good Elf,

I edited in a bit in my last post while you were posting.

If we zap a peice of photographic film with a single photon .. what would you say was the minimum size of a dot?

-C2.

Good Day Everyone!
I'm waiting until you get to discussing

The people who do LQG.... string.... quantum geometry....Bohmian Mechanics and (of course ... me) etc. are trying to figure out the geometry of that space.
Your presentation, with your elf bits, is understandable, but not accepted by all. The part about .....the waves are individual "bubbles" that expand to infinity and that the information can get to and from there instantaneously.
I'll wait until everyone is ready to go to this level of discussion.
jal

C2- I SEE THE DOTS! LOL! Now to put a wrinkle in your argument.

1. We have a radio tower that is broadcasting. Is it broadcasting waves or particles?
2. We are in the center of our house, in the bathroom with no windows, with the
door closed.
3. We have the radio in the bathroom playing, and we are listening to the radio
broadcast playing tunes.

Are we listening to particles or waves of energy? Logic says that if they were
particles they would have been totally absorbed by the walls of the house and
no energy would have reached the receiver antenna.

Keep in mind that a radio antenna broadcasts (radiates) long wavelengths
in all directions perpendicular to the length of the antenna that is designed so that it is tuned to the wavelength that it transmits.

The wavelength of the photon is the issue here, as I see it. How long is the
wavelength of the light hitting the target surface....for simplicity sake lets call it 600nM That is 600 BILLIONTHS of a meter. You can't see it with the naked
eye, but you will see it if it is amplified a million times by the CCD photon
intensifier. And you would see the effect of billions of them reacting with
the silver crystals of the film, acting as individual pixels to form a composit
picture. Consider the silver crystals as an antenna sensitive to the wavelength
and energy level of the visible light that strikes it. Which was my point in a
prior discussion with GE regarding the hologram image.

I do agree with your assessment that the photon energy does react with the
silver atoms of the film to release an electron and change the phase state
of the silver ions back to silver atoms.

Now how wide are the slits that the single photon wave is passing thru? Say 50uM
that is roughly 100 times wider than the wavelegth of the photon. So how is
the single photon influenced by the dual slit? If it is a massless uncharged particle
it should go straight thru with no flight deviation and generate no interference
pattern, but it does.


I take it you didn't like my analogy of the ping-pong balls and the cascade
"time duration" wavefront that resulted from a single event triggering numerous
other events?

LL

This post has been edited by Laserlight on Nov 21 2006, 05:37 PM

Hi LL,

Since you have been kind enough to admit that you can see the dots..

We can see that that the energy of an optical photon is high enough to break the bond in AgBr (photographic film) simply because it does. One electron is sufficient to detect the photon .. the spare electrons from the reaction just amplify the process and allow it to propagate (possibly) through the whole crystal. Pretty magical but the reaction wasn't selected by accident.


Let us take the example of a radio transmitter at (say) 1 MHz

We know the energy of a photon is E = hf .

since E is in Joules and electron Volts are a more convenient measure .. lets go for eV

1 eV = 1.6 E-19 J

Planck's constant = 6.62E-34 Js .

So for our 1Mhz

E = 1 E^6 x 6.62 E-34 /(1.6E-19)
= approx 10 E (6 -34 + 19) = 1 E-8 eV assuming I haven't made a mistake.

Looking here ( http://www.sfu.ca/~boal/mocex/Bextra1.pdf ) for sample chemical bond energies .. they're millions times higher so bricks and stuff like that which is mainly covalent will not absorb our radio photons. Wet bricks are a slightly different matter .. let's not go there now.

So what can be affected by our radio waves? .. you've got it .. conductors .. with a sea of electrons with virtually no bandgap for our radio photons to overcome. Sooo .. how do we set the quantum states for a lump of metal? I think you've guessed .. geometry. The wavelength of our 1Mhz signal is about 300 metres .. my little transistor radio used to pick up Medium Wave very nicely. By adding capacitors and inductors we can choose the photons our aerial will respond to, the energy level, if you like. We say our arial is resonant at (say) f. We look at E = h f and see we have set the QM energy states of our arial to match that of the photons we want to collect, exactly as we would expect. Because we are mostly in the game of communicating with the lowest possible energy we use coherent photons (like in a radio transmitter).. we notice that we are collecting zillions of photons and our aerial can only have one superposition of states over time (call it frequency if you like) and we are very happy. The exception to this rule is when the photons are not coherent .. that would be the radar you mentioned some time back . For radar you just want a raw photon count.. different strategy required .. this is where your parametric diode comes in .. we avoud superposition (tuning) so every returning photon contributes to changing the parameter of the diode .. and you get (effectively) a raw photon count.

That's the best I can do at present.

Now I would ask you to count how many maxima you see.

Best wishes,

-C2.

If you look at the diffraction pattern of some of the links to single photon interference you can check that the slits really are in the region of a wavelength wide (check out GE's geometric optics if in doubt.)

This post has been edited by Confused2 on Nov 21 2006, 08:46 PM

Hi Confused2,

Simple Answer: The size of a single silver halide crystal. It will critically depend on the wavelength of light though... This is because the photoelectric effect is not the same at all frequencies so the size of silver halide crystals in the emulsion affects the sensitivity at different frequencies. You will need a "lot" of those photons to significantly darken a single crystal. Additionally the chemical transition will only occur "if" the absorbing crystal is larger than 1/2 a wavelength of light "and" is sensitive to the impacting photons at the "excitation frequency". The 1MHz "light" will not be effective on a photographic plate. This is Einstein's Photoelectric Effect in action. If the silver halide crystals were much smaller than 1/2 wavelength in size the incident photons would not be able to notice their existence and tunnel right past them regardless of the frequency. It is a "resonance". Now a question for you...

(My emphasis) What "color" do you think the "spread out wavelength" of light appears on the backing screen? If I had a 660 nm CW laser as the source of illumination? Does this affect one bit the actual frequency of the "spread out" light you are seeing on the screen? (Oops! two questions... )

Cheers

This post has been edited by Good Elf on Nov 21 2006, 10:23 PM

High Good Elf,

On some points we may just have to agree to differ unless we can find an experiment to cut one way or the other. Since I believe a photon is a bit of the SM which deals with EM interaction .. my money is on virtually no size. A big crystal would (obviously) have a better chance of detecting a photon .. without a new state available I don't think anything happens regardless of wavelength and with it then one electron is enough. We've been here before with hyperfine transitions .. that only took 1 atom to make an umpteen centimetre microwave (sloooowly!).

The 'colour' of the light on the backing screen is given by the energy of the photon. One photon doesn't have a frequency or a wavelength .. the words may be convenient when dealing with many photons but they both need to be treated with caution, we should abandon tradition and concentrate on energy.

-C2.

C2- I agree with most of your basic premise. My problem is with the
"particle" aspect of your argument. To misquote Shakespear's McBeth:
"Photon, it a wave or is it a particle? THAT is the question." (To be....or, not to be?) OK enough melodrama...

First, a receiving antenna receives ALL radio signal frequencies that correspond to
its resonant tuning "length". The antenna and receiver hardware are tuned to
the specific harmonic resonant frequency to filter out or shunt all non-desired
RF signals to ground. This is the resonant cavity optimized for the desired
frequency. We agree on this point. Now what about the antenna that is
located 10 miles in the other direction of the antenna. It is picking up the
exact same frequency wave and "photon" and the process is reproduced there.
But wait....if it is a particle, how could it be in both places at the same time?

Second,

Radar frequencies are coherent. They are transmitted at a specific frequency
(there are some that use multiple frequencies) at a specific wavelength.
They are precision tuned but they are focused and directionalized at relatively
high power levels. It is the phase and timing difference between the transmitted
pulse and the target return pulse that is detected and compared to yield the
distance and location information. The detection electronics just compares and
amplifies the phase and timing differences between the outgoing and incoming
signals, and cancels out "in phase" or "constant frequency" signal returns to
prevent return signal "saturation" from fixed objects. The transmittted signal is
also circularly polarized to eliminate clouds and rain reflections so the signal
can pass thru them with minimal return interference. Tuning is a HUGE part
of radar physics both on the transmission and receiving systems. That is where
the parametric amplifier comes in. It is the 1st "phase shift" signal detector,
its output is amplified and from there the phase comparison electronics kicks in.

Third,

By maxima, I assume that you are referring to the 3 elliptical interference pattern bands
described by the dots? The next question, that we have beaten to death, but
still not beaten a confession out of, is how are discrete photon (waves), each
arriving at a different tiime, create what appears to be mutual interference by
traveling thru the geometry of the slits? The patterns formed are in the horizontal
and vertical orientations, because we have vertical displacement and horizontal
displacement differences between each individual photon and we have interference nulls between photon hit patterns. GE has given some
very long and thoughtful answers to these issues, but there are still voids or
inconsistencies in the theory, there are some fundamental optical mixing
properties as light inteacts with matter that affect this experiment, IMO.


Regards,
LL

C2,

TIME OUT!
.
Frequency is number of 360 degree cycles over time (per second)
.
Wavelength is the measurement of 1 cycle over distance (meters).
.
Energy is momentum at the speed of light and is determined by the
amplitude of the frequency(Electron Volts).
.
Intensity is the number of photons per unit area (Lumens)
.
Color is determined by frequency as it relates to other frequencies (colors) on
a color scale (Chroma)

Each photon has a specific frequency of periodic cycle rotation per second,
as EM fields interact. The wavelength is a linear measure of 1 cycle/meter.



Other opinions, definitions welcome

LL

This post has been edited by Laserlight on Nov 21 2006, 11:47 PM

Hi Laserlight and Confused2,

You are dead right there about "voids" but I think you may be wrong about the "inconsistencies". Remember we "elves" are all ears on where you may think there are actual inconsistencies. As to the "voids"... well it is a big Universe for a "sound byte"... I cannot cover all the bases at once. Remember that the halide particles suspended in an emulsion is for a rather easy to explain purpose... You are dead right about resonant systems and the relative importance of these phenomena. The scale of the resonant systems vary across the entire range and size of the Universe from the sub-nuclear to RF waves in the single figure Hz... they are all the same phenomena. Mostly I am recently concentrating on far field phenomena but near field phenomena can also be dealt with as well... the maths get a little more difficult though. "Elves" do not like actually doing the maths. but "cash resourced" Universities, Institutions and their staff have access to "tools" we elves do not possess.

I am sticking with my semi-classical wave theory until someone can actually find an inconsistency. Remember just pointing to classical theory's inability to nail where an individual photon actually ends up is a problem with all theories. The problems above have all been dealt with using old style classical concepts and without some new concepts do look inadequate. But this simply requires expanding to "semi-classical" concepts. I do not need to resort to a roulette wheels or games of chance to provide answers. "God does not play dice with man"... This does not mean that man does not like to play dice with God. LOL

Cheers

Laserlight .. I'm posting this because it's ready to go.. we may (or may not) come back to it.

Your call for TIME OUT is more important.

Um.. I thought "particle" was my basic premise .. never mind.

At 1 Mhz a 1 Watt transmitter would be spitting out 1/ (hf) or about 10^27 photons per second .. give or take an order of magnitude. There are plenty to go round.

The amplitude and phase of the 'bounce' is not coherent. The difference between [one ship here] and [one ship there with another ship behind it] exists only in the time domain. The point is interesting but possibly beyond the scope of the present discussion.
Counting maxima..
This one ..
http://www.teachspin.com/instruments/two_s...periments.shtml
MUST be more than three on this one .. the last ones were a bit faint .. running out of the good diffraction zone .. but this little beauty .. you must give me at least five maxima.. surely?
In the unlikely event that we agree that there are more than three maximums AND there is only one photon AND the effect is the result of the difference in path length .. then there is a problem with 'c'.
TIME OUT......