Configuration “A photon going from A toward 1”: (0 + -i)
Configuration “A photon going from A toward 2”: (-1 + 0i)
Why does the bolded configuration still exist in the same way? Shouldn’t it go back to zero once the photon has reached A, since the rest of the post seems to imply a timely order of things?
It basically states that in order to calculate the amplitude of a photon going to 1 is a product of the amplitude of it going to A and then from A to 1. So we do need to remember what the amplitude was for a photon going toward A.
There is one thing that confuses me about this post, which I haven’t found in any of the comments
Why does the bolded configuration still exist in the same way? Shouldn’t it go back to zero once the photon has reached A, since the rest of the post seems to imply a timely order of things?
silver, check out rule #3 for calculating probability amplitudes:
https://en.wikipedia.org/wiki/Probability_amplitude#The_laws_of_calculating_probabilities_of_events
It basically states that in order to calculate the amplitude of a photon going to 1 is a product of the amplitude of it going to A and then from A to 1. So we do need to remember what the amplitude was for a photon going toward A.