This old synagogue in Matera is a cavern cut deep into the limestone.
The very precise alignment of the cavern allows sunlight to reach far into the ground. Over the years, the light and the special climate have enabled cyanobacteria to become established. Hence, the green growth on the rocky walls provides an insight into the light that has entered the cavern over many years.
In the mirror installation Solar Plexus, the light entering the cavern is deflected twice to arrive at a point, which has never previously been illuminated and has hence remained free of any growth of cyanobacteria.
The mirror on the right of the image captures the sunlight and reflects it onto the small circular mirror on the opposite side. This combination of light and time is now enabling the cyanobacteria to grow and, eventually, leave its green circular trace behind on the rock face.
