Friday 30 January 2009

More Tampering with Nursery Rhymes

My attention was drawn to this strange story on the BBC site.

A charity called 'Bookstart' has changed:

'What shall we do with a drunken sailor'   to

 'What shall we do with the grumpy pirate.'

The story mentions other expurgations of nursery rhymes, include a general condemnation of any mentioning pigs.

I wanted to record the imbecility. Further comment seems unnecessary.

Wednesday 28 January 2009

Google Chrome

When it first appeared I hated it because I couldn't find any easy way of managing the bookmarks. After a month or two, someone pointed me to the bookmarks manager, which was somewhere I'm almost sure I'd originally looked in vain. I gather Chrome quietly updates itself  all the time. That's wonderful while it works, but I hope they never make a bad mistake.

I like the way it handles tags, and shows frequently visited sites on the home page, but I still have some reservations. When I bookmark a site, I have to move the mouse very cautiously to avoid the bookmark going in the wrong place, and there's no indication that it has gone anywhere even when it has. There are a few sites that don't look their best with Chrome - over wide margins sometimes obscure material I want to read, and on one site every time I move to another page I have to press the maximise button before I can read it.

Still, overall I'm growing quite fond of Chrome and it is now my default browser. 

Friday 23 January 2009

Big Prime Numbers

When big pimes are discovered, they are always Mersene numbers, of the form 2^p - 1 for p prime.

I used to assume that was because the binary epresentation of such a number consists entirely of 1's so that the number could easily be generated in instalments in a computer, but while browsing through Hardy and Wright's Introduction to the Theory of Numbers, I came upon another relevant fact.

For some Mersenne numbers there is a very short short cut to finding whether they are prime.

If the prime p is greater than 7, and of the form 4n + 3, that is if it leaves remainder 3 when divided by 4, then:

 if 2p + 1 is prime, that number is a factor of 2^p - 1, otherwise 2^p - 1 is prime.

So, for example, to check whether or not 2^19 - 1 is prime, consider 2*19 + 1 = 39

39 is not prime, therefore 2^19 - 1 is prime.

To check whether or not 2^251 - 1 is prime, consider 2*251 + 1 = 503; that is prime and is therefore a factor of 2^251 - 1 which is therefore not prime.

Next time you hear of the discovery of a large prime of the form 2^p - 1, check to see if p leaves remainder 3 when divided by 4; I bet it will.

Sunday 18 January 2009

A wayside shrine

About two years ago a young man aged about 20 was killed on the nearby main road. Ever since people have been lodging flowers between two branches of a tree at the side of the road. I don't think those responsible live at the house nearest to the tree, because I've seen someone arrive, deposit flowers and the leave.

Recently I noticed a few Christmas decorations and two paper plates with bits of food. I suspect someone had delivered Christmas dinner, though only potatoes were left when I noticed it, so I expect the foxes had eaten the rest.

I suppose that paying tributes to the victim may now have become such a deeply ingrained habit, that to stop would feel disloyal. I find it most depressing.

I wish people would think of less banal ways of remembering someone. One could read some of their favourite books, or tend their favourite part of the garden, though not in an obsessive attempt to preserve it in precisely the same state as they knew it, and there is always the traditional memorial - a tombstone.



Thursday 15 January 2009

Radio Four discussed a book I'm reading.

This morning's edition of In Our Time was devoted to Henry David Thoreau, best known as the author of Walden and Civil Disobedience.

For the last few weeks I've been reading a book containing both those works together with various essays on Thoreau. My impressions are recorded on the books page of my web site.

Tuesday 13 January 2009

A Poetess on Radio 4

Listening to Radio 4 as I took my morning bath, I heard an interview with the winner of the T. S. Eliot poetry prize. She read one of her poems, which was about (what her poetry is about).

 I found it quite incomprehensible, not just in some respects puzzling, but so baffling that I could find no clue as to what it was supposed to convey, unless that bafflement was itself the message.

Between the ages of about 15 and my early 40's I used to read a fair amount of poetry, but then gradually lost interest.

I quite like the cheerful jingle of humorous light verse, but have come to mistrust what is called 'serious' poetry. That now strikes me as an attempt to present difficult ideas with obscure indirection, so that the wilful impenetrability of the exposition shall match the intractability of the subject matter.

If we are to get to grips with difficult ideas, we need to be discuss them in a very different way,  in the plainest of plain prose, possibly augmented  in emergencies by a little symbolic logic.

As the prize was set up by Eliot and the winner was a young lady living on one of the Shetland Isles, the following thoughts of Eliot's seem pertinent:

Under the bamboo
Bamboo, bamboo
Under the bamboo tree
Two live as one
One lives as two
Two live as three
Under the bam
Under the boo
Under the bamboo tree.

Where the breadfruit fall
And the penguin call
And the sound is the sound of the sea
Under the bam
Under the boo
Under the bamboo tree.

Where the Gauguin maids
In the banyan shades
Wear palmleaf drapery
Under the bam
Under the boo
Under the bamboo tree.

Tell me in what part of the wood
Do you want to flirt with me?
Under the breadfruit, banyan, palmleaf
Or under the bamboo tree?
Any old tree will do for me
Any old wood is just as good
Any old Isle is just my style
Any fresh egg
Any fresh egg
And the sound of the coral sea.

T.S.Eliot, Sweeney Agonistes, Fragments of an Agon.

Thursday 8 January 2009

Barack Obama may turn out to be a great disappointment

I've just listened to part of a speech he made, and noted two promises.

He said that in the next two years he'd double the output of energy from alternative sources. He also promised to computerise all American medical records.

Alternative energy is both very fashionable and relatively new, so the annual rate of increase is a high proportion of the total. Output might well double in two years without any intervention from the president elect. Furthermore it takes quite a while to build and commission new generating equipment, so it is unlikely that anything Obama does do will have much effect in the next two years. The promise about energy is empty.

The promise about medical records should worry all Americans. There have been attempts to computerise all medical records in England too. The cost has been enormous, but the system still doesn't work properly. Obama sounded a bit like Harold Wilson promising in the 1960's to harness the 'white heat of the technological revolution' for the public good. Has he an ulterior motive for building a central database of information about the entire population ?