Monday, April 14, 2014

How to coil a hose

I just bought a hose to water the newly planted roses at our mountain house.  Here is one Nicoletta planted last year:

The hose came rolled so:
After unrolling it looked like this:

and no water issued. This is a well-known problem in mountaineering, sailing, in the storing of electrical cables etc.
They recommend that you coil rope/hoses/cables either like:
or like this:
A simple calculation in the braided monoidal category of tangles shows that these expressions are equal to the identity braid (whereas the expression of the first is the composite of 2n twists).

You may have noticed that I have not blogged for months. That is because the family has had a sequence of serious illnesses over the last two years. The last was the most stressful.

I hope we are back to a period of tranquility.



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