On Monday night I unexpectedly came across a TV programme about the code-crackers at Bletchley Park during World War II. Usually such a programme focuses on Turing and the cracking of Enigma but this was about two of the lesser known players: William Tutte who was a mathematician like Turing and Tommy Flowers, a Post Office engineer who arguably built a programmable computer before anyone else. Seeing Tutte was a coincidence as just last week I was trying to understand his graph embedding theorem. [I’d met the theorem before but had forgotten all about it until I was trying to understand the “No Free Lunch Theorem” for discrete Laplace operators by Wardetzky et al, see here. Well, I think I understand the theorem but I don’t understand the proof. In my attempt to understand the basics of discrete Laplace-Beltrami operators I set aside a day last week to understand the proof and perhaps attempt to give a different one. Unfortunately after three days I still didn’t understand all the details of their proof and didn’t have a version of my own either! If anyone knows the details, then get in touch. But I digress…]I found a good description of the theorem on a site by Graham Farr at Monash. You can find it here. It’s a bit long but the important bits are in the first part. I liked the programme, for a start it didn’t assume you were stupid (even though it assumed I wouldn’t have heard of Tutte). The codebreakers programme is of course available for the next few days on the...

## The number of spots in a deck is 365?...

posted by Kevin Houston

Today’s TED video is an augmented reality card trick by Marco Tempest. Now, I’m a fan of card tricks but this was a bit too cutesy for me. However, I draw your attention to his computer’s claim (at 3:20) that if you add up all the spots on the cards in a deck then you get 365 which is the number of days in a year. I make the same claim in one of my school talks but I follow it by pointing out that obviously it can’t be right. (Obvious in the sense that you don’t need to get a deck and count but just use some simple maths.) Usually at least one of the pupils gets it. Anyhow, here’s the...

## Tails you win: The Science of Chance

posted by Kevin Houston

Last night David Spiegelhalter presented a TV programme on the science of chance. As usual it’s available on the BBC’s iPlayer for seven days. Spiegelhalter is an entertaining speaker, I’ve seen him give talks a number of times, but I felt this programme was a bit pedestrian. There’s lots in it but that just makes it too “bitty”. For example, there is a brief bit about Apple making iPods less random and an overlong bit about a cricketer who was “unlucky” to break an ankle and so on. Nothing was dealt with in depth. Upon reflection I think that the problem (leaving aside that I am not the target audience, but hey, I can have an opinion) is that there is a lack of drama and tension in the programme. It’s just one thing after another. So although the programme did progress through the history of chance there was no sense in these historical pieces of dramatic fights to uncover the truth. In fact, I felt that the only attempt at tension was rather misguided. To create drama Spiegelhalter jumps out of an aeroplane after explaining how at his age the risk of dying is in some sense less than that of a younger person as he is more likely to die in the next few years. As he heads toward the ground the screen freezes, a caption asks “what happened next?” and the programme moves on to another topic, returning much later. Are we supposed to think that perhaps the parachute didn’t open and he tumbled to his death? Well the tabloids would have told us: “Risk Prof dies in ‘unlikely accident'” or the announcer would have dedicated the programme to his memory. So of course there was no tension or drama in this piece. Particularly since the programme titles showed the parachute opening. Anyhow, there were many bits I did like such as the explanation of average age until death and the graphics used. Mercifully, he didn’t do the Monty Hall problem which has rather been done to death. And of course, as I said, Spiegelhalter is an entertaining speaker so at least he wasn’t putting me to...

## Robin Ince on science communication...

posted by Kevin Houston

This one is slightly outside my maths remit but I felt that Robin Ince made some serious points (and maybe some not so serious points) about science communication on this Saturday’s Saturday Live on Radio 4. You can hear it here for the next few days provided you can use the BBC’s iPlayer where you are. Ince’s website lists upcoming performances should you wish to see him live in the UK. He is good – I saw him doing non-science when he was promoting his Bad Books Club. (I have a signed copy of the book. I persuaded him to break the spine of the book so that it falls open at the frostbitten hands picture. Read the book to find out...

## In Liverpool

posted by Kevin Houston

I’m back in Liverpool. Rob Sturman and I were reprising the British Science Festival talk for the Liverpool Mathematics Society and today I’m giving a research talk at the University. I had hoped to write about all this last night when I was in my hotel, the famous Adelphi Hotel, but they don’t have internet access in the rooms, only in the lounge. I can’t remember when the last time I stayed in a hotel without free wifi access was. Anyhow, I’m currently in an office in the Mathematical Sciences Building. It may even have been the office I had here back in the 90s but I’m not sure maybe it was the one next door. A lot has been happening since I last wrote. Did you see that the University of Leeds held a talk by, Iain Lobbam, the director of GCHQ on Alan Turing? If not then see the Guardian article or the Telegraph...