Love it! I'm fascinated by all things Spirograph and built my own digital version of the more traditional toy here: <a href="https://nathanfriend.com/inspiral-web" rel="nofollow">https://nathanfriend.com/inspiral-web</a>
I also once got distracted by Spirographs. We got a Spirograph kit for our kids one Christmas, so I spent some time during the holidays writing a python package to draw them. Nothing fancy, just uses python’s built-in turtle graphics.<p><a href="https://pypi.org/project/spiro/" rel="nofollow">https://pypi.org/project/spiro/</a>
Fascinating. The heliocentric view made me wonder: how are we going to cope, culturally, with Mars colonists when they are stuck on the other side of the sun for two weeks every two years?<p>The <i>Red Mars</i> books deal with the bonus half hour every night neatly, as a social phenomenon — Martian days are 24.5 hours long — but I don’t recall the solar occlusion coming up.
I knew that Venus mostly moves in one direction across the sky, but occasionally has "retrograde" movement where it temporarily moves "backwards". This spirograph model is a wonderful explanation of why that happens.