purplecat: Hand Drawn picture of a Toy Cat (Default)
purplecat ([personal profile] purplecat) wrote2010-12-05 08:36 am

Hyperbolic Plane, Negative Curvature 5:6

Mum bought me Crocheting Adventures with Hyperbolic Planes for my birthday. I have just finished chapter 1 (go me!!!)







The curvature of a surface is a measure of, well, how curvy it is. Most curved surfaces have positive curvature, turning them into spheres or ellipsoids and the like. If a surface has negative curvature you end up with, well, a frill, which is what I crocheted above by the cunning device of adding in an extra sixth stitch for every 5 on the row below (hence the ratio of 5:6).

This entry was originally posted at http://purplecat.dreamwidth.org/26700.html.

[identity profile] lukadreaming.livejournal.com 2010-12-05 09:28 am (UTC)(link)
I now know what positive and negative curvature is. Don't test me on the rest!

[identity profile] lukadreaming.livejournal.com 2010-12-05 02:29 pm (UTC)(link)
*Iz impressed*

OK! You are broadening my education no end *g*.

[identity profile] bigtitch.livejournal.com 2010-12-05 10:53 am (UTC)(link)
Excellent. I am impressed by anyone who can crochet - I can knit and tat, but have never got away with crocheting!