Well, it’s been a bit quiet on the blog front, but on the weekend my clever wife gave birth to our first child – Evelyn Felicity. So I’ve had one or two distractions of late.
But it’s Friday and therefore time for a dose of end-of-week thinking, and what I want to think about in this post is the concept of emergence.
This was articulated in a way which particularly resonated with me in The Science of Discworld 2: The Globe, by Terry Pratchett, Ian Stewart, and Jack Cohen. The Science of Discworld books address various areas of scientific knowledge and research, shadowed and illuminated by a beautiful Discworld narrative. If you’re interested in popular science, they are probably worth reading.
Emergence was discussed regarding systems, or phase spaces – a conceptual space containing all possible moves and positions of matter contained within that space, subject to the underlying constraints. For example, my being sat here at this time in this position is a point in the phase space of all possible positions (and times) I could have been sat here. Emergence happens when the observed system changes in some fundamental way, when it takes on a new perspective or a totally new dynamic, but the fundamental rules and constraints have not changed.
A simple yet excellent example of this is Langton’s Ant. This is a simple 2D plane with an “ant” moving across it in the standard four directions – up, down, left and right. The ant only follows two rules:
- At a black square, turn 90° right, flip the color of the square, move forward one unit
- At a white square, turn 90° left, flip the color of the square, move forward one unit
This demonstrates that from the perspective of an outside observer (the researcher running the experiment), everything about the ant’s universe is completely understood. This should mean that predicting the ant’s behavior is very straightforward, but in fact, the opposite is true. The ant starts of quite randomly before exploding into patterns of behavior varying from fixed and regimented to absolutely chaotic. Prediction within the confines of this seemingly simple world is difficult if not impossible.
When you scale up from the basic world of Langton’s Ant and look at vastly more complex models – social groups, city infrastructure, global economies, cosmic expansion – you start to appreciate that to gain an understanding of the world around you, easy-to-understand reductionist arguments simply won’t do. Reductionism is everywhere we look and particularly in the media, who love a good sound bite: “THIS means THAT which equates to THOSE” and so on. To an extent it’s human nature – we like our worlds, our phase spaces to be explainable via easy-to-understand stories. Explanations which are not quite true (or even wildly untrue) but which we can make fit to our observations.
That’s not to say that some quests for increasingly fundamental information are misguided. Far from it. The search for ultimate fundamental particles such as that which is going on in the Large Hadron Collider is part of a quest to get all the information available. You might have a brush and canvas, but you can’t illustrate anything if you can’t find all the paint.
The lesson to take from the concept of emergence is that the world in which we live is vastly complex and interconnected such that sometimes we start to wonder whether we will ever understand it, particularly as we are ourselves an integrated part of those systems. But this just makes the search for knowledge ever more important – something which you don’t understand isn’t simply mysterious and wonderful in its fogginess. It’s something you just don’t know about, and the quest to understand who we are, how we came to be here and even where “here” actually is is one of our defining characteristics and something to be encouraged and celebrated.