I had woken up at 5am to work the day shift from 6:15am to 6:15pm, so got home at about 6:45, fed the cats, ate some toast and a sandwich and then hit the road again. The journey up was nice and easy, though something seemed to give the car a heck of a whack at some point. (I probably just ran over a large twig.) Entering Newcastle by the A184 and across the Redheugh Bridge is surprisingly easy and surprisingly logical. Newcastle also have a very visitor-friendly policy of making the council-run car parks free after 5pm, of which I approve. I picked the Eldon Garden multi-storey car park and got slightly panicked by a sign suggesting it closed at 10pm.
I got to the Charles Grey pub shortly after 8pm and wandered around until I found some stairs that led to another floor with, among other things, a triple table of people writing things and a Rubik's Cube. This seemed likely to be the right one, so I nipped back downstairs, picked up a drink and eventually found a gap at the tightly-packed table. People did seem somewhat caught up in their conversations and activities, but the guy in charge said "Well, I was hoping to try a card game about set theory at one point..." so I said I was interested.
He later described it as being a game about Abelian groups. It's a long, long time since I studied set theory, and the only thing I remember about Abelian groups is that - all together now - as maths' one good pun goes, they're purple and commute. While the game is effectively based around an Abelian group as promised, describing it as such is possibly not the best way to sell the game, even among maths-friendly folks; the game might more simply be described as being about modulo arithmetic. It's actually rather fun, if not a little mind-bending, and called Mad Abel.
The game was played with the Ace to Five of each of four suits. Each card was given, effectively, two orthogonal values; a pip value from 1 to 5 according to its rank, and a suit value from 0 to 3 according to its suit. You add together two or more such cards by taking the sum of all the pip values, modulo 5, and the sum of all the suit values, modulo 4.
Now there are 24 possible ways to biject the values 0 to 3 to the four standard suits, and one of them is much more intuitive and easy to learn than the others. Courtesy of David Parlett's Ninety-Nine, a diamond (♦) has the 0-nature because it looks like a 0, a spade (♠) has the 1-nature because it has one point, a heart (♥) has the 2-nature because it has two cheeks and a club (♣) has the 3-nature because it has three blobs. Unfortunately, this was not the bijection we used in practice, which made figuring out the addition patterns of the suits much slower.
Anyway, each player starts with a hand of four cards and two of the remaining cards are displayed face up. The value of these cards is added together. For instance, the 2 of hearts plus the 4 of clubs add up to a total pip value of 2 + 4 = 6, which is 1 modulo 5, and add up to a total suit value of 2 + 3 = 5, which is 1 modulo 4. Accordingly, they add up to the card with a pip value which is 1 modulo 5 and a suit value which is 1 modulo 4: the Ace of spades. (The Ace of Spades! The Ace of Spades! ...ahem.)
The player whose turn it is then plays as many or as few cards from their hand as they like, with the stipulation that the sum of the cards played must match the required total. If the active player cannot play, then they draw two more cards. If they do play, they specify in which order they play their cards, so that the two cards most recently played are to be added together and provide the target for the next player. The first player to play all their cards wins. If you like modulo arithmetic, it's a fun game.
A few of you, half a lifetime ago, might be in the position to compare this with the sort of fun we had at the Invariant Society... or, specifically, when we were hanging around chatting after the lectures finished. Based on a tiny sample size, I think it would be fair to say that there was more maths actually going on here than used to happen there, or perhaps my experience of the Invariants tended to err on the passive side. It would probably not be unfair to raise that same comment about my experience of maths at university in general.
An issue MathsJam meetings face is trying to set the level of assumed mathematical experience to something that is sufficiently accessible not to be off-putting, but sufficiently toothsome to be of interest to the participants. There is no subjectively correct answer here, as the clientele varies from meeting to meeting. I wound up also trying a couple of pencil-and-paper problems from a schools' contest, and my geometry and trigonometry are really, really rusty, and my algebra is not what it was. In truth, I'd probably consider it a fairly tight mathematical contest between my 13-year-old self and my 36-year-old self of today, with my 14- to 21- year old selves leaving us both firmly in the dust. This was quite uncomfortable at times, though the fault was purely my own, rather than being that of the MathsJam meeting or other people there.
There were about a dozen or so people there (see this photo of the throng), mostly current students, but a couple of faculty members and possibly a couple of other non-academics as well. I didn't get the chance to speak to very many of them outside an actively mathematical context, but they were impressive, enthusiastic and remarkably far from cynical. Many - most? - of them were from Durham, which leads me to believe that the Durham Uni Mathsoc is likely flourishing. Good for them! I also enjoyed getting to meet guest star Matt Parker, whose brand of comedy leads him to style himself a stand-up mathematician.
I had brought a set of octiamonds, which I considered unusual and fun. Unfortunately, people started playing with them fairly late, and mindful of the 10pm garage lock-up time, I did not properly allow time to put the octiamonds back away. Accordingly, I swept them into my bag, but may well have lost one on the floor; certainly 66 octiamonds went out, 66 octiamonds were still there just before I started to get them ready to come home, but only 65 octiamonds have made it home. (I'm missing a number 14.) Sulk. My fault and nobody else's, though I fear it will be very hard to replace.
All told, an entertaining evening. Slightly awkward in parts, as I was so different from the majority of the clientele, and frankly a little out of my depth. (Never nice to have the truth brought home.) Still, not more awkward than you would expect - or, considering this was the first time I had been there, and people had been drinking and talking for over an hour that day and up to half a dozen sessions previously, only about as awkward as you'd hope.
If part of the MathsJam mission is to bring something of the university maths society feel to a slightly wider audience, perhaps there is some scope to work on outreach and accessibility, to ensure that newcomers are absolutely made to feel welcome and can contribute and participate at their level... whatever it might happen to be. This is a fairly self-selecting audience but if it is to cope with the amateur (and the word essentially comes from the Latin verb amare, to love) as well as the academic and thus professional, whether student or teacher, then thought and preparation may be required.
Nevertheless, I had a good time and was glad I went. The schedule is regular, though the monthly frequency is not demanding. The journey is just long enough, especially after a long day shift, to give me pause for thought - and, cynically, wonder whether the event might be better-suited still to be held in Durham if that's where so many of the students are based. I certainly enjoyed myself and look forward to getting stuck into further MathsJam in the future.
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