The Science of Discworld IV Judgement Da - By Terry Pratchett, Ian Stewart Page 0,74
powder are in different arrangements. To understand the bird, the frog, or the soap powder, it’s not enough to know about the underlying atoms or subatomic particles. It’s how they are arranged that matters. In fact, they could be made of rather different stuff, but if it were arranged to carry out similar functions, you’d still end up with effective birds, frogs and soap powder.
It’s the arrangements that make the magic, not the goup.
Atoms in different arrangements have different properties: an atom in a piece of rock is probably one of millions in a crystal array, and is essentially a permanent part of that array. An atom in a living creature is probably part of a very complex network, changing atomic and molecular partners all the time. Moreover, this changing system is not typical of the unaided activities of matter obeying the fundamental laws, despite being consistent with those laws. It has been selected over many generations so that it works, so that it does something. And the something that it does, while not having any ‘extra something’ in Feynman’s sense, contributes to the life of the organism that it’s part of. It may even be part of a virus, destroying the organism, but it’s still enmeshed in all the processes that make up life.
Life has lifted itself out of the simple laws of nature, where it started, and is now a whole complex world, at least as different from that origin as a modern aeroplane is from a flint axe. The scene at the beginning of the film 2001, where the ape throws up a thighbone and it morphs into a space station, is a lovely illustration of just that kind of evolution. And that transformation is minor, compared to how life has transcended its origins.
Let’s look at it from a different perspective. The material world, the world of physics and chemistry, has many continuing processes, from the unimaginable physics in the middle of stars to the freezing and thawing of ethane and methane on Saturn’s moon Titan. Stars explode, scattering the elements that have formed within them into the cosmos, and planets condense from that mixture, according to the laws of physics and chemistry. Then, perhaps in the deep ocean near the rift in the ocean floor from which highly reduced compounds are pouring, some anomalous chemistry sets up a hereditary system. It may be a mixture of chemical processes that is in some sense heritable, it may be RNA, it may be a pre-metabolic system … But it’s the beginning of a story, a narrative that has lifted itself out of the frame of the laws, and is about to transcend them. Spaceships and witches are in its future.
As life first starts, it’s not remarkable. It proceeds more or less according to the rules of physics and chemistry, according to the laws. Then it begins to compete, perhaps for space, or for particular chemicals, or for membranes that are fatty layers on clay. Those systems that work better lift themselves out of the laws, into a tiny simple narrative that says ‘A does a little bit better than B or C, so there’s more of it in the future …’ Come back in a million years, and the oceans are full of A, while there’s no C to be found. And by then, A has diversified into A1 and A2 and A3. Now, lurking – a good narrative word – in the depths is Q, which loves to include A3 in its system. So later we have QA3XYZ, and the system is well started.
It’s all gone according to the laws, for sure; but there’s a mite of competition, selection of this over that. Come back in a million years, or perhaps six weeks, and there will be a bacterial cell that has lifted itself into a story …
The laws facilitate such changes, but they don’t direct them. They are merely history, with all the living stuff transcending them in every direction. Come back in 3000 million years, you’ll find a mess of Burgess Shale organisms. Come back 580 million years later still, and you’ll find a physicist denying that any of this is important. But the action transcends the laws: it’s the spaceships and witches that drive the narrative.
Life originally emerged from non-living systems, with laws, but it has gone on to complicate itself out of all recognition. Biology isn’t just physics and chemistry with knobs on. It’s a whole new world.