The Science of Discworld II

…
    One of them signalled. The prey was close at hand. And now they saw it, clustered in the trees around a clearing, dark blobs against thesunset.
    The elves assembled. And then, at a pitch so strange that it entered the brain without the need to use the ears, they began to sing.
    1 And in this short statement may be seen the very essence of wizardly.
    2 This one was apparently the result of a curse some 1,200 years ago by a dying Archchancellor, which sounded very much like ‘May you always teach fretwork!’
    3 Lord Vetinari, the Patrician and supreme ruler of the city, took proper food labelling very seriously. Unfortunately, he sought the advice of the wizards of Unseen University on this one, and posed the question thusly: ‘Can you, taking into account multi-dimensional phase space, meta-statistical anomaly and the laws of probability, guarantee that anything with absolute certainty contains no nuts at all?’ After several days, they had to conclude that the answer was ‘no’. Lord Vetinari refused to accept ‘Probably does not contain nuts’ because he considered it unhelpful.

TWO
THE UMPTY-UMPTH ELEMENT
    D ISCWORLD RUNS ON MAGIC , Roundworld runs on rules, and even though magic needs rules and some people think rules are magical, they are quite different things. At least, in the absence of wizardly interference. This was the main scientific message of our last book, The Science of Discworld . There we charted the history of the universe from the Big Bang through to the creation of the Earth and the evolution of a not especially promising species of ape. The story ended with a final fast-forward to the collapse of the space elevator by which a mysterious race (which could not possibly have been those apes, who were only interested in sex and mucking about) had escaped from the planet. They had left the Earth because a planet is altogether too dangerous a place to live, and had headed out into the galaxy in search of safety and a long-term chance of a decent pint.
    The Discworld wizards never found out who the builders of the space elevator on Roundworld were. We know that they were us , the descendants of those apes, who’d brought sex and mucking about to high levels of sophistication. The wizards missed that bit, although, to be fair, the Earth had been in existence for over four billion years, and apes and humans were present only for a tiny percentage of that time. If the entire history of the universe were compressed to one day, we would have been present for the final 20 seconds.
    Quite a lot of interesting things happened on Roundworld while the wizards were skipping ahead, and now, in this present book, the wizards are going to find out what those things were. And of coursethey’re going to interfere, and inadvertently create the world we live in today, just as their interference in the Roundworld Project inadvertently created our entire universe. It has to work like that, doesn’t it?
    That’s how the story goes.
    Seen from outside, as it sits in Rincewind’s office, the entire human universe is a small sphere. Large quantities of magic went into its manufacture and, paradoxically, into maintaining its most interesting feature. Which is this: Roundworld is the only place on Discworld where magic does not work. A strong magical field protects it from the thaumic energies that surge around it. Inside Roundworld, things don’t happen because people want them to or because they make a good narrative: they happen because the rules of the universe, the so-called ‘laws of nature’, make them happen.
    At least, that was a reasonable way to describe things … until human beings evolved. At that point, something very strange happened to Roundworld. It began, in various ways, to resemble Discworld. The apes acquired minds, and their minds started to interfere with the normal running of the universe. Things started to happen because human minds wanted them to. Suddenly the laws of nature, which up to that point had been blind, mindless rules, were infused with purpose and intention. Things started to happen for a reason, and among these things that happened was reasoning itself. Yet this dramatic change took place without the slightest violation of the same rules that had, up to that point, made the universe a place without purpose. Which, on the level of the rules, it still is.
    This seems like a paradox. The main content of our scientific