The Science of Discworld Revised Edition by Terry Pratchett Read Free Book Online

Discworld, too – or at least rational engineering. Balls get thrown and caught, the biology of the river Ankh resembles that of a typical terrestrial swamp or sewage farm, and light goes in more or less straight lines. Very slowly, though. As we read in
The Light Fantastic:
‘Another Disc day dawned, but very gradually, and this is why. When light encounters a strong magical field it loses all sense of urgency. It slows right down. And on the Discworld the magic was embarrassingly strong, which meant that the soft yellow light of dawn flowed over the sleeping landscape like the caress of a gentle lover or, as some, would have it, like golden syrup.’ The same quote tells us that as well as rational engineering there’s a lot of magic in Discworld: overt magic which slows light down; magic that allows the sun to orbit the world provided that occasionally one of the elephants lifts its leg to let the sun pass. The sun is small, nearby , and travels faster than its own light. This appears to cause no major problems.
    There is magic in our world, too, but of a different, less obvious kind. It happens around everybody all the time, in all those little causalities which we don’t understand but just accept. When we turn the switch and the light comes on. When we get into the car and start the engine. When we do all those improbable and ridiculous things that, thanks to biological causality, make babies. Certainly many people understand, often to quite a detailed degree, what is going on in particular areas – but sooner or later we all reach our Magical Event Horizon. Clarke’s Law states that any sufficiently advanced technology looks like magic ‘Advanced’ here is usually taken to mean ‘shown to us by advanced aliens or people from the future’, like television shown to Neanderthals. But we should realize that television is magic to nearly everyone that uses it
now
– to those behind the camera as well as to those sitting on the couch in front of the moving picture in the funny box. At some point in the process, in the words of cartoonist S. Harris, ‘a miracle occurs’.
    Science takes on the aura of magic because the design of a civilization proceeds by a type of narrative imperative – it makes a coherent
story
. In about 1970, Jack gave a lecture to a school audience on ‘The Possibility of Life on Other Planets’ 2 . He talked about evolution, what planets were made of – all the things that you’d expect in such a lecture. The first question was from a girl of about 15, who asked ‘You believe in evolution, don’t you, sir?’ The teacher went on about it not being a ‘proper’ question, but Jack answered it anyway, saying – rather pretentiously –‘No, I don’t
believe
in evolution, like people believe in God … Science and technology are not advanced by people who believe, but by people who
don’t know
but are doing their best to find out … steam engine … spinning jenny … television …’ At that, she was on her feet again: ‘No, that ain’t how television was invented!’ The teacher tried to calm the discussion by asking her to explain how she thought television was invented. ‘My father works for Fisher Ludlow making pressed steel for car bodies. He gets paid and he gives some of the money to the government to give him things. So he tells the government he wants to watch television, and they pay someone to invent television, and they do!’
    It’s very easy to make this mistake, because technology progresses by pursuing goals. We get the feeling that if we pour in enough resources, we can achieve anything. Not so. Pour in enough resources, and we can achieve
anything
that is within reach of current know-how, or possibly just a bit beyond if we’re lucky. But nobody tells us about the inventions that fail. Nobody tries to raise funding for a project that they know can’t
possibly
work. No funding body will pay for research projects in which we have no idea where to start. We