[quote]This miniature ecosystem has been thriving in an almost completely isolated state for over 40 years. Only once in that time has it been watered. It grew and multiplied from a single spiderwort plant. Having access to light, it continues to photosynthesize. The water builds up on the inside of the bottle as condensation and then drips back down on the plants in a miniature version of the water cycle. As leaves die, they fall off and rot at the bottom producing the carbon dioxide and nutrients required for more plants to grow.[/quote] So that's pretty neat.