For more than 40 years, Oliver O'Reilly's shoelaces have been coming untied pretty much every day. And for most of those 40 years O'Reilly didn't think too much about it.
But then, about a decade ago, his daughter Anna was learning to tie her shoes, and O'Reilly decided his shoelace problem wasn't worth passing on to another generation.
"I didn't want her to inherit my problems, so I went online and found some really helpful videos to teach me how to tie her shoelaces," he says.
And, perhaps if O'Reilly had had a different job, that's where the shoelace problem would have stopped. But Oliver O'Reilly is a professor of mechanical engineering at the University of California, Berkeley, and as he looked at videos of shoelace knots, he started wondering why they came untied in day-to-day life.
"That problem always stuck in my mind," he says.
Now, he and two graduate students have published a paper, in Proceedings Of The Royal Society A, titled "The roles of impact and inertia in the failure of a shoelace knot."
http://www.youtube.com/watch?v=_-aiynIphTwhttp://www.scpr.org/news/2017/04/17/70853/untangling-the-mystery-of-why-shoelaces-come-untie/