The Science of Discworld II

Home > Other > The Science of Discworld II > Page 29
The Science of Discworld II Page 29

by Terry Pratchett


  ‘What are you doing, wizards?’ she snapped.

  Ridcully gave her a nod of annoying friendliness. ‘Oh, just a little … what are we calling it, Stibbons?’

  ‘A sociological experiment, Archchancellor,’ said Ponder.

  ‘But you’ve been teaching them art! And sculpture!’

  ‘And music,’ said Ridcully happily. ‘The Lecturer in Recent Runes is rather good with a lute, it turns out.’

  ‘Only in a very amateur way, I’m afraid,’ said the Lecturer in Recent Runes, blushing.

  ‘Dashed easy to make, a lute,’ said Ridcully. ‘You just need a tortoise shell and some sinews and you’re well away. I myself have been renewing my acquaintance with the penny whistle of my boyhood, although I fear that the Dean’s expertise with the comb-and-paper leaves something to be desired …’

  ‘And why are you doing all this?’ the queen demanded.

  ‘Are you angry? We thought you’d be pleased,’ said Ridcully. ‘We thought you wanted them this way. You know – imaginative.’

  ‘He created music?’ said the Queen, glaring at the Lecturer in Recent Runes, who gave her an embarrassed wave.

  ‘Oh, no, I assure you,’ he said. ‘Er, they’d worked up to, you know, basic percussion, the conch shell and so on, but it was all rather dull. We just helped them along a bit.’

  ‘Gave them a few tips,’ said Ridcully, jovially.

  The Queen’s eyes narrowed. ‘Then you are planning something!’ she said.

  ‘Aren’t they doing well?’ said Ridcully. ‘Look at that chap over there. Visualisin’ a god. One with woodworm and knotholes, but pretty good all the same. Quite complex mental processes, really. We thought that if you want people with wild imaginations, then we’d help them to be really good at it. They’ll fill the world with dragons and gods and monsters for you. You want that.’

  The Queen gave him another look, and it was the look of a person with no sense of humour who nevertheless suspects that there’s some joke somewhere that is on them.

  ‘Why should you help us?’ she said. ‘You told me to consume your underthings!’

  ‘Well, it’s not as though this world is important enough to fight over,’ said Ridcully.

  ‘One of you isn’t here,’ said the Queen. ‘Where is the stupid one?’

  ‘Rincewind?’ said the Archchancellor, with an innocent air that would not have fooled any human for a moment. ‘Oh, he’s doing pretty much the same thing, you know. Helping people imagine things. Which, I think, is what you want.’

  TWENTY-FOUR

  THE EXTENDED PRESENT

  ART? IT LOOKS SUPERFLUOUS. Few of the stories we tell about human evolution, the Homo sapiens bit, see music or art as being integral to the process. Oh, it often comes in as a kind of epiphenomenon, as evidence of how far we’d got: ‘Just look at those wonderful cave paintings, statuettes, polished jewellery and ornaments! That shows that our brain was bigger/better/more loving/nearer to that of the Lecturer in Recent Runes …’ But art has not been portrayed as a necessary part of the evolution that made us what we are; nor has music.

  So why are Burnt Stick Man and Red Hands Man dabbling in art, and why does Rincewind want to encourage them?

  We’ve been told the story of The Naked Ape doing sex, we’ve had Gossiping Apes and Privileged Apes, various kinds of apes becoming intelligent on the seashore or running down gazelles on the savannah. We’ve had lots of development-of-intelligence stories culminating in Einstein; we have given you the privilege/puberty ritual/selection story that culminates in Eichmann and Obedience to Authority; but we have not presented a version of our evolution whose culmination is Fats Waller, Wolfgang Amadeus Mozart, or even Richard Feynman on the bongo drums.

  Well, now we will.

  Music is an important part of most people’s lives, and this is continually reinforced by film and television. Background music is constantly informing us of imminent screen events, of tension and release, of characters’ thoughts and, particularly, of their emotional states. It is very difficult for anyone brought up in the muzak environment of the twentieth century to imagine what the ‘primitive’ state of human musical sense can have been.

  When we listen to the music of far peoples, of ‘primitive’ tribes, we have to appreciate that their music has had as long to develop as Beethoven, and much longer than jazz. Like the amoeba or the chimpanzee, their music is contemporary with us, not ancestral, though it sounds primitive, just as they look primitive. And we wonder whether we are listening for the right things in the right way. It is tempting to think that popular music, going for instant appeal, might illuminate whatever inner structure of our brains ‘fits’, and is satisfied by, a musical theme. If we were orthodox geneticists, we might have said ‘genes for music’ there. But we didn’t.

  In recent years, neuroscientists have developed techniques that allow us to look at what brains do when we carry out various actions. In particular, they reveal which bits of brain are active when we enjoy music. At the moment, with the terribly poor spatial and temporal resolution that we get from MRI and PET scans, all we can see is that music excites the right side of the brain. If we are familiar with the music, then the brain’s memory-regions turn on, and if we analyse it or try to pick up the lyrics, then the verbal-analysis parts light up. And opera picks up both of them, which could be why Jack likes it: he enjoys having his brain put through a blender.

  Our affinity with music starts early. In fact, there’s a lot of evidence that if we hear music in the womb, then it can affect our later musical preferences. Psychologists play music to babies as soon as they start kicking, and have discovered that they can categorise it, like we adults do, and into the same categories. If we play them Mozart, they stop kicking for a bit, about fifteen minutes; then they start kicking again, perhaps with some relation to the rhythm. The evidence is claimed, but it isn’t very persuasive. If we then continue with a different bit of Mozart, or Haydn or Beethoven, then the kicking pauses, but it resumes after a minute or so. The Beatles, Stravinsky, sacred chants, or New Orleans jazz, make them pause for much longer, ten minutes or so.

  Playing the same pieces months later reveals that the baby has some memory of the style as well as of the instruments. Apparently, a quartet by Mozart triggers recognition of the ‘Mozart’ style just as effectively as a Mozart symphony. Our brains have sophisticated music-recognition modules, and we can use them before we speak, indeed before we are born. Why?

  We’re looking for the essence of music – as if we knew what the essence of sex was for the Naked Ape, or the essence of obedience for Eichmann – or come to that, what it means to be the most intelligent/extelligent creature on Roundworld. What we want is a story that puts the arts, and music, into an explanation of How We Got Here, and why we waste all that money on the arts faculties of universities. Why is Rincewind so keen to bring art and music to our ancestors?

  It was very common in the early years of the twentieth century to copy the music of ‘primitive’ tribes. Examples include Stravinsky’s Rite of Spring and Manuel de Falla’s Fire Dance, where the musical style was thought to give a primitive authenticity. People thought that Bronislaw Malinowski’s tales of the Trobriand Islanders, with their amazing lack of the civilised sexual repressions so publicised by Freud in Viennese society, showed that Natural Humans were happier and less corrupt, and that their music – for flutes and drums – conveyed their state of innocence more effectively than classical symphonies. Jazz, invented by supposedly ‘primitive’ black musicians down in New Orleans, had resonances that seemed natural, animal (and, for certain Christians, evil). It was almost as if music were a language, parallel to the words, developed in different societies with different emphases, and more revealing of the nature of the people than other aspects of their culture.

  This is the way the media have played it, and like the Flintstones and Stone Age society, we have an overlay of this outlook that it’s very difficult to get away from. Margaret Mead, who w
as taken for a ride by her native girl friend and told the resulting story in Coming of Age in Samoa A Psychological Study of Primitive Youth for Western Civilization, romanticised their music and dances in exactly this way. When Hollywood needs to show the primitive-but-spiritual nature of Indian braves, cannibal tribes in Borneo, or Hawaiian indigenes, it shows us the rain dance, the marriage music, and the hula girls. When we go to these places, the locals put on these dances for us because it brings in tourist money. The complicity between muzak, hula dances, opera and background music in Hollywood films has completely buried our abilities to sort out what constitutes ‘natural’ art or music.

  However, that’s not what we want anyway. ‘Natural’ is an illusion. Desmond Morris made a lot of money selling paintings done by apes. The apes clearly enjoyed the whole business, and so did Morris, and presumably so did the people who bought them and looked at them in art galleries. There is also an elephant that paints, and signs its paintings. Sort of. There’s a segment of modern painting whose philosophy seems to relate to this quest for the genuinely primitive. One side is the tackiest, painting by children, which clearly demonstrates the stepwise effects of the culture – the extelligence – on their burgeoning intelligence. To our inexpert eyes, though, these paintings demonstrate only the enormous gratification achieved by some parents in response to minimal effort by their children.

  Another aspect, more intellectual, is the move towards apparently real-world constraints, like cubism, or attempts to develop styles that force us to re-evaluate how we see, like Picasso’s profile faces but with the two eyes on one side. There is a very common modern form that arranges rectangles of paper with different textures, or sprays sparse paint droplets according to some minimal rule, or scatters charcoal dust on a bold swirly bright oil-paint background and then combs it into the texture and pattern of the whole canvas. All of these can give pleasure to the eye. Why? How do they differ from natural objects, some of which also give considerable pleasure?

  Now we want to make a giant leap and bring Mozart, jazz, paper-texture and charcoal-swirl oil paintings into the same frame. We think that this frame naturally includes ancient cave-paintings, which we know to be early, so have more claim to being genuinely primitive, if we could only look at them with the eyes and minds of viewers contemporary with the artist. The same problem occurs with Shakespeare, too: we no longer have the ears or minds – the extelligence – of the first Elizabethan age.

  We have to be more than a bit scientific here. We have to consider how we perceive light, sound, touch – what our sense organs tell us. For a start, they don’t, and this is the first lesson. In his book Consciousness Explained, Daniel Dennett is very critical of the Cartesian Theatre1 picture of consciousness. In this picture, we imagine ourselves sitting in a little theatre in our minds, where our eyes and ears pipe in pictures and sounds from the outside world. In school we all learned that the eye is like a camera, and that a picture of the world is imaged in the plane of the retina, as if that was the difficult bit. No, the difficult bit starts there, with different elements of that picture taking different routes into different parts of the brain.

  When you see a moving red bus, the features ‘moving’, ‘red’ and ‘bus’ are separated fairly early in the brain’s analysis of the scene … and they don’t just get put together again to synthesise your mental picture. Instead, your picture is synthesised from lots of clues, lots of bits, and nearly all of what you ‘see’ as you look around the room is only ‘there’ in your brain. It’s not at all like a TV picture. It is not picked up instantly and updated, but nearly all of that ‘detailed’ surround is invented as a kind of wallpaper around the little bit that has your attention. Most of the details are not present as such in your mind at all, but that’s the illusion that your mind presents to you.

  When we see a painting … except, again, we don’t. There are several ways to convince people that they invent what they ‘see’, that perception is not simply a copy of the eye’s image on the retina. There is, for example, a blind spot on the retina where the optic nerve leaves it. This is big. It’s as big as 150 full moons (that’s not a misprint: a hundred and fifty). Not that the moon is as big, to our eyes, as we usually think – and certainly not as big as Hollywood repeatedly shows it. We ‘see’ the full moon as much bigger than it ‘is’ (sorry, we have to use some trick to separate what’s in your mind from reality out there),especially when it’s near the horizon. The best way to appreciate that is to demonstrate to yourself that the moon’s image is the size of your little fingernail at arm’s length. Hold out your arm, and the tip of your littlest finger more than covers the moon. So the blind spot is smaller than our description may have suggested, but it’s still a big chunk of the retinal image. We don’t notice any hole in the picture we get of the outside world, though, because the brain fills in its best estimate of what’s missing.

  How does the brain know what’s missing from right in front? It doesn’t, and it doesn’t have to: that’s the point. Although ‘fills in’ and ‘missing’ are traditional terms in this area of science, they are, again, misleading. The brain doesn’t notice that anything is missing, so there isn’t a gap to be filled in. The neurons of the visual cortex, the part of the brain that analyses that retinal image into a scene that we can recognise and label, are wired up in elaborate ways, which reinforce certain perceptual prejudices.

  For example, experiments with dyes that respond to the brain’s electrical signals show that the first layer of the visual cortex detects lines – edges, mostly. The neurons are arranged in local patches, ‘hypercolumns’, which are assemblies of cells that respond to edges aligned along about eight different directions. Within a hypercolumn, all connections are inhibitory, meaning that if one neuron thinks it has seen an edge pointing along the direction to which it is sensitive, then it tries to stop the other neurons from registering anything at all. The result is that the direction of the edge is determined by a majority vote. In addition, there are also long-range connections between hypercolumns. These are excitatory, and their effect is to bias neighbouring hypercolumns to perceive the natural continuation of that edge, even if the signal they receive is too weak or ambiguous for them to come to that conclusion unaided.

  This bias can be overcome by a sufficiently strong indication that there is an edge pointing in a different direction; but if the line gets faint, or part of it is missing, the bias automatically makes the brain respond as if the line was continuous. So the brain doesn’t ‘fill in’ the gaps: it is set up not to notice that there are gaps. That’s just one layer of the visual cortex, and it uses a rather simple trick: extrapolation. We have little idea, as yet, of the inspired guesswork that goes on in deeper layers of the brain, but we can be sure that it’s even more clever, because it produces such a vivid sensation of a complete image.

  What about hearing? How does that relate to sound? The standard lie-to-children about vision is that the cornea and lens make a picture on the retina, and that allegedly explains vision. Similarly, the corresponding lie-to-children about hearing centres on a part of the ear called the cochlea, whose structure allegedly explains how you analyse sound into different notes. In cross-section, the cochlea looks like a sliced snail-shell, and according to the lie-to-children, there are hair-cells all the way down the spiral attached to a tuned membrane. So different parts of the cochlea vibrate at different frequencies, and the brain detects which frequency – which musical note – it is receiving, by being told which part of the membrane is vibrating. In support of this explanation, we are told a rather nice story about boiler-makers, whose hearing was often damaged by the noise in the factories where they worked. Supposedly, they could hear all frequencies except ones near the frequency that was most common in making boilers. So just one place on their cochlea was burnt out, and the rest worked OK. This proved, of course, that the ‘place’ theory of hearing was correct.

  Actually, this story tells you only how the ear can discriminate n
otes, not how you hear the noise. To explain that, it is usual to invoke the auditory nerve, which connects the cochlea to the brain. However, there are as many connections, or more, that go in the other direction, from brain to cochlea. You have to tell your ear what to hear.

  Now that we can actually look at what the cochlea does when it’s hearing, we find not one place vibrating for each frequency, but more like twenty. And these places move as you flex your outer ear. The cochlea is phase-sensitive, it can discriminate the kind of difference that makes an ‘ooh’ sound different from an ‘eeh’ at the same frequency. This is the kind of change to the sound that you make when you change the shape of your mouth as you speak. And surprise, surprise, that’s just the difference that the cochlea – after your outer ear and your own particular auditory canal, and your own particular eardrum and those three little bones – can best discriminate. A recording from someone else’s eardrum, played back up against yours, makes little sense. You have learned your own ears. But you have taught them, too.

  There are about seventy basic sounds, called phonemes, that Homo sapiens uses in speech. Up to about six months old, all human babies can discriminate all of these, and an electrode on the auditory nerve gives different patterns of electrical activity for each. At about six to nine months old, we start talking scribble, and it very soon becomes English scribble or Japanese scribble. By a year old the Japanese ear cannot distinguish ‘l’ from ‘r’, because both phonemes send the same message from cochlea to brain. English babies can’t discriminate the different clicks of the !Kung San, nor the differences between the distinct ‘r’s in French. So our sense organs do not show us the real world. They stimulate our brains to produce, to invent if you like, an internal world made of the counters, the Lego™ set, that each of us has built up as we mature.

 

‹ Prev