## Archive for the ‘Uncategorized’ Category

### Adventures with a kora, 3

January 23, 2017

After belatedly posting no.2 in this series, I thought I’d better post another update. A couple of weeks ago I tried suarta tuning (with B natural, instead of the B flat of silaba tuning, so roughly tuned to a C major scale) and started practising Jarabi, from the video tutorial I bought from the Kora Workshop. The video does not play properly even on my new laptop, so this is a frustrating experience. Nevertheless, I think I’ve got the basics, although I’ve probably misunderstood some of the subtleties of the rhythm. I’ve memorised the introduction and both versions of the kumbengo (thumb version and finger version), and can play them more or less up to speed, though not with all the right notes every time! When I’ve practised them a bit more, I’ll move on to the variations.

### Adventures with a kora, 2

January 23, 2017

Oops! I forgot to post this. It’s a bit out of date now:

Eventually I was forced to replace all 21 strings. Mixing the old and new strings simply did not work, as they were very different in thickness and in tension. It took about a week of what felt like fulltime tuning to get it to the point where the strings were all compatible lengths and tensions, so it could be tuned correctly. Each adjustment of one string would require detuning all the shorter strings, and tuning them back up again. The whole process started to feel like the Towers of Hanoi! (I’m exaggerating, of course, it was more like n^2 retunings rather than 2^n.)
The new strings are a lot heavier than the old ones, and so have a much higher tension. Several of the tail loops broke and I had to make new ones out of the old strings. Anyway, to cut a long story short, the strings are now tuned up to F major, and I’ve learnt a few tunes. Kelefa Ba is the one traditionally taught first to beginners, and I reckon I can give a fairly accurate rendition of the basic version by now. No frills yet. That comes later, I suppose. I’ve been working on some more difficult ones, Kuruntu Kelefa and Alla La Ke.

July 9, 2016

I have been prevented from playing the violin or piano by a damaged finger, and yesterday saw a secondhand kora for sale in a local music shop. Since this instrument is played with the thumb and index finger of each hand, I couldn’t resist the temptation to buy it and give it a try. Sold as seen, I knew it was missing a few of its 21 strings. I soon found out that  most of the strings were in the wrong slots in the bridge, and two were even on the wrong side of the bridge. Four or five of the top strings had been replaced by steel guitar strings. No matter. I started to try and tune it. This is when I discovered that most modern koras are made with tuning pegs like guitars. Not this one, which has the traditional animal hide tuning rings. Steep learning curve. After half a day or so, I reckoned to have 16 of the remaining 17 strings tuned to a decent approximation to E flat major. Apparently I should be aiming for F, but this instrument just isn’t interested in F major, so I let it have its way and settle in E flat. Now the 17th string (second lowest) I found would not tune up to the required B flat, and I put this down to the fact that it is made of a twisted pair of nylon strings, and is probably too heavy for that note. I must order a set of new strings and try to set the instrument up properly. Then comes the real challenge – learn to play it, even to a basic level.

### Letter to THE about USS

September 30, 2014

I wrote to THE two days ago about the proposed destructive changes to the Universities Supperannuation Scheme. This is the letter I actually wrote, before editing. The published version will appear on Thursday.

Dear Sir,
Have we learnt nothing in the past six years about the difference between mathematical models and the real world? If you put garbage into a mathematical model, you will get garbage out. If you model the long-term viability of the USS on the ludicrous assumption that all UK universities go out of business tomorrow, why should anyone listen to you? Unfortunately, this is exactly what the USS is doing. This is pure mathematics, not economics, and the USS should leave pure mathematics to us pure mathematicians.
As a Trustee for several years of the London Mathematical Society, which celebrates its 150th anniversary next year, and hopes to keep going for another 150 years, I learned something about long-term viability. Of course you have to keep the nightmare scenario in the back of your mind, but you do not build your entire business model on it. Your business model must be built on prudent but reasonable assumptions, or else your business will not survive in the long term.
Ironically, the proposed changes to USS might actually bring about the nightmare scenario that the USS seem so concerned about. If, as seems likely, the scheme becomes so unattractive to new members that it becomes viable to set up a rival scheme, then this will eventually happen, and the USS will have dug its own grave.

### Maximal subgroups of classical groups

August 21, 2013

The long-awaited book The maximal subgroups of the low-dimensional finite classical groups’ by John Bray, Derek Holt, and Colva Roney-Dougal has just appeared in the LMS Lecture Notes Series. It contains, in marvellously complete form, with proofs, the material which appeared in Peter Kleidman’s PhD thesis (1987), without proof, on maximal subgroups of simple classical groups in dimensions up to 12, and extends this to the almost simple groups. The latter is what really makes the achievement so impressive. The book satisfies a long-felt need in finite group theory, and will be an important work of reference for a long time to come.

### Credo

April 16, 2012

I believe in a university which

* teaches students by challenging them, not mollycoddling them;

* researches the fundamental questions about life, the universe and everything, not superficial questions about how to make money;

* administers itself to support teaching and research, not the other way around.

### The real HE market

May 25, 2011

My attention has been drawn to this devastating article in the London Review of Books on the folly of the government’s move towards the marketization of HE.

http://www.lrb.co.uk/v33/n10/howard-hotson/dont-look-to-the-ivy-league

### solving yesterday’s problems tomorrow

May 8, 2011

The University of Birmingham has a very clever slogan, which it advertises widely, that is “Solving tomorrow’s problems today”.  As a mathematician, I immediately thought of the possibilities of replacing these temporal references by arbitrary combinations of “yesterday”, “today” and “tomorrow”. As a slogan for our Government, how about “Solving yesterday’s problems tomorrow”? Or, as a slogan for mathematics, how about “Solving tomorrow’s problems yesterday”?

### How to write LaTeX in this blog

May 8, 2011

Write a $\LaTeX$ expression in between $\$ signs in the usual way, but write the word latex immediately after the opening $\$ sign. Just for the fun of it, here is an example: $\sum\limits_{i=0}^\infty \frac{1}{i!} = e.$ This works equally well in posts or in comments.