Spirograph 1

from Robert S Donovan @ Flickr

I have always loved Spirographs.  When I inherited my sister's I was in heaven - I think the exact box pictured here, supposedly from 1968.

Seeing this tumblr entry with an animated Spirograph picture when I had a few minutes sorta free, inspired me to finally put together a sketch.  So I thought I'd share it.  It's definitely good for experimenting to see if you can figure out what is going on.  Very fun to make.  The webpage lets you see the patterns, but doesn't give nearly the control that the GeoGebra file does.  It succeeded insofar as you can make some pretty pictures, and I didn't have to cheat by parameterizing the curves..

I'm interested in developing some lessons on ratios that could be visualized in interesting ways with the curves traced. If you have feedback on the sketch or on the lesson idea, I'd love to hear it.

The View menu should allow you to refresh views in the applet below, but it can get hung up.  I sometimes have to click pause several times before it pauses.  As I said, on this one I recommend the GeoGebra file, if you're going to do any serious playing around.



Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)