Anyone who caught any of this summer’s BBC Proms may have noticed that in the midst of the World’s Greatest Classical Music Festival, someone managed to sneak in a bit of mathematics. Emily Howard, whose degree was in Mathematics and Computing at Oxford, has become a composer whose works are performed alongside Glinka and Shostakovich. I spoke to Emily about her latest composition, Calculus of the Nervous System, which was part of this year’s Prom 51, on 21st August.

# You're reading: Features

### Let’s talk about X

It’s an unpresupposing little letter, $x$. In fact, that’s the reason we use it to represent something we don’t know. But *how do you write it down*? When Vijay Krishnan tweeted a link to an American college professor’s page on mathematical handwriting, I was shocked to learn that he thought adding a hook to a simple cross was sufficient to differentiate letter-$x$ from times-$\times$.

So I asked our Twitter followers how they write $x$. The Cambrian explosion of diversity in answers I received was eye-opening – I’m glad I asked!

### π vs τ: FOTSN/Tau Day special

Since it’s $\tau$ Day, we thought we’d give Festival of the Spoken Nerd constant-fans Matt Parker and Steve Mould a chance to air their respective viewpoints in the $\tau$ vs $\pi$ debate. It’s a maths showdown!

### Turing Round Up

Today is the 100^{th} anniversary of Alan Turing’s birth. Turing did not just one but several hugely important things during his life, none of which were properly appreciated while he lived or for a long time after he died. In the run up to his centenary, a campaign to make people aware of Turing and the enormous impact he made on so many fields, and most importantly to clear his reputation, has been more successful than anyone could have hoped. Turing is now rightly recognised as one of the greatest mathematicians of the twentieth century, as a victim of persecution, and as a war hero.

The Turing Centenary campaign has been so successful that we’ve decided there’s no need for us to write a biography of Turing, or to highlight some obscure thing he did, or really anything. Literally hundreds of pieces have been written, by some of the greatest writers and thinkers in the world, covering every detail of Turing’s life from his school days to his more obscure mathematical work, up to the circumstances leading to his suicide.

So instead, we’ve collected together some of the best exposition, reporting, and creative expression we’ve found to commemorate the life of Alan Turing.

### The Table Never Lies

The table never lies, or so they say. So when Manchester City were crowned Premier League Champions last week everyone seemed to agree that they were the best team in the league. As Roberto Mancini said, they had scored more than United and conceded less and beaten them twice in the league. Although United finished on the same number of points it would be difficult to find a measure by which they deserved the title over City. Or would it?

### In what flipping dimension is a square peg in a round hole just as good as a round peg in a square hole?

In what flipping dimension is a square peg in a round hole just as good as a round peg in a square hole?

Let’s start at the beginning.

My Plus magazine puzzle from March asks “Which gives a tighter fit: a square peg in a round hole or a round peg in a square hole?” By “tighter” we mean that a higher proportion of the hole is occupied by the peg.

### Grow Your Own Food

I recently heard about Herman, the German Friendship Cake (bear with me), a cake which is divided and spread among friends, and it got me thinking about some other foodstuffs I’ve heard of which are made in such a way that the amount you have will grow exponentially. A Herman cake is a special type of sourdough cake which is made with yeast. It’s explained fully here, but the idea is that you start with a solution of yeast, which lives in a little milk, sugar and flour. This small amount of goo can live happily at room temperature on a shelf, and if you stir it every day and give it a little more flour and sugar to eat every few days, after ten days it’s ready to make into a cake.