They’re slimy and slippery. They’re part of the green film you see on garden ponds. They can clump together and wash up on the shores of beautiful beaches. A lot of them are invisible to the naked eye. These underappreciated organisms called algae are indispensable to the presence of life on earth but not all is straightforward about them. They can be single celled or multi cellular. They can be ugly and slimy or sometimes beautiful: indeed are even a tourist attraction. They may be found in the sea or on land. They can be life-creating and yet life-destroying and toxic in excess. So perhaps it’s time we paid more attention to algae and their evolution. Rajan Datar is joined by Ruth Kassinger, author of Slime: How algae created us, plague us and just might save us; Dr Brenda Soler-Figueroa, a marine scientist at the Smithsonian Environmental Research Centre; Dr Gothamie Weerakoon Senior Curator of Lichens and Slime Moulds at the Natural History Museum of London and author of Fascinating Lichens of Sri Lanka; and Stefan Bengtson, emeritus professor at the Swedish Museum of Natural History. (Photo: Volvox algae colonies, spherical forms outlined by biflagellate cells interconnected by cytoplasmic bridges. Credit: DeAgostini/Getty Images)

The Goths were a Germanic tribe infamous for their brief sack of Rome in 410 AD but their cultural and political influence was felt throughout Europe for centuries. They re-shaped the Balkans, preserved the Roman way of life in Italy and presided over a cultural flourishing in Spain. But how, many centuries after their demise, did they come to give their name to an important architectural style in medieval Europe and, in the 20th century, to a subculture popular all over the world? Bridget Kendall talks all things Gothic with David Gwynn, historian at Royal Holloway, University of London, and author of Goths, the Lost Civilisation. Also on the panel are Janina Ramirez, a cultural historian, broadcaster and author who focuses on the Middle Ages, based at the University of Oxford, and Mischa Meier, professor of ancient history at the University of Tubingen in Germany.

The 1821 Greek war for independence from the Ottoman empire became an inspiration for people all over Europe who wanted to dismantle the old multi-ethnic empires. But it is less well known that a number of women played key roles in the uprising. In this programme, Bridget Kendall and guests focus on Laskarina Bouboulina, perhaps the best known of Greek women freedom fighters. For the last two centuries, Bouboulina's deeds as as a brave sea captain and a generous financier of the uprising have enthralled people in Greece and elsewhere but how many of these stories are based in fact? And what is the significance of Bouboulina today? To find out Bridget is joined by: Dr. Margarite Poulos, a historian of modern Greece from Western Sydney University whose book Arms and the Woman surveys the role of Greek women in the country's military struggles; Dr. April Kalogeropoulos Householder from University of Maryland, Baltimore County, who has not only written about Laskarina Bouboulina but also made a documentary film about her; and Pavlos Demertzis-Bouboulis, who is a descendant of Bouboulina as well as the director of a museum dedicated to her on the island of Spetses. [Image: Portrait of Laskarina Bouboulina, 1830, by Adam Friedel. From the collection of Bouboulina Museum, Spetses. Credit: Fine Art Images/Heritage Images/Getty Images]

For someone who was largely self-taught, Mary Somerville's rise to renown in the male-dominated world of science was quite remarkable. Although women were barred from being members of the learned societies where knowledge was shared in the early 19th-Century, Somerville found alternative ways to become one of the most respected figures in maths and science of her day. Scottish-born Somerville played a crucial role in communicating the latest findings in science through a series of successful books. She regretted never making any original discoveries herself however, so does her experience suggest we should re-evaluate the role of originality in science? Bridget Kendall is joined by Jim Secord, emeritus professor of History and Philosophy of Science at the University of Cambridge, who has edited the works of Mary Somerville; Dr Brigitte Stenhouse, lecturer in the History of Mathematics at the University of Oxford whose doctoral thesis looked at the mathematical work of Mary Somerville; and Ruth Boreham, former project curator at the National Library of Scotland, who is writing a biography of Mary Somerville. Producer: Fiona Clampin (Photo: Royal Bank of Scotland £10 note featuring Mary Somerville)

One of the earliest Cold War conflicts was a 12-year guerrilla war commonly known as the Malayan Emergency and fought from 1948 in the jungles of what is now Malaysia. This communist insurgency was fuelled not only by ideology but also by the desire for Malayan independence from British colonial rule. There have been a number of books and documentaries devoted to the subject but relatively few in English capture the experiences of the Chinese community in Malaya that was at the centre of the Emergency. Rajan Datar is joined by three guests, all with family links to the Emergency: Sim Chi Yin, a photographer and artist from Singapore whose book She Never Rode that Trishaw Again tells the story of her grandmother widowed during the war in Malaya; Show Ying Xin, a postdoctoral fellow at the at the Australian National University’s Malaysia Institute in Canberra; and Rachel Leow, Associate Professor in Modern East Asian History at the University of Cambridge and author of Taming Babel: Language in the Making of Malaysia. [Photo: Malayan police officers keeping watch from the Pengkalan police station in 1950. Credit: Haywood Magee/Picture Post/Hulton Archive/Getty Images]