Isn't There A Much Simpler Way To Explain Why Quantum Entaglement At Distance Isn't Utile - That Spins Already Exist & React To Detection Predictably? [closed]

Question

Tell me if this concept works for explaining in a much simpler way, why purposeful entanglement outcomes like FTL communication cannot work - and without relying on complex analyses of 'spooky action', 'hidden variables', Bell's theorem, etc.

Can't we just say that when two particles are entangled, that the entanglement 1) creates mirroring properties in each particle to the other, because of their orientation and influence on each other, 2) that when the two particles separate, they naturally retain those properties until interfered with (by, for example, a spin measurement), and 3) even if the same measurement performed separately on each particle changes the particles' properties, the properties are still mirrored, and so deliver predicable 'spinup/spindown' type results?

Here's a simple visual analogy for this lay explanation.

Let's picture two identical tops with geared edges, spinning together each with gears fully enmeshed in the other so that one is spinning clockwise and the other counterclockwise. The tops are held up in a magnetic field in a friction-less environment so that they do not tilt or fall and keep spinning indefinitely in the same plane. The tops are induced to separate and go spinning away from each other meeting no resistance (each still mirroring the other). The tops are spinning so quickly that it is not possible for a new observer to see which direction each is spinning. For each top, an observer 'measures' its spin by very precisely pegging an identical vertical rod in its path, in each case causing each top, on contact with its rod, to slow down and visibly spin off away from the rod, with the spin direction of each top now evident. It is a given when these measurements are taken, that one top will be spinning clockwise and the other counterclockwise. No spooky action, no hidden variables, no equations, just basic predictable mechanics.

So again the question. Isn't this both an easier way to explain the actual phenomenon taking place, and explain it in simple lay terms that don't require any in depth quantum explanations, speculations or proofs?

thanks

Eric Brooks SF, CA

Answer 1

That would work, if you were only ever allowed to measure spins along a single axis. But, in fact, we can measure the spins along any axis we want, and it can be along a different axis for each "top." Before you have a complete theory, you have to pick a probability distribution for what result you get for each "top" if you measure it a specific angle.

As it turns out, it doesn't matter what probability distribution you pick for each individual top- no probability distribution can replicate the joint probability distribution predicted by quantum mechanics.

Answer 2

If you want to turn this into a post that's somehow related to entanglement, you should change your thought experiment to something like the following:

1. After the tops are separated, if you and I each measure our tops, we always find that they have opposite spins.

2. Except: If either you or I scratches our nose while measuring, then we find that the tops have opposite spins only 99% of the time.

3. Except: If we both scratch our noses while measuring then we find that the tops always have the same spin.

Note that you can maybe explain the second result by suggesting that a nose scratch causes you to mis-measure about 1% of the time. But now how do you explain the third result?

These particular numbers (100%, 99%, and 0%) are not achievable in quantum mechanics, but numbers that are equally unrealizable in any classical model are achievable. If you have a model that works for quantum mechanics, it should work for the above as well. (I exaggerated the numbers to make the issue crystal clear, but exactly the same issue arises with the numbers that are both predicted by quantum mechanics and confirmed by experiment).

If you don't have a story that fits a scenario like this, then you are not talking about entanglement.

Answer 3

The whole confusion with polarised entanglement of particles comes from the fact that, firstly, you insist on the notion of spin and, secondly, the polarisation is generated randomly in the experiment. Let me explain this briefly.

Spin - in which nothing rotates - manifests itself when a particle moves through a magnetic field in which it is deflected. At the same time, the concept of spin always correlates with the magnetic field of the particle (its magnetic moment). If we leave the concept of spin completely aside for the moment, the following picture emerges.

1. the particle is deflected in the magnetic field due to the interaction of its magnetic dipole with the external field under the emission of EM radiation (the concept of spin is thereby invalid).

2. when polarised entangled particles are generated, their magnetic dipoles are entangled, up and down.

3. the up and down refers only to the fact that the particles are aligned antiparallel. Their common orientation in space is purely coincidental. Only such experimental results are accessible to us so far.

4. when the particles are detected, the polarisers, which are supposed to detect the particle orientation, are fixed in their rotational position, which leads to a random result in the detection. Only statistically can the correlation between the two particle orientations be detected, but a 100% result cannot be achieved. Our measuring device is therefore imperfect - naturally because of the random alignment when the particle entanglement is generated.

You are absolutely right when you interpret the results of the entanglement experiments as you describe above. However, science is based on consensus and so you get minus points here (and a plus from me).