Lots of people have pointed me in the direction of a book called ‘Crocheting Adventures with Hyperbolic Planes’. Actually I still haven’t bought the book but this week I decided to make one, and here’s how I got on.
I was surprised at how easy it was, really. I’ve known how to crochet, oh about a month, and I only used one stitch. I decided to make it in the round, because firstly I hate sewing up and secondly I knew if I was crocheting rows it would get more and more depressing as the rows became ever longer. Whereas in the round you just keep going!
So how do you make it? Well, start with 10 stitches. Join the round, and do 5 double crochets and then increase 1. Repeat. That’s it! Just keep going until you’re bored, or you’ve run out of wool, or it’s become unmanageable. I used cotton dk yarn for mine, and it turned out pleasantly weighty and dense, and it holds its shape nicely.
The idea is that the number of stitches in each row grows exponentially (it will double every 3 or so rows), so right out near the edge, where it’s really frilly, if you want to go to another point on the edge, it’s quicker to cut back through to the middle and out to the edge again than it is to go in a conventional straight line. So straight lines on a hyperbolic plane are curves. Hyperbolic geometry is really cool, actually, and models of hyperbolic planes are really pretty. I really fancy making this design into a rag rug. Watch out for hyperbolic homewares!