On 07/19/2003 08:56 AM, Robert B Zannelli wrote:
> To clarify, Bell State measurement is when two photons are made to
> meet at a half silvered mirror at the same time. Two detecters are
> set up which will detect the photons whether they are reflected or
> not.
There are many different experiments designed to
measure things related to the Bell Inequalities.
This particular variant is a new one on me, and
I suspect the description is incomplete and/or
garbled.
...
> Possibility 3 and possibility 4 are indistinguishable and put the two
> photons in an entangled state. Here's my question. It seems obvious
> that with this arrangement the probability that the two photons will
> become entangled should be .5. However it is not. It is actually
> .25. Could someone explain why this is so?
Usually the details of the production of the two
photons are crucial. You can't do it with just
any two photons.