Melvyn Bragg and guests discuss enzymes, the proteins that control the speed of chemical reactions in living organisms. Without enzymes, these reactions would take place too slowly to keep organisms alive: with their actions as catalysts, changes which might otherwise take millions of years can happen hundreds of times a second. Some enzymes break down large molecules into smaller ones, like the ones in human intestines, while others use small molecules to build up larger, complex ones, such as those that make DNA. Enzymes also help keep cell growth under control, by regulating the time for cells to live and their time to die, and provide a way for cells to communicate with each other.

With

Nigel Richards

Sarah Barry

And

Jim Naismith

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the flourishing of the idea of Purgatory from C12th, when it was imagined as a place alongside Hell and Heaven in which the souls of sinners would be purged of those sins by fire. In the West, there were new systems put in place to pray for the souls of the dead, on a greater scale, with opportunities to buy pardons to shorten time in Purgatory. The idea was enriched with visions, some religious and some literary; Dante imagined Purgatory as a mountain in the southern hemisphere, others such as Marie de France told of The Legend of the Purgatory of Saint Patrick, in which the entrance was on Station Island in County Donegal. This idea of purification by fire had appalled the Eastern Orthodox Church and was one of the factors in the split from Rome in 1054, but flourished in the West up to the reformations of C16th when it was again particularly divisive.

With

Laura Ashe

Matthew Treherne

and

Helen Foxhall Forbes

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the life and work of Louis Pasteur (1822-1895) and his extraordinary contribution to medicine and science. It is said few people have saved more lives than Pasteur. A chemist, he showed that otherwise identical molecules could exist as 'left' and 'right-handed' versions and that molecules produced by living things were always left-handed. He proposed a germ theory to replace the idea of spontaneous generation. He discovered that microorganisms cause fermentation and disease. He began the process named after him, pasteurisation, heating liquids to 50-60 C to kill microbes. He saved the beer and wine industries in France when they were struggling with microbial contamination. He saved the French silk industry when he found a way of protecting healthy silkworm eggs from disease. He developed vaccines against anthrax and rabies and helped establish immunology. Many of his ideas were developed further after his lifetime, but one of his legacies was a charitable body, the Pasteur Institute, to continue research into infectious disease.

With

Andrew Mendelsohn

Anne Hardy

and

Michael Worboys

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the life and works of Emily Dickinson, arguably the most startling and original poet in America in the C19th. According to Thomas Wentworth Higginson, her correspondent and mentor, writing 15 years after her death, "Few events in American literary history have been more curious than the sudden rise of Emily Dickinson into a posthumous fame only more accentuated by the utterly recluse character of her life and by her aversion to even a literary publicity." That was in 1891 and, as more of Dickinson's poems were published, and more of her remaining letters, the more the interest in her and appreciation of her grew. With her distinctive voice, her abundance, and her exploration of her private world, she is now seen by many as one of the great lyric poets.

With

Fiona Green

Linda Freedman

and

Paraic Finnerty

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss The Battle of Lincoln on 20th May 1217, when two armies fought to keep, or to win, the English crown. This was a struggle between the Angevin and Capetian dynasties, one that followed Capetian successes over the Angevins in France. The forces of the new boy-king, Henry III, attacked those of Louis of France, the claimant backed by rebel Barons. Henry's regent, William Marshal, was almost seventy when he led the charge on Lincoln that day, and his victory confirmed his reputation as England's greatest knight. Louis sent to France for reinforcements but in August these, too, were defeated at sea, at the Battle of Sandwich. As part of the peace deal, Henry reissued Magna Carta, which King John had granted in 1215 but soon withdrawn, and Louis went home, leaving England's Anglo-French rulers more Anglo and less French than he had planned.

The image above is by Matthew Paris (c1200-1259) from his Chronica Majora (MS 16, f. 55v) and appears with the kind permission of the Master and Fellows of Corpus Christi College, Cambridge

With

Louise Wilkinson

Stephen Church

and

Thomas Asbridge

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the text and context of The Book of the Dead, also known as the Book of Coming Forth by Day, the ancient Egyptian collections of spells which were intended to help the recently deceased navigate the underworld. They flourished under the New Kingdom from C16th BC until the end of the Ptolemaic era in C1st BC, and drew on much earlier traditions from the walls of pyramids and on coffin cases. Almost 200 spells survive, though no one collection contains all of them, and one of the best known surrounds the weighing of the heart, the gods' final judgement of the deceased's life.

With

John Taylor

Kate Spence

and

Richard Parkinson

Producer: Simon Tillotson.

The 13th-century English philosopher Roger Bacon is perhaps best known for his major work the Opus Maius. Commissioned by Pope Clement IV, this extensive text covered a multitude of topics from mathematics and optics to religion and moral philosophy. He is also regarded by some as an early pioneer of the modern scientific method. Bacon's erudition was so highly regarded that he came to be known as 'Doctor Mirabilis' or 'wonderful doctor'. However, he is a man shrouded in mystery. Little is known about much of his life and he became the subject of a number of strange legends, including one in which he allegedly constructed a mechanical brazen head that would predict the future.

With:

Jack Cunningham

Amanda Power

Elly Truitt

Producer: Victoria Brignell.

Melvyn Bragg discusses the life and times of Rosa Luxemburg (1871-1919), 'Red Rosa', who was born in Poland under the Russian Empire and became one of the leading revolutionaries in an age of revolution. She was jailed for agitation and for her campaign against the Great War which, she argued, pitted workers against each other for the sake of capitalism. With Karl Liebknecht and other radicals, she founded the Spartacus League in the hope of ending the war through revolution. She founded the German Communist Party with Liebknecht; with the violence that followed the German Revolution of 1918, her opponents condemned her as Bloody Rosa. She and Liebknecht were seen as ringleaders in the Spartacus Revolt of 1919 and, on 15th January 1919, the Freikorps militia arrested and murdered them. While Luxemburg has faced opposition for her actions and ideas from many quarters, she went on to become an iconic figure in East Germany under the Cold War and a focal point for opposition to the Soviet-backed leadership.

With

Jacqueline Rose

Mark Jones

and

Nadine Rossol

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the life and ideas of Wolfgang Pauli (1900-1958), whose Exclusion Principle is one of the key ideas in quantum mechanics. A brilliant physicist, at 21 Pauli wrote a review of Einstein's theory of general relativity and that review is still a standard work of reference today. The Pauli Exclusion Principle proposes that no two electrons in an atom can be at the same time in the same state or configuration, and it helps explain a wide range of phenomena such as the electron shell structure of atoms. Pauli went on to postulate the existence of the neutrino, which was confirmed in his lifetime. Following further development of his exclusion principle, Pauli was awarded the Nobel Prize in Physics in 1945 for his 'decisive contribution through his discovery of a new law of Nature'. He also had a long correspondence with Jung, and a reputation for accidentally breaking experimental equipment which was dubbed The Pauli Effect.

With

Frank Close

Michela Massimi

and

Graham Farmelo

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss Katsushika Hokusai (1760-1849), the Japanese artist whose views of Mt Fuji such as The Great Wave off Kanagawa (pictured) are some of the most iconic in world art. He worked as Japan was slowly moving towards greater contact with the outside world, trading with China and allowing two Dutch ships to dock each year. From these ships he picked up new synthetic colours and illustrations with Western compositions, which he incorporated in his traditional wood block prints. The quality of his images helped drive demand for prints among the highly literate Japanese public, particularly those required to travel to Edo under feudal obligations and who wanted to collect all his prints. As well as the quality of his work, Hokusai's success stems partly from his long life and career. He completed some of his most memorable works in his 70s and 80s and claimed he would not reach his best until he was 110.

With

Angus Lockyer

Rosina Buckland

And

Ellis Tinios

Producer: Simon Tillotson.