fromwww.scientificamerican.com
2 weeks agoCan You Solve Math's Knottiest Puzzles?
Find a string. Really. Do it. Now twist, tie and tangle it as much as you like. Finally, attach the two loose ends of your string together to make a closed loop. (This is a crucial step.) What you hold in your hands is one of the most exciting mathematical objects of the 20th century: a knot. (Hopefully you didn't use your headphone wire.)
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