© Philip B. Yasskin, 2008-10.
Last updated Feb 15, 2010
Four people stand in a square holding the ends of two ropes. There are two movements: Two people on one side trade places or all four rotate around. As they move, the ropes get tangled. It turns out that each tangle can be assigned a rational number and if you know this rational, you can figure out how to untangle the ropes.
For more information, see the article by Tom Davis on
© Philip B. Yasskin, 2008-10.
Last updated Feb 15, 2010