Knitting reinvented: Mathematics, feminism and metal
For some people knitting is an ancient art, one they saw their granny do and one, because it takes so much time, that seems to have little relevance for the modern age.
But there are growing numbers of people reclaiming the craft and trying make it evolve.
Dr Sarah-Marie Belcastro uses knitting to explore the mathematical concepts that she uses, encounters and thinks about every day.
She is not alone.
Many knitters try to reproduce mathematical concepts in wool to stretch their skills. Some, such as Brits Pat Ashforth and Steve Plummer, use it as a teaching aid.
Why? Because, Dr Belcastro said, the thinking required to turn a mathematical concept into a pattern, then into a finished knitted object forces a greater understanding of that shape, idea or object.
"Sometimes," she added, "turning a concept or object into a knitting pattern is often a mathematics problem on its own."
Take, for instance, the job of knitting a surface. As Dr Belcastro points out, surfaces are continuous unbroken sheets.
By contrast, knitting is discrete, being made up of individual stitches like the pixels on a TV screen.
"Converting a smooth curve into a knitted pattern is a math problem because one has to figure out where exactly to place the discrete changes in curvature so that the object as a whole has as close as possible to the desired smooth curving," she said.
Dr Belcastro got the idea to unite yarn and maths at college after having knitted on and off since childhood. As a left-hander, knitting had always involved more thinking, and frustration, than it did for right-handed people. But it also made her adept at knitting without patterns.
She now uses the skill to turn fiendishly complex mathematical concepts into woolly objects.
The most complicated object she has knitted might, to the uninitiated, look like a squashed hat, but mathematicians would recognise it as the "non-orientable surface of genus 5".
It represented, said Dr Belcastro, the connected sum of five projective planes.
She has since worked on an even more complicated object but is reluctant, so far, to give details.Metallic knits
Someone else stretching knitting into a 21st Century mould is crafter and maker Charmione Lloyd. She has kept the needles but dropped the yarn in favour of wire.
She uses very fine needles and narrow-gauge wire - 0.4mm thick to form rings, and 0.5mm thick to make bracelets.
The inspiration to use wire came about because she had seen another crafter using recycled copper coaxial cable to form part of a corset.
At the time Ms Lloyd had a big spool of fine wire sitting around at home and decided to see what she could turn it into.
"No-one else seems to have gone the same way," she told the BBC.
Part of the reason for that, she said, is because wire is not as forgiving a material as yarn or wool.
"I can only do so many before my fingers start to ache," she said.
"It's quite stiff and you have to work it quite a lot."
Knitting is going through something of a renaissance, said Ms Lloyd, its growing attraction is revealed by the success of local groups where knitters regularly gather.
What they get up to there is captured in the name of the meeting: Stitch 'n' Bitch.
At least, she said, that is what it used to be called. Some of the older women who attend objected to the name and now it is just called Knit and Natter.
A title, she said, which doesn't have quite the same anti-establishment ring.Feminist fun
The Stitch 'n' Bitch name is still used by other groups all over the world, from Israel to Thailand.
The first was established by New Yorker Debbie Stoller.
As a pastime, she believes, it is far more suited to the fractured nature of modern life than a casual onlooker might suppose.
She also thinks it deserves to be reclaimed because it has explicit feminist credentials.
It's not a view everyone shares, she said.
"If I had said I was into soccer, that would have been fine, but because it is knitting people look down on it," she said.
She believes knitting and other crafts should be reclaimed for exactly the same reason that feminists in the 1960s and 70s rejected them - because of their historical link to women.
Those early feminists tried to forge a new identity by setting themselves apart from such traditions.
But, said Ms Stoller, this missed the point that knitting was a hard craft to master and had played a social role.
"It's something that women have traditionally done and I went on a mission to take it back," she said.
Many have joined her. There are now more than 1,300 Stitch 'n' Bitch groups around the world, and many more that are as well established but have not taken that modern name.
For Ms Stoller, the most important part is that those people, men and women, young and old, have turned to knitting and found what it can do for them.
"In the same way that fishing is not just about getting something to eat, knitting is not just about making something to wear," she said.