hyperbolic planes! and yarn

I'm not a crocheter, but I'm learning the basics. I've been crocheting hyperbolic planes. A professor at Cornell originally discovered this possibility - there's more info here. I had the good fortune of hearing her speak at Carleton this spring. There was an exhibit of her work in the library during the term, and she came to campus towards the end of the term to talk about it. I feel like I grasp the concept of hyperbolic planes a bit more now. What made it make more sense to me was this description: a sphere has a constant positive curve, right? Well, a hyperbolic plane is the opposite: it has a constant negative curve. It's the opposite of a sphere. (What I don't get is why the *inside* of a sphere isn't the opposite of a sphere, but I guess technically a sphere doesn't have an "inside.") Anyhow, her site explains how to crochet a basic hyperbolic plane, and I found another site (here) that shows examples of other varieties with basic instructions on how to crochet them.

This is one of the "hyperbolic version of a cone" variety that I crocheted. It's about 8" across (but that darn chenille yarn won't stay woven in...):



Also, I worked today on some yarn that I'd spun and plied before; I hadn't been incredibly happy with how it came out, colorwise. I'd been trying to make another skein like Sunshine & Violets, using more of the same roving. If I'd even bothered to look at the picture, I would've remembered that I alternated yellow and lavender in the same single, plying that with a single of dark purple. Instead, this time, I alternated the two purples and plied them with yellow. Didn't like that quite so much. But I pulled out a ball of green yarn I'd spun and some black crochet thread, plied the two of those together, and plied that yarn with the yellow-and-purple one. It came out like this:



The color is kinda off (grr, why does Photoshop keep giving out on me?) - the blanket is a definitely green, not blue; and the yarn is a deeper color throughout than it appears in that picture.

Anyway, I like it much better than the original, and I think I'm going to try making a scarf out of it now!