Out beyond the planets, light fades as the suns rays diminish in intensity. The absence of light produces different kinds of darkness: sharp shadows certainly but also an infinite gradation of different kinds of shade. The shadows have their own existence.
But back on Earth, the planet suffers from light pollution. Too much light is seeping into the sky, blocking out the stars and making it more and more difficult to see what can be seen. Cities now stand in for the stars, making their own starry night sky wrapped around the planet. And, just like the night sky, there are still all of the blank spots where light does not reach: the social equivalent of caves, waiting to be illumined.
Should we be concerned about this distribution of light? Should access to light be seen as a basic human right like access to water? After all, no one would think of cutting off water from a population as anything other than a heinous act.
The problem is that light has become so much a part of how we apprehend the world that we both maximize and minimize its influence. We write all kinds of paeans to the sublime effects of natural sunrises and sunsets but we overlook how artificial light figures in our everyday lives: it is right in front of us but it is hidden from view, rather like the three pounds in weight of bacterial biome that we carry around with us, an ecosystem that is an unfamiliar familiar.
We need to think of artificial light like this bacterial biome, as an ecosystem of different and diverse practices of lighting. Modern cities show why. At night, they appear from space as though they were a single light source but they are actually a multitude of different practices of lighting: multiple, fragmented and superimposed infrastructures each of which have their own different forms and technologies of light - and darkness.
Look around you and you can see this straight away: practices of communication involving blinking message lights, practices of transport involving street lighting and car headlights, practices of entertainment and advertising involving a multitude of screens, each with their standby lights acting like the pilot fish running after a whale, practices of security involving not just outside security lights but also the small security lights that flash as people cross a room, practices of making a home with their extended history of aesthetic advantage and disadvantage … the list goes on and on. It is as if these practices of illumination are too obvious to deserve much comment but each of them is another way in which humanity has become increasingly wrapped up in technology such that human and light simply merge together as practices of lighting lighting up practices.
And if we want to effect the distribution of light, we need to think it through practice by practice. That way, perhaps we can produce a kind of luminary moderation which allows us to light our way but without the kind of environmental overload which is currently the main consequence. There can be no great plan but by working step by step there can be great results for our cities – and for the planet.
Professor of Geography, Vice-Chancellor and President, University of Warwick, Coventry, UK