Quick Question: Double Slit experiment

[platonic]

This little link here:

says that if there is a detection device that observes the electron before it gets to the slits, the observation collapses the wave function. This leads to the electron behaving like a particle rather than a wave as it enters the slit, so two bands are produced on the wall rather than a diffraction pattern. But if no such observation takes place as electron enters, it goes through the slits as a wave of probability, and this wave interferes with itself, and a diffraction pattern is eventually produced.

So the question is this. Is this experimentally correct? Is a two band pattern produced when the electron is observed as it enters the slit/s? I read Wikipedia and it does not agree with the video. Thanks.

 

[nomisrosen]

Yes, a two band pattern is observed as it enters the slit, and there are no real explanations for this except some very far fetched (but plausible) ones.

Some theorists believe in what is called the many-worlds interpretation. This theory suggests that there are an infinite number of superimposed universes being created all the time. Only subatomic particles can "fit" through to these alternate universes.

Basically, what is going on (according to this theory) is that the particle does not split in two and go through both slits at once. It splits the universe in two and goes through each slit in one of them. It can then interfere with itself because as i mentioned, subatomic particles can interact with each other even if they are in different "parallel universes"


http://en.wikipedia.org/wiki/Many-worlds_interpretation#Interpreting_wavefunction_collapse

Also, if you want a crazier theory, there is one called the "simulated reality" theory. It also explains mysterious things like wave/particle duality and virtual particles, and can be applied to the two slit experiment.

http://en.wikipedia.org/wiki/Simulated_reality

 

[Lost in Space]

I've read that if the conditions for the double slit experiment are planned to be changed that light can somehow 'predict' this and alter its behaviour accordingly.

Could it be that the reason for this is that there is a collapsing probabilistic wave function somehow originating from the future? Could these states already 'exist' as in the 'Many Worlds' theory but in a time sense rather than a spatial sense?

 

[platonic]

Anybody have a reliable link with proof that observer effects behavior?

 

[San K]

This little link here:

says that if there is a detection device that observes the electron before it gets to the slits, the observation collapses the wave function. This leads to the electron behaving like a particle rather than a wave as it enters the slit, so two bands are produced on the wall rather than a diffraction pattern. But if no such observation takes place as electron enters, it goes through the slits as a wave of probability, and this wave interferes with itself, and a diffraction pattern is eventually produced.

So the question is this. Is this experimentally correct? Is a two band pattern produced when the electron is observed as it enters the slit/s? I read Wikipedia and it does not agree with the video. Thanks.

two bands are produced over time (when which-way can be deduced)...by single photons...striking the screen one by one...

 

[San K]

Anybody have a reliable link with proof that observer effects behavior?

setup (not observer) effects "behavior" of photon.

setup A = such that which-way info can be deduced/inferred/got
setup B = such that which-way info cannot be deduced/inferred/got

observer presence/absence does not matter

 

[Fiziqs]

This little link here:

says that if there is a detection device that observes the electron before it gets to the slits, the observation collapses the wave function. This leads to the electron behaving like a particle rather than a wave as it enters the slit, so two bands are produced on the wall rather than a diffraction pattern. But if no such observation takes place as electron enters, it goes through the slits as a wave of probability, and this wave interferes with itself, and a diffraction pattern is eventually produced.

So the question is this. Is this experimentally correct? Is a two band pattern produced when the electron is observed as it enters the slit/s? I read Wikipedia and it does not agree with the video. Thanks.

As you can see from the previous responses there are many ways of interpreting the results and implications of the double slit experiment. But nonetheless the results are real.

What confuses me is why you would say that Wikipedia does not agree with the video.

http://en.wikipedia.org/wiki/Double-slit_experiment

They appear to be in perfect agreement to me.

It's been a few years since I looked closely at the double slit experiment, but my own personal interpretation of the results, is that it is not actually the particle's wave function that collapses, but rather the observer's.

That's the beauty of the double slit experiment. It is so contradictory to common sense, and it opens up so many possibilities and interpretations. The follow on experiments just add to the mystery.

If you love a good puzzle, you just got to love this one.

 

[platonic]

As you can see from the previous responses there are many ways of interpreting the results and implications of the double slit experiment. But nonetheless the results are real.

What confuses me is why you would say that Wikipedia does not agree with the video.

http://en.wikipedia.org/wiki/Double-slit_experiment

They appear to be in perfect agreement to me.

It's been a few years since I looked closely at the double slit experiment, but my own personal interpretation of the results, is that it is not actually the particle's wave function that collapses, but rather the observer's.

That's the beauty of the double slit experiment. It is so contradictory to common sense, and it opens up so many possibilities and interpretations. The follow on experiments just add to the mystery.

If you love a good puzzle, you just got to love this one.

I added the last paragraph in "when observed emission by emission" myself. Initially there was no reference to two slits resulting when observed going into the slits.

 

[platonic]

setup (not observer) effects "behavior" of photon.

setup A = such that which-way info can be deduced/inferred/got
setup B = such that which-way info cannot be deduced/inferred/got

observer presence/absence does not matter

There is nothing special about the dedection device other than the fact that it can be checked on by us as we make an "after the fact observation." Device is made of inanimate matter, just like everything around the slits. The innanimate matter of the detection device changes the behavior of the particles (or at least what we percieve to be the behaivor of the particless). The only difference between the detection device and the other innanimate matter is that we use the detection device to make after the fact observations. There is nothing physically special about the setup.