LightClock

The LightClock is an ongoing project by Rupert Griffiths (Lancaster University) that measures time according to the changing luminosity and colour of the sky over the day and night and throughout the year. Daily and annual variations in natural light choreograph the behaviour and life cycle events of most life on earth. Meanwhile, artificial light at night adds noise to the natural cycle of night and day and can disrupt both human and non-human biologies and behaviours. The LightClock makes these cycles of natural and artificial light legible.
 
Using light sensors in Bonn Botanical Gardens, the clock traces out the changing ambient light as a helix of coloured dots. Each revolution corresponds to the changing light over a period of 24 hours. The helix is shown in perspective and thus appears as a spiral, with the present moment at the head of the outer ring (at the 12 o’clock position) and the past spiralling anticlockwise towards the centre. Cumulatively, this locates the viewer in the daily and seasonal variations of light and dark that act as a master clock for life on earth.