## MathsJam 2011

This post is a VERY long overdue one… I had meant to write a post after the (very first) MathsJam conference in November 2010, then after the first few Edinburgh MathsJams… We’ve now had the second national MathsJam conference and 5 Edinburgh ‘Jams so it’s about time I told you readers what it’s all about!

Balloons at MathsJam 2010

In a nutshell, MathsJam is a place for people to meet to share mathematical puzzles, games, toys, ideas, stories and tricks. It was originally the brainchild of Colin Wright, who organised the first ever MathsJam conference last year, bringing together geeky enthusiasts from all over the country for a weekend of mathematical fun. We had Rubiks cubes of all shapes and sizes, mathematically folded balloons, mirrors, Klein bottles, magic tricks, soma cubes, post-it note dodecahedra, vortex cannons… And that was just the list of physical toys! I also learnt facts like:

• Round pegs fit into square holes better than square pegs fit into round holes…until you get to 9 dimensions!
• Almost every integer contains a 3.
• That given 5 numbers, you can always find 3 of them which add up to a multiple of 3. (But what is the generalisation?)
• That there is only one number whose spelling is in alphabetical order. (Can you find it?)
• That a blindfolded person given an even number of coins, placed on a table so that half are facing heads up and half are facing tails up, can separate them into two piles so that the number of heads in each pile is the same.
• That you can work out the distance to the moon using only a pendulum.

The weekend was such a success that people started asking “Can’t we have a MathsJam every month?”. Pretty soon there were ‘Jams in Manchester, Nottingham and London with Edinburgh, Glasgow, Reading, Liverpool, Newcastle, Dorset, Leeds, Bath, Dublin and Belfast following on their tails.

Attempting topology at the August Edinburgh MathsJam

Everyone meets on the second to last Tuesday of the month and we have a shared Twitter account, @MathsJam, so that everyone can see the puzzles being worked on around the country. The Edinburgh ‘Jam was set up by myself and Ewan Leeming, and we meet at Spoon Café Bistro on Nicholson Street. Further details are on the MathsJam website, together with an email address and Facebook page, and also contact details for all the other ‘Jams around the UK (and indeed, the world!).

This weekend I travelled down to somewhere near Crewe for the second annual MathsJam conference, together with my buddies Albert, Julia and Michael. I was very excited about all the toys and games I’d get to play with, but at the same time incredulous that the weekend could possibly be better than the first MathsJam weekend. Well, I shouldn’t have had any such thoughts.

Albert wearing his ring-on-a-chain

One thing I loved about this year’s conference was the chance to purchase goody bags with exciting toys to take home and show friends. Last year I shot some videos and got photos, but nothing compares to being able to go home and show your friends in person the amazing things you’ve seen. My favourite was the ring-on-a-chain trick (pictured left) where a ring is dropped from a chain with unexpected consequences. Next favourites the falling rings and James Grime’s amazing non-transitive dice.Maths and science is much more cool than sleight-of-hand magic. 🙂

Here are some pencil and paper questions you might like to get your teeth stuck into (metaphorically speaking):

• A consecutive sum is a sum of consecutive digits. Are there any numbers which are not consecutive sums? How many ways can a number be written as a consecutive sum?
• Why is 100/81 equal to 1.2345678…?
• How can you cut any shape out of a piece of paper using only one cut?
• Does a running sand timer weigh more, less or the same as a finished sand timer?
• How do you make 2 paperclips link together using a strip of paper?
• Given that we can make a regular pentagon by tying a knot into a strip of paper, is it possible to make a dodecahedron by folding 12 knots into a piece of paper and then folding it up?
• How is it possible to randomly play two games, each of which would individually lose you money, and make an overall gain? (This is called Parrondo’s Paradox.)
• Split the numbers 1,..,16 into two sets X and Y so that the sum of the elements in X equals the sum of the elements in Y; the sum of the squares of X equals the sum of the squares of Y; the sum of the cubes of X equals the sum of the cubes of Y. (I am currently working on a generalisation!)

Plus I learnt  that a 9999-sided polygon is called a nonanonacontanonactanonaliagon. (This seems to be the most popular thing I have ever posted on Twitter.) I encountered Pat Ashforth, one of the founders of Woolly Thoughts, who showed me her dragon-curve blankets and crocheted hexaflexagons. I also saw a magic square that worked upside down and some Platonic solid maps of the world.

Dragon curves and other mathematical knitting by Pat Ashforth

A magic square cushion which works both ways up

Julia found herself on the panel for the Math/Maths podcast, which you can listen to here,with contributions also from Matt Parker, James Grime and Katie Steckles. The laughter on the podcast is a really good reflection of the fun that everyone had at the MathsJam, and once again I have to extend a huge thank you to Colin and all the other people who helped to organise the event this year. There’s no other conference in the world which is this enjoyable and it is wonderful to see so many people enjoying the fun and beauty of mathematics.

If you’ve never been to a MathsJam, I hope this article persuades you to go along to the next one on 22nd November! They are all over the country now so there’s bound to be one nearby. And if there isn’t, start one up yourself! All you need is a pub and a couple of people willing to come sit with you on a Tuesday evening. I look forward to seeing more people MathsJamming in Edinburgh in a week’s time!