Problem with the two slit experiment, Observing later

Well actually I recommended using a single rotating polarization filter to remove the possibility that delays over space could affect the result.

I'll try to explain the idea a bit more clearly:

Let's say we have a round trip delay of 1 second from the laser to the mirror and back. If we place the filter in front of the laser and rotate it, then it will be sweeping through various polarization angles over time.

If the rate of rotation is such that it sweeps 90 degs during the delay between the filter and the mirror and back, then if polarization is a local property of the photon that's communicated at light speed, all photons should be blocked either on the forward pass or the reverse pass because at the two times a photon would cross by the filter, it would be at 90 deg angles.

There are some issues that could add problems in explaining the result, though knowing the result would help delve into these.

Now if the beam intensity drops as the filter is rotated faster, then polarization could still be local but the delayed choice experiment could be the result of a selection made in some manner by an observer. In this case, the beam intensity could still drop and the observer would simply have no physically possible "choices" that allowed the polarization information to be communcated at light speed. I assume this would be the case and admit such a result wouldn't necessarily deny a more classical explaination though it would help clarify what "window of opportunity" exists in such a selection.

On the other hand, if the path and wave characteristics of a photon are determined ahead of time, by possible information tied to spacial locations, or some instantaneous state of the environment (which can include prior entangled information as this information is static, whether or not it's envisioned to be physically moving) then the polarization information doesn't need to physically travel through space nor be subject to being filtered twice by the filter and likely would only be filtered at some instant in time and frozen in that state.

Basically, if the polarization property is local to the photon and communicated at light speed, then you should be able to dim the beam by rotating the filter during the delay time of the trip, whereas if the polarization is a non-locally determined property then the polarization information would not need to pass through the filter twice at two seperate times and be blocked. In the case of not being blocked, the question becomes one of determining when the polarization occured and if it occured relative to either the emitter or detector time frames, then this should be determinable by looking at which phase of polarization was selected.

There's still a question here, for me, regarding acceleration also. If there's an "event" that requires a polarization to be selected, what comprises that "event"? It would appear to be an "external" alteration in the state of the system, but if we had such an experiment set up in space and isolated from everything else (as much as possible), where would this input come from?

Acceleration can alter event horizons, which can be viewed in terms of information limits. An acceleration could be seen as an alteration to a steady state condition, or a new input of energy/information, that distorts the prior contents of it. A spinning polarization filter isn't necessarily the same, in terms of where information is flowing or what information is already entangled in a system, as having a more remote and isolated input modulating the polarization - like a shutter. In the case of an external input, it may be physically impossible to have any knowledge of what the input will be ahead of time (lots of assumptions made here).

For example, from relativity, we'd expect to see space appear distorted travelling at high speeds, yet the Earth could easily already be travelling at high speeds and not notice the distortion because it's a pervasive effect that alters all your surroundings on a similar scale - just as it's assumed travelling inside a closed spaceship at high velocities would internally not appear distorted, but relative to external information not already "entangled" or subjected to the same acceleration, the distortion would become more apparent.

Whether or not accelerating the rotation of the filter would affect anything would be harder to test without a larger delay, but it would seem the results should be similar to the experiment using delayed quantum observations as it wouldn't be much different than selecting a shutter "in mid flight" for the photon, but those are just extended considerations for the experiment.

WhyNot,

You are correct, good catch....gotta preserve the conservation of energy.


LL

My best guess would be that rotating the filter blocks the photons and that what's being observed in the delayed choice experiment is analogous to changing the color of light you see by quickly switching what sunglasses you're wearing. You can change the "color" of the entire universe instantly, though the light may be coming from light years away.

Of course the funky part is that this wouldn't seem just limited to altering the wavefunctions of light and it leaves some interesting considerations over divergences between observers that don't see the same thing.

This post has been edited by StevenA on Nov 11 2006, 07:39 AM

In case it's not clear what effect the rotating filter would have, here's a simple example using bars to represent the filter and spinning sticks to represent polarized light:

Imagine throwing some spinning sticks through vertical bars - the only sticks that would pass through would be those with vertical rotations and sticks with horizontal rotations would be blocked by the bars. Now if you placed a rubber sheet behind the bars (a mirror), the vertically spinning sticks would bounce off this and, assuming the direction of spin didn't alter, they'd all come back through the bars.

But if you rotated the bars so that in the time it took for the sticks to bounce back, it had rotated into a horizontal alignment, then all sticks would be blocked either on the forward pass, when bars block horizonally spinning sticks or the "reflected" return pass, when the bars are horizontal and block the returning vertically spinning sticks. It doesn't matter what initial angle the bars are at as long as they rotate 90 degs in the time it takes the sticks to bounce back.

But in the delayed choice experiment the interference function can be modulated after a photon would be assumed to have passed through the slits. The question is when the result was determined.

If the results of the delayed choice experiment can be altered immediately before an observation, then you have a couple explainations (though I assume more are possible) either 1) the input selecting the observation method created an instantaneous, faster than light, alteration to the entire system or 2) both (all possible) results were already being propogated through the system at light speed and a selection of which result to observe was made at the end.

In case (1) a faster than light, or non-local determination of the wave function is necessary and in (2) the observation is altered instead and this can occur without any faster than light communication, though it requires parallel processes to exist.

So in the case of the rotating polarization filter, if faster than light or non-local (to the photon) determination of the polarization occurs, then the polarization need not be filtered twice at two separate times and only one instantaneous determination of the polarization need be made, which could allow the photons to be detected on the return path, whereas with the second case, the polarization information can still reside locally with a photon and travel at light speed without any concerns with relativity but in this case, they act normally and are blocked by the rotating filter as all photon paths would have to pass through the filter twice at right angles and thus be blocked by one of these.

If you just had two separate filters rigidly fixed at 90 degs to each other, then there's no time component involved and all photons are blocked because at no point in time would a path through them be possible, whereas for a single rotating filter you have a filter that's time variable and places tight restrictions on the path and timing of the polarization information.

Compared with the results of the delayed choice experiment - if the wave function of a photon can appear to be altered at any point in time then it doesn't need to be anything specific during the transit, or even a property physically attached to it during transit, in which it wouldn't need to be filtered twice in time but could be determined at some instant in time in which the filter would appear frozen in one position and correlate wave information both ways through it. In that case you could determine when the polarization selection occured by looking at what the polarization angle was.

This post has been edited by StevenA on Nov 11 2006, 07:37 AM

StevenA and All,

Just a thought exercise in SR, (it's late and my brain is mush, so this may be
irrelevant)

If you have a dual opposing output pulse laser (light exiting from both ends of the
laser in opposite directions) and the wave pulses are coherent and in phase.
What is their relationship as they move at light speed in opposite directions?

Both pulses are moving at light speed relative to each other, there is no
doubling of the distance covered even though they are moving in opposite
directions. For all intents and purposes, for each pulse time has stopped relative
to the physical universe.
They are phased the same but their phasing is inconsequential to their relationship
since from a relative perspective time has stopped for each pulse.

According to SR they have no relationship. They couldn't see each other
because from a time relative perspective they are moving at the same speed
away from each other and relative time for each opposite pulse has stopped.
There would be no observable red shift because they are traveling at light speed.
so no red phase shift could be detected.

Conversely, if they were moving toward each other there would be no blue
phase shift detected because they are traveling at light speed relative to each
other, and internally to each light pulse, time has stopped relative to everything
physical outside of each pulse.

Now let's say space warps back on itself and the two opposing coherently phased
pulses inevitably approach each other from opposite diirections, what happens
when they are perfectly time coincident and and the phases overlap again?

Anyone got an answer?
LL

This post has been edited by Laserlight on Nov 11 2006, 07:49 AM

I suspect Why Not? and StevenA (and yq?) are the ones on roughly the same path as me..

Classically, a radio..
We start with information ( Music)
We have a transmitter that launches this signal into space,
It travels through space
Our receiver picks it up and turns the signal back into information (the music)


[Input]->[F1 (the transmitter circuit) ]->[F2 ('space') ]->[F3 (the receiver circuit) ]->[Output]

Suggestion .. F3 (the receiver) is profoundly influencing the perceived properties of F2 (space) by virtue of its 'most probable detection' properties. If we look at photons and space in another way (eg the DSE ) then without the filter of a radio receiver we see a somewhat different picture. If we look at a hologram we see a third apparently 'new' version of space and photons.
Radio .. time selective .. looks (loosely) like it receives 'wavefronts'
DSE .. allows many wavefronts to be seen.. not time selective
Hologram .. shows the path of a single photon is the result of the entire image (could be 12 inches by 12 inches or more) .. not space selective.
A prism .. selectively removes all paths except the 'refracted' one.

StevanA's experiment ... woooo .. if I had to predict .. I'd guess polarisation propagates pretty damn fast.

Can anything other than 'probability' explain how the same sweet seems to have so many different flavours?

-C2.

Comments from other most welcome (of course)

This post has been edited by Confused2 on Nov 11 2006, 01:01 PM

Hi Laserlight,

He he he... yep... you would be right about nter-dimensionality. That is what Alain Aspect was intimating in that earlier post. Now I do not believe in Aether. This was disproved by the Michelson-Morley Experiment. What I have been saying is we live in unbounded finite space. This means like a bug inside a toy balloon it can wander around the inner surface of that "globe" forever , never finding any boundary to its travels. Our Universe is such a topology. Where I differ from standard philosophy is instead of being on the "outside" of such a pherically curved space (a de Sitter Space) wearer on the inside of a dimensional bubble (an anti-de Sitter space). This ties into Juan Maldacena's Theory which is a very important breakthrough in conceptual physics.
Wikipedia: The AdS/CFT correspondence
Here is a recent article about this concept.
The Illusion of Gravity: Juan Maldacena, Scientific American
I have copied the text of another article from New Scientist here...
The elephant and the event horizon @ 26 October 2006 NS
The Holographic Concept is not confined to just "two dimensional" surfaces but higher dimensional surfaces as well. In the same "general" way in which photographic Holograms "map" flat spaces from two dimensional surfaces into higher dimensional fully developed spaces, the nature of volumetric space is "transcendental". The Hologram is the way in which our Universe is expressed and our physics is based on "optics" of higher dimensions.

Now I do not believe in "Aether" (some universal substance to carry electromagnetic waves) but I do believe in higher dimensions so that we all reside on a hypersurface of our Universe and its outer "layer" is on the light cone. We are the little bugs "crawling" around inside an optical hall of mirrors created by matter waves.
A cosmic hall of mirrors: PhysicsWeb Sept 2005

The electric and magnetic fields "reside" in higher dimensions not on the surface of our 4 dimensional Universe and everything about the quantum is "hidden" in a greater dimensional realm which we are unable to directly appreciate. The electric and magnetic fields are really a reflection of a single entity... the brane wall of our Universe and the way in which energy is able to "shuffle" between the electric and magnetic duals through that "resonance" on this brane wall... via the non-local limits of our Universe. The "projection" of this entity into our "Spacetime" world gives us the particle interactions. That is actually what I am on about and have been for quite a long time on this forum. It is all one way to describe "everything".

Looks like you are in for one hell of a migraine... You will thank me later!

Cheers

This post has been edited by Good Elf on Nov 11 2006, 01:17 PM

"Single entity" or as I say "Duality"; good luck cobber, hope the world will one day thank us.

This post has been edited by fivedoughnut on Nov 11 2006, 01:41 PM

Hey StevenA, LL, C2, TRoc, GE, 5D, and yq,

StevenA, Thanks for the further detail. Once you run the beam through the polarizer, you will be filtering out all but one polarization, yes? If you determine the polarization angle at the first pass, you will know what it will be on the second pass and can confirm the results by detecting whether or not any light makes it through the second pass. It should be either yes or no, not some value in between. I can't see how the experiment would determine the "speed" of polarization.

LL,

I think (in essence) you are describing a Michelson Interferometer where the path lengths differences are 1/2 of the wavelength used. In this case, the light will destructively interfere and head back to the emitter. With regard to your specific question... Intuitively, I think the photons will pass through each other, switch spins, and then make another transit around. However, I do not think there is any way to ever measure such an effect.

C2, I think I finally found a someone that has actually run your Michelson Interferometer Experiment… http://arxiv.org/PS_cache/quant-ph/pdf/0012/0012028.pdf

(emphasis added)

Comments not just welcome, but expected!

GE,

One good migrane, deserves another....tit for tat....

Ok, I will delve more into the links that you have posted. However there are
serious inconsistencies in this theory as they relate to physical phenomena
that don't exist in the metaphysical interdimensioal realm. Ocean waves,
sound waves, waves on a string, are physical manifestations, with physical
effects that aren't interdimensional and interact with the 4 dimensional
space/time continuum that we inhabit. I also find some difficulty as to how
an interdimensional manifestation can cause physical changes and dislocations
in a 4 dimensional physical universe.

There are lots of competing theories, all vying to explain a complicated and
baffling topic. The problem is...how do you prove extra/inter dimensionality
when you are constrained to a 4 dimensional physical continuum?

LL

"The photon goes through all possible entrances". Sure it does. This is a carefully set up experiment. chhange it a little and it does not work. as Nick said, it is a phenomenon. a trick which if you get everything right, you get a strange effect. Unfortunately with science nowadays, it is not; look for Occam's razor, but for the most craziest idea anyone can think up.

Laserlight. Actually 3 dimensions. Time is merely a convenience created by Man to allow us to cope with the world around us. Animals manage very well without the concept of time.

To prove other dimensions exist you would have to find something that cannot be explained by the normal 3 dimensions. Like superstrings, which we have now given up on as a dead end.

WhyNot,

You are correct, it is a Michelson interferometer type experiment....and as
the wavelenths merge with 180 degree polarity inversion there should be destructive interference of the wave
energy pattern. The opposing wave energies should destructively cancel....when they
do infra-red heat should be the byproduct of the destruction process. In
radar and RF waveguides there is a "dummy load" configuration which is basically a waveguide
shunt that sets up reflective 180 degree out of phase standing waves in a frequency tuned internal cavity.
The waveform reflected from the end of the cavity destructively interferes with
the incident waveform and the byproduct is heat, which is radiated away across
cooling fins external to the cavity. Energy is transformed from
microwave to infra-red and energy is conserved.

Kaneda,

I agree to some extent, but time is a linear manifestation of physical reality.
Actions, Reactions, and interactions all need a point of referece....time.
Humans have just quantified it based on periodic physical
observations/interactions. All matter has a basis in tme so it must be given
some relevance as a metric of the interactions of the 3 physical dimensions
since they are all interdependent and time is the dimension which binds them
and gives them consistent and measurable "standards" or operational constraints.

You can't measure or quantify "THOUGHT" either, but it occurs. It isn't measurable
or quantifiable but it is a manifestation of an advanced lifeform. It isn't real or
tangible but it occurs as a pattern recognition that is purposefully modified
and interpreted in 4 dimensions.

An enigma, wrapped in a conundrum, tied by a paradox.


LL

Hi everybody,




This thread has resembled a conversation a couple of times here and there, but the rest of the time?

WhyNot?,

It requires a "re-model" of the "B list", or particle interpretations, of the key QM founding experiments. [black-body, photoelectric]


A little "netiquette" is in order. Everyone can have their say, we can have multiple conversations going on too, but at the MINIMUM:

If you ask a question of someone, you should read the answer. You should then acknowledge by responding in some way (yea, nay, abstain, alter).

If someone asks a question of you, you should respond as above.

It is more important, with many people involved, to specifically name the person to which you are asking the question, or making the comment to. This sounds basic, but it is not being done.


There are seemingly some questions being directed at me, but I'm not sure. I am saying that I have a better answer, and I fully realize what this requires. GE?

C2, lets play Q&A tennis with just one ball, ok?

An answer to your last question to me: ("..you assume reflections will introduce new frequencies .. there will be phase changes .. but that is not the same as a change of frequency")

No, I'm not the one assuming these things, Science is.

Let's put all the theories that start with "Assume: a. A perfect reflector, or b. a perfect absorber (blackbody) into a "pile".

When someone (you included) can show to the world (and me) a perfect reflector, or blackbody, then we can talk about the theories that ASSUME them.

Until then, I'll postulate a theory that doesn't require them.

Can you explain the "phase" of a "single photon" (1-at-a-time photon)? They will be the same. So, it is the same, in the case of the "smallest moment", fundamental, causal analogy.

Consciousness, and the experiments that it develops, disregards the majority of signals that are always present. Focus narrows, and seeks resonance with a very specific quanta of energy. The process of focusing can be seen as the simultaneous logical reduction of all of the impossibles. In Science, this results in the ability for others to reproduce an experiment, and find resonant (same) results. If a theory has NOT reduced all possibilities, it is not finished; the door is open for a better theory. The best theory will have eliminated ALL the impossibles, and derived the fundamental truth: arriving at a single conclusion, unmarred by doubt. The ultimate simplicity will be self-evident, and not allow for differing results, or require anything more than a simple explanation.

Simple IN , Simple OUT ; Complex IN , Complex OUT , Garbage IN , Garbage OUT. What do we want, and need?


No amount of "dimensions" suffer from the inability to be described fully by 3, and derived from 1 rotating, oscillating point.

If ONE thing is NOT a String, then NOTHING is a String.



It is not the strings per se, that we need to be focusing on. It is the interactions thereof, that we seek. We must not only explain the resonance, that takes place in a "fixed" measurement, we must also explain (account for) the things that didn't happen (according to our fixed measurement). One way to do this is to change the measurement process. A varying measurement may be the solution.


Let me ask everyone here a question. Please include the "heavy-weight" validating link if possible.


What is the distance between Nodes of a wave?


The term "wavelength" is not what I'm looking for, I am seeking a NUMBER.



ciao!

T.Roc



This post has been edited by TRoc on Nov 11 2006, 07:48 PM