# [ExI] R: Re: Cramer on impossibility of FTL communication

Fri Sep 4 02:25:40 UTC 2015

```On Thu, Sep 3, 2015 at 10:37 AM, John Clark <johnkclark at gmail.com> wrote:

> 4) Some gears and pulleys so that each time the rotary switch is advanced
> one position the filter is advanced by 30 degrees. This is because it's
> been known for many years that the amount of light polarized at 0 degrees
> that will make it through a polarizing filter set at X degrees is [COS
> (x)]^2; and if x = 30 DEGREES then the value is .75
>
Here is where your analogy breaks.  (COS(60)^2)/2 != COS(30)^2 !=
2*(COS(60)^2).  So you can have full alignment at 0, 75% at 30 degrees, and
0 at 90; 60 degrees is neither 50% nor 25%.  This is not a direct
consequence of quantum mechanics (save for the distribution of photons) or
hidden variables, but rather how cosine is a non-linear function.

Further, your original example assumes that because 12 o'clock and 2
o'clock differ by a certain amount, that 2 o'clock and 4 o'clock must
differ by the same amount.  That does not have to be the case.  If 12
o'clock represents perfect alignment with polarization, then 2 o'clock does
not represent perfect alignment.  The lookup table for 4 o'clock can be
more different from 2 o'clock than 2 o'clock is from 12 o'clock.
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