The view on careers from a tower overlooking London

I spent the day in London and gave my careers talk at London Metropolitan University. I had to modify this as the first and second year students had a class which started half way through my talk, while the final year students could stay for the whole hour (or hour and 15 as it turned out). I gave the skills development part of the talk and then talked, by request of my host Dr Amir Khossousi, about mathematics societies and what the students may gain by setting one up (as a commuity and individually). They might do just that, with the help of an IMA University Liaison Grant.

I told them student Mathsocs activities include events – social, mathematical and careers based – peer support sessions, newsletters, sports teams and generally building a sense of community among the student body. I gave a plug for the IMA RUMS blog in that regard, where people can find out what other societies are up to. I told them about the UL Grant funding and the electronic copy of Mathematics Today that I can send to student reps. Finally, I told them about the London group of universities, run on behalf of the IMA by Noel-Ann Bradshaw (and having a Facebook group “London University Maths Societies – IMA”). It was nice when saying what fantastic opportunities there are to attend mathematical events in London (not least Gresham College and the Lighthill Institute) to be able to gesture and take in the whole of central London with a sweep of my hand from the window in the 11th floor of the Tower Building (pictured below).

After the first and second year students left I returned to the usual talk, telling the students to look at career profiles (including Maths Careers, Plus and the Travels in a Mathematical World podcast) to find an area of mathematics that interests them and what a great benefit to their career IMA membership and chartered status can be. Actually the real hard sell in that regard was given by Dr. Pargat Singh Calay CMath FIMA CSci who gave a passionate speech on the benefits of association with the IMA.

Tower Building, London Metropolitan University

Podcast: Episode 23 – Paul Shepherd, Decimation and Subdivision

These are the show notes for episode 23 of the Travels in a Mathematical World podcast. Readers of this blog will know I am relieved to have remembered to note that 23 is prime. 23 is an interesting number thanks to the birthday problem: In a group of 23 or more randomly selected people there is a more than 50% probability that a pair of them will share a birthday. You can read a serious article on the Birthday Problem at Wolfram MathWorld, or a more light hearted one at Damn Interesting. More about the number 23 from Number Gossip.

This week on the podcast we hear from Dr. Paul Shepherd of the University of Bath. Paul is a mathematician working in the Department of Architecture and Civil Engineering and speaks about two aspects of 3D modeling – decimation and subdivision. Decimation is the process of simplifying a computer model of a 3D shape by selectively reducing the number of triangles used to make up the model so it can be practically handled inside a computer. Subdivision is the opposite process, in which a very simple 3D model has extra triangles added to make it look more realistic. Paul also talks about what a mathematician can bring the world of engineering and architecture. There is more information on Paul’s work in these areas on his website.

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Podcast Episode 22: Mike Maher, Transport modelling

These are the show notes for episode 22 of the Travels in a Mathematical World podcast. 22 is the smallest multidigit number such that the sum of its digits equals the product of its digits. More about 22 from Number Gossip.

Recently I visited Scotland and while there I met Mike Maher, Professor of the Mathematical Analysis of Transport Systems at the Institute for Transport Studies, Leeds University. Mike sat down with me at the University of Edinburgh and talked about his work in transport modelling.

You can find details of the research carried out in the Network Modelling group at ITS, Leeds, a brochure for the SATURN traffic assignment software suite and further details about microscopic traffic simulation modelling and the DRACULA program (including a downloadable software demo).

If you are interested in the topic, there was another episode of the podcast on transport optimisation problems, episode 3 with Joanna Hartley.

You can find out more about my work with the IMA by following me on Twitter, reading this blog and visiting

9 is an experimental error

As many will know, at the start of episodes of the Travels in a Mathematical World podcast I give a number fact. My intention at the start was that I would also point out when numbers are prime, buoyed on by enthusiasm for prime numbers.

In episode 9 of the Travels in a Mathematical World podcast, the first of two in which Dr. Adrian Bowyer talks about his fascinating career, I make an extraordinary claim: 9 is prime. There’s a joke along these lines:

How to prove that all odd integers greater than or equal to 3 are prime.

Mathematician: 3 is a prime, 5 is a prime, 7 is a prime, and by induction – every odd integer higher than 2 is a prime.
Physicist: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an experimental error, 11 is a prime. Just to be sure, try several randomly chosen numbers: 17 is a prime, 23 is a prime…
Engineer: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an approximation to a prime, 11 is a prime,…
Statistician: 100% of the sample 5, 13, 37, 41 and 53 is prime, so all odd numbers must be prime.
Programmer: 3 is prime, 5 is prime, 7 is prime, 9 will be fixed in the next release, …

and so on. There are more of these all over the web, including a substantial list on

So I need to apologise for and retract my bold claim. As for an explanation, I do not know what happened! There is also an issue that I say “excluding 1, for which the case is trivial, 9 is the smallest number which is equal to the sum of the digits of its square.” Whereas the entry in trusty Number Gossip tells us 9 is “the only number (except one) which is equal to the sum of the digits of its square” (emphasis added). Now, my statement is not wrong, per se, but strange to have added the extra clause (although my weaker claim is easier to prove by exhaustion, I suppose). I struggle to remember where I got the result from – the reference I give in the show notes for episode 9 points to, where the result is not claimed.

I think we might just have to assume I switched off my mathematical brain for that week. Anyway, I am grateful to an anonymous poster on the show notes for episode 9 of the Travels in a Mathematical World podcast for pointing out my error. I wonder if the first 294 people who downloaded the episode: (a) didn’t notice; (b) noticed but didn’t tell me; or, I suppose, (c) downloaded the episode but didn’t listen to it. Any of these leaves me a little disheartened.

This also led me to look at the other prime episodes and realise my original intention of noting prime number episodes is erratic at best. Quite apart from the erroneous, I state the fact for episodes 2, 3, 7, 13 and 17 but am guilty of omission in episodes 11 and 19. Episode 23 will be the next maths news episode and we will see if I remember to note the fact.

Podcast Episode 21: History with Noel-Ann Bradshaw, Turing

These are the show notes for episode 21 of the Travels in a Mathematical World podcast. 21 is the number of squares in the unique smallest simple squared square. You can see the square with some more information on the page about its use as the logo of the The Trinity Mathematical Society at Cambridge. There is more information on squaring problems at More about the number 21 from Number Gossip.

In the regular Maths History series, Noel-Ann Bradshaw of the University of Greenwich and also Meetings Co-ordinator of the British Society for the History of Mathematics talks about the life of Alan Turing. You can read a biography of Turing at the MacTutor History of Maths Archive and there are a large number of links to further reading on the Alan Turing Wikipedia page.

You can find out more about my work with the IMA by following me on Twitter, reading this blog and visiting