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Comment by Gunax | Hacker News Reader

I've been posting this explaination for more than 10 years now:

http://www.felderbooks.com/papers/bell.html

I think I prefer Felder's explaination more than Quanta's. It's omitting some details (eg. the angles) but is better at explaining the difficulties of Bell's Inequality--why it seems like spooky action at a distance and why it cannot be used for communication.

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One thing I've not been able to clarify is whether Bell accounts for the possibility that passing through a polarization filter could effect the waveparticle in some way, like altering its polarization angle.

Yes, the "altering" you're describing is what the theorem would call a hidden variable. Seems reasonable, but when you do the math it's exactly he kind of theory Bell's inequality rules out. There's no way to set the "polarization angle" (or any other set of variables) such that they obey the probabilistic laws we've observed (without violating some other assumption, like single measurement outcomes, statistical independence, determinism, or locality)

As I understand the P(passing) through a second filter is related to the blue line here:

https://upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Be...

Couldn't the passage through the first filter effect the polarization angle in such a way that it matches the blue line instead of the red line. One could devise a physical contraption to demonstrate this is possible by sending bar magnets through slits of magnets of the same charge. Any magnet oriented such that it's too close to a slit will reorient slightly. Visually...

https://ibb.co/gDnpqCb

That is, if both photons or magnets happen to pass through the first filter, their probability of both going through the second filter is boosted from the slight reorientation, and thus their outcome correlation will be boosted, which is what the blue line in the graph above shows.

My main contention is that it's possible to construct a physical apparatus using visually observable non-quantum macro objects (like pairs of bar magnets) that pass through such filters with the same correlations shown by the blue line in the graph above. Such correlations would apparently violate Bells theorem, even though the objects were obeying classical laws of motion.

And it's certainly conceivable that passing through a slit could change the orientation of a wave, whether mechanical wave...

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSrnPB4...

or the wavefunction of a photon...

https://cronodon.com/images/Single_slit_diffraction_1.jpg

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