About the path sum in the interference pattern of a wave field generated by two coherent point sources

In the paper the character of the phase relationships between oscillations at different points of the wave field generated by two coherent point sources is discussed. It is shown that on the surfaces of the maxima and minima of the amplitude, the in-phase or anti-phase of the oscillations is determined by the multiplicity of the path sum to the wavelength. The locations of the phase points in the interference pattern were defined.