## Sunday, 19 November 2017

### MathsJam

Here is my overdue post on last weekend's MathsJam gathering.  MathsJam is always a wonderfully exciting and enjoyable weekend, and this one was particularly good.  I can honestly say that I enjoyed every talk, and was entertained, surprised and educated in roughly equal measures.

I'm nervous about selecting highlights, because almost everything was a highlight, and my list inevitably leaves out many excellent talks. There is a list of all the talks on the MathsJam website but here are some I particularly remember (in the order in which they were presented):

• Simon's 3D-printed robot which solves Rubik's cube (time-lapse video shown here with Simon's permission);
• Matt on logical deduction games, which brought back memories of playing Eleusis when I was a student and introduced others I need to find out about;
• Noel-Ann on data and how to it can be represented (and misrepresented);
• Zoe's poem about e, which (understandably) seems to be on everybody's highlight list;
• Matthew's amazing recreation of a problem from Captain Scarlet about the bongs of Big Ben;
• Andrew's paradoxical balloon monkey, which although made from a single balloon, has an underlying graph which is not semi-Eulerian;
• Angela's poem;
• Rachel on spinning yarn;
• Alison on illogical units, and Dave on illogical scales;
• Will on non-binary cellular automata;
• Miles finding striking similarities between mountaineering and mathematics;
• Glen showing how many holes a constructed object (equivalent to a T-shirt) possessed (most of MathsJam seem to have got it wrong, going for four rather than three!);
• Paolo using a pack of cards to find two numbers from their sum and difference;

And of course the "extra-curricular" puzzles, games and magic, Tiago showing me how to tie a knot with one hand, and the spectacular mathematical cakes.

So once more a memorable MathsJam, with an excellent range of speakers and talks, friendly atmosphere and fascinating and surprising mathematics.  The organisers once again did an amazing job!

## Wednesday, 8 November 2017

### Looking forward to MathsJam

With only three days to go till the MathsJam Gathering - the best weekend of the year, I've been thinking of some of my favourite MathsJam discoveries. Sticking to pure mathematics, here are my memories of three gems.  I could have chosen many others, but perhaps because these happen to relate to my current teaching, and I showed two of them to my graph theory students immediately upon my return from the gathering, they are the first that come to mind.  Since I believe all MathsJam presentations are available online, further details should be readily available.

• Colin Wright's amazing talk on graph colouring, which started by asking us to complete a partially-completed 3-colouring of a small graph, and turned into a more-or-less complete proof, within a 5-minute talk, that there is no polynomial-time algorithm for 3-colouring a graph.
• Ross Atkins's talk about Braess's Paradox - a simple situation in which adding an extra road to a network, with no increase in traffic, results in longer average journey times.  I should have known about this counter-intuitive result so I'm very glad to have found out about it, and especially with the wonderful demonstration with a network of springs that showed a mechanical realisation of the paradox.
• David Bedford's "What's my polynomial?"  I love this because it is arguably what the late Raymond Smullyan called a "monkey trick".  David asked you to think of a polynomial p(x) with non-negative integer coefficients, and, for a single value of x of your choice, greater than any of the coefficients, tell him both x and p(x).  He would then tell you your polynomial.  Knowing that one needs n values to determine a polynomial of degree n, I was taken in by this!

I could have chosen many more examples: I'm certainly not ranking these presentations or any others. On another day I might have chosen a completely different set!  But I'm certainly looking forward to coming across more wonderful mathematics this weekend!

## Wednesday, 1 November 2017

### Black Mathematician Month

One of the best things to have happened for mathematics in the UK recently is the arrival of Chalkdust magazine - an exciting, witty magazine with a unique style.  (It's very different in feel from the equally admirable, and much missed, iSquared, which is happily preserved online.)

And the best thing that Chalkdust has done is the Black Mathematician Month which has just finished - a month of interviews, conversations and activities "promoting black mathematicians, and talking about building a more representative mathematical community".  The stories that were told were sometimes shocking, sometimes horrifying, often inspiring, and very important. I was lucky enough to be one of the large audience for the final event, an excellent talk about the Black Heroes of Mathematics by Nira Chamberlain (and I was particularly pleased that several undergraduates from the University of Greenwich were also there).   Nira told us about a number of great black mathematicians: despite his own negative experiences as a young black man wishing to become a mathematician, and the obstacles in his way, his presentation was overwhelmingly positive in tone and his passion communicated strongly with the audience.

I myself was a very privileged mathematics student.  I had an adequate grant and did not need to work while I was studying.  I had a supportive family.  Both my parents went to university (probably quite unusual for the time although I didn't realise that), as did my father's sister (I believe the first woman from her school to do so) and all my siblings.  I was supported not only by their academic expectations but by their understanding of university education.  I was well prepared by excellent schoolteachers.  Careers advisers encouraged me to study maths, not to forget that ambition and aim to be a boxer (as Nira was advised) or a singer (as Nira's son, alarmingly recently, was told).

I understood some of that privilege at the time.  But of course, I was also white and male.  It is only now, when I look at the achievement of people like Nira, and many of our students at Greenwich who have overcome enormous obstacles, that I am beginning to understand just how that contributed to my privilege.  My mathematics cohort as an undergraduate was almost all white (possibly even entirely white: I don't remember any exceptions) and largely male.  When I look at my classes (and colleagues) at Greenwich, I feel very glad to have the opportunity to work with such diverse people.

Chalkdust's reflections on Black Mathematician Month deserve wide circulation.  This feels like an important initiative, which hopefully will help all potential mathematicians, whatever their race or gender, have the opportunity to follow their dreams, inspired by people like Nira and the other mathematicians featured.