Here& #39;s an amateurish claymation video I made in 2008 showing a topological magic trick. It shows that you can go from one of these configurations to the other without breaking a loop. https://www.youtube.com/watch?v=S5fPwE7GQOA">https://www.youtube.com/watch...

(It has a lot of downvotes because, given the title, many people thought they were going to see something else... not math. That& #39;s also why I had to turn off the comments.)