If a photon hits two full mirrors at right angles, then its amplitude is changed by i*i = −1. Does it matter whether the second mirror turns the photon back towards its source, or causes the photon to continue in the direction it was going originally? Do you get −1 in both cases?
If a photon hits two full mirrors at right angles, then its amplitude is changed by i*i = −1. Does it matter whether the second mirror turns the photon back towards its source, or causes the photon to continue in the direction it was going originally? Do you get −1 in both cases?