First transmitted 31 October 1970, Professor Alexander Thom asserts his theory that Stonehenge and other megalithic sites were used to record time and predict solar and lunar eclipses. Magnus Magnusson looks at Thom's evidence and hears what different archaeologists think of the suggestion that Stone Age Britons could make such elaborate calculations. If Thom's theory is correct, previous archaeological certainties about the knowledge and ability of people in the Stone Age would be overturned.

Professor Alexander Thom puts forward his theory that Stonehenge and other megalithic sites were used to record time and predict solar and lunar eclipses. Magnus Magnusson looks at Thom's evidence and hears what different archaeologists think of the suggestion that Stone Age Britons could make such elaborate calculations. If Thom's theory is correct, previous archaeological certainties about the knowledge and ability of people in the Stone Age would be overturned.

DID YOU KNOW?
Alexander Thom's book 'Megalithic Sites in Britain', published in 1967, caused huge controversy within academic archaeology. Thom's premise that Stone Age culture used complex mathematics and applied this to constructing monuments undermined the progressional idea of culture as continually advancing from savagery to civilisation. Glyn Daniel commissioned the eminent astronomer Sir Fred Hoyle to consider Thom's evidence for 'Archaeology' magazine. Hoyle found that Thom's theories were essentially accurate.