Two points circle at different speeds. Change ratio of speeds for different patterns (known as Lissajous figures). Shows that two circling points is enough to generate Lissajous patterns of coupled harmonic motion. No need for sine functions.
Pen matches the X position of circling point A and the Y of point B. B moves at A's speed times the ratio of circling speeds. This generates a type of harmonic motion that creates Lissajous figures. Usually the presentation of Lissajous is complex, with sine or cosine functions, but the underlying principle is simple. Two circling motions can generate these Lissajous patterns.
