Wednesday, August 20, 2008

Crocheted science

So is crochet so divorced from science?

Sometime back I read an article in the New York Times where mathematicians have used crochet to create hyperbolic plane. I did not save the article but you can find Daina Taimina's work here. She is a mathematician at Cornell University who has been working with crochet to create mathematical shapes (is this the correct term?)

There is one more article on the same vein but by a different group.

I am not an expert crocheter in the sense I hardly ever create my own patterns. But then I do not ever create patterns for cross-stitch or knitting. So in a sense I can copy patterns but cannot create one.

But for the past few years I have been facing dilemma. Essentially I teach the structure of DNA to the first semester M.Sc students. The first year I taught the course a bright young Chinese student asked me why if DNA is like a ladder then how does it form major and minor groove. It was something I had never pondered on. So I thought a lot about it, read few articles and found out that DNA is actually asymmetrical. Duh! of course. It is just I had never thought about it but had absorbed the notion.

Anyway, ever since that day I try to impart this knowledge to my students but it is extremely difficult for the students to visualize a symmetrical ladder and what would happen if it was twisted like the DNA. Whenever I would quiz them on this point later in the exams I would get varied answers clearly indicating that it has not penetrated their understanding.

So this year I fell back on crochet. It is fairly simple to create a ladder in crochet. You just make a chain say of 50. Then do a row of double-crochet (or a treble crochet depending on which nomenclature you follow). Do another row of the same on top of the first row and end. You will have a ladder. While making the ladder you will observe that the ladder twists much like a DNA would. It is natural consequence. You can also count the number of rungs between each twist. I was delighted to find that it approximates 10- the same number as in a DNA helix. And finally you will not find any major and minor grooves because all the bond angles (so as to speak) are exactly the same.

The class was in whoops when I pulled out my crocheted ladder. I think I have managed to get the point across. It would have been nice if I had an asymmeteric crochet ladder. I have to think how to crochet such a ladder.

Oh, the best part of it all was when a girl came up and asked me whether she could have the DNA ladder I had made. She said she wanted to try it out at home and see if it really would work. Now, that was the best reward of all.

3 comments:

Suresh said...

knitting and crochet involve geometry and topology and hence are related to mathematics. Do a google search for "mathematics knitting" and you'll find quite a few links. Your idea of using crochet to illustrate the structure of DNA is nice. Incidentally, a search for "mathematics DNA" throws up quite a few links too; some may be relevant to you.

Rohini Muthuswami said...

It is amazing that for someone who took Chemistry just to avoid Math, how much of it I am ending up doing! Both of my recent papers quite a lot of mathematical derivation that I am stunned at the very thought.

Thanks for the tip. I should do the search and see what is relevant to me.

Arvind Narayanan said...

math being just a formulation of thinking, you can't really avoid it if you're doing science :) it's like the air we breathe.