The International Mathematical Union is trying to get UNESCO to make March 14, commonly known as π Day, the International Day of Mathematics.

# You're reading: Posts By Christian Lawson-Perfect

### Magic Numbers: Hannah Fry’s Mysterious World of Maths on BBC Four

The ubiquitous Fry is on our screens again, with a programme about Platonism, on BBC Four.

In *Magic Numbers: Hannah Fry’s Mysterious World of Maths*, “Dr Hannah Fry explores the mystery of maths. Is it invented like a language or is it discovered and part of the fabric of the universe?”

Episode 1 is on the iPlayer for about three more weeks, and episode 2 of 3 is on tonight at 21:00.

### This matrix joke is only barely worth your time

If you see me doing a maths thing, I’m probably wearing one of my maths t-shirts. I’ve got quite a few, but the one that reliably produces the much-sought-after look of total indifference even once I’ve explained the joke is this one:

It’s a NERD identity matrix, get it?

That t-shirt was made by Festival of the Spoken Nerd, and by the way they’ve recently put together some new designs.

It’s long bothered me that the nerd identity matrix contains so many zeros. It’s also only an identity matrix if $N = E = R = D = 1$. Surely there’s a joke matrix somewhere with a bit more meat to it?

### A puzzle for another day

A few months ago, my faculty’s PR person sent an email round asking if anyone would like to write a puzzle for the Today programme’s “Puzzle for Today” slot, to be broadcast during the programme’s trip to Newcastle in Freshers’ Week. A colleague said this might be the kind of thing I’d like to do, which it was, so I started thinking, and eventually came up with a brand new puzzle which I thought would work well.

If you listened to the Today programme this Thursday morning, you’ll have heard not my name, but that of Dr Steve Humble, who’s got a lot more experience doing this kind of thing. Turns out, they wanted something more ‘visual and interactive’, so asked him instead. I think that was a polite way of saying they just didn’t like my puzzle. Oh well!

Steve chose a classic puzzle that coincidentally appeared on Twitter about a month ago, prompting much discussion. It’s a good puzzle, much better than the one I came up with, but I don’t think Steve was completely right to say “It is possible that you can always create a winning game” – that’s only the case if there are an even number of coins, but his statement said “around ten coins”. I suppose he might’ve meant that, starting from having a handful of coins, you can decide to only use an even number of them.

The upside is that I can now talk about the puzzle here, where someone might actually enjoy it.

### Atiyah Riemann Hypothesis proof: final thoughts

After Sir Michael Atiyah’s presentation of a claimed proof of the Riemann Hypothesis earlier this week at the Heidelberg Laureate Forum, we’ve shared some of the immediate discussion in the aftermath, and now here’s a round-up of what we’ve learned.

### The Big Internet Math-Off – The end

It’s all over! The votes are in, they have been counted, and I can announce that the winner of The Big Internet Math-Off is:

**Nira Chamberlain!**

Massive congratulations to Nira, you may now refer to yourself as The World’s Most Interesting Mathematician*.

* of the 16 people I asked to take part, who were available in July, and wanted to play.

Nira’s pitch on applied mathematics won 56% of the vote in the final, with 1207 votes against 960 for Matt Parker’s pitch on naive fraction addition.

I don’t *get* applied maths – it never appealed strongly to me – so I really appreciated Nira sharing his obvious enjoyment of it. And apparently so did the voters!

### The Big Internet Math-Off – The Final! Nira Chamberlain v Matt Parker

Well, this is it: the final of The Big Internet Math-Off. Just one more match stands between the two remaining competitors and their destiny: the title of World’s Most Interesting Mathematician (modulo the previously described factors of knowing me, interest in taking part, and availability in July to indulge my whimsy).

Nira Chamberlain and Matt Parker each have one pitch left to wow you and get your little grey cells a-quivering. So what have they picked? Find out below!

There’s no twist in the format for the final round, the rules are the same as always: take a look at both pitches, vote for the bit of maths that made you do the loudest “Aha!”, and if *you* know any more cool facts about either of the topics presented here, please write a comment!

So, with all that said, let’s begin the final round of **THE BIG INTERNET MATH-OFF!**