Sunday 28 November 2010

Newman and Turing under the hammer

Christies' auction of computing memorabilia last week included one lot with a strong Manchester connection: Max Newman's annotated collection of Alan Turing's papers. Newman was one of my predecessors as Head of Mathematics at Manchester (on the Owens side) and we called our new building the Alan Turing Building, so both carry some personal resonance. The Newman papers did not make their reserve price (though the bidding went to £240,000) so there is still a chance that they may end up at either the Rylands Library in Manchester or in Bletchley Park.


Newman (on the left here) was a topologist, but his greatest achievement was probably his codebreaking work during the Second World War and the development of Manchester mathematics -- he was a mentor of Turing and instrumental in bringing him to Manchester after the war.

 Turing was, well, Turing! Obviously a very difficult man, but equally an extraordinarily gifted mathematician. In his doctoral thesis he (re)proved the law of large numbers, he was the central figure in the code-breaking activity during the Second World War, where he developed the electronic proto-computers. He continued to work on computers in Manchester after the war. His work on fundamental mathematics (the universal machine (Turing machine) and pattern formation in biology  was also ground-breaking. Persecution for homosexuality led to his
suicide in 1954. The 100th anniversary of his birth will be celebrated next year.


Here are three Turing-related anecdotes (except for the last, I cannot vouch for their accuracy).

1. The symbol of Apple Computers (an apple with a bite removed) is a reference to Turing, who committed suicide by biting an apple injected with cyanide.

2. Some computer scientists in Manchester believe that Turing would have put progress in computing back by twenty years due to his obstinate disdain for higher level computer languages.

3. The naming of the Alan Turing Building in Manchester came about almost by accident. Because it houses both mathematics and astronomy the original idea had been to give the building a name (or failing that, two names) connected with both disciplines and with Manchester. Newton was rejected by the University because of the lack of a strong Manchester connection and we had a list of worthy suggestions to put before the School Board. On a whim I added Turing to the list I wrote on the blackboard and got an overwhelmingly positive response. It required a bit more work to convince Physics that Turing was such an iconic figure that the addition of a worthy Manchester astronomer to the name would not work, but to their credit they agreed, and the Alan Turing Building was named. 

Friday 19 November 2010

Statement of the bleedin' obvious #147 (Category: Fish)

Ten thousand years ago the UK was covered in glaciers and no freshwater fish could have survived. At the end of the Ice Age the glaciers retreated northwards, but the only way freshwater fish could have recolonized the country would have been by following immediately after the glaciers in the meltwater (unlikely) or crossing the sea some time later. To cross the sea they would need to be able to tolerate salt water.

Hence the number of freshwater species of fish in the UK is likely to be very small.

It is. There are 57 species, only 43 of which are classed as native, compared to 13,000
worldwide.

Simple.

The Romans invasion and later the feudal/monastic fish ponds of the twelfth century onwards may have led to an influx of new species. I wonder how many of the 43 native species were established over 2000 years ago.

[See Maitland & Craig in Silent Summer: The State of Wildlife in Britain and Ireland, ed. N. Maclean, CUP 2010.]

Tuesday 16 November 2010

Dave Broomhead @ 60

We have just hosted a two day meeting to celebrate Dave Broomhead's 60th birthday (the picture shows Dave and my wife, Fiona, in the Malvern Hills -- is it my imagination or can you see the curvature of the earth in the background?). It was a great meeting (well done to Kieran, Jerry, Mark and Helen), with an eclectic mixture of science and mathematics which reminded me of dynamical systems in the early 1980s when engineers, physicists, applied mathematicians and pure mathematicians engaged with each others problems. I was asked to give a short speech at the end of the first day, and this made me think about what makes someone a world-class researcher.

Some of it is sheer hard work (genius is 5% inspiration and 95% perspiration) but Dave also has the confidence and ability to follow his own instincts. He doesn't enter a new area because it is popular or well-funded, but because it is interesting and  he wants to learn about it. In a bean-counting era his strategy carries risks from the point of view of immediate publications, but it clearly carries long term success and keeps his ideas fresh and exciting.

Dave has many good qualities -- modesty, a democratic view of others, and a deep sense of humanity -- but what makes him outstanding as a researcher is his pig-headed insistence on setting his own agenda and not following the herd. This means that when the rest of the world catches up he always has something worthwhile to say.

Friday 5 November 2010

Camouflage

My latest View from the Pennines (a regular piece for Mathematics Today, the magazine of the Institute of Mathematics and Its Applications) is about invisibility and optics/scanning; if you want to see the details go to the View from the Pennines Homepage. As always my starting point was an observation on life on the moors around us, or our pond -- in this case the amazing silver and black carapace of the water boatman.
We usually see the underside of a water boatman as it swims below the surface -- black, with a couple of paddle-like legs on either side. But in the late summer they emerge onto plant stalks and show off their wonderful backs (the picture was taken in early September). I suppose that this is camouflage, though whether aggressive or for their own protection I cannot guess. Seen from below against the silvery surface of the water they must be almost impossible to spot.

Conventional camouflage is about matching colour and shade. The surprising thing about the water boatman in the picture is that the metallic sheen seems to match material/refractive properties of the water surface seen from below. This suggests that a good theory of camouflage would include some measure of the 'feel' of the background. It would be interesting to see a mathematical description of camouflage. An obvious comment is that stripes should not be too regular (I have a great picture of a dragonfly I'll dig out) -- does this mean we should be using Fourier space? Another aspect any good theory should encompass is behaviour. The caddis fly larva actually uses its environment to provide it with camouflage -- it glues bits of leaf and mud to its back -- but seen from the side of the pond it is relatively easy to spot because it does not move with the local currents. I suppose its prey doesn't have the advantage of position (or brain processor power) to see this flaw.

Both the water boatman and the caddis fly larva show that camouflage needn't be perfect from all vantage points, only those of the object being stalked or avoided. Thus any serious mathematical description would have to specify what the camouflage needs to achieve as well as how to achieve it. I wonder whether there is any serious work in this area?