The Science of Discworld IV

humanity, and Isaac Newton, who would provide science. With considerable difficulty, and some interesting failures along theway requiring ceilings to be painted black, the wizards nudged humanity back onto the only timeline that would save it from annihilation. Shakespeare’s
A Midsummer Night’s Dream
tipped the tables decisively by exposing the elves to ridicule. Newton’s
Principia Mathematica
completed the job by pointing humanity at the stars. Job done.
    It couldn’t last.
    By the time of
The Science of Discworld III
, Roundworld was in trouble again. Having safely entered its Victorian era, which should have been a hotbed of innovation, it had once more departed from its proper history. New technology was developing, but at a snail’s pace. Some vital spur to innovation had been lost, and the gerbil of humanity was sick once more. This time, a key figure had written the wrong book. The Reverend Charles Darwin’s
Theology of Species
, explaining the complexity of life through divine intervention, had been so well received that science and religious belief had converged. The creative spark of rational debate fn3 had been lost. By the time the Reverend Richard Dawkins finally wrote
The Origin of Species (by Means of Natural Selection &c &c &c
…) it was too late to develop space travel before the ice came down.
    This time, getting Darwin born was not the problem. Getting him to write the correct book … that was where everything went pear-shaped, and it proved remarkably hard to nudge history back on track. Contrary to the proverb, supplying a missing nail from a horse’s shoe does not save a kingdom. It generally has no effect, aside from making the horse feel a bit more comfortable, because hardly anything important has a single cause. It took a huge squad of wizards, making over two thousand carefully choreographed changes, to get Darwin onto the
Beagle
, stop him jumping ship when he was being as sick as a dog, and perk his interest in geology so that he stayed with the expedition fn4 until it got to the Galápagos Islands.
    They wouldn’t have succeeded at all, but the wizards eventually realised that something was actively interfering with their efforts to reset history to manufacturer’s specifications. The Auditors of Reality are the ultimate Health and Safety officers: they much prefer a universe in which nothing interesting ever happens, and they are willing to go to extreme lengths to ensure that it doesn’t. They had been blocking the wizards’ every move.
    It was a near thing. Even when the wizards successfully arranged for Darwin to visit the Galápagos and notice the finches and mockingbirds and turtles, it took years for him to understand the significance of those creatures – by which time all the turtle shells were long gone, tossed overboard after their contents were eaten, and he’d given away the finches to a bird expert. (He
had
realised that the mockingbirds were interesting.) It took even longer to get him to take the plunge and write
The Origin
instead of
The Ology
; he kept writing scholarly books about barnacles instead. Then, when he had finally managed to write
The Origin
, he still messed up with
Origin II
, calling it
The Descent of Man
– oh dear.
The Ascent of Man
would have been a better marketing ploy.
    Anyway, the wizards finally achieved success, even contriving to bring Darwin into Discworld to meet the God of Evolution and admire the wheels on his elephant. The publication of
The Origin
established the corresponding timeline as the only one that had ever happened. (The Trousers of Time are like that.) Roundworld was saved
again
, and could rest undisturbed on its shelf, gathering dust …
    Until—
    fn1 Falling off deliberately is another matter, about which they can be as imaginative as they wish. See
The Light Fantastic
,
The Colour of Magic
and
The Last Hero
.
    fn2 This may be misleading since it is the opinion of the inhabitants concerned.
    fn3 That is, insults, name-calling and shameless point-scoring.
    fn4 Loosely speaking. He remained on land whenever feasible, about 70% of the entire ‘voyage’.

ONE
----
GREAT BIG THING

    Every university must have, sooner or later, a big or, more preferably, a
Great Big Thing
. According to Ponder Stibbons, head of Inadvisably Applied Magic at Unseen University, it was, he said, practically a law of nature; and it couldn’t be too big, and it had to be a thing, and definitely not a small one.
    The senior wizards,