Click the buttons to increase or decrease the numbers of the lines, its fully interactive!

I inspired this effect from a video by brusspup. However, when I search for the video I found the illusion was actually created by Arthur Shapiro and Alex Rose-Henig unfortunately I couldn't find the original paper. Circles within a larger black circle (actually I coded it into a rectangle). The inner circles in turn seem to form a circular shape that's rolling around the inside of the larger circle. But, believe it or not, the direction that each circle is linear, not circular.

To me, after 5 circles the illusion is starting. Increasing or decreasing the radius of the circles or animation speed didn't affect my perception. However, you can try it and see what happens.