Acknowledgements
Except for third party materials and otherwise stated (see terms and conditions [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] ), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence
Course image: K2 Space in Flickr made available under Creative Commons Attribution 2.0 Licence.
All other materials included in this course are derived from content originated at the Open University.
Figure 1 © Science Museum/ Science and Society Picture Library
Figure 2 © Science Museum/ Science and Society Picture Library
Figure 3 © Steve Catlin/ Redferns
Figure 4 © Wildscape/ Alamy
Figure 5 (left) © Rex Features; (right) © Empics
Figure 6 © Empics
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