Electron/photon interference pattern questioned

[Upisoft]

I did not notice any effort from your side of understanding my arguments.

What I am stressing is that there is a difference between a measurement and an interaction. If there would be any - the concept of measurement would be unnecessary. Moreover, I want to stress that measurements are being dome without any whatsoever participation of human beings. Very often human beings learn about the results of these measurements thousands of years later (like measurements of the Earth magnetic field).

But I am not going to insist on these points or continue to argue.

Thank you for making a positive effort. Now I understand where our misunderstanding lies. Difference between a measurement and an interaction is the difference between classical and quantum information. Probably you consider only classical information as being information, while I consider them both. There is some correlation between them. The classical information seems to be a macro effect of the quantum information.

For example you cannot learn if there is 1-slit or 2-slits by simply sending and observing one photon, you need a lot of them to create an image on your retina. You cannot observe the interference if you send only one electron as well, you will need a lot of them.

This also reflects on the information you obtain. In the case of measurement you get information about single real value (the perfect case when you can measure the value with 100% certainty). In the case of interaction you get information about some real function (or perhaps complex function - I'm not quite sure about that).

 

[etamorphmagus]

When you perform the experiment, you consider some time window. You cannot really say "when" the wave originated and "when" it arrived. If you could, you would be obtaining information and that might color the results so that there is no interference.

Ok Dr.Chinese that would solve the problem. This is clearly uncertainty on time.

But it has nothing to do with the time-energy relation for particle decays now, is it?

This time indeterminacy makes sense in the QM world, but what is it connected to? I never saw anyone talk about the point I made here, which is kinda crucial and fundamental.

Thanks.

 

[etamorphmagus]

As a follow up to my last comment + more visual representation of my thoughts:

* I know there is no such thing as a "probability wave" consider this a pulse in the wave function, something like that.

[PLAIN]http://img839.imageshack.us/img839/4782/problem1.gif

Note: I do not speak of the interference of waves, that is obvious, just of the mechanism.

 

[DrChinese]

Consider the initial setup and the final context. There are a large (infinite?) number of ways the photon could travel (and there is interference). So one of these paths is "selected" at random. The time issue is not really relevant in the sense you imply. It is not a series of decisions, each a fraction of a second after the other. One path could be a nanosecond. Another could be many years (say to a nearby star).

 

[etamorphmagus]

Consider the initial setup and the final context. There are a large (infinite?) number of ways the photon could travel (and there is interference). So one of these paths is "selected" at random. The time issue is not really relevant in the sense you imply. It is not a series of decisions, each a fraction of a second after the other. One path could be a nanosecond. Another could be many years (say to a nearby star).

Fine, initial setup and end result! the end result has to be created somehow, and that somehow is the propagating wave-function. does it travel as a wave? yes, or else it wouldn't be called that and wouldn't interfere. I want to understand how the interference map gets to the screen, what I drew was a propagating probability wave, so what's the problem? and what infinite paths? I'm talking about those getting to the detector.

And why not series of decisions? the wave gets to the screen. That means that some probability for finding that particle there exists - if you decide to measure - which you do. So if it is not detected, it will in the next roll or the next roll. Or are you saying time has no relevance here? It is all instantaneous? special relativity for photons and 0 distance 0 time?

 

[DrChinese]

And why not series of decisions? the wave gets to the screen. That means that some probability for finding that particle there exists - if you decide to measure - which you do. So if it is not detected, it will in the next roll or the next roll. Or are you saying time has no relevance here? It is all instantaneous? special relativity for photons and 0 distance 0 time?

Well, we know the correlated observation results of spacelike and timelike separated Alice and Bob depend on decisions they make as to context. So that tells us that the die is not rolled over and over again. Else you will be trying to figure out how one knows about the other.

 

[etamorphmagus]

I found this under Complementarity in Wiki:

In a restricted sense, complementarity is the idea that classical concepts such as space-time location and energy-momentum, which in classical physics were always combined into a single picture, cannot be so combined in quantum mechanics. In any given situation, the use of certain classical concepts excludes the simultaneous meaningful application of other classical concepts. For example, if an apparatus of screens and shutters is used to localize a particle in space-time, momentum-energy concepts become inapplicable. This is reflected in the formalism in the fact that a localized wave-packet is a superposition of plane waves, and therefore does not have a definite energy-momentum. This reciprocal limitation in the possibilities of definition of complementary concepts corresponds exactly to the limitations of the classical picture, where any attempt at the localization of a particle through objects such as slits in diaphragms introduces the possibility of an exchange of momentum with those objects, which is in principle uncontrollable if those objects are to serve their intended purpose of defining a space-time frame. Another famous example is 'Heisenberg's microscope', using which Heisenberg first discovered his uncertainty relations.

So time and energy are also intertwined in the quantum-uncertainty. You don't know when the "wave" reaches the screen, so for all we know, it reached averagely at the same time at every point on the screen, and therefore the probability is like a line on the detector, and from there the result is clear - interference pattern.

Just wanted you to confirm this. What I drew was a probability wave propagating in space-time, but you have uncertainty on space-time --> It's everywhere at the same time. The interference map was created at the moment the electron reached the screen, at any point. Of course, metaphorically.

One of my teachers said that time-energy uncertainty are not in the formalism of QM, but proven for specific cases. So what is this thing?? How can they say it is space-time and energy-momentum which are intertwined in quantum uncertainty?