The topic of the “smart city” is one that is cropping up over and over again in various streams and sources, as much a sign of the rapidly urbanising times as of how technology is striding ahead purposefully in the city, albeit in a much different way to development in the countryside.

An interesting and captivating article on the BBC News website from September 2013 is a typical example. It highlights the various ways in which residents of some of Brazil’s favelas use a combination of simple (kite) and new (smartphone and camera) technologies to map out and instigate change in their communities. Much of the new technology associated with smartphones in particular seems to fit snugly into the environments of these dense social worlds, and it would appear that the people living there are by themselves able to modify and improve their surroundings by simple means, rather than by edict from above.

Nevertheless, one interesting facet that appears time and time again is that at some stage, no matter how intricate the technology, there is always a human node, a gatekeeper perhaps, or at the very least a transition stage through which the information has to pass, and who consequently and inevitably has an impact on the form and shape of the data passing through. Information is selected, favoured, filtered as it flows: all these macroscopic changes that are seen at the end of the day come from microscopic inputs and manipulations along the way.

It is at this stage that once again technology intersects with psychology, economics, and geography, and is presumably the reason why even an identical technical solution in one location is bound to have a very different flavour when applied to another. Changes start at this microscopic level and then propagate outwards: after all,  how can individuals change the flow of a city in a substantial way? By moving away from a roundabout, spreading news about congestion, proposing or crowdsourcing an easier route, anything that will change people’s behaviour might be said to influence the currents of a metropolis. By logging in at a specific place, a reference, a rapid dispersion of a key event, this might trigger further steps and stops down the line, if only enough connections are fired up.

In cancer there is talk of a microenvironment, and if you want to influence the tumor it is really necessary to focus on what goes on at the microenvironment level rather than just the systemic (with therapies to match). The interaction between individuals and the environment is not that different: there are systemic changes that will influence all city-dwellers (e.g., the weather: some more, some less), and then local/microenvironmental changes (street-related, drain-related, connections, internet, maintenance) that have an impact on groups, how individuals interact with groups, and consequently how localities shift. Most normally I suspect that this results in local oscillations, and minor changes in a specific locale do not have much of an impact on neighbouring areas, let alone spaces on the other side of a metropolis.

Sometimes, however, an idea might catch hold and spill over from one region to another. Again there is an analogy in the natural world: systems that change might reach a critical mass, a certain power and influence that by its very nature causes a shift away from equilibrium in spatially distant zones. And here again is the key influence of the human element: any geography story always contains elements that can be used in a human story, the psychogeography, trying to pinpoint and define specific focal points, corners, familiar pavements that serve as anchors for an individual. Unlike what is normally found in physical systems there are dotted lines between individuals, a certain tunnelling of ideas across social and spatial divides, that can distribute change in a multitude of often unexpected ways, and eventually takes over society like a slowly creeping bacterial colony across a petri dish.