The Science of Discworld Revised Edition

trillion miles across. But Archchancellor Ridcully pointed out that this was not very useful thinking, because of the ancient principle of WYGIWYGAINGW . 1
    1 ‘What You Get Is What You’re Given And It’s No Good Whining.’

SIX
BEGINNINGS AND BECOMINGS

    PONTENTIALITY IS THE key.
    Our immediate task is to start from a lot of vacuum and a few rules, and convince you that they have enormous potentiality. Given enough time, they can lead to people, turtles, weather, the Internet – hold it.
Where did all that vacuum come from?
Either the universe has been around forever, or once there wasn’t a universe and then there was. The second statement fits neatly with the human predilection for creation myths. It also appeals to today’s scientists – possibly for the same reason. Lies-to-children run deep.
    Isn’t vacuum just … empty space? What was there before we had space? How do you make space? Out of vacuum? Isn’t that a vicious circle? If in the past we didn’t have space, how can there have been a ‘there’ for whatever it was to exist in? And if there wasn’t anywhere for it to exist, how did it manage to make space? Maybe space was there all along … but why? And what about
time
? Space is easy compared to time. Space is just … somewhere to put matter. Matter is just … stuff. But time … time flows, time passes, time makes sense in the past and the future but not in the instantaneous, frozen present. What makes time flow? Could the flow of time be stopped?
What would happen if it did?
    There are little questions, there are medium-sized questions, and there are big questions. After which there are even bigger questions, huge questions, and questions so vast that it is hard to imagine what kind of response would count as an answer.
    You can usually recognize the little questions: they look immensely complicated. Things like ‘What is the molecular structure of the left-handed isomer of glucose?’ As the questions get bigger, they become deceptively simpler: ‘Why is the sky blue?’ The
really
big questions are
so
simple that it seems astonishing that science has absolutely no idea how to answer them: ‘Why doesn’t the universe run backwards instead?’ or ‘Why does red look like
that
?’
    All this goes to show that it’s a lot easier to ask a question than it is to answer it, and the more specialized your question is, the longer are the words that you must invent to state it. Moreover, the bigger a question is, the more people are interested in it. Hardly anybody cares about left-handed glucose, but nearly all of us wonder why red looks the way it does, and we vaguely wonder whether it looks the same to everybody else.
    Out on the fringes of scientific thought are questions that are big enough to interest almost everybody, but small enough for there to be a chance of answering them reasonably accurately. They are questions like ‘How did the universe begin?’ and ‘How will it end?’ (‘What happens in between?’ is quite a different matter.) Let us acknowledge, right up front, that the current answers to such questions depend upon various questionable assumptions. Previous generations have been absolutely convinced that their scientific theories were well-nigh perfect, only for it to turn out that they had missed the point entirely. Why should it be any different for our generation? Beware of scientific fundamentalists who try to tell you everything is pretty much worked out, and only a few routine details are left to do. It is just when the majority of scientists believe such things that the next revolution in our world-view creeps into being, its feeble birth-squeaks all but drowned by the earsplitting roar of orthodoxy.
    Let’s take a look at the current view of how the universe began. One of the points we are going to make is that human beings have trouble with the concept of ‘beginning’. And even more trouble, let it be said, with ‘becoming’. Our minds evolved to carry out rather specific tasks like choosing a mate, killing bears with a sharp stick, and getting dinner without
becoming
it. We’ve been surprisingly good at adapting those modules to tasks for which they were never ‘intended’ – that is, tasks for which they were not
used
during their evolution, there being no conscious ‘intention’ – such as planning a route up the Matterhorn, carving images of sea-lions on polar bears’ teeth, 1 and calculating the combustion point of a complex