# [ExI] Demonstration of Bell's Inequality

John Clark johnkclark at gmail.com
Mon Nov 21 20:33:13 UTC 2016

On Mon, Nov 21, 2016 at 2:37 PM, Adrian Tymes <atymes at gmail.com> wrote:

> ​> ​
> Spins of 0
> ​ ​
> and 90 degrees may differ, but both may be detected at 45 degrees off.
>

​
The only way you could know that a photon is at 0 degrees is that it had
already gone through a filter set at 0 degrees, and then you'd know there
is a 100% chance it will make it through another filter set at 0 degrees
and a 0% chance it will make it through a filter set at 90 degrees and a
50% chance it will make it through a filter set at 45 degrees. A 90 degree
photon also has a 50% chance of making it through a polarizer set at 45
degrees so it can
​not distinguish between the two. ​

​>> ​
>> Is your mind blown yet?
>
>

​> ​
> Not really.  If the particles change identity between observations,
> ​ ​
> then that is what they do.

I'll try to put the problem in as extreme form as I can to get at the
essential weirdness. Some physical process produce 2 photons that have the
same polarization but move in opposite directions. A billion years before I
was born somebody in the Virgo Cluster started making pairs of photons that
have identical but unknown polarizations. He sent one stream of photons to
the earth, a billion light years away and he sent the second stream of
photons to the Coma cluster in the opposite direction from the earth also a
billion light years away.

A billion years later on Earth I spin my polarizer filter (like Polaroid
sunglasses) to a random direction and record its position, I observe if the
photon made it through the polarizer or not and record that too, the exact
time also. Now I spin the polarizer
​ ​
again and do the same thing for the next photon and then for the next
several thousand photons. When his stream of photons reach my friend in the
Coma Cluster he does the same thing with his photons. Both of us observe
that 50% of the time the photon makes it through the polarizer and 50% it
does not.

Now I decide to visit my friend. I get in
​to​
a spaceship with my records and blast off for the Coma Cluster at 99% of
the speed of light. After 2 billion years I arrive in the Coma Cluster
​.​

I now compare notes with my friend. I notice that the direction I had my
polarizer turned to and the direction my friend had his turned to were
different, not very surprising since both were picked at random, but then I
find something astounding. The square of the cosign of the angle between
the 2 detectors for each photon pair is proportional to the probability
that a photon will make it through my friend's detector. Or to put it
another way, if the photon is stopped by my friend's polarizer 2 billion
light years away and if by chance mine is orientated in the same direction
then there is a 0% chance it will make it through mine, and if my polarizer is
oriented 90 degrees from that there is a 100% chance it will make it
through.

That is weird, either the photon knew how I was going to spin that polarizer a
billion years in the future or the random spin of the polarizer instantly
influenced a photon 2 billion light years away.  Neither of these
possibilities violate relativity because relativity only says that matter,
energy, and information can't travel faster than light and this is none of
those things, there isn't really a good word in the English language for
what it is, but it's something, an influence of some sort, and it's weird.

John K Clark
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