Google Classroom
GeoGebraGeoGebra Classroom

Circular Standing Wave

I read somewhere that electron orbits can be thought of as circular standing waves. This made me wonder how to draw an oscillating circle. Pretty simple really: you just superimpose a sine wave on the radius r of your circle. In polar coordinates: (for angle ω = 0 To 360 Step 0.3) x = (a sin(fω) + r) cos ω & y = (a sin(fω) + r) sin ω, where a is the amplitude and f the frequency of the sine wave. For a < r you get the expected ‘doily-look’ result, but for a > r you get orbits that remind me of the good old ‘spirograph’. Shown is r=2 a=6 f=3.