Two blog posts in as many weeks? “Is something wrong with you Haggis?”, I hear you asking. No, I am just still caught up in all the Fringe excitement, plus the fact that it’s all change at home. I have myself a new flatmate, Jacqui, who is a final year vet student and who has already been teaching me plenty of interesting things. This week I have learnt about horse anaesthesia, why you can’t turn cows upside down (they apparently blow up because they can’t burp) and what a cat heartworm is. Fun fact of the day about sheep: if they roll onto their backs then they are unable to get back on their feet. Farmers have to regularly inspect the flock and give a push to any unfortunate animals in this position, or else they will die!

Yesterday afternoon I was very delighted to meet with James Grime, who works for the Millennium Mathematics Project as the Enigma Project Officer. This involves touring the country (and sometimes other countries!) to tell people about the Enigma machine and the part it played in helping the Allies win World War 2. The Enigma machine was a German contraption to encode messages, and even when the Allies got their hands on the machine it was still very difficult to crack the codes. In the end, it was a little foolishness on the part of the Germans that provided the key. They were signing all their messages with “Heil Hitler”, so because the British knew how to decode the last two words of the message, they were able to find the key for the rest of the message too. If the Germans had ever stopped signing their messages, then it is unlikely that we would have been able to read their secrets (especially since the code changed every day!).

James (alongside Matt Parker, Colin Wright and Rob Eastaway) is also part of the organising committee for the MathsJam. No, it is not a numerological toast spread, but a weekend of getting down with some jiggin’ maths puzzles. Deep down it is a tribute to the legend Martin Gardner, who was a puzzle writer for *Scientific American* for 25 years and a great populariser of recreational mathematics before his sad death in May this year. Here’s a statement about what the MathsJam is about, from the website itself:

“The MathsJam is an opportunity for like-minded self-confessed maths enthusiasts to get together and share stuff they like. This can be puzzles, games, problems, or just anything they think is cool or interesting.”

You don’t need to be a professional mathematician to come along; you just need some enthusiasm for fun maths problems! Julia and I have already signed up (partly to get the ‘earlybird’ 10% off deal) and we are going to take along a problem which has appeared in Julia’s thesis. There is a particular knot which may or may not be slice. In fact, it is the only knot out of nearly 3000 specimens whose sliceness is unknown. If it **is** slice, then we should be able to find some special ‘moves’ on the knot picture which proves it. If it **isn’t **slice, then the mathematicians should be able to spot it using some complicated algebra. Since the mathematician haven’t spotted anything, it seems reasonably likely that the knot is slice, and a bunch of dedicated puzzle enthusiasts may well find the right moves to show it! I’ll write more details about the problem in November when the MathsJam comes around.

Ooh, one more thing I mustn’t forget to mention. Over the summer Julia has been busy re-learning how to crochet and, in particular, learning how to crochet a hyperbolic plane. The instructions are very easy once you know the basic crochet stitch. For her project, she started with 20 stitches, and then for each new row she added a new stitch after every five. So in the second row there were 24 stitches, in the third row 28, and by the 26th row there were 2290 stitches! Here are some pictures of the finished product:

The amazing thing is that there is as much light green as dark green wool! Well, it might not look so amazing in that second picture there, but it is very counterintuitive when you see the thing in person. And why is it called ‘hyperbolic’, you may ask? Well, there are three different kinds of spaces: ones where angles in a triangle sum up to exactly 180 degrees, ones where they sum to more than 180 degrees, and ones where they sum to less than 180 degrees. You should all be familiar with the second kind of space, because you live on one! (Yes, spheres.) But what does the third kind of space look like? Well, exactly like the crochet above! I will try to write another blog post shortly which goes into more detail about this.

For now, enjoy the pretty pictures, enjoy the last few days of the festival, and make the most of that remaining summer sunshine!

Posted by lns on October 7, 2010 at 3:05 pm

Oh, what a lovely crocheted hyperbolic plane! Two days ago, out of curiosity, I knitted a Fibonacci sequence (well it’s first eleven numbers) and it looks very very very similar… I’m now using it to knit anklesocks with a Fibonacci Frill… iirc, it involved casting on 365 stitches to end up with 35 at the turnover, but it’s worth it for practical applications of pretty numbers, isn’t it?

lns

Posted by haggisthesheep on October 8, 2010 at 12:29 pm

That sounds like a great idea! You should take photos and post them online when you’re finished!

– Haggis