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Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/15/2007 9:37 PM

Light (or electrons or atoms) can be shined through a small hole in an opaque plate, then continuing on, through two other small holes in another plate to form interference patterns. (see Quantum Mysteries Part 1)

Imagine setting up a pair of detectors alongside of each of the holes, and sending the electrons through one at a time. Now you can see if a wave or a particle passes through one hole or both, and what the screen looks like. What you find is that each electron is seen as a particle, passing through one hole or the other, and no interference pattern develops. The pattern on the screen is like little bullets have gone through, and made the appropriate pattern. The act of observing the electron wave seems to have made it collapse and behave like a particle. You only need to look at one hole to change the pattern. How do the electrons going through one hole 'know' that we are looking at the other hole? This phenomenon is known as non-locality. Einstein called it 'spooky action at a distance.'

The Austrian Erwin Schrodinger thought that all this was ridiculous, and came up with his story of the cat in the box, which appeared in print in 1935. Albert Einstein, Boris Podolsky, and Nathan Rosen also came up with a 'thought experiment' about the same time. It is known as the 'EPR paradox.' In the mid 60's, John Bell, an Irish physicist, found a way to express the paradox in terms of an experiment that could be carried out on pairs of photons emitted from an atom simultaneously in two different directions. Several researchers took up the challenge. The most conclusive of these experiments was carried out by Alain Aspect & colleagues in the early 1980's. They demonstrated beyond any reasonable doubt that non-locality really does rule in the quantum world, and that Einstein and the others were wrong.

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#1

Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/17/2007 11:43 AM

well, isn't the detectors themselves need some influence on the electrons to do their detection ?

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#2
In reply to #1

Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/17/2007 11:56 PM

It's not a mystery that observing a photon changes it, the mystery is why the photon avoids the hole that is being observed.

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#3
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/18/2007 2:03 AM

Got it. Thanks.
So both photons are choosing the same hole?
what happens if you put detectors on both holes?

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#4
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/18/2007 9:58 AM

Chance is that it will be detected in this hole or that hole or go undetected on both holes. That a photon will be detected is a probability. If photon is influenced by perturbed field due to electrons in a hole then it may change path or its energy may get altered or may get absorbed. You may also get two photons for one and that depends on the energy of the incident photon.

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#5
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/18/2007 8:14 PM

There are more than 2 photons involved, maybe millions, but it was my assumption that they all went through the other hole when one was observed. Assumptions are dangerous though, and the universe is full of surprizes. I wish I could obseve this experiment directly, and had more info on it. To answer your second question, stay tuned.

Regards,

S

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#6
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/18/2007 11:26 PM

What is a hole?

Hole is generally a space guided by surface structure fields, which is slightly different from ordered structure or compact structure fields with lots of space within. Hole also has some unbound atoms or molecules with random velocities. These atoms and molecules are part of partial vacuum. What is the hole you are talking about?

When you deal with numbers, statistical data becomes very clear and with some meaningful result. Events are happening irrespective of observers. Observer may find or miss the event depends on its synchronization with the event which may or may not happen. Chance that, you may observe something and may never observe again in entire life is also a possibility. However, there are other possibilities that can be nearly repeated and these form part of scientific data more than that can not be repeated even though both data are scientific.

If I say that tomorrow is a big bang day. Then this may have remote possibility and no one can rule out. Such data do not get scientific importance. Predicting weather becomes somewhat scientific and predicting solar eclipse is more scientific.

Whatever you wish to say, also will have reason within. Less one knows, more one get surprised. I do not see anything in black hole is not because I am observing it. That is the way it is. We are not so important that nature will avoid us from being revealed. Observation is multiple synchronization of conversions of energy up to the final link that gives us an idea. Without this link, the event remains undetected. Detection is a process. Match your detection phase with the event and you will find it. Mismatch it and you will never detect it.

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#10
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Re: Detect Match/missMatch Quantum Mysteries, Prt 2: Non-Locality... EPR Paradox

12/15/2007 7:40 PM

Designed hole detection changes vitually in priciples to results which can cause changes that do not matter..

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#9
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

12/15/2007 6:55 PM

I should have read through this entire thread first but BECAUSE this comment pulled up first in my search I went back to the original post, as it was, reply to #2 took refrencing for thoughts as how it could stand alone.

Not to sell Einstein short or dispell either theory, the life of the light cell in source can have a varience that holds some of the effect, and the connections to it in many dimensions can have impededing affects as the swining balls on the pendalum

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#7

Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/25/2007 9:05 AM

Dear StandardsGuy,

I must apologize for referring you in Quantum Mysteries Part 5. Predicting the Future? to EPR, and "Cat-In-A-Box", having missed your detailed introduction here.

I need to be more attentive, and less impulsive, both, some of my shortcomings, sorry again.

Yours,

Yuval

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#8
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Re: Quantum Mysteries, Part 2: Non-Locality and the EPR Paradox

03/25/2007 8:23 PM

Hi Yuval,

Apology accepted. I came down pretty hard on you, so I understand. I think maybe I should have posted these in the general section. Now that the air is clear, I hope that we can be friends and have a lot if good "chats".

regards,

S

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