Ein bioenergetisches Paradoxon

The first known life forms on Earth were probably bacteria. Blue-green algae, cyanobacteria, a specific group of phototrophic bacteria that are the only prokaryotes able to produce oxygen, began to convert the early Earth’s atmosphere, which lacked free oxygen, into an oxygen-rich atmosphere about 3.2 billion years ago – through their ability to split free molecular oxygen from water under the action of sunlight through photosynthesis. In the installation with living blue-green algae »Ein bioenergetisches Paradoxon« [A Bioenergetic Paradox] Peter Weibel presented a paradoxical bioenergetic situation in the context of his exhibition »Zur Kosmologie des Paradoxen« (I) [On the Cosmology of the Paradox (I)] at the Galerie nächst St. Stefan in Vienna. Blue-green algae normally live in the oceans, in an open system. In an aquarium, however, they live in a closed system in which the positive effect of light is reversed by self-shading. The more light, the greater the growth of the algae and the more self-shading occurs. Algal growth is curtailed by too much shadow. The energy source of light, which makes life possible, ultimately leads to its extinction in a closed system.