## Saturday, October 31, 2009

### What are complex numbers?

A lot of people find complex numbers mysterious and counter-intuitive.

Defining i to be "the square root of minus one" is about as sane as defining it to be the square root of the colour blue.

The first people who thought about it followed that approach, and were rightly scared stiff and confused by it. Even Euler made trivial mistakes. They called them "Imaginary Numbers" because they seemed to be useful for calculating, but no-one really believed that they existed.

Argand came up with the right way of thinking about it:

Take all the tuples (x,y). (Where x and y are just integers). Define on them addition and multiplication rules.

Oh look! There's a big system of these things, and embedded within it is a sub-system which works exactly the same as the integers and their rules.

Since they're exactly the same for all practical purposes, we may as well forget about the difference and say that we'll write (a,0) as a and (0,b) as ib, and (a,b) as a+ib

And although none of the pairs in the  sub-system square to be (-1,0), also known as -1, there are two other things that do!

So now we know that both (0,1) and (0, -1), otherwise known as 1i and -1i, or i and -i, are square roots of -1.

No slight of hand or magical thinking necessary, and we have the complex integers.

As it happens, we can do the same thing starting from the reals, to form something that embeds the reals. But the reals really are dark and mysterious and need to be brought about by a kind of magic.

According to me. Some people think they're as real as the complex numbers.

## Friday, October 30, 2009

### e^(i pi) = -1

Imagine you're a complex number, which is just a type of arrow.

Exponentiation is to do with growth.

Growth at a speed which is a multiple of how big you are already.

i is the multiplication which turns you through ninety degrees.

If you grow in a direction which is at right angles to yourself, you turn rather than increasing in magnitude.

Your head moves at the speed which is your length. So pi is how long it takes you to turn through a half circle.

So if you grow at right angles to yourself for time pi, you are pointing the opposite way.

That is the meaning of the famous identity e^(i*pi) = -1.

If we know what sin and cos are, we can see equally easily that e^it = cos t + i*sin t, which is known as Euler's formula. Sin and cos are just the coordinates of a point on a circle that has moved a distance t anticlockwise round a circle of radius 1.

## Thursday, October 29, 2009

### some more titles

Blog posts I want to write: I'm a bit short of time so I'll save the titles here in case I forget.

A foundation for not being evil
What can we do to get rid of the car?
The mind expander (forgot what I meant by this, so it can't have been too important)
Building a language: attempt to reconstruct Guy Steele's masterwork
A moment of religion outside the Queen's Head at Newton

### What does it mean to be a good translation? (boring)

WARNING: This article has been judged boring, and will at some point be rewritten.

How can we tell if two texts are the same?

Compare them letter by letter (space is a letter) and see if they are all the same.

Is it possible to measure the distance between them if they are not?

A mathematician's first answer would be a metric on letter differences.

So "arfle" is 1 away from "arfly".

That's a bit rubbish.

We'd like "The cat sat on the mat" to be similar to "A cat sat on the mat".

Those two phrases are so close in meaning that there are languages where it's hard to express the differences. But the first letters are different (AT), and the second( h), and the third (ec), and the fourth.

So we might try something like an editing metric. How many operations does it take to turn one sentence into another. So saying "Swap cat for mat" is a distance of one. Insert "green" is a distance of one, etc.

Latin would translate them both as something like: "Catus mate satavit". Which can be interpreted as "The verb sat takes cat as its subject and mat as its indirect object, in time past and the action is completed.

Both English phrases are valid translations of the Latin phrase, and indeed both are as close as you can get to the original.

It is also possible to say in Latin "mate catus satavit". This means almost exactly the same thing, but there's a slight feeling of emphasis on the mat.

We can't do the same thing in English, "The mat sat on the cat" isn't what we meant at all. It would have to be "It was the mat that the cat sat on".

So we've made a small change to the Latin (one step). But in the English we've moved "the" and "mat" and added "It" "was" and "that".

So

phrase A -> translate -> phrase B -> move 1 -> phrase C -> translate -> phrase D

Alternatively phrase A -> move 2, add 3 -> phrase D.

It looks like whatever editing metrics we choose we're going to have them be unstable under translation.

And yet the four phrases are obviously very close in meaning.

You can imagine a conversation where Mulder says "The cat sat on the sofa", and Scully replies "The cat sat on the mat.". And one where she says "It was the mat that the cat sat on." And the information communicated is no different.

Perhaps there's another attack?

We could say "The difference between two texts is defined by the reader". Texts don't have meanings by themselves. It takes a conscious mind to measure the difference between two things.

OK, so now what is a good translation? By good I mean "conveys the same meaning".

Well, you need to take someone who can speak both languages, and ask them if the two things mean the same to them.

I'm a good speaker of English, and a poor speaker of French.

My interpretation of French is different because I am an English speaker.

When I hear the French word "boulingrin", which means lawn, I cannot help but imagine a lawn which is like a bowling green.

When I hear "C'est ma femme, actuellement". I hear "This is my wife, actually", and only later do I hear "This is my current wife", which is what the French phrase really means. "This is my wife, actually" would be "C'est ma femme, en fait".

So you can't ask me whether a French text and an English text mean the same thing. Because a French text doesn't mean the same thing to me as to a Frenchman.

Neither can you ask a good French speaker who is also a poor English speaker, for the same reason.

Neither can you ask a true bilingual, I would imagine. Because in every language there are clusters of concepts which are separate in other languages.

In English "Free Software" means software that is unrestricted, but it also means software that costs nothing.

In French, these two concepts "Software libre" and "Software gratuit" are completely separate and there is no easy way to conflate them.

It is not that the distinction is meaningless, which explains why English speaking Free Software loonies say things like "Free as in speech, not as in beer".

And in fact the phrase "Software libre" is taking off in English as a shorthand way of expressing an important difference in meaning that English has no easy way to express.

Notice that the problem is in the English language. English brains can hold the concept of "software libre" even before they hear the phrase.

Similarly in French "J'ai raison" means "I am right". But it also means "I am correct".

In English these concepts are quite distinct. But if you're French, you can't be wrong without your reasoning being incorrect.

Don't get me wrong. There are ways to say in French "I am morally right" and "I am correct". It is just that they're not expressed normally. As in free software being the usual term as opposed to 'liberated software' or 'costless software'. They're artificial-sounding circumlocutions.

This idea of rightness being the same thing as correctness is a very fundamental philosophical difference! France and England have different legal systems and ways of thinking about things, but I think that if the two concepts weren't as firmly separated in the French brain as they are in the English, then the differences would be very much greater. Indeed I suspect that one of the differences would be that France would have ceased to exist. There'd be too many religious wars.

But when you speak in French, you destroy the difference as the information gets passed from mind to mind, and who knows whether it gets reconstructed properly?

What about if the two languages you're translating between are the same language at different times?

When I was a boy, I was worried about the fact that Shakespeare's comedies aren't funny. There are funny bits, to be sure. But the funniest bit I can think of is the porter scene, in Macbeth. Which isn't one of the comedies.

My father told me that in Shakespeare's time, "Comedy" meant something different to what it does now. They would have called our comedies "Farces".
He told me to look, not for humour in Shakespeare, but for poetry and truth.

I was puzzled by this answer, since that seemed to leave Comedy meaning "Any play which is not a tragedy or a farce". Also it meant that Shakespeare then, as he is now, would be a very elevated sort of taste.

Not many people are going to pay to watch a TV program that they have to study in order to understand.

I don't think it's the right answer. Shakespeare's Globe theatre was on the wrong side of the river. Amongst the prostitutes and bear baiters of Elizabethan Southwark. About the nastiest place in England.

And he was a popular entertainer. He made himself rich and famous with his plays. People flocked to them, and contemporary reports have them rolling in the aisles.

Perhaps the comedies were funny. Humour fades so fast. Even the immortal Monty Python seems a little pale now. You'd need to study to understand why the ministry of silly walks is subversive, or why the army's effete drilling is so shocking. Or who the Pirhana brothers are.

I can still remember why these were hideously, screamingly, achingly funny things. I can't imagine that modern kids understand at all, even when it's been explained.

In four hundred years time, I can well imagine a father telling his son to look for the poetry and truth in Monty Python. Except that there isn't any, so they'll probably be about as well known as Shakespeare's great commercial rivals, X and Y.

It does make me wonder, if they're still good enough to be considered the best things ever written in English, how good they actually were when they were new.

But at the time they were just disposable entertainment. It's a happy accident that some friends of Shakespeare liked them enough that after he was dead they gathered up some of the old scripts and published them.

So now it looks like we might need an English to English translation process.

And what about dialects? Where I grew up, people would say "Can tha borrow us twenty pence till tomorrow?".

That's so meaningless in the Standard English of the South that the meaning is immediately obvious!

Some people deal with this by saying that the Northern version is "wrong". These people need to explain what they mean by "right". Notice that the Northern phrase uses "tha", the singular you form that Shakespeare also uses. Is that "right" or "wrong". Maybe "right" is time dependent, and Shakespeare gets to use thee but moderns don't?

What about "Our father, which art in Heaven, hallowed be thy name?". Surely that's Standard English. It's old, but people say it every day. And even modern religious men call God Thou instead of You in their prayers. Is is right or wrong?

What about "to boldly go?" What about "That is a rule up with which I refuse to put?" (The rule up with which Churchill refused to put was never to end a sentence a preposition with).

What if all the people in the South of England were to die of some guacamole-related disease which didn't make the jump to mushy peas?

What would be right then? After all the reason that Elizabethan English isn't modern English is that the Elizabethans are all dead.

Anyway. It looks like we need a way of translating from English to English.

Almost certainly, we need a way of translating from one person's English to another person's English.

But we're not done yet. As you age, you learn new things.

If I say "The best way to handle an exception is to throw a trampoline", I'm making a point about computer science. If my fifteen year old self had said this, then he'd have meant that when you run into weirdos you should throw sporting equipment.

These two perfectly comprehensible sentiments have very different translations into French, but they probably have very different translations into the English of almost everyone else in the world. Including me at thirty.

So, to recap.

How can we tell if two texts are the same? How can we tell how different they are?

We can't.

It's all subjective.

Two texts that are absolutely identical can have different meanings to different people.

Two texts that are different can have the same meaning to one person.

Two texts that are arbitrarily close can have arbitrarily different meanings.

Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.
The king of France is bald.

The problem with this is that it is all horse-shit.

Of course one thing can be a translation of another thing. Of course you can read a document in French that doesn't tell you anything you don't already know from reading a document in English.

I have read Alexandre Dumas and Fritz Lieber and Douglas Adams and Edgar Allen Poe and Asterix and the Bible in English and in French.

The books are recognisably, obviously the same books. There are little differences that make it a pleasure to compare them. There are mistranslations, there are places where one language can't express the thought in the other language without going all round the houses, and thus introducing new ideas, which weren't in the original.

But it's nothing serious.

Or is it?

Dumas and Lieber and Adams are both better in their own language. The translations are poor shadows. The joy is gone.

Edgar Allen Poe (translated by Baudelaire, no less) is much better in French!

The Bible is flat and dull in French (as the Vulgate is in Latin). The English Bible (Authorised Version) is one of the most beautiful books in the language. I can't imagine a non-religious Frenchman loving the Bible.

On the other hand, there are lots of really tedious English bibles. They often have the word 'modern' in their titles. But the content is always exactly the same.

Accurate translation matters to these people a lot. Accurate translation mattered very much more to the people who translated the King James.

Asterix is hugely funny in English and in French, but the jokes are different!

When Asterix goes to visit his British cousin, he remarks that he likes his cousin's tweeds, and asks if the fabric is expensive.

The cousin replies that his tailor is rich.

This is funny in English because of the understatement. I thought it was hilarious when I was a little boy.

It is the same sort of thing that is going on when someone rants on for twenty minutes about how bad a restaurant is, and someone else says "So you wouldn't recommend it then?".

It is a form of humour that only the British understand. Even the Americans, who speak what is recognizably a subset of English, don't really get it.

In French it is funny because "My tailor is rich" is a famous useless phrase from a post-war English course that every French schoolchild once knew, like "The pen of my aunt is larger than the garden of my uncle" or "My postillion has been struck by lightning" or "My father was a war profiteer and made all his money on the black market" (seriously, my father has a German phrase book with this in).

An absolutely literal translation of the same phrase means two completely different things.

And if you read it now, you'll see both meanings at once. So I've just changed the meaning of a pre-existing text for you.

What on earth is going on?

### Thirst (Film)

I imagine that if you

(a) are into vampires
(b) grew up with enough far easteners that you can read their facial expressions
(c) speak Korean
(d) don't find the film's grubby aesthetic a complete turn-off

then this is one of the best films ever made.

I don't tick any of the above boxes, but I still enjoyed it.

I can't imagine a British or American remake capturing the spirit of the original, but if the French could get the guy who made Mesrine to rip this off, it could be awesome.

In a summer of fine films, this is the first one that I wouldn't immediately pay to see again if a friend wanted to go, but I don't think it's bad.

Far from it. An interesting tale well told. I think the acting's good too, but it's just impossible for me to tell since I'm so bad at reading the emotions of the actors.

## Wednesday, October 28, 2009

### Twisted Wing (Ruth Newman)

I ought to declare an interest here. Ruth is an old friend from college and I read her book before it was published. I'm told one of the characters is me. I'm not sure which one, although everyone else says it's obvious.

It's just come out in English, having been published in various translations first. I bought a copy for Ruth to sign, and read it, for the third time, last night.

It's very good! It's about a series of killings in Cambridge, at a (very thinly disguised) King's College, where we were both students.

I don't usually read detective fiction, but I would if it was all like this. It's been impossible to put down on all three occasions that I've read it. I started at about 10pm last night, and finished it at about 3am. As a result I'm completely knackered today. I recommend starting it just after tea on a quiet night.

This despite the fact that I already knew what was going to happen.

The plot twists violently and intriguingly, which I think is why you can't stop reading. The sense of the rather claustrophobic student life is spot on. It's heart-rending to see the characters forming the same sorts of life-long friendships that we made, only to see them ruined by the actions of a maniac.

The villian is the most terrifyingly evil character I've ever read about. I don't know if that's a commonplace of crime novels, but it scares all hell out of me.

## Tuesday, October 27, 2009

### Agora's elevator pitch

The web is an advance in communications technology

The new literary forms have not settled down yet.

Examples of new forms are wikis, search engines, ranking sites, social networks, blogs, newsgroups, e-mails, homepages, and mailing lists.

Spam is also a new form. There has never before been a malevolent literary form. It plagues all the above forms. It might be better described as a parasitic meta-form. It must be dealt with by concepts of reputation.

None of these new forms looks like a final form. They will all be improved upon.

It might be possible to make a new form by examining all the features of these forms, and combining them. In the process new features may become obvious by their absence in the space of known features.

For instance why should threads be a tree rather than a DAG or general graph?

Why should a post not be able to become an ancestor of an earlier post?

I intend to attempt to construct a new form.

I am going to call it Agora, after the market place in Ancient Athens where the philosophers once debated.

### A meta rhetorical tree (boring)

WARNING: this article has been judged to be boring, and will at some point be rewritten.

In Ancient Athens, there were two ways to explore an idea:

Dialog, spoken conversational philosophy
Rhetoric, written philosophy

Of course a dialog can be written down, and rhetoric can be read out.

So perhaps a better way of putting it would be:

Dialog, where two or more minds compete or collaborate whilst exploring an idea.
Rhetoric, where one mind takes an idea and runs with it.

### Just tickled me

A quote from: http://www.joelonsoftware.com/items/2009/10/26.html

We got to talking, and he told me about his latest brainchild, UCOSP, which stands for “All The Good Names Are Taken.”

### Science Fiction Idea

Supernova explosion screws up faster than light drives.

Supernova suddenly chops off a part of the galaxy.

Explosion effects spread outwards at speed of light.

Therefore no way to know about it before the effect reaches you.

People trapped in the nova system just die.

People on nearby systems are suddenly isolated from the rest of the universe.

They can send messages, but only to those already caught.

To the outside universe it is simply an incomprehensible Bermuda Triangle.

What warning do you get of supernova? Would the star be obviously about to nova, or would it need to be worked out from astronomical records later, or is it a sudden, surprising thing? Actually just an ordinary nova or flare would do.

How long does the expanding Bermuda Triangle puzzle the outside for?

Do ships jump in to try to find out what's happening, only to realize that they can't go back?

Do people go in on humanitarian missions?

Three part novel?

Part One

Outside society trying to work out why ships have stopped coming from a star system. Ships that jump in are goners.

Then the effect claims another system, the nearest to the first at lightspeed.
Maybe someone gets out? How? By the time they realise that they're getting no response it's too late? Only if someone sends a hyperspeed probe and it doesn't return can they realise that there's something screwy going on. Then they need to send a second. Then on a freakish hunch they can jump in a straight line away from the first system. But they still haven't seen the supernova!

Panic and evacuation in the second nearest system either way. Terror everywhere else.

How far will the effect spread?
Once they've worked out what's happened:
What will have gone on inside the boundary?
Perhaps someone's isolated without supplies somewhere?
Discovery that one can jump in, but never leave.
Mission is sent.

Part Two

Description of the end of the world on a planet in the nova system.
Or if it's a flare, redo Inconstant Moon.

Description of the arrival of the wave front in the second system.

Description from the point of view of the people stranded without supplies. Efforts to achieve self sufficiency, even knowing that they're doomed in the medium term.

Part three

Arrival of the rescue team from Part One.

How do they save the day? Bring enough supplies to endure long term?
Bring enough to get through the crisis? How long will the effect last?
Bring cryogenic coffins to wait it out in?

Bring an awesome ramjet drive to escape in? It can't outrun the nova, but the effect may cease eventually? Alternatively you could go on a long loop to make time pass faster.

Has this already been done? It's nothing that couldn't have been done in the sixties and there aren't that many ideas.

Maybe there's a part four where a planet is awaiting its doom, sees the supernova light, but its drives are only screwed up, some engineering work can make them usable. Just after this is discovered, the escaping ramjet streaks through the system. Now they have to rescue it somehow. It will take ages to slow down on its own.

How does the rescue happen? I think you have to accelerate to match, take off just the people, and then accelerate back down to normal speed.

You're still left with an enormous pocket of trapped people. Maybe the outside universe, and most of the planets in the pocket go all mote in god's eye, but on one planet they manage to get control of their population, and are the only remaining conscious beings?

What happens to them when the effect subsides, thousands of years later?

## Monday, October 26, 2009

### Stuart: a life backwards (Alexander Masters)

I'm deliberately writing this before I go and find out whether Stuart was a real person.

If not, then the writer has done an utterly convincing job of character creation.

Stuart was a man of my own age, living in my home town (Cambridge is technically a city, but it's very small for a city). Many of the places he hung out in are places I hang out in. We must have seen each other many times.

To be precise, he must have asked me for money many times. I must have ignored him many times. I hope I never gave him any.

He died seven years ago. He may or may not have thrown himself under a train.
Certainly he often felt like doing so.

His relatives probably still live here. I probably ignore some of his friends, despise them or meet them socially every day. I used occasionally to play chess with a homeless man. I know at least one person who is a permanent resident of one of the hostels mentioned in the book.

It's pretty clear that everything that happened to Stuart had at least some causes that were nothing to do with his own desires. There are certainly original sinners in the book, but they must have started down the primrose path when they were little more than children themselves. And who knows what black causes moved them? And who knows how much difference they actually made to Stuart's life?

But then I can't imagine any sort of morality that could have anything to say about a life as chaotically abnormal and packed with misery as Stuart's.

Bastard world. Bastard God.

It's even possible to see Stuart as brave and noble, triumphantly overcoming the worst possible hand of cards to become someone worthwhile. Certainly I pray that if I ever found myself in his predicament I'd be able to hold it together long enough to kill myself.

When I was young, I used to give money to anyone who asked. I believed that anyone who could lower themselves to asking probably needed it more than I did. It was possible to believe this then because there just weren't many homeless outside London. And I didn't live in London.

I can still remember the shock of seeing my first street sleeper in Sheffield. And how much we hated it when the problem grew so bad that the council sawed up the communal benches in the 'Hole in the Road'.

Someone wrote "Sheffield People Sit Together" in huge letters on the concrete, and I thought it was a wonderful statement. How could anyone be so cruel as to deny the desperate a bench to sleep on? How could my proudly socialist city hate the poor?

In my mid-twenties, I remember telling a police officer that I gave money to the homeless. He told me that I was a fool, and that they were laughing at me behind my back. And I remember how proud I was to tell him that the fact that they were sitting in pools of their own urine took the edge off their laughter for me. He had no response. He was a good man, that policeman. He tried very hard to help my sister.

But later on, there were so many homeless, and plenty of people willing to provide beds and plenty of money for them to live decent lives, and how could anyone so alienate their friends and relatives that no-one would give them a sofa for long enough to get them off the streets?

I began to put it down to some mysterious combination of drugs and laziness and insanity and learned helplessness and welfare dependency and began to believe that they were a sort of poisonous parasite that corrupted human generosity.

And I stopped giving them money. Partly because it obviously didn't help. Partly because it was costing me a fortune. And I was already giving half what I earned to the state, supposedly to help the poor. How much more money could these very few people need?

And I began to despise them. And I've carried on despising them until now. But I never thought that they were happy. And I never thought that they were in their situation by any real choice of their own.

But I'd never really thought about what it must be like to be homeless. Or what it must take to both survive and stay homeless.

And this book has changed me. And now I've stopped despising them. And started fearing them. And they don't deserve fear. Fear leads inexorably to hate.

## Sunday, October 25, 2009

### Cars: A Rant

A friend of mine is in hospital after she was hit by a car. She has a broken pelvis and a crushed ribcage. She may never walk properly again.

About fifteen years ago my little sister had a similarly awful experience, and spent three months in hospital after some witless bitch turned right in front of her and knocked her off her motorbike. She's still scarred, one of her hands doesn't work properly, and she has a not unreasonable fear of roads.

About a month later, the exact same thing happened to me, but I got away with just a wrecked bike and a week of not being able to walk or breathe properly.

When I was in my twenties, a friend of mine was killed when he was walking down a rural road and a car just wiped him out for no reason.

A few years ago, I heard that another old friend had been killed on his way to work in a similar manner.

My grandmother in her seventies was knocked down and horribly injured on a zebra crossing. It took her six months to recover.

Is this concentration of horror a statistical fluke, or are these things just ludicrously dangerous?
We wouldn't dream of allowing people to inflict this sort of toll of death and injury on others in any other aspect of life whatsoever. Even wars aren't usually fought against defenseless old ladies.

None of the above incidents involved alcohol. Why have we got such a downer on drink-driving? It's not the drinking that's the problem.

For comparison, I know one person who's died of lung cancer, and he was seventy-eight years old, and no people at all who even know any people who've been murdered or killed in accidents not involving cars.

Can you imagine what the reaction of Health and Safety would be to an industrial plan to allow semi-trained angry morons to control huge pieces of deadly machinery moving at lethally fast speeds amongst members of the public protected at best by two inch high barriers?

I once lost control and skidded across a zebra crossing on ice. Until I put the brakes on and lost all grip on the road, I wasn't even aware that I was doing anything dangerous.

Fortunately the four people on the crossing had time to scatter out of the way. I could quite easily have killed them all. Why on earth should anyone be allowed to take that sort of risk with other people's lives and health?

Recently I've been hearing a lot of bleating from various murderous psychopaths about forcing cyclists to wear helmets, so that the psychopaths in question don't need to drive as carefully in order to reduce their chances of killing them.

Can anyone explain why this is morally different to requiring people in shopping centres to wear flak jackets so that people who like to let off shotguns in shopping centres don't have to be as careful where they aim?

Briefly this summer I lived on a road in the centre of town which is effectively a dead end, and on which so many cars are double-parked that it's very hard to drive down at all. The four or five children who lived on that road played together every day in the street, with balls, and with roller skates, and with scooters, and seemed delightfully happy. They always smiled at me and said hello when I went out and came home. They reminded me of my own childhood. I haven't seen anything like it for thirty years.

When I was a child, it was possible to play around my home village. When my parents were children it was possible for them to play in the streets of towns.

I have just moved from a comparatively car-free part of Cambridge, to Mill Road, a filthy, permanent traffic jam, where enraged idiots make daily attempts on my life in order to overtake me as I cycle. Their usual reward for successfully squeezing two cars and a bike into enough space for two cars is to join the next stoppage five seconds earlier than they would have managed if they'd driven safely.

I enjoy flicking them the finger as I pass them, and I fantasize about beating them to death with my bike lock. From talking to people, it seems most people who live there feel the same way. Some other people drive down Mill Road because it's too dangerous to cycle. They spend hours in screaming frustration in traffic jams and hate cyclists. They fantasize about mowing us down. There's nowhere to park in town. A significant number of them are driving to the gym.

If I cycle in the middle of the road, as recommended in the highway code, to prevent drivers overtaking in the face of oncoming traffic, then their response is insane in its fury, usually involving sitting on their horn, and occasionally involving deliberate attempts to knock me off. Probably meant more as a warning than as an actual assault. I hope.

I know one man who was actually knocked clean off and run over by a taxi driver who objected to being behind him. Apparently the next car in front was about fifteen feet away at the time.

I find this so distressing that I am going to move to a place with less insane roads as soon as I can, which is a shame, because I like my new house, and wouldn't leave otherwise. If I had children, I not only wouldn't let them cycle on Mill Road, I wouldn't let them walk near it either.

And Cambridge is unusually bike friendly. I don't think Mill Road would be considered a particularly dangerous road in most cities.

Almost all modern children, it seems to me, are forced to rot inside because if they go out they'll be killed by some stupid cunt who wants to get to Tesco's and thinks they're a bit too important to drive carefully.

If children are allowed out, then they have to be driven! It's the only safe way to get around unless you've got a degree in road safety and also have a lot of luck.

OK, so that's the case against.

What benefits do we get from widespread car ownership and use?

Well, people can live much further away from where they work than would otherwise be practical. Which is obviously a good thing, because if people lived near where they worked and where their friends and families lived, they wouldn't have time to watch so many adverts. Then they wouldn't need to work so hard and the economy would collapse.

They can shop in horrid soulless shopping centres miles from where they live. In fact they have to, because all the local shops have closed down.

And it gives people a nice way of honestly communicating how wealthy or sophisticated they are. In England, what with class getting in the way, this system is complex and very entertaining. See Kate Fox's "Watching the English" for an overview and many amusing details. This is probably a great help in mate selection and alliance forming.

Anything else?

I suppose it's possible that the fact that everywhere's filthy and ugly and smells of petrol might be a benefit.

And certainly the building of roads has destroyed a lot of areas of natural beauty and inconvenient wildlife which were wasting a lot of space.

And it's sliced a lot of communities in half. Smaller communities are tighter knit.

And a lot of very unpleasant angry people are isolated from decent society by having to spend hours every day sitting alone in antisocial little steel boxes in traffic jams and on motorways. Listening to morons on the radio.

Is there anything good about these fucking things at all?

-------------------------------------------------------------------

Don't get me wrong, by the way. I actually love cars and motorbikes and petrol engines and the freedom of the open road. I even like driving dangerously as long as I'm nowhere near anyone else whom I might hurt.

I currently own a big transit van, and there was a point where I owned four motorcycles simultaneously. I can strip and reassemble an old engine without a manual. And it will still work afterwards.

It's just that the benefit of driving to me is very small indeed compared with the cost imposed on me by the vehicles of everyone else.

And much as I love my van, if we could all agree to put all our vehicles on a big bonfire I'd be happy to put mine on too.

But even if we can't do that for some reason that I don't really understand, could we perhaps agree to keep them at the edge of town, and then if we want to go somewhere a long way away, we could cycle the first mile or so?

And we could have race tracks and rally courses for petrolheads like me to go and play on. Because I really don't mind people hurting themselves, or even other consenting adults. It's only the innocent and non-consenting victims I want to save.

And at the moment that's all of us.

### Anathem (Neal Stephenson)

This is an extraordinary book.

http://www.nealstephenson.com/anathem/

It's difficult to imagine a more flagrant breach of xkcd's fiction rule of thumb, especially since one of the made-up words is actually "fraas".

And for this reason, the first few chapters of this massive book are heavy going.

But there's just enough of interest to start to draw you in, despite the seemingly needless difficulties caused by repeatedly making new words for both familiar and unfamiliar things.

You rapidly get comfortable with the strangeness of Fraa Erasmas' world, and are slowly drawn into the detective story which is one of the main themes.

Soon there are terrible injustices and secret conspiracies that are crying out to be explored and rectified. Small strangenesses start to pull apart the fabric of the world and its history.

Like all really classic fiction, the novel manages to evoke a world of vast age and wonder, without ever really going into details about it. As well as the actual story, there is a huge hinterland to be imagined, and you start to really care about the exploits of ancient philosophers and long dead saints who aren't mentioned more than in passing in the text. There are hints of ancient technologies, now lost, and hints of conspiracies, and hints of technologies so far advanced that they are indistinguishable from magic. Echos of ancient horrors, and hidden reasons, and secret cabals.

The book launches ambitiously into maths and logic and physics and their philosophy. Geometry, Dynamics, Platonism, Sophism, Formalism and consciousness itself are discussed by the characters as they grope towards quantum mechanical formulations. The influence of Penrose and Deutsch become obvious as the Hylean Theoric World of the ancients becomes a flow in a vast phase space.

The book becomes simultaneously a book about ancient magicians and alien invasion.

The triumph is that all of this works. The philosophy seems vital and important. It's not side material. It's the plot. There's no contradiction between the wizards and the scientists. There are genuine mysteries and moments of heartache.

If Cryptonomicon was nine-tenths of a barnstorming novel followed by a surprisingly weak ending, Anathem is a true masterwork with a slow start and a climactic ending which is damned near incomprehensible.

It took me four days to read this book. I am going to give myself a couple of days before I read it again. There is no way that I am not going to read it again. I feel utterly compelled to try to work out what the hell was going on.

Ever since I finished reading it there have been bombs going off in my brain.

I can't think of a higher compliment to pay to the author.

I can imagine, as with "The Mote in God's Eye", that some people might not like the setting and style. I cannot imagine that anyone with an interest in intelligent science fiction would not be pleased to have read this book.

### Nick Griffin on Question Time

This persuaded me to watch television for the first time in about ten years. It was truly remarkable to see British politicians talking openly about race, which is pretty much the only taboo subject in the UK.

I think I must have felt something of the thrill which people in the 1950s had reading 'Lady Chatterley', back when sex was taboo and racism was commonplace.

Almost from the word go the debate made me proud to be British. The majority of the white panellists and audience clearly found the BNP shameful, and attacked Griffin relentlessly. Many of the black and asian members, however, seemed to be going out of their way to try to understand what the concerns of the BNP voters were.

Even Griffin himself, the closest thing we've had to a fascist demagogue since Mosley, seemed to be amused by jokes made at his own expense. Which during a live debate on national television is quite a feat. Maybe he was faking it as part of his scheme to not come over as a nutter.

I was reminded that Orwell thought that the British were immune to fascism because they'd find it ridiculous.

Certainly Hitler and Mussolini have always been comic figures to us. Given what they did, and how many of us died to stop them, that's quite remarkable. I don't think anyone else in the world finds them funny. We did at the time.

The only exception to this classically British orgy of embarrassment and smoothing-over was the American, Bonnie Greer, who came over as insincere and patronising. On the other hand, she was the only person who stood up for the classical Mill/Voltaire view of free speech. A form of uncompromising American fundamentalism that I can absolutely identify with.

I wonder if the reason that we don't seem to do extremism is because we don't really care too much about anything as long as no one gets too upset.

After Kate Fox's demolition job on our national character, Watching the English, which I found all too convincing, it's nice to be reminded that embarrassment, squirming, hypocrisy, evasion and reserve have their good sides too.

## Thursday, October 22, 2009

### The Imaginarium of Doctor Parnassus

Lavish, beautiful, wonderfully acted (Lily Cole, Tom Waits, Christopher Plummer are all awesome), entertaining.

Weirdly flat. I don't know what's missing. But go see it anyway. It's well worth the time and money. It's just not quite as good as you'd think, given how good it is.

Go see it at the pictures. The point will be lost on TV.

### Fish Tank (Film)

A triumph.

I spent the first fifteen minutes of the film in the state of sick horror entered by the British middle class when contemplating the poor, and the rest of it rooting for Mia.

God, I know she's fictional, but I really hope she's ok.

### Do vegans hate animals?

In conversation with a vegan friend the other day, it came up that she would feel bad about eating meat, since it takes so much more land area under cultivation to produce beef than grain. She said four times. She felt that by eating meat she would be depriving other people of food.

I presume that by this she meant "The area sufficient to sustain one human life if that human were to live exclusively on meat could sustain four humans should they live entirely on wheat".

Obviously this is a somewhat meaningless statement, since either diet would kill you! I also have no idea whether it's true. But let's run with it for a bit. More rigorous versions can probably be concocted if necessary.

She probably also meant to say "And for at least some parts of the world, the limit on population growth is food supply". After all, if nobody's short of food, what is she feeling guilty about?

Our planet has a finite amount of farmable land area. Therefore, if population were to be restricted by food supply, the population would be four times greater if we were all vegans than if we were all meat eaters.

On the farmable land, there would either be lots of farm animals in the meat eating case, and none whatsoever in the vegan case (vegans don't exploit animals in any way).

Obviously in neither case would there be any room left for wild animals or plants on the farmable land. So the remaining wild creatures would have about the same land area left to them in either case (the bit we haven't worked out how to exploit yet).

But there'd be four times as much pollution and that would have amplified consequences in the vegan world. There'd be higher greenhouse effect , more poisoning of ecosystem, and so on. This might well have bad consequences for both the animals and the people.

So the vegan world would have many fewer farmed and wild animals, probably of many fewer types than the meat eating world.

I think domestic pets would probably have been 'phased out' in either case. When children are short of food, dogs and cats aren't likely to be a priority for many people.

The only sort of animal I can see doing better in the vegan world would be the various pest species.

Lots more humans and lots more grain in the world probably means vast numbers of rats and cockroaches.

Maybe that's what she meant. She claimed to like animals. I didn't get the feeling that her veganism was a plot to destroy them or anything.

### Miracle Diet

OK, here's how to lose weight, cheer up, and enjoy your food much more than you usually do. It takes very little willpower as far as I can tell, once you understand the reasons for it.

I worked this out on my own by weaving together a vast skein of half-understood pseudo-facts and crank diets. There's no evidence to support it. It's probably wrong.

I have conducted a single poorly designed experiment on myself over a period of two years and it works a treat for me.

Here we are:

II. Grains and potatoes count as processed foods.
III. So do sugary drinks.
IV. Fruit juice is a sugary drink.

Or, expressed more positively:

Eat lots of vegetables, lots of fruit, and lots of meat.
Prepare them however you like.
High-fat things like sausages, olive oil and grated cheese are fine in small quantities, but don't make them the main substance of meals.

Every time you consider the purchase of a piece of food, ask yourself "Could my distant pre-farming ancestors have found this anywhere in the quantities I'm about to eat it?"

You might think this is a bit extreme! I'm telling you to abstain from almost everything. Actually no. You are still allowed to eat almost everything that human beings and their ancestors have eaten right up until the invention of agriculture.
That's absolutely stacks of stuff. We are omnivores. (Everything-eaters.) The reason that it looks as though everything's off limits is because we have almost completely replaced our natural diet with a very few things we can farm, namely wheat, rice, potatoes and sugar.

We eat a monotonous diet of bland, tasteless pap which needs to be artificially flavoured before we can eat it.

Imagine what a sandwich would be like without the filling. A pizza without its toppings? Chips (french fries) without salt and vinegar?

And have you ever seen what factory made food looks like before they add the stuff that makes it edible? You need a list of flavourings and colourings as long as your arm to make it into something you'd put in your mouth voluntarily.

Once you stop eating this slurry, you'll realise that there are lots and lots of other things to eat, all of which have their own interesting flavours. Don't get me wrong. I love chips (french fries) as much as the next man. But I wouldn't go back to eating my monotonous old diet even if it was conclusively demonstrated that the new stuff was killing me and you were offering me money as well.

You don't have to be a freak about it. You don't have to stop eating in restaurants or with your friends. You don't have to be ungrateful to your Mother when she makes you your favourite pasta and baked potato rice pudding with sugar and puts a glass of fruit juice and coke next to it.

This stuff isn't poison! Just be careful with it. A mild heroin or cocaine habit won't do you any real harm. It's only when you start taking the stuff every day that you start to collapse.

Actually you can break these rules all the time once you're sensitive to what's going on. Understanding the "theory" behind them is a much better guide to what you should do.

But if you ain't into all that thinkin' stuff and just want another miracle diet to try out my four-rules-which-are-really-one-rule above are pretty good.

You should learn to be aware of what happens when you eat these things:

The processed foods (including potatoes and grains) divide into:

1. Large amounts of fast carbohydrates:

Characteristics
They taste bland and need to be flavoured.
They are really filling.
Shortly after you eat them you feel really tired.
Once the tiredness clears, you are hungry again.

They will cause mood swings and tired-all-the-time
They will make you fat
They will give you diabetes

Examples: Rice, Potatoes, Bread, Pasta, Breakfast Cereals.

2. Sugary Drinks (Including Fruit Juice!!)

In large quantities, see above.
In small quantities, the problem with these things is that they provide extra calories without taking up any space in your stomach.

3. High Fat Products

Things like vegetable oils (including olive oil), cheese, sausages.

I don't have a specific problem with these, but you probably shouldn't eat big stacks of them, just because they contain very great quantities of calories, and it's not at all clear that your body knows how to react to a diet unnaturally high in fats any more than to one unnaturally high in carbs.

But using olive oil to stir fry vegetables, or putting it in a curry, or adding bits of cheese to a salad, or having a couple of sausages with something else is probably perfectly ok.

Just don't do what I used to do when I rowed a lot, and eat a whole pack of sausages at once, or a block of cheese for lunch, or drink olive oil out of the bottle.

Or, for that matter, down an entire two-litre bottle of full fat milk over the course of the morning.

Dairy products probably need a separate section.

Milk is definitely a recent, unnatural food. And there are plenty of people in the world who just can't metabolize it at all. But we in the West seem to have dealt with milk pretty well, by extending the infant mammal's ability to use milk into adulthood. It may have bad effects still, but on the other hand, it may not.

Use it in tea, use the real stuff rather than the nasty skimmed variety, but don't go mad with it. It's calories without substance.

4. Unnatural Fat Products

These are things like margarine, or any sort of spread that doesn't call itself butter.

Stuff like this is contained in just about anything you can buy that has a complicated list of ingredients.

They're basically vegetable oils that have been made into room temperature solids in fiendish chemical reactions. They're absolutely bloody everywhere.

As far as weight gain goes, see the section on fats above.

However there's increasing evidence that the old distinction between 'good' unsaturated fats and 'bad' saturated fats is completely bogus, and the killers are these semi-saturated trans-fats.

Given the chaos that the artificial high-GI carbs cause in our metabolism, I can completely buy the idea that these completely new things do something terrible too.

But that may just be me being superstitious.

2a. Beer.

Hmmm...... You probably don't want to drink too much beer if you're serious about losing weight. It's got calories but no nutritional value and it's not filling.

I don't think the GI is that high. But it's proverbially true that beer leads to more beer and more beer leads to eating even though you weren't hungry. And if that's not a recipe for overweight, what is?

But there are limits right? I love beer. Who wants to sit in and read improving books on a Friday night? I'd rather have friends and be fat than be thin and lonely any day.

Luckily kebabs are about as healthy as you can get. Lots of lovely lean lamb meat and vegetables. The only bad bit is the pitta bread. But there's not much of that. And curries themselves are fine, even though many of the extras are the devil incarnate.

But careful now! No drunken pizzas.

## Wednesday, October 21, 2009

### Fast Carbs Kill

OK, here's my explanation for why the Developed World is suffering a crisis of obesity, diabetes, depression, malnutrition and the ubiquitous 'tired all the time' syndrome that all doctors see every day and have no idea what to do about.

If it's true, then any Third World society that adopts our lifestyle will suffer.

Those descended from wheat growing, potato growing, or rice growing ancestors will suffer from the problems that we're suffering from.

Those that are descended from hunter-gatherers who never went through a farming phase, or from those who farmed crops which are low in fast carbohydrate will suffer horrific problems. Epidemic Diabetes, Widespread Uncontrollable Obesity, Widespread Suicidal Depression.

----------------------------------------------------------------------

The staples of our modern diet are wheat, rice and potatoes.
Almost all our foods are based on them. What did you have to eat today? A sandwich? A pizza? Pasta? A curry? Rice with that or chips?

Wheat and rice are just types of grass. Grasses distorted out of all recognition from their ancestors by generations of selective breeding so they've got huge seeds. Potatoes are just some freaky stuff from the other side of the world. No ancestral human ever ate one.

We were never really meant to eat grass! Wheat and rice are absorbed far too fast into our blood, causing "sugar shock".

The sugar shock, although dangerous, is actually pleasant. A feeling of fast relief from hunger. We become addicted to it in the same way that smokers become addicted to cigarettes.

By releasing insulin we can deal with the sugar shock, but the recently absorbed carbohydrates are quickly stored as body fat, blood sugar levels overshoot on the way down, and we soon feel tired and hungry again.

We get into a cycle of over-eating, with periods of satiation interspersed with periods of lassitude.
The mood swings and tiredness make our lives burdensome, and can lead to full scale depression.

Anyone trying to resist this cycle feels as though they are constantly trying to give up smoking. Anyone just going with the flow get steadily more and more obese.

If you do large amounts of exercise, you can hold your weight steady, but even this doesn't really work, because if you actually manage to put yourself into a state where you're using more calories than you're consuming, you get hungry and eat more to make up. And every time you take a week off....

So anyone eating wheat or rice or any other high carbohydrate, high GI food is on a sort of ratchet.

If you act as you like, you will get steadily fatter and fatter.
If you exercise heavily, you will stop the increase in weight, but not reverse it.
If you starve yourself deliberately, you can actually reduce your weight, but you will do it mainly by reducing muscle mass, which just makes the fat gain problem worse once you stop starving yourself.

Unfortunately, "high carbohydrate, high GI food" describes the normal diet of Europeans and Americans, and indeed is the diet generally considered to be healthy in the West.

High carbohydrate, high GI food is the diet recommended by governments and most organisations promoting weight loss.

The constant sugar shocks cause our insulin system to fail. After many years of them, we develop type II diabetes. This combination of overweight and diabetes, together with a few fat-related conditions that are probably to do with crap like margarine and the trans-fats that are ubiquitous in processed food, are known as the 'metabolic syndrome'.

Luckily for us, we've had some time to adapt. The invention of agriculture was maybe 10 000 years ago. The new foods must have killed in vast numbers at the same time as they caused the population explosion that led to civilization.

We are the descendants of those that survived. We are better able to tolerate this stuff than the wild hunter-gatherer humans we descended from and have largely exterminated.

But we're still ironing out a few wrinkles.

## Tuesday, October 20, 2009

### The Invention of Agriculture

Once we were all hunter gatherers. Omnivorous animals that can and do eat almost anything which contains energy. For countless millions of years we ate unprocessed meat, vegetables, and fruit. But we didn't eat grass. Natural grass is so energy poor that it's not worth it. Without the special digestive equipment that grazers have, it's no use to us. We can eat the seeds of grasses, but they're very small and not worth the bother.

Then we domesticated grasses. There are many theories about how this could have happened. But they all add up to the carbohydrate-rich seeds being somehow selectively bred to become a viable, and more importantly, a farmable human food source.

Suddenly we had a plentiful, cheap source of vast amounts of edible energy in the form of the easily digested carbohydrates in the big new grass seeds.

Our systems weren't designed to consume such things, because they had never before existed in the history of the world.

When we eat these new things, two things happen.

They cause massive blood sugar rises. This means that they satisfy hunger very quickly. This programs us to crave them when we are hungry in the same way that a smoker craves a cigarette when his nicotine levels are low.

There is a massive release of insulin to cope with the fast rise in sugar. This drives the blood sugar into the fat cells, to be stored for future use. In fact it overcompensates. By the time the shock and response have died down we have lots of new fat, and we are low in blood sugar. We are both tired and hungry. The thing that cures hunger fastest is more grass seed.

So our new foods put us on a cycle of eating and feeling hungry, sugar shocks and insulin release, an addiction to the new food. Drug addiction itself is only a shadow of this mechanism. This was the real thing.

This cycle had bad effects long term as well. The effects of insulin become tolerated over time. Eventually the insulin response to the sugar shock stops working. This is known as Type II (adult-onset) diabetes.

And it must have killed us in our millions.

What else happens as a result?

Well, our new grasses may not be the best food, but they are food, and we can eat them. And a creature with a newly abundant food supply suffers a population explosion.

So the new farmers, malnourished and unhealthy as they were, took over the world. And anywhere that the new grasses would grow, the farmers wiped out by virtue of their sheer numbers any other people who for whatever reason carried on living in the way they were evolved to live.

And once the process was over, any part of the world where the farmers could get to and the new grass would grow was covered in masses of short lived ill overcrowded farmers eating pretty much only grass.

Not for nothing has the invention of agriculture been called the worst mistake in the history of humanity.

### The Glycaemic Index

Diabetes patients were once told to avoid sugar.

They still are.

What's changed recently is the understanding that it's necessary for diabetics to avoid eating anything that will raise blood sugar levels above normal.

So researchers came up with a way of putting a number on the speed at which blood sugar rises after eating.

This is called the Glycaemic Index, and it's a bit counter-intuitive.

You say "how much of this food do I need to have eaten 100g of carbohydrate?"

If your food is sugar, a pure carbohydrate, that's about 100g. If it's carrots, which don't contain a great deal, then it's lots and lots.

Then you eat that much.

Then you see how fast your blood sugar rises. That speed is called the GI.

This leads to some very strange results, and should be treated with care.

For instance, watermelons don't contain many carbs, so you have to eat far more watermelon than would be reasonable.

If you do, then you actually produce quite a sugar shock! So watermelons have a high GI.

But that doesn't mean that eating watermelon leads to sugar shock. Quite the reverse. You'd normally eat them in reasonable amounts. They don't contain many carbs. Therefore they don't cause sugar shock.

To cause a sugar shock, you need both a high GI and a high carbohydrate content.

With that caveat, which foods are likely to cause sugar shock?

Well,

Sugar (not quite a no-brainer, since blood sugar and table sugar are different things)
Rice
Potatoes
Pasta

There are others, but these are the big dangers, simply because our modern diet is full of them.

Three of them are derivatives of wheat, which is a recent domesticated form of grass probably not more than a few thousand years old.

Rice is another form of grass which has been domesticated, and over the years made to produce huge edible seeds.

Potatoes came from the New World. No human being or human ancestor ate them until the first Americans, and we're not descended from them. My ancestors first met the potato about three hundred years ago.

Sugar is a highly processed product. I doubt there was much around in the diet of our hunter-gatherer forebears.

Our distant ancestors would not have eaten anything like these things. Those of us who are descended from farmers have recent ancestors who have eaten them, so we can deal with them, but not very well.

## Monday, October 19, 2009

### Atkins and Diabetes

Dr Atkin's low carbohydrate diet seemed to work, but no-one knew why, and it was thought to be a grossly unhealthy thing to do. By traditional reckoning, it just shouldn't work at all. In fact it's the opposite of the traditional weight-loss advice.

Diabetes is a disease of carbohydrate metabolism. Fat and protein take a long time to metabolize.

Carbohydrates, however, can be digested very quickly. When you eat carbohydrates, your blood sugar levels rise much faster than when you eat fat or protein.

This is because carbohydrate is the active form of energy. Fat is for long term energy storage. Protein is for building actual body structures, and its energy value is a by-product.

But carbohydrate is how living beings store energy that they may need to use in a hurry.

There is little carbohydrate in nature. Animals such as ourselves contain it only as blood sugar. Most plants contain it only in the form of cellulose, a structural building block that plants use but animals don't.

Humans and our fellow omnivores can't even digest cellulose. Herbivores can, which is why they can make a living eating grasses, but they need complex digestive systems to break it slowly down.

Our ancestors would not have eaten much carbohydrate.

But there was some carbohydrate in our ancestor's world. Honey and fruit sugars are the obvious examples.

We love both, especially as children. Often the only way to get a child to eat a new thing is to cover it in honey or sugar.

If you're tired, and your blood sugar is low, a little honey or sugar can bring you back to life almost instantly. Athletes like rowers or cyclists know this. Another thing they know is that eating these things just before a race doesn't help. You end up being strangely tired. They only help for recovery. Weird huh?

But honey is very hard to get hold of. And fruits are not densely sugary. And what sugar there is in fruit needs to be extracted slowly from the fibrous matrix of the fruit.

Another source of carbohydrate is in the seeds of plants. But that would have been very fiddly to get at for our ancestors. Not least because modern forms of domestic grasses are, like the dog and the cat, very recent human inventions.

The ancestral grasses would have been very thin stuff. With tiny seeds. They might have been worth something in a pinch, but you'd have had a hard time living off them.

So our ability to metabolize large amounts of carbohydrate is a recently evolved thing, and it doesn't work very well.

Say you eat a large quantity of carbs, say a bowl of sugar or a few slices of bread or some rice or some of that delicious breakfast cereal with the pictures of the thin women jumping up and down on it. (they're not too different in terms of energy content or compostion. If you keep any of them in your mouth for a few minutes you'll taste it starting to turn into sugar).

It doesn't stay in your stomach very long. It's already so close to being blood sugar that a couple of simple chemical reactions can turn it into the right form, and at that point it goes straight into your bloodstream.

At that point, if  you're diabetic, you're in big trouble. Your blood sugar levels go far too high and the stuff starts causing havoc.

If you're not diabetic, you have a coping mechanism. People whose ancestors were farmers do it better than people whose ancestors weren't.

You release insulin. This is like an alarm signal for 'blood sugar too high'. All your cells start sucking sugar in as fast as they can and frantically turning it into fat. Very soon you're safe. You actually overcompensate a bit. Your blood sugar levels are now too low because you've cleared all the glucose from your blood.

You know that feeling you get after a heavy meal, say a nice pizza or baked potato. Where you feel lethargic and don't want to do anything for a bit? People call it 'digesting'. Actually all the digesting was done a while ago. You're now hypoglycaemic, which is a greek word meaning that you're blood sugar's too low for you to be able to do anything.

Not to worry though. Your body soon notices, cancels its over-sugar panic response, and blood sugar starts being released from the places where it's stored, and goes back into your bloodstream.

You're now in a state where your blood sugar is a bit low, and your blood sugar reserves are a bit depleted, because you've just used some of them to recharge your blood.

The name for this new state is 'hunger'.

---------------------------------------------------
Footnotes
---------------------------------------------------

Rereading, there's a lot of stuff here that I've just picked up without noticing, and some of it looks suspicious now I come to write it down. I may have made some of it up! Does anyone reading this know one way or the other?

I've said that people whose ancestors were farmers are better at carbohydrate metabolism. The reason I think this is because I read a book where it was claimed that the introduction of the Western diet to Pacific Islands caused large scale diabetes and obesity. I can't even remember the name of the book.

And I don't know what the high blood sugar havoc actually is in diabetics. I think it's quite bad though.

I know several people who "don't get fat whatever they eat". All women. That may be selection bias. Men don't talk about weight much.

I wonder if these lucky girls are at risk of diabetes? Or perhaps they have some super-controlled insulin response that doesn't overcompensate and leave them hungry?

I wish I had a continuously sampling blood sugar monitor I could wear on my arm to test all this out!

### Atkins shouldn't work.

"Give up all forms of carbohydrate, eating whatever else you want in whatever quantity you like."

I don't know if the good doctor ever said this. I'm pretty sure that the modern version is nothing like this. But that's the folklore version, and plenty of people have tried it, and it seems to work in many cases.

An Atkins dieter has to avoid anything with carbs in it. No bread, potatoes, rice, fruit, beer, pastry, etc. etc.
No pizzas. But you can eat all the steaks and eggs and sausages and cheese and fish and vegetables that you like.

And that's absolutely ridiculous, and cannot be true, according to the traditional advice. You do exactly the wrong things, eat all the high fat stuff, and you lose weight.

You probably also make yourself very ill! If you're living on bacon and eggs and steak, where are you getting vitamins from? Why don't you just die of scurvy or something?

Let's ignore the question of vitamins. Probably no-one can stick to the pure diet. They'd be desperate for vitamins and they'd crave them. They'd probably sneak the odd fruit or the odd vitamin pill. Besides, it takes ages to die of scurvy.

If we're interested in why it works, more interesting is the fact that you need carbohydrates to burn fat. Without some sort of carbohydrate supply, you can't metabolize fat at all. How can you be burning it? What is going on?

Originally, it seems that there were two explanations for the success of the Atkins diet:

(1) The diet is so restricted and tedious that it is simply impossible to eat enough calories to make up for the exercise that you do as a normal part of daily life. Hence, weight falls off.

This was the initial reaction of  diet experts. It seems unlikely to me. There are lots of things to eat that don't have carbohydrates in them.

(2) Your only sources of energy are protein and fat. The complete lack of carbohydrate disrupts your metabolism so badly that you burn fat very inefficiently. So you fail to extract much energy either from the fat you eat or from your body fat. So you lose weight fast (because you are dying!). This was Atkin's explanation.

I'm not at all sure about this one either. There is this thing called 'ketosis', that you can induce if you successfully get rid of all carbohydrates, but by that time you'd have managed to make yourself very ill indeed. I can't imagine that that sort of behaviour is any more sustainable than starvation.

But as I said before, I knew a couple of people who'd tried it, and it seemed to work, without any weird side-effects. Neither of them had taken it seriously enough to induce this ketosis thing.

A much more plausible explanation was provided by people who were into diabetes research.

### Dr Atkin's Diet Revolution!

A chap I knew had recently turned himself from a conspicuous lardy into a fairly trim young man. So I asked him how he'd done it.

He looked rather sheepish and mumbled something about 'Atkins Diet'. He described how the thing was to give up all carbohydrates. Apparently he'd spent a few months craving potatoes while the weight came off but it was all fairly easy. I decided to look this up on the web.

It turns out that the general opinion on dieting is pretty much summed up by the Dilbert cartoon where the pointy-haired boss is trying to choose diets, and says "should I go on the one that will kill me, or the one that will make me miserable, but won't work?"

It does seem to be agreed that the Atkins diet works, but no-one's entirely sure why, and everyone's convinced that giving up carbohydrates entirely and just living on protein and fat has to be horribly bad for you in some way. And for some people the Atkins diet doesn't seem to work at all.

But it did prompt a whole new raft of investigation into why it works.

### Calories Don't Count

The western world is full of overweight people desperately trying to starve themselves thin. They clearly can't do it. Hunger is as overriding a drive as sex, and trying to resist it is impossible for normal people. All you'll manage to do by cutting down on what you eat is to make yourself permanently hungry whilst eating exactly the same amount. As well as the hunger you'll manage to store up vast feelings of self-loathing about your lack of willpower.

I think we all know grossly overweight people, usually women, who really, really want to be thin, but would settle for 'not grossly obese', or even 'a bit less grossly obese'. These poor people are forever eating single salad leaves instead of proper meals, and their reward is that they feel appalling because occasionally their hunger gets the better of them and they wolf down uncontrollable amounts of food. You would too, if you were in their constant state of semi-starvation. It would be like trying to torture yourself to death.

Their reward for this is to be considered weak and greedy by the less afflicted portion of the population. They get fatter and fatter and are in a permanent state of misery and self-loathing. Pity them.

Exercise doesn't seem to help much either, for the simple reason that if you exercise, you get hungry to match. It will make you fitter, stronger, happier (as long as you don't take it too seriously), and has a host of other benefits, but it won't make you lose weight. In fact since muscles weigh more than fat, exercise will make you weigh more (but look better). It is, in moderation, entirely to be recommended, but not as a technique for weighing less.

In fact, let's get one thing clear here. Losing weight in and of itself is not interesting. Most people want to lose fat. Most men would actually rather have more muscle mass.

### Calories

I had no real idea what a calorie was, except that miserable people seemed to count them a lot.

I remembered from school that it was an antique unit that measured the energy it took to heat up water. It was clearly time to start investigating these things.

The conventional wisdom is that you take a certain amount of energy in as food, and expend a certain amount in exercise (and just staying alive is quite energy-intensive exercise), and if there's any energy left over then you store it as fat, whereas if there's a deficit, you can use your stored fat to make up the difference.

So:
Eat lots, exercise little -> gain weight
Eat little, exercise lots -> lose weight

It's slightly more complicated than that, in that the energy content of food is variable. You can digest three things, fat, carbohydrate, and protein. A gram of fat is worth 9 calories, a gram of carbohydrate or protein is worth 4.

So 'eat lots' and 'eat little' really mean 'eat lots of calories', 'eat few calories'. Foods with fat in them are to be avoided if you want to lose weight. Foods with carbohydrates and protein should be favoured, because for a given amount eaten, there's more than twice as much energy in the fat.

And the more energy you spend, the faster the weight will come off, so the conventional advice to people wishing to lose weight is 'eat less, exercise more', or in its more sophisticated version, 'eat less, and especially less food with fat in it, and exercise more'.

Unfortunately, whilst the conventional wisdom is a well researched, lovely theory, confirmed in many experiments, and absolutely and uncontroversially true, it's completely useless to people trying to lose weight.

### A farewell to oars

I took up rowing in Cambridge at the age of 25. I'm not built for it, (5'10', broad shouldered, but real rowers are very tall and a different shape) but there are lots of little clubs in Cambridge and lots of local competition, so normal people can have fun. It's the sport everyone cares about here, in the same way that people care about football or cricket elsewhere.

I loved it and I got hooked. I'm a decent coach, have been a successful captain of my club three times, and at one point I was rowing for two hours a day, six times a week, plus various weights sessions and ergos. That's about as much training as you can do unless you're a professional athlete.

The thing about rowers is that they can pretty much eat what they like. That's a lot of calories being burnt off, and it needs to come from somewhere. I don't have a sweet tooth, so I never ate much sugar or chocolate, but my idea of a quick snack was a block of cheese. And dinner would be a huge plate of pasta with a spot of tomato sauce for decoration and flavour. I also loved sausages, eggs, chips, steaks, pizzas, and ate as much as I could as often as I could. And drank lots of beer.

Through absolutely heroic feats of eating and drinking I actually managed to be somewhat overweight. Strong and fit, but with a definite spare tyre at 90kg.

And then a couple of years ago, rowing didn't seem so important any more. Just burnt out I guess, but with a feeling that I'd taken my average frame and small club about as far as they could be reasonably taken.

And so, after the Town Bumps (the big local competition) two years ago, my boat disbanded as it always does, but this time I made no attempt to find anyone else to row with. I kept the captaincy of the club, but delegated my powers and responsibilities to a promising beginner who I thought would be able to do a good job as long as his decisions looked like they were mine. But I stopped being actively involved.

And I began to explode. I'd been something like 90kg at the time of the races. Three months later I was horrified to notice that I was 95kg, despite an obvious loss of muscle. Since fat is 20% lighter than muscle, this actually rather understates the catastrophic charge I was making towards obesity. It was pretty clear that in another three months I'd be on the road to becoming one of those poor Americans who can't fit through supermarket checkouts.

I clearly needed to go on a diet.

### Losing weight and cheering up

Over the last two years I've lost fifteen kilos. I was just on the borderline between overweight and obese, and I'm now told that my body fat is just hovering on the low limit of what's healthy for a 38 year old.

I did this without ever going hungry, or following any strict rules, or increasing the amount of exercise I did.

Rather more importantly, my personality has changed. It seems strange to write it now, but from adolescence until two years ago, I'd always assumed that I'd commit suicide. This was not in fact as bad as it sounds. It meant there was no bar to riding a motorbike, I've never felt guilty or unhappy about smoking cigars (which I love), I never felt the need to get a pension, or buy in to the British housing bubble when despite everything I know about the behaviour of markets the peer pressure was incredible.

But the reason I'd assumed it was not so good. Despite a generally sunny personality, every so often I'd be seized by a terrible fit of depression. In this state I felt that everything was going wrong, my life was a waste, my friends despised me. I called it the black dog, and when it was sitting on me I had got into the habit of hiding. It was not a mood to inflict on friends.

Usually this only lasted a couple of days. If I noticed what was going on I could cure it with intense exercise. But usually I didn't realise what was happening until the mood was already lifting. I pinned a note to the fridge 'If everything is going wrong do an ergo! It will help.'.

At one point in my early twenties, when everything really was going wrong, the black dog had sat for several months. And when it was sitting I could do nothing to change the things that needed changing, because every scheme, every ray of hope was dismissed out of hand as dreadful, too much trouble. Some days I didn't get out of bed because I could see no reason to.

I had assumed that the periodic mood swings were part of my personality. I'd seen enough evidence of similar behaviour in others to not find it suspicious. And although in hindsight the bout of depression in my twenties had probably needed treatment, the little swings I got every month or so just struck me as part of normal life.

I haven't had a trace of the black dog now for two years. And it happened because I got bored of my favourite sport.

## Tuesday, October 13, 2009

### Cricket lesson 1: Batting against overpitched off-side balls.

You need two people.

Bowler repeatedly throws the ball at a point on the popping crease to the off-side of the batsman, to simulate a wide, over-pitched delivery.

Batsman is the one learning. He must:

1. Keep his eyes level at all times.
2. As the bowler raises his arm to throw,
(a) raise the bat to a high backlift
(b) step across with his back foot to put it in line with the ball
3. Step forward and play the ball with a straight bat, driving it gently to the off side.

Repeat the exercise until the bowler is too bored to continue, or until Jacob drives the ball straight back at the bowler from six feet away, striking him sharply on the elbow and making him cry like a girl.

The point of the lesson:

We want to get the batsman's feet moving, and make this sequence an automatic reaction to an offside ball.

Putting the back foot into line with the ball makes it possible to play with a straight bat, instead of swiping.

Stepping forward means that the ball is played down, and that the bat is moving faster when the bat strikes the ball. Cricketing types say that the "batsman's weight is behind the ball", and that there is a feeling of "leaning into" the shot.

## Monday, October 12, 2009

### Tosca at the Met at the Cinema

Quite on impulse, I went to see Tosca on Saturday, at the Arts Picture House in Cambridge.

The New York Metropolitan Opera is broadcasting its performances live to cinemas across the world.

As you'd expect, it was much better than watching on TV, but lost something intangible but very important when compared to actually being there.

Well, I have no idea really. I've never been to the Met. But it lost something when compared to being at the Coliseum, or even at the Arts Theatre.

I could tell that the performance was bloody wonderful. All three main characters were superb, the voices and music were perfect. If I'd been there I'd have been absolutely transported, and at the end I'd have been on my feet for minutes. As it was, at the end I just thought "That was jolly good. Wish I'd seen it for real."

The camera work was absolutely brilliant, meaning that I hardly noticed it at all. The cameras were always pointing exactly where you would have wanted to look. This in marked and excellent contrast to the last one of these I saw, Tristan und Isolde, where the festooning of the screen with little break-out boxes annoyed me so much that I hated the whole thing and haven't been back since.

In fact, the cameras are too good. Opera singers mainly spend their time fighting desperately for breath whilst trying to act and sing both beautifully and loudly at the same time.

This is too much for any mortal, and to show a twenty foot high close up of the face of someone who's trying to do it is a bit much. I'd rather have the more distant view that a live audience would have.

On the other hand, the sound was stupendous. Much better than actually being there, I think. It makes me wonder why there is such resistance to the idea of amplifying live opera.

I found the feeling of disconnection strange. I love the cinema, and whilst watching films I usually completely forget that it's all made up, and lose myself completely in the world of the film.

I wonder what the problem is. With the better sound and visuals, the cinema experience should actually be better than the opera house. But it isn't. I wonder if it's something simple, like missing bass frequencies. Maybe they need to talk to whatever cinema's equivalent of a nerd is.

### Evolution (Film)

Yesterday I saw the film Evolution. It's rather wonderful.

There's not much science in it. Just enough to explain the overwhelming horror of the new world view Darwin is drawn to, when contrasted with the previous ideas about a loving God who cares for every sparrow. I don't think there's a great deal of historical detail either.

It's mainly about a man's anguish after the death of his delightful elder daughter. About his loss of faith. About how these two things destroy his relationship with his friend the vicar and his religious wife.

I cried in the theatre. I guess I'm fairly tear-prone for a man, but this still only happens to me once or twice a year. And Remembrance Day accounts for most of those occasions.