Lissajous Interactive 2.21

Jules Antoine Lissajous [..] was a French physicist, after whom Lissajous figures are named. Among other innovations, Lissajous invented the Lissajous apparatus, a device that creates the figures that bear his name. In it, a beam of light is bounced off a mirror attached to a vibrating tuning fork, and then reflected off a second mirror attached to a perpendicularly oriented vibrating tuning fork (usually of a different pitch, creating a specific harmonic interval), onto a wall, resulting in a Lissajous figure.
[wikipedia - en]
Change x and y-speed by slides on the rulers.
Special thanks to 
> mattgig <
for some code and inspiration
Danke schön!