The Science of Discworld IV

books, but not so much that she wouldn’t have wanted another foray the following day. There would be no chance of that, however; the day was going to be tied up with lawyers.
    The Archchancellor had agreed with her request to be in the law chamber, but since she was in Discworld by accident her origins would not be mentioned, just in case; and in whose case it was, she didn’t know.
    But nobody said she couldn’t talk, or watch the case like a hawk, moreover like a hawk with extremely acute eyesight. She had found time from gloating over the books to read the papers, and it seemed that most of the population weren’t really interested in the outcome at all or even aware of the stakes.
    They were much more interested in the fight.

TWELVE
----
LONG ARM OF THE LORE

    Discworld has a Guild of Lawyers, even though it has no systematic legal system. This is only to be expected: lawyers never let little things like that get in their way. It does have a traditional method for settling legal disputes, however: a tribunal, over which Lord Vetinari, Patrician of Ankh-Morpork, is entitled to preside, should he so wish. On Discworld, as in many parts of Roundworld, disagreements about the law, or alleged infringements of it, are subjected to formal procedures, often involving a written body of legislation, precedents from other (often totally unrelated) cases, arguments, counter-arguments, expert witnesses and … oh, yes, evidence.
    What, though, counts as evidence?
    On Roundworld, even in countries that consider themselves to be democratic, a surprisingly large part of the legal process involves one or other party trying to arrange for key evidence to be excluded or included, doing its best to rig the jury in its client’s favour, plea-bargaining, and generally subverting the process of obtaining a fair trial. Law trumps justice.
    This tendency is universal among lawyers on both worlds.
    Roundworld, however, also has laws of another kind. Its inhabitants optimistically call them ‘laws of nature’, by which they mean the rules according to which their world operates. Human laws can be broken;nature’s laws cannot. They are not regulations made by people, but statements about how the universe behaves. The law-court of science also judges evidence, but for a different purpose. Instead of deciding the guilt or innocence of the accused, scientific evidence decides the truth or falsity of
the law
.
    If only it were that simple.
    That’s what we used to think, back in the heady days when gravity really did seem to fall off inversely as the square of distance, light was a wave, and time was independent of space. God was a mathematician and the universe was clockwork. But now, alongside the T-shirt bearing the equations of relativity, we find others that read ‘I used to be uncertain, but now I’m not so sure’.
    That pretty much sums up the current status of physical law among scientists. Today, we expect longstanding ‘laws’ of nature to be occasionally overturned when better observations become available, or when new contexts for the laws arise. The laws of chemistry do not allow base metal to be transmuted into gold, but the laws of nuclear reactions do. What we call ‘laws’ seem to be recurrent patterns in the physical world, which we can approximate very closely using mathematical equations, in limited contexts. We often call them ‘models’ or ‘rules’ instead, but on the whole we still use ‘laws’ for the deepest and best supported among them.
    This rejection of certainty makes science stronger, because it gives scientists the opportunity to revise their views when the evidence proves them wrong. But people
like
certainty, and many seem unable to understand why informed doubt is a strength. This opens up a huge opportunity for the storytelling ape, who insists on courtroom drama and the struggle between prosecution and defence. The case may pit one scientist against another, because individuals have their own ideas about what nature’s laws
are
. Or it may pit science against anti-science in the court of public opinion – lung cancer
v
the tobacco industry, evolution
v
intelligent design, climate change
v
scepticism and denial.
    Now nature’s laws, and humans’, start to look much more similar, because once again what determines the outcome is not the evidence as such, but whether it is allowed to be taken into account, and how it is interpreted. In place of humans united in a quest to find out