Archive for November 28, 2013

Pseudospheres Corner..

Posted in Cute Problems with tags , , , , on November 28, 2013 by telescoper

I’m sure you have all seen a knitted pseudosphere, but this is a particularly fine collection made by the excellent Miss Lemon and briefly displayed in my office this morning.


A pseudosphere is a space of negative curvature (whereas a sphere is one of constant positive curvature). There are various ways to realize a two-dimensional surface which has negative curvature everywhere; this knitted version is based on hyperbolic space. If you’re keen to have a go at making one yourself you can find some instructions here. I’m advised, though, that the better way to approach the task is to start out with a large circular ring onto which you cast about 400 stitches, gradually working your way in with fewer and fewer stitches (say 400,200,100,50 etc), which is much easier than working outwards as described in the link. The folds and crenellations are produced quite naturally as a consequence of tension in the wool.

Happy knitting!