Originally Posted by: snojones

These dots also mark where you can find harmonics.

That's a good observation! I've sometimes wondered if that is the reason for their placement. Those are some of the fundamental harmonics (musically the 5th, octave, 3rd). There are also harmonics at the 2nd, 2.6, 4th, 6th, 8th, 10th, but those are mostly duplicates or higher octaves of the fundamentals.