what is interfering with what?
It has been said many times already; the circular pattern is interfering with the pixel sampling grid. At the center of the ball, the frequency of the circular patterns are low and do not alias when you sample it at the discrete pixel locations. At the higher frequencies, the circular patterns do alias becuase you cannot capture the high frequency details with the low sampling frequency. That is where the interference patterns are coming from.
this is not dependant at grid resolution if you will have many times larger grid of pixels you will see a wide waves of color, grid is not more important for visualisation here as with normal bitmap thing - it does not produce the effect only downsamples it - so i still not see where is interference here i do not see it, the image isa an effect of colouring not
intefrerention (image as i said is 'downsampled' but this is the same like when for example mandelbrot set visualization or raytracing images visualisation)