Tango is easy to recognise: those daring steps, the tight hold of the dancing partners, the intense yet melancholy music dominated by the plaintive sounds of the bandoneon. But if you ask what exactly tango is and where it came from, the answer may not be so immediately clear - because it's more than a genre of music, more than just a style of dance.

Photo: Argentine dancers on stage at the World Tango Championships in 2014 (Getty Images)

Carl Linnaeus, today a largely unknown figure, is one of the giants of natural science. He devised the formal two-part naming system we use to classify all life forms. With Quentin Cooper is botanist Dr Sandra Knapp, from the Natural History Museum in London, life sciences expert Professor Staffan Müller-Wille from Exeter University in the UK, and science writer and biographer of Linnaeus, Dr Lisbet Rausing.

Photo: Carl Linnaeus painted by Per Krafft the Elder (Permission of The Linnean Society of London)

China, Iran, Afghanistan, Syria, Uzbekistan and India: if you went to any of these places a thousand years ago, you would find goods and produce from the others. But how did they get there and why? This week’s Forum explores the ancient pattern of trading networks which criss-crossed the plains, deserts and mountains of China, Central Asia and points further West, and which encouraged not just the exchange of commodities like silk, paper and horses but ideas and people too.

Bridget Kendall talks to Valerie Hansen, professor of history at Yale University who has a particular interest in trade and exchanges across Eurasia; historian Dr. Susan Whitfield who is curator of the Central Asian collections at the British Library in London; and Tamara Chin, professor of comparative literature at Brown University whose work focuses on ancient China.

Photo: A man rides a horse overlooking Band-e-Amir lake, through central Afghanistan, on the former Silk Road that once linked China with Central Asia and beyond. Credit: Getty Images

At the time of the Partition of India 70 years ago this year, there were more than 500 Princely States. These were states nominally ruled by Indian Princes but ultimately under the control of the British colonial powers. Many of these princes - male and female members of the Royal Family - had kingdoms dating back to the 8th and 9th Centuries. But after the British curbed their powers, was their role largely ceremonial or did they have a deeper impact on the Indian people? And how did these Princes survive after Partition? Joining Rajan Datar is the writer and historian William Dalrymple, the director of the King’s College London India institute Sunil Khilnani, and the Indian social scientist Nikita Sud from Oxford University.

(Photo: A view of the Umaid Bhawan Palace, set high above the desert city of Jodhpur in Rajasthan. Credit: Getty Images)

150 years ago three British North American colonies came together to form what was to become the world’s second largest country.

To explain how this union came about and who the key players were, Bridget Kendall talks to historians Margaret Macmillan, Phillip Buckner and Sean Kheraj.

Photo: The Canadian flag at an ice-hockey game (GETTY IMAGES)

Why do humans have such a long period of immaturity? And how have our ideas about childhood changed through the ages and across the world?

Photo: a young girl walks through an entrance to a walled garden (BBC)

Since appearing in print in the late nineteenth century, Sherlock Holmes has become one of the world’s most famous detectives, known for solving crime and mystery in London and beyond. But who was the man that made this fictional super-sleuth? And what inspired him to write?

Bridget Kendall explores the life and work of Sir Arthur Conan Doyle - the doctor and literary superstar who embraced both science and the spiritual world - and who changed crime fiction forever.

She’s joined by biographer Andrew Lycett and the scholars Catherine Wynne and Stefan Lampadius.

Photo: Sir Arthur Conan Doyle (Getty Images)

Many of us can find the time of day quickly and accurately but where did the idea of time keeping originate and how did our ancestors manage without the instant access we take for granted today?

From ancient shadow and water clocks to the latest super accurate optical clocks, Bridget Kendal explores time keeping with the Curator of the Royal Observatory in London, Dr Louise Devoy, the Director of the Museum of the History of Science in Oxford, Dr Silke Ackermann and watch and clock expert Grégory Gardinetti from the Fondation de la Haute Horlogerie in Geneva.

Photo: World Clocks (Credit: EyeWire, Inc.)

Perhaps the island of Taiwan makes you think of those familiar "Made in Taiwan" labels on computer and electrical goods but it was nicknamed 'Ilha Formosa' or the 'beautiful island' by the Portuguese in the 1500s. Bridget Kendall explores its rich and surprising history with Emma Teng, Professor of Asian Civilisations at the Massachusetts Institute of Technology (MIT), Dr Jie Yu, Head of China Foresight, focused on Chinese foreign policy, at the London School of Economics and Dr Bi-yu Chang and Dr Dafydd Fell from SOAS (formerly known as the School of Oriental and African Studies) in London.

Photo: people celebrate Taiwan' s annual Lantern Festival, which marks the end of the Lunar New Year festivities. (Getty Images)

This year is the 80th anniversary of the record-breaking attempt by the US aviator Amelia Earhart to circumnavigate the globe. It was a mission that cost her life, but helped to cement her place in history as one of the most inspirational and celebrated pilots of the 20th century.

Bridget Kendall looks back at the life of a pioneering woman determined to break through barriers - with Susan Butler, author of ‘East to the Dawn: The Life of Amelia Earhart’; Dorothy Cochrane, Curator in the Aeronautics Division of the Smithsonian Institution's National Air and Space Museum in Washington; and Susan Ware, author of ‘Still Missing: Amelia Earhart and the Search for Modern Feminism’.

Photo: Amelia Earhart in June 1928 (Getty Images)