In Environmental Systems and Societies (ESS), students have been creating their own biospheres or mesocosms. Their mesocosms contain soil, vegetation, and perhaps some insects that crept inside. They are sealed, and due to the flows of energy and matter inside, as well as the flow of energy entering the mesocosm, life inside will survive for many, many years. (Well, hopefully until the end of the two-year ESS course!) This links to the ESS course because students have been studying systems in terms of their inputs, flows, stores, and outputs.