Science of Discworld

BEGINNINGS AND BECOMINGS

POTENTIALITY 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 'begi

That is: begi

Let us leave becomings for a moment, and think about begin­nings. Thanks to our evolutionary prejudices, we tend to think of the begi

Maybe there was something else in existence already ... but now we have to decide how that got started, and the same difficulties arise. All right, let's go the whole hog: something, perhaps the uni­verse itself, perhaps some precursor, was around forever. It didn't have a begi

Satisfied? Things that exist forever don't have to be explained, because they don't need a cause? Then what caused them to have been around forever?

It now becomes impossible not to mention the turtle joke. According to Hindu legend, the Earth rides on the back of four elephants, which ride on a turtle. But what supports the turtle? In Discworld, Great A'Tuin needs no support, swimming through the universe unperturbed by any thought about what holds it up. That's magic in action: world-carrying turtles are like that. But according to the old lady who espoused the Hindu cosmology, and was asked the same question by a learned astronomer, there is a different answer: 'It's turtles all the way down!' The image of an infinite pile of turtles is instantly ludicrous, and very few people find it a satis­fying explanation. Indeed very few people find it a satisfying kind of explanation, if only because it doesn't explain what supports the infinite pile of turtles. However, most of us are quite content to explain the origins of time as 'it's always been there'. Seldom do we examine this statement closely enough to realize that what it really says is 'It's time all the way back.' Now replace 'time' by 'turtle' and 'back' by 'down' ... Each instant of time is 'supported', that is, a causal consequence of, the previous instant of time. Fine, but that doesn't explain why time exists. What caused that infinite expanse of time? What holds up the whole pile?

All of which puts us in a serious quandary. We have problems thinking of time as begi