sci.physics.research

On Thu, 9 Aug 2007 16:55:02 +0000 (UTC), Benjamin wrote:

> a student wrote:
>> On May 28, 10:20 am, Benjamin wrote:
>>
>>>a student wrote:
>>>
>>>>A very quick readthrough appears to give a contradiction in their
>>>>model. Look at Eq. (13), defining a set of joint probabilities P'.
>>>>The righthand side of this equation, summed over the + and - symbols
>>>>clearly sums to 1
>>>
>>>Sorry, but I do not get 1!
>>>At least when I put this in mathematica....
>>
>>
>> Why use mathematica?....
>
> Dear a student,
> after I saw the problems you have had with these equations (which I did
> not have, of course since I thought it was clear what they do there), I
> asked the authors to clarify this in their eprint and they seem to have
> done this.
>
> There was simply a typo and too much "shortening". The misconception you
> seemed to have might have been arousen because they omitted a quick
> manipulation one can do in a single line (or in ones head) due to keep
> tha paper short.
>
> The senior author was a professor emeritus who seemed to like feedback
> about the preprint which is (as he wrote in his answer to me) a draft
> for a paper to be sent to phys. rev. A.
>
> But he wrote, that he wants more reports before he will send it to the
> journal in the next months. Because of sending it to phys rev he wanted
> to keep it as short as pssible and that was the reason for this
> forgotten line).
>
> Well, they have updated it and still, I cannot find any error.
> It has now a version 2:
>
> /abs/

Consider the case where the polarizers are in the same direction. Then the
polarization of the two photons will be measured to be the same. Using the
authors' notation, the joint probabilities are as follows:

P++ = 1/2
P+- = 0
P-+ = 0
P-- = 1/2

The conditional probabilities for the polarizations of photon 1 given the
polarization of photon 2 are:

Pc++ = 1
Pc+- = 0
Pc-+ = 0
Pc-- = 1

Thus the expressions in Equations (12) and (16) should be equal to 1 and 2,
respectively. However, the formulas given in the paper (Eq. 11 and 17)
yield 1/2 and 1, which is only half the observed correlation. Thus their
model is empirically falsified.

--
Jim E. Black