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Comment author: John1122 13 June 2008 02:13:10AM 1 point [-]

"So... I'm confused. You say:

"...the half-silvered mirror rule is "Multiply by 1 when the photon goes straight, and multiply by i when the photon turns at a right angle."

We appear to have defined everything needful, except the word "when".

Accepting that we are just performing 'operations' on 'configurations', what decides which operation will be performed? Is it the configuration of the incoming photon? Is it some magical (i.e.quantum) property of a half of a silver?" ~ Hendrik Boom

I feel the same way as above.

Comment author: mogwaipoet 30 December 2009 08:44:47PM 6 points [-]

My understanding is fuzzy, but the sense I get is that the word "when" just attaches to the possible configurations rather than being a condition. A rephrasing of the idea might be:

"Multiply by 1 for the configuration in which the photon goes straight, and multiply by i for the configuration in which the photon turns at a right angle."

Which results in two configurations every time, rather than different configurations depending on what the photon does.