Archive for knitting

Knitted Omnibus

Posted in Uncategorized with tags , , on September 21, 2017 by telescoper

The inestimable Miss Lemon, who occasionally operates under the pseudonym Dorothy Lamb, has sent me a picture of her latest knitting exploits, i.e. two buses in the livery of the Brighon & Hove Bus Company!

They add a whole new meaning to the term `bendy bus’!

To find out what inspired these contributions please see related the University of Sussex news item here.

Achilles and the Tortoise(s)

Posted in Uncategorized with tags , , , on January 16, 2015 by telescoper

The inestimable Dorothy Lamb has yet again been doing her bit for our outreach effort here in the School of Mathematical and Physical Sciences at the University of Sussex. Charged with the task of coming up with some props to explain Zeno’s Paradox to schoolchildren. One famous version of this paradox features in the form of a story about Achilles and the Tortoise:

Achilles, the fleet-footed hero of the Trojan War, is engaged in a race with a lowly tortoise, which has been granted a head start. Achilles’ task initially seems easy, but he has a problem. Before he can overtake the tortoise, he must first catch up with it. While Achilles is covering the gap between himself and the tortoise that existed at the start of the race, however, the tortoise creates a new gap. The new gap is smaller than the first, but it is still a finite distance that Achilles must cover to catch up with the animal. Achilles then races across the new gap. To Achilles’ frustration, while he was scampering across the second gap, the tortoise was establishing a third. The upshot is that Achilles can never overtake the tortoise. No matter how quickly Achilles closes each gap, the slow-but-steady tortoise will always open new, smaller ones and remain just ahead of the Greek hero.

Anyway, we now have a splendid knitted Achilles along with not one but three lovely tortoises…DSC_0035

Achilles is a bit short in the leg, although I suppose that doesn’t necessarily mean that he can’t be fleet of foot, and we had to prop him up against the wall lest he should heel over, but nevertheless I think these are great. Could this be the next big thing in toys for mathematically inclined students?

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.

IMG-20131128-00223

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!