In June of 2005, someone, I know not whom, left an envelope for me at a coffee shop I frequented. Inside the envelope was an article by Elizabeth Svoboda titled “A Mathematical Yarn” published in WIRED in June of 2005. At that time, I was between jobs, and when I was not studying to take the Praxis II so that I could become eligible to teach middle school math, I drank coffee and crocheted. Whoever it had left the envelope, had correctly surmised that the article would be of interest.

So, with a 3.25mm hook Red Heart Kids yarn in hand, I began experimenting with hyperbolic planes crocheted around a point. I used a half double crochet stitch rather than a single crochet stitch, as using the half double made the curves of the plane come more quickly. After some practice, which included both failures and successes, I began to lay an additional strand of yarn across the stitches I was crocheting over to give the planes made from the more pliable half double crochet stitch a bit more structural integrity than they would otherwise have.

Eventually, I assembled the six planes shown below onto a length of chained yarn and hung either end of the yarn chain from two points such that the the planes formed a catenary curve that I came to term “hyperbolic swag.”

So, a special thank you to whomever it was who left that envelope for me.