, 18 August 2016
For many of us, tying shoelaces is something we learned long ago. And yet, a surprising number of people do their shoelaces incorrectly! So how can you tell, and how do you fix it? Read on to find out!
Don’t worry about doubling up the bow – if you do your shoelaces properly, they shouldn’t untie themselves!
Bows are probably the most commonly tied knots in the world. Millions of people tie their shoelaces in bows every single day. But it’s not surprising that many people miss-tie their laces. To understand why, it helps to look at some simpler knots.
A miss-tied bow is very similar to a granny knot. You can tie a granny knot by simply doing the first step of a bow twice. A granny knot is twisted and wonky, and it doesn’t hold well. To improve a granny knot, you can mirror the second knot – go right over left and then left over right. This is a reef knot, which is straight and much stronger.
So why is a granny knot wonky and a reef knot straight? It has to do with symmetry. A reef knot is very symmetrical, because the second part of the knot is a reflection of the first. In a granny knot, each half-knot twists slightly, making one big twist. In a reef knot, the second half twist counters the first, making the knot nice and straight.
If you’re after more maths activities for kids, subscribe to Double Helix magazine!
Tags:
18 June, 2019 at 6:47 pm
I can tie my laces in a reef knot bow, then tie the loops of a bow in another reef knot – and they will still come undone when I walk through blackberries 🙂
(recently found a fairly good solution to that though … not sure why I didn’t think of it years ago … tie the first half of the bow as normal, then, with a lace in each hand, reach around each side of my ankle and start again at the beginning and tie a bow at the back of my leg … much harder for the prickles to grab and undo them there – lol)