Monday, 4 March 2019

Shannon, Entropy and Guardian Crosswords...

As part of the Fifteensquared discussion of a Crossword by Brummie in the Guardian last Wednesday, this thread started:-

Dr. Whatson says:
There’s something about Brummie you folks may find interesting.  His puzzles have the most helpful crossers of all setters here.   This is following the notion that the more unusual the letter (e.g. Z, J) the more helpful it is as a crosser, the more common (e.g. E, T) the less helpful.  I won’t go into details, but you can calculate the helpfulness via entropy, and his numbers are statistically significantly higher than the average.  At the other end of the spectrum is Chifonie, with Pan nipping at his heels.  Nobody else stands out. I don’t imagine this is intentional on any of their parts, but rather a side-effect of their grid-filling methods/software.
How is this useful?  Probably not much, except if you’re stuck on a Brummie, maybe that crosser is a B or a C.

thezed says:
Dr. Whatson @1 – re entropy, the first time I came across comments on this was in Claude Shannon (engineer, inventor of a juggling robot and, more famously, the man who invented information and communication theory, giving us Shannon’s Law) who discussed information contained in language in terms of its entropy. In his seminal paper “A Mathematical Theory of Communication” (free link) on page 15 he even briefly detours into the necessary redundancy in a language in order to be able to make crosswords possible. English is well-suited it turns out. He goes into more detail on language, but not on crosswords, in his “Prediction and Entropy of Printed English” (here). I’ve not read a biography recently so do not know if he was a cruciverbalist on top of his other talents, but I’ve always treasured that little detour in one of the most important papers of the 20th century.

Well, crikey, I thought.

Sunday, 18 November 2018


As its Autumn, its about time we had some colour-full trees...

Wednesday, 7 November 2018

Waterloo bird of prey

Waterloo station this morning.
Because of the tube strike there are huge queues for taxis, and none to be had.
There have been signalling failures and lots of trains are cancelled or delayed.
People swirl and clump on the concourse.
And overhead, a beautiful, large bird of prey swoops around, under the station roof, scaring away the pigeons.  Her handler watches from the balcony.

Very strange.

Wednesday, 26 September 2018

The Trees on Tour: Amiens 1

On the way back to London we stayed a night in Amiens.  A real contrast to the near-empty countryside around Le Petite-Pressigney.  Lively, a lot more young people and significantly greater ethnic diversity.  Then there is the stunning medieval cathedral.

The nighttime light show.  I didn't see it live - these pictures are from Judith's phone.

While some of the effects are random, it seems or just use the west end of the cathedral as a huge screen, the most impressive effects were when the figures around the three doors were coloured.

These colours are based on detailed research.  Fragments of paint found by specialists indicate the original painted polychrome look of the west end of the building.

The next morning we visited and went inside just before Sunday mass.  The light from the newly-risen sun created a wonderful space inside the cathedral.

Thursday, 13 September 2018

The Trees on Tour: France

Back in France again, scarily close to Ste Catherine de Fierbois (and see the other posts here and here from  2010). We decided to try and avoid the places we visited then.

In any case this is a different sort of visit.  Further South, in a cottage in the village of Le Petit Pressigny.
The village is in the middle of the countryside.  We have had hot sunny days.  A lazy time.

We've seen lizards and squirrels, grasshoppers and other creatures around the cottage.  We also went to an  ├ętang in the Brenne conservation area, and saw a cormorant, kingfisher, dragonfly and other creatures.

We went to the prehistory museum in Le Grand Pressigny (I finally believe I understand flint napping).

And we briefly visited the Chateau de Montresor.

More adventures tomorrow!