This free course was written by Sarah Vicary and Alun Morgan.
Figure 1: © bubaone/Getty Images
Figure 2: © szefei/123rf
Figure 3: © Ilkefoto/Getty
Except for third party materials and otherwise stated (see Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence.), this content is made available under a
The material acknowledged below is Proprietary and used under licence (not subject to Creative Commons Licence). Grateful acknowledgement is made to the following sources for permission to reproduce material in this free course:
Every effort has been made to contact copyright owners. If any have been inadvertently overlooked, the publishers will be pleased to make the necessary arrangements at the first opportunity.
Don't miss out
If reading this text has inspired you to learn more, you may be interested in joining the millions of people who discover our free learning resources and qualifications by visiting The Open University – www.open.edu/ openlearn/ free-courses.