In Our Time

Melvyn Bragg and his guests discuss comets, the 'dirty snowballs' of the Solar System. In the early 18th century the Astronomer Royal Sir Edmond Halley compiled a list of appearances of comets, bright objects like stars with long tails which are occasionally visible in the night sky. He concluded that many of these apparitions were in fact the same comet, which returns to our skies around every 75 years, and whose reappearance he correctly predicted. Halley's Comet is today the best known example of a comet, a body of ice and dust which orbits the Sun. Since they contain materials from the time when the Solar System was formed, comets are regarded by scientists as frozen time capsules, with the potential to reveal important information about the early history of our planet and others.

With:

Monica Grady

Paul Murdin

Don Pollacco

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Thomas Malory's "Le Morte Darthur", the epic tale of King Arthur and his knights of the Round Table. Sir Thomas Malory was a knight from Warwickshire, a respectable country gentleman and MP in the 1440s who later turned to a life of crime and spent various spells in prison. It was during Malory's final incarceration that he wrote "Le Morte Darthur", an epic work which was based primarily on French, but also some English, sources.

Malory died shortly after his release in 1470 and it was to be another fifteen years before "Le Morte Darthur" was published by William Caxton, to immediate popular acclaim. Although the book fell from favour in the seventeenth century, it was revived again in Victorian times and became an inspiration for the Pre-Raphaelite movement who were entranced by the chivalric and romantic world that Malory portrayed.

The Arthurian legend is one of the most enduring and popular in western literature and its characters - Sir Lancelot, Guinevere, Merlin and King Arthur himself, are as well-known today as they were then; and the book's themes - chivalry, betrayal, love and honour - remain as compelling.

With:

Helen Cooper

Helen Fulton

Laura Ashe

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the cult of Mithras, a mystery religion that existed in the Roman Empire from the 1st to the 4th centuries AD. Also known as the Mysteries of Mithras, its origins are uncertain. Academics have suggested a link with the ancient Vedic god Mitra and the Iranian Zoroastrian deity Mithra, but the extent and nature of the connection is a matter of controversy.

Followers of Mithras are thought to have taken part in various rituals, most notably communal meals and a complex seven-stage initiation system. Typical depictions of Mithras show him being born from a rock, enjoying food with the sun god Sol and stabbing a bull. Mithraic places of worship have been found throughout the Roman world, including an impressive example in London. However, Mithraism went into decline in the 4th century AD with the rise of Christianity and eventually completely disappeared. In recent decades, many aspects of the cult have provoked debate, especially as there are no written accounts by its members. As a result, archaeology has been of great importance in the study of Mithraism and has provided new insights into the religion and its adherents.

With:

Greg Woolf

Almut Hintze

John North

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss The South Sea Bubble, the speculation mania in early 18th-century England which ended in the financial ruin of many of its investors. The South Sea Company was founded in 1711 with a view to restructuring government debt and restoring public credit. The company would ostensibly trade with South America, hence its name; and indeed, it did trade in slaves for the Spanish market even after the Bubble burst in 1720.

People from all walks of life bought shares in the South Sea Company, from servants to gentry, and it was said the entire country was gripped by South Sea speculation mania. When the shares crashed and the company collapsed there was a public outcry and many people faced financial ruin, although some investors sold before the crash and made substantial amounts of money. For example, the bookseller Thomas Guy made his fortune and founded a hospital in his name the following year.

But how did such a financial crisis develop and were there any lessons learnt following this early example of a stock market boom and bust?

With:

Anne Murphy

Helen Paul

Roey Sweet

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the epic poem the Shahnameh of Ferdowsi, the 'Book of Kings', which has been at the heart of Persian culture for the past thousand years. The poem recounts a legendary history of Iran from the dawn of time to the fall of the Persian Empire in the 7th century and serves, in a sense, as a creation myth for the Persian nation.

The Shahnameh took Ferdowsi thirty years to write and, consisting of over 50,000 verses, is said to be the longest poem ever written by a single author. Laced with tragedy, Ferdowsi's epic chronicles battles, romances, family rifts and Man's interior struggle with himself. Although the stories may not always be true they have a profound resonance with Iranians even today, and the poem has been referred to as both the 'encyclopaedia of Iranian culture' and the identity card of the Persian people.

With:

Narguess Farzad

Charles Melville

Vesta Sarkhosh Curtis

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the influential British philosopher Bertrand Russell. Born in 1872 into an aristocratic family, Russell is widely regarded as one of the founders of Analytic philosophy, which is today the dominant philosophical tradition in the English-speaking world. In his important book The Principles of Mathematics, he sought to reduce mathematics to logic. Its revolutionary ideas include Russell's Paradox, a problem which inspired Ludwig Wittgenstein to pursue philosophy. Russell's most significant and famous idea, the theory of descriptions, had profound consequences for the discipline.

In addition to his academic work, Russell played an active role in many social and political campaigns. He supported women's suffrage, was imprisoned for his pacifism during World War I and was a founder of the Campaign for Nuclear Disarmament. He wrote a number of books aimed at the general public, including The History of Western Philosophy which became enormously popular, and in 1950 he was awarded the Nobel Prize in Literature. Russell's many appearances on the BBC also helped to promote the public understanding of ideas.

With:

AC Grayling

Mike Beaney

Hilary Greaves

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the history of crystallography, the study of crystals and their structure. The discovery in the early 20th century that X-rays could be diffracted by a crystal revolutionised our knowledge of materials. This crystal technology has touched most people's lives, thanks to the vital role it plays in diverse scientific disciplines - from physics and chemistry, to molecular biology and mineralogy. To date, 28 Nobel Prizes have been awarded to scientists working with X-ray crystallography, an indication of its crucial importance.

The history of crystallography began with the work of Johannes Kepler in the 17th century, but perhaps the most crucial leap in understanding came with the work of the father-and-son team the Braggs in 1912. They built on the work of the German physicist Max von Laue who had proved that X-rays are a form of light waves and that it was possible to scatter these rays using a crystal. The Braggs undertook seminal experiments which transformed our perception of crystals and their atomic arrangements, and led to some of the most significant scientific findings of the last century - such as revealing the structure of DNA.

With:

Judith Howard

Chris Hammond

Mike Glazer

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Borgias, the most notorious family in Renaissance Italy. Famed for their treachery and corruption, the Borgias produced two popes during their time of dominance in Rome in the late 15th century. The most well-known of these two popes is Alexander VI, previously Cardinal Rodrigo Borgia. He was accused of buying votes to elect him to the papacy and openly promoted his children in positions of power. Rodrigo's daughter, Lucrezia, is widely remembered as a ruthless poisoner; his son, Cesare, as a brutal soldier.

Murder, intrigue and power politics characterised their rule, but many of the stories now told about their depraved behaviour and evil ways emerged after their demise and gave rise to the so-called 'Black Legend'. The sullied reputation of the Borgia dynasty endures even today and their lives have provided a major theme for plays, novels and over forty films.

With:

Evelyn Welch

Catherine Fletcher

Christine Shaw

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the French philosopher and social activist Simone Weil. Born in Paris in 1909 into a wealthy, agnostic Jewish family, Weil was a precocious child and attended the prestigious Ecole Normale Superieure in Paris, achieving the top marks in her class (Simone de Beauvoir came second).

Weil rejected her comfortable background and chose to work in fields and factories to experience the life of the working classes at first hand. She was acutely sensitive to human suffering and devoted her life to helping those less fortunate than herself. Despite her belief in pacifism she volunteered on the Republican side during the Spanish Civil War and later joined the French Resistance movement in England.

Her philosophy was both complex and intense. She argued that the presence of evil and suffering in the world was evidence of God's love and that Man has no right to ask anything of God or of anyone whom they love. Love which expects reward was not love at all in Weil's eyes.

Weil died of TB in Kent at the age of only 34. Her strict lifestyle and self-denial may have contributed to her early death. T.S Eliot said "she was not just a woman of genius, but was a genius akin to that of a saint"; Albert Camus believed she was "the only great spirit of our time."

With:

Beatrice Han-Pile

Stephen Plant

David Levy

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Upanishads, the ancient sacred texts of Hinduism. Dating from about 700 BC, the Upanishads were passed down through an oral tradition in priestly castes and were not written down until the 6th century AD. They constitute the final part of the Vedas, the collection of texts which form the foundation of the Indian Hindu world, and were originally spoken during sacrificial rituals.

Yet the Upanishads go beyond incantations performed during sacrifices, and ask profound questions about human existence and man's place in the cosmos. The concepts of Brahman (the universal cosmic power) and Atman (the deeper soul of the individual) are central to the understanding of the Upanishads. Each individual treatise has its own character. Some are poetic; some are scientific; others are dialogues between kings and sages or metaphysical reflections. More than one hundred Upanishads were produced, thirteen of which are regarded as the canonical scriptures of Hinduism.

With:

Jessica Frazier

Chakravarthi Ram-Prasad

Simon Brodbeck

Producer: Natalia Fernandez.