BOB HIRSHON (host):
A knotty problem. I’m Bob Hirshon and this is Science Update.
Science Update listener Alan Dittrich of Wellesley, Massachusetts called us with this question:
Why do shoelaces become loose after they’re tied?
Dorian Raymer conducted knot research at University of California, San Diego. He says the problem with shoelace bows is that they’re terrible knots.
Sort of the purpose of tying a knot in a shoelace is so that later you can easily untie it without it being too difficult so that you can take your shoe off easily. It’s pretty much made so that it’s easy to come undone.
So they relax and fall apart from simple jostling. Fortunately, there are other shoelace knots like the double slipknot, that are both secure and easy to untie. Visit Science Update dot com for links to knot-tying videos, and while you’re there, send us your science question. If we use your question on the air, you’ll win a Science Update mug. I’m Bob Hirshon, for AAAS, the science society.