The Science of Discworld Revised Edition

system, the idea that a living amoeba is a billion-year-old ‘primitive’ organism, the image of DNA as the blueprint for a living creature, and the connection between relativity and Einstein’s hairstyle (it’s the sort of crazy idea that only people with hair like
that
can come up with). Quantum mechanics lacks a public ‘icon’ of this kind – it doesn’t tell a simple story that a non-specialist can grab and hang on to – so we feel uncomfortable about it.
    When you live in a complex world, you have to simplify it in order to understand it. Indeed, that’s what ‘understand’ means. At different stages of education, different levels of simplification are appropriate. Liar-to-children is an honourable and vital profession, otherwise known as ‘teacher’. But what teaching does
not
do – although many politicians think it does, which is one of the problems – is erect a timeless edifice of ‘facts’. 3 Every so often, you have to unlearn what you thought you already knew, and replace it by something more subtle. This
process
is what science is all about, and it never stops. It means that you shouldn’t take everything
we
say as gospel, either, for we belong to another, equally honourable profession: Liar-to-readers.
    On Discworld, one of Ponder Stibbons’s lies-to-wizards is about to come seriously unstuck.
    1 Actually you
can
eat salt. But nobody outside Discworld goes to a restaurant to order a basalt balti.
    2 Now turned into a book:
Evolving the Alien
by Jack Cohen and Ian Stewart.
    3 As humans, we have invented lots of useful kinds of lie. As well as lies-to-children (‘as much as they can understand’) there are lies-to-bosses (‘as much as they need to know’) lies-to-patients (‘they won’t worry about what they don’t know’) and, for all sorts of reasons,
lies-to-ourselves
. Lies-to-children is simply a prevalent and necessary kind of lie. Universities are very familiar with bright, qualified school-leavers who arrive and then go into shock on finding that biology or physics isn’t quite what they’ve been taught so far. ‘Yes, but you needed to understand
that
,’ they are told, ‘so that
now
we can tell you why it isn’t exactly
true
.’ Discworld teachers know this, and use it to demonstrate why universites are truly storehouses of knowledge: students arrive from school confident that they know very nearly everything, and they leave years later certain that they know practically nothing. Where did the knowledge go in the meantime? Into the university, of course, where it is carefully dried and stored.

FIVE
THE ROUNDWORLD PROJECT

    ARCHCHANCELLOR RIDCULLY AWOKE from an afternoon nap in which he had been crawling through a baking desert under a flamethrower sky, and found that this was more or less true.
    Superheated steam whistled from the joints of the radiator in the corner. Ridcully walked over through the stifling air and touched it gently.
    ‘Ouch! Damnation!’
    Sucking his right hand and using his left hand to unwrap the scarf from his neck, he strode out into the corridor and what looked like Hell with the heat turned up. Steam rolled along the corridors, and from somewhere overhead came the once-heard-never-forgotten
thwack
of a high-energy magical discharge. Violet light filled the windows for a moment.
    ‘Will someone tell me what the
heck
is going on?’ Ridcully demanded of the air in general.
    Something like an iceberg loomed out of the steam. It was the Dean.
    ‘I would like to make it
absolutely
clear, Archchancellor, that this is
nothing
to do with me!’
    Ridcully wiped away the sweat that was beginning to trickle down his forehead.
    ‘Why are you standin’ there in just your drawers, Dean?’
    ‘I – well, my room is absolutely
boiling
hot –’
    ‘I demand you put
something
on, man, you look thoroughly unhygienic!’
    There was another crack of discharged magic. Sparks flew off the end of Ridcully’s fingers.
    ‘I
felt
that one!’ he said, running back into his room.
    Beyond the window, on the other side of the gardens, the air wavered over the High Energy Magic building. As the Archchancellor watched, the two huge bronze globes on its roof became covered in crawling, zig-zagging purple lines –
    He hit the floor rolling, as wizards are wont to do, just before the shock of the discharge blew the windows in.
    Melted snow was pouring off the rooftops. Every icicle was a streaming finger of water.
    A large door bumped and scraped its way