Faster-than-light communication

[IMP]

There are 2 observers, Alice and Bob. They get a stream of photons arriving as you say, perhaps 10. They EACH have a polarizing beamsplitter and 2 detectors. When Alice gets a dectector hit on the first detector, she marks it a +. The other detector registers as a -. Ditto for Bob.

Alice can vary her beamsplitter orientation so she can "send" a message. (Not really of course as we will find out.) Bob holds his beamsplitter fixed and steady so he can receive a "message". The beamsplitter separates the photons to one of the 2 detectors as mentioned, and he records a + or a - according to which of his 2 detectors fires.

Now what does Bob see when he records his results? He see a random series of + and - results, something like this:

++-+-+---+

Since the "message" is random, no information is received. It doesn't matter what Alice does, Bob's message is totally random by any measure. That is because the source of the entangled photons is random itself. The pattern that indicates there is entanglement is ONLY evident when Alice AND Bob's results are correlated.

But the results Bob gets could be thought of as 1101010001 (++-+-+---+ as you stated). Just because Bob cannot confirm the string until he and Alice get together does not mean the string is random. Correct?

 

[DrChinese]

But the results Bob gets could be thought of as 1101010001 (++-+-+---+ as you stated). Just because Bob cannot confirm the string until he and Alice get together does not mean the string is random. Correct?

Recall that polarization entangled photons always have a random orientation. Therefore the string Bob sees is ALWAYS random. Ditto for Alice. But when you correlate the results, you can estimate the angle between their polarizer settings by using Malus.

 

[Albert V]

A question just for fun:

It seems that it is the beamsplitter in the quantum eraser that ruins our FTL communication and Nobel. What if we throw out the beamsplitter and insert a black box containing a device that inserts a mirror by random. We still have no which path information and no polarizer that interacts with the system, but will we have the interference fringes?

View attachment Black box eraser.pdf

 

[DrChinese]

A question just for fun:

It seems that it is the beamsplitter in the quantum eraser that ruins our FTL communication and Nobel. What if we throw out the beamsplitter and insert a black box containing a device that inserts a mirror by random. We still have no which path information and no polarizer that interacts with the system, but will we have the interference fringes?

View attachment 19840

Recall that an uncorrelated group of entangled photons do not display the interference pattern ever.

Although is it amazing that the entire set does not produce interference, but Alice-Bob correlated subsets clearly display the interference fringes and anti-fringes at all times (i.e. when considered as 2 groups). So actually, some kind of interference is occurring behind the scenes. But the summation is NO interference!

[fringe] + [anti-fringe] = [no interference pattern]

 

[Descartz2000]

Refuting the existence of free choice experiments is a way to explain the results without turning to FTL.

 

[DrChinese]

Refuting the existence of free choice experiments is a way to explain the results without turning to FTL.

I don't consider the hypothesis of "no free choice" to be science (any more than the hypothesis of God is science). And I don't think it is possible to refute free choice by any experiment (just as it is not possible to refute the existence of God).

 

[Demystifier]

I don't consider the hypothesis of "no free choice" to be science (any more than the hypothesis of God is science). And I don't think it is possible to refute free choice by any experiment (just as it is not possible to refute the existence of God).

That's probably true. Still, one can use logic (rather than an experiment) to show that "free choice" is not compatible with some theories. For example, both classical and quantum mechanics interpreted as UNIVERSAL theories (by an "universal" theory I mean a theory for which one assumes that EVERYTHING, including the human mind, is completely described by that theory) are not compatible with "free choice".