2/5 Pearl Buck's missionary family face violence and famine in early 20th-century China.
27/30 Heather Couper looks at research that shows stars are like controlled nuclear explosions.
1/5 Lindsay Duncan reads from Hilary Spurling's biography of American writer Pearl Buck.
26/30 Heather Couper looks at William Herschel's discovery of infrared radiation 200 years ago.
5/5 Stanley is determined to continue Livingstone's quest to find the source of the Nile.
25/30 Heather Couper looks at arguments over the laws of physics and the universe's creation.
What is the truth behind the mermaid story? Janet Ellis investigates.
4/5 David Livingstone aims to solve the mystery of the Nile's source once and for all.
24/30 What we can see is only a fraction of matter in the cosmos. Heather looks at dark matter.
3/5 Samuel Baker and his mistress Florence go in search of Lake Albert.