Eleven thousand years ago Siberia was an even colder place than it is today. Stone Age man made a discovery and invented pottery. It was noticed that clay left out in the sun dried and became hard but was brittle and broke easily. If dried clay was left in the rain it became soggy again. Fires were used to keep people warm and to cook food. When these fires were made on top of ground which contained clay, the ground around the fire changed and became stronger. Clay vessels baked in fire became pottery. It is believed the origins of pottery date back to the Ice Age. The process is still very common and used today.

First broadcast:
4 March 2008

The clip could be used as a plenary after carrying out an investigation about chemical and physical changes. Initially, pupils could be given three vessels made of wet clay, dry clay and fired clay, predicting which would make the best drinking vessel. They could design and carry out an experiment to test their prediction, recording the changes to the clay when liquid is added. Discuss the irreversible change that occurs when clay is heated at high temperatures. As an extension, the pupils could try to explain what they think has happened to the clay so that it cannot return to its original form (due to the loss of gases).