Book describes double-slit experiment but does not explain it. I read that when I was student 20 years ago. So, WHY single particles are developing interferenc

Book describes double-slit experiment but does not explain it. I read that when I was student 20 years ago. So, WHY single particles are developing interference pattern when sent one by one? Shut up and calculate is not an answer: https://en.wikipedia.org/wiki/Double-slit_experiment#Copenhagen_interpretation https://en.wikipedia.org/wiki/Double-slit_experiment#Copenha... Just by looking at video, it's clear that interference pattern appears because of interference of particle wave with itself. It's also clear that speed of sound in water is constant regardless of speed of particle, particle cannot reach speed above speed of sound in water, speed of particle affects particle itself, and so on.