The web comic xkcd is well-known for its humour. I’ve also got a soft spot for the educational infographics, such as the following. (Not all the information should be...

## Summer Hiatus…

posted by Kevin Houston

My unscheduled summer hiatus from blogging arose from a family emergency that meant I was in stuck in Brazil for about 5 weeks. Not a bad place to be stuck but under the circumstances it was difficult to find time to finish my planned summer posts. For example, I had planned to post about the Fields Medals and as it happened lost the opportunity to report from Brazil about a Brazilian winner. The short story is that, to me, the Brazilians seemed mostly proud but surprised that a Brazilian was even in the running. The hiatus also meant that the deadline for my next textbook wooshed by. Ok, in reality I was never going to make it but I’m even further behind than expected. Anyhow, service will resume when I get back on track after all the time lost. For instance, I’ll let you know what the book is...

## Wolfram on Leibniz

posted by Kevin Houston

The usual busyness at the end of the teaching term and a holiday last week have meant that I’ve not been posting for a while. Today’s post is a short one from me directing you to a fairly long post by Stephen Wolfram on his recent visit to the Leibniz archive in Hannover. Read it...

## Lagrange book sale

posted by Kevin Houston

I never miss a chance to rummage around in second-hand book shops. In the past bargains were easy to come by but now the internet has killed that off. Now all books are priced pretty much the same and I no longer have the experience of approaching the counter carrying a much-underpriced book with the feeling that I am stealing from the shop and am about to be discovered. Those days are gone. As they are not experts, unfortunately charity shops price their books by consulting the web. This leads to setting the price of some dog-eared copy at just below the price of a mint condition one. Also, I miss the end-of-search feeling as I come across a long sought-after book. These days if I want a book I can find it on Amazon or Abebooks in minutes. The latter is my favourite second-hand book-seller site. They often send me emails about books and a recent one is worth sharing. One of the most expensive sales on the site in March was a book by Lagrange. The relevant part of the article is the following. Our list also includes an historic textbook from 1788 that has had a lasting influence on mathematics. Sounds a bit dull? Not at all. Méchanique Analitique by Joseph Louis Lagrange sold for $13,112. Born in Italy, Lagrange became a famous academic in France and Germany, and managed to survive the French Revolution despite the carnage surrounding him. Méchanique Analitique advanced analytical mechanics beyond the work of Isaac Newton and Galileo Galilei. He wrote the book while in Berlin where he was director of mathematics at the Prussian Academy of Sciences. It was his greatest piece of work, although he contributed widely to mathematics and astronomy. He laid down...

## End of the year…...

posted by Kevin Houston

It’s the end of the year. It seems only like yesterday we were all saying “What? I can’t believe it’s the end of January already”. So what was the year like? I feel I’ve had a good year – I’ve been having a lot of fun trying to understand discrete surfaces and if I hadn’t succumbed to a virus just shortly before Christmas I might have written the bulk of my first paper on the subject. I also had fun with the Beatles story which garnered a lot of attention. Interestingly the most read blog entry was on the passing of Vladimir Zakalyukin. In the world of science the big story was not in mathematics but in the discovery of the Higgs boson. Given that the evidence is hardly overwhelming, it wouldn’t surprise me if the big story in 2013 was its ‘undiscovery’ and the scientists admit a mistake or a misreading of the data. For 2013 one of my top resolutions is to finish my next book. Feel free to write and remind me of that at the end of 2013 if it remains uncompleted. It will be tricky as this coming semester I have a lot of teaching (if there are any of my History of Maths students reading, then watch The Two-Thousand-Year-Old Computer, there are two days left to watch.) Have a good...

## William Tutte and Tommy Flowers...

posted by Kevin Houston

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...