The Science of Discworld Revised Edition

volcanic vents. Or hot rocks deep underground. Or they could be seashores. Imagine layers of complicated (because that’s easy) but disorganized (ditto) molecular gunge on rocks which are wetted by the tides and irradiated by the sun. Anything in there that happens to produce a tiny ‘space elevator’ establishes a new baseline for further change. For example, photosynthesis is a space elevator in this sense. Once some bit of gunge has got it, that gunge can make use of the sun’s energy instead of its own, churning out sugars in a steady stream. So perhaps ‘the’ origin of life was a whole series of tiny ‘space elevators’ that led, step by step, to organized but ever more complex chemistry.
    1 Everyone knows what science fiction is – until you start asking questions like ‘Is a book set five years in the future
automatically
SF? Is it SF just because it’s set on another world, or is it simply fantasy with nuts and bolts on the outside? Is it SF if the author thinks it isn’t? Does it have to be set in the future? Does the presence of Doug McClure mean that a movie is SF, or merely that the men-in-rubber-monster-suits quotient is going to be high?’ One of the best SF books ever written was the late Roy Lewis’s
The Evolution Man;
there is no technology in it more sophisticated than a bow, it’s set in the far past, the characters are barely more than ape-men … but it is science fiction, nonetheless.
    2 They were fortunate, given the names of some places in Australia, that they ended up merely
sounding
like a minor
Star Trek
species.

TWENTY-FIVE
UNNATURAL SELECTION

    THE LIBRARIAN KNUCKLED swiftly through the outer regions of the University’s library, although terms like ‘outer’ were hardly relevant in a library so deeply immersed in L-space.
    It is known that knowledge is power, and power is energy, and energy is matter, and matter is mass, and therefore large accumulations of knowledge distort time and space. This is why all bookshops look alike, and why all
second-hand
bookshops seem so much bigger on the inside – and why all libraries, everywhere, are connected. Only the innermost circle of librarians know this, and take care to guard the secret. Civilization would not survive for long if it was generally known that a wrong turn in the stacks would lead into the Library of Alexandria just as the invaders were looking for the matches, or that a tiny patch of floor in the reference section is shared with the library in Braseneck College where Dr Whitbury
proved
that gods cannot possibly exist, just before that rather unfortunate thunderstorm.
    The Librarian was saying ‘ook ook’ to himself under his breath, in the same way that a slightly distracted person searches aimlessly around the room saying ‘scissors, scissors’ in the hope that this will cause them to re-materialize. In fact he was saying ‘evolution, evolution’. He’d been sent to find a good book on it.
    He had a very complicated reference card in his mouth.
    The wizards of UU knew all about evolution. It was a self-evident fact. You took some wolves, and by careful unnatural selection over the generations you got dogs of all shapes and sizes. You took some sour crab-apple trees and, by means of a stepladder, a fine paintbrush and a lot of patience, you got huge juicy apples. You took some rather scruffy desert horses and, with effort and a good stock book, you got a winner. Evolution was a demonstration of narrativium in action. Things improved. Even the human race was evolving, by means of education and other benefits of civilization; it had began with rather bad-mannered people in caves, and it had now produced the Faculty of Unseen University, beyond which it was probably impossible to evolve further.
    Of course, there were people who occasionally advanced more radical ideas, but they were like the people who thought the world really
was
round or that aliens were interested in the contents of their underwear.
    Unnatural selection was a fact, but the wizards knew, they
knew
, that you couldn’t start off with bananas and get fish.
    The Librarian glanced at the card, and took a few surprising turnings. There was the occasional burst of noise on the other side of the shelves, rapidly changing as though someone was playing with handfuls of sound, and a flickering in the air. Someone talking was replaced with the absorbent silence of empty rooms was replaced with the crackling of flame and displaced by laughter