Posted by Martin Orr on
Friday, 30 April 2010 at 20:29

I had a week at home in Belfast last week. Since I resolved a couple of years ago not to fly for routine journeys, it is quite a long journey between Belfast and Paris. In the past I have always done this with a night's stop in England, taking most of two days. This time I broke my journey Paris to Belfast in Leeds for the Future Sounds of Swing weekend. This was almost the only lindy classes I have gone to since last June. It was a great weekend.

On my way back from Belfast to Paris, I took the sleeper train from Edinburgh to London. This allowed me to get from Belfast to Paris in 24 hours (with a bit more time required for travel at either end). It takes about 7 hours leaving at 11.40. The train during the day, which makes several stops, takes less than 5 hours. I suppose it goes slower to give a smoother ride and so that you can get a decent night's sleep. In fact you can stay in your cabin for another hour after it arrives. It cost me £35 with a rail card.

The room is very small with not much more than a pair of bunk beds and a sink. When I saw it I worried whether there would be space for my suitcase, but there was a shelf for it. I was sharing with one other man. It was very comfortable and the movement was barely noticeable. You get brought tea or coffee and a biscuit when the train arrives (in a disposable cup, I suppose so you can take it away if you want).

When I got back to Bures, as soon as I looked across the valley I could see that something had changed. The woods which cover all the upper part of the valley side had gone from brown to green. The leaves have come out on all the deciduous trees on the campus, which was only just starting when I left. This makes everything greener but less open.

Tags
lindy, paris, train, travel

Posted by Martin Orr on
Thursday, 16 October 2008 at 22:11

We've had almost a week of lectures now. I have fairly definitely committed to Algebraic Number Theory. It's getting a bit hard to describe the courses I'm doing now, so here's just a list with a few comments:

- Local Fields (central to number theory)
- Arithmetic of Abelian Varieties (algebraic number theory; this is a graduate course, so goes pretty fast)
- Algebraic Geometry (these ideas underlie a lot of algebraic number theory)
- Commutative Algebra (the algebraic techniques needed for all the above)
- Differential Geometry
- Finite-dimensional Lie Algebras and their Representations

The last two are less directly important for number theory, and are just for fun. Six courses is too much work, so I need to drop one of those two, but I don't know which. These courses are all significantly harder than last year.

The Cambridge Lindy Exchange starts tomorrow evening, so I'll be pretty busy with that all weekend. I'm also trying to get together some organised accounts for the Lindy Hoppers.

Tags
lindy, partiii

Posted by Martin Orr on
Tuesday, 30 September 2008 at 13:26

Another while with no post, reflecting the quiet nature of life in Belfast (although I do have a partially written mathematical post). I have produced a website for Grass Roots Conservation Group; and I've been studying Miranda's *Algebraic Curves and Riemann Surfaces* (an unusual approach to the subject I think) and Mac Lane's *Categories for the Working Mathematician* (which leaves me feeling that I know the formal stuff but not the reasons why).

I managed to find some swing in Belfast. It's a pretty small scene, and the girls were quite happy to have a new lead. Muriel's, where people gather on Thursday nights, has room for about three couples to dance, which is plenty. A teacher has recently started beginners classes (broader swing more than lindy) on Tuesdays in McHugh's.

I spent the weekend at the Edinburgh Lindy Exchange, a much bigger dancing experience, and now feel like I've had plenty for a while. After that, I'm back in Cambridge and there is lots to be done now in preparing for the Cambridge Lindy Exchange for which we've had lots more bookings following ELX.

Tags
lindy, travel, website

Posted by Martin Orr on
Thursday, 10 April 2008 at 20:03

I have been back in Cambridge for a week now, having come back for the Maths Olympiad training camp which ran last Thursday to Monday. My role was to discuss things with the school-age students when they needed someone with more mathematical experience, and especially to hang around in problem sessions and provide hints. Of course that assumes that I can do the problems myself - sometimes greater mathematical maturity makes that easier, sometimes it has got harder because I am out of practice with Olympiad style problems.

I also took a session on Euclidean geometry, the first time I have attempted to teach a group of people maths. This was quite easy teaching, because mostly I just had to give out a sheet of problems and let people try them. (I have collected up a couple of thousand problems from the IMO training I have gone through over the years, so I had plenty to choose from.) I did start off by spending about 10 minutes revising the basic facts about Euclidean transformations, which would have been familiar to most people, and then showing them one particular nice transformation which noone seemed to know (despite it being quite useful - I even used it in the 2005 IMO). My attempt to prove the properties of this transformation interactively was not too successful, as people proposed a different proof from what I knew, and I was not fast enough to keep up.

I now have two weeks in Cambridge until term starts. This weekend I am going to the London Lindy Exchange.

Tags
imo, lindy, teaching

Posted by Martin Orr on
Tuesday, 19 February 2008 at 17:09

Well it seems I have let it go for ages without posting anything. It is now week 5, which means we are just over half way through down. This term I am just doing four courses, because I didn't want to work as hard as I had to for last year's six courses.

The courses are: Algebraic Topology (using algebraic techniques to show that different types of object cannot be deformed into each other), Set Theory and Logic (formalising logic and the foundations of mathematics), Geometry and Groups (symmetries in normal 2 and 3 dimensional space, and the more exotic world of hyperbolic space - lots of this appears in Escher's pictures) and Number Fields (how concepts like prime numbers generalise to bigger sets of numbers than the usual integers). It becomes increasingly difficult to give one sentence descriptions of the courses as they build up on top of earlier concepts (e.g. topological spaces).

Last week I just stepped down as President of the Music Society. It was fun and I learnt a lot from it, but it was also hard work and I am quite relieved to give it up. I am confident that Vicky and the new committee will do a very good job. I have also recently become Treasurer of the Cambridge Lindy Hoppers.

Tags
lindy, tcms, tripos