Adam Hart-Davis continues his search for unsung heroes of science when he cycles around the south of England. On a stop-off in Surrey, he uses a tin of tuna to explain the physics behind Neville Barnes-Wallis's invention of the bouncing bomb.
Other subjects include Charles Darwin, whose theory of evolution is explored in a series of programmes beginning on Friday, and Thomas Young, who discovered how the eyes focus.
(The series continues on Thursday at 8pm) (Stereo)

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