The Science of Discworld IV

phenomena, with no ‘extra something’.
    Like Feynman, we don’t think that there’s an ‘extra something’, an
élan vital
(‘life force’) that drives life. No, it’s much simpler than that. Organisms have
evolved
, and whereas at the outset of life they were very limited, mostly ‘doing what their atoms did’, as Feynman would have it, they acquired new properties, like cell division. They got a workable heredity, they acquired eyes and the nervous systems to use them. They moved up
out
of physico-chemical systems, just as we’ve moved up
out
of the law of gravity. Organisms have new tricks, exploiting new contexts. For instance: birds, despite being heavier than air, can fly.
    We’re not saying that what birds do is inconsistent with the ‘fundamental’ physical laws for the matter out of which they are made. That would be very close to making Descartes’s error, postulating that mind and matter are two different things. In fact, flight is entirely consistent with physical law. The force of gravity, acting on the atoms that make up the bird, must be counteracted by the lifting forces generated by the wings as they move through the air. If not, the bird won’t fly. Ditto jumbo jets. Our point is that flight is not something that you can naturally deduce from the fundamentallaws. Molecules can’t fly, but birds – made from molecules – can. A molecule can fly if it’s included in a bird. Context makes a big difference. Life has acquired a multitudinous list of complex systems, each resulting from natural selection, to lift organisms out of ancient incompetences into new competences.
    The goup in a frog isn’t a bit like the goup in a rock. The atoms may be much the same, but the different arrangements, to use Feynman’s words, completely change how you expect frog goup to behave. Similarly, the atoms in a person or a penguin or a packet of soap 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 andit 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