Here are two classic youtube videos on the topic of sphere eversion; they mostly overlap, but I am posting both for double the hilarity in the comment sections

Here are two classic youtube videos on the topic of sphere eversion; they mostly overlap, but I am posting both for double the hilarity in the comment sections :) (the full 21 minute one) https://www.youtube.com/watch?v=wO61D9x6lNY https://www.youtube.com/watch?v=wO61D9x6lNY (the first 10 minutes) https://www.youtube.com/watch?v=sKqt6e7EcCs https://www.youtube.com/watch?v=sKqt6e7EcCs If I remember correctly, I think the 10 minute one has the more hilarious comment section.