1. The problem statement, all variables and given/known data If the phase of vibrating sources was changed so that they were vibrating completely out of phase, what effect would this have on an interference pattern? 2. Relevant equations n/a 3. The attempt at a solution This question undermines my understanding of interference, 2 sources in phase of equal wavelength will cause both destructive and constructive interference, the pattern consists of a constructive band m=0, 2 destructive bands n=±1, 2 constructive bands m=±1 etc. I thought that constructive/destructive interference all depended on the existence of a point of distance x from each source (the waves could overlap or be shifted by ∏/2 rads along the x axis) My question to you, physics people is: is this question viable, how will the interference pattern change if the sources are completely out of phase.