An Australian mathematician has solved a problem that has confronted generations of youngsters and stumped a few adults — lacing shoes. Most people use the criss-cross or the straight lace technique but Burkard Polster, of the Monash University in Victoria, Australia, has shown that although they are the strongest, neither is the most efficient method.‘‘We demonstrate mathematically that the shortest lacing is neither of these, but instead is a rarely used and unexpected type of lacing known as bow-tie lacing,’’ Polster said. The bow-tie technique uses all of the shoe’s eyelets but the least amount of lace.Bolster incorporated friction, eyelet alignment and the material of the laces in his equation, but he doesn’t expect his findings to change the way people lace their shoes. ‘‘For me it was a fun, quirky problem to think about for a while,’’ he said.Polster’s preferred method is the criss-cross, although he does admit to sometimes straight lacing one shoe and criss-crossing on the other. But he has no doubt about the best knot to use.
