Melvyn Bragg and guests discuss the most abundant lifeform on Earth: the viruses that 'eat' bacteria. Early in the 20th century, scientists noticed that something in their Petri dishes was making bacteria disappear and they called these bacteriophages, things that eat bacteria. From studying these phages, it soon became clear that they offered countless real or potential benefits for understanding our world, from the tracking of diseases to helping unlock the secrets of DNA to treatments for long term bacterial infections. With further research, they could be an answer to the growing problem of antibiotic resistance.

With

Martha Clokie Director for the Centre for Phage Research and Professor of Microbiology at the University of Leicester

James Ebdon Professor of Environmental Microbiology at the University of Brighton

And

Claas Kirchhelle Historian and Chargé de Recherche at the French National Institute of Health and Medical Research’s CERMES3 Unit in Paris.

Producer: Simon Tillotson

In Our Time is a BBC Studios Audio Production

Reading list:

James Ebdon, ‘Tackling sources of contamination in water: The age of phage’ (Microbiologist, Society for Applied Microbiology, Vol 20.1, 2022)

Thomas Häusler, Viruses vs. Superbugs: A Solution to the Antibiotics Crisis? (Palgrave Macmillan, 2006)

Tom Ireland, The Good Virus: The Untold Story of Phages: The Mysterious Microbes that Rule Our World, Shape Our Health and Can Save Our Future (Hodder Press, 2024)

Claas Kirchhelle and Charlotte Kirchhelle, ‘Northern Normal–Laboratory Networks, Microbial Culture Collections, and Taxonomies of Power (1939-2000)’ (SocArXiv Papers, 2024)

Dmitriy Myelnikov, ‘An alternative cure: the adoption and survival of bacteriophage therapy in the USSR, 1922–1955’ (Journal of the History of Medicine and Allied Sciences 73, no. 4, 2018)

Forest Rohwer, Merry Youle, Heather Maughan and Nao Hisakawa, Life in our Phage World: A Centennial Field Guide to Earth’s most Diverse Inhabitants (Wholon, 2014)

Steffanie Strathdee and Thomas Patterson (2019) The Perfect Predator: A Scientist’s Race to Save Her Husband from a Deadly Superbug: A Memoir (Hachette Books, 2020)

William C. Summers, Félix d`Herelle and the Origins of Molecular Biology (Yale University Press, 1999)

William C. Summers, The American Phage Group: Founders of Molecular Biology (University Press, 2023)

Melvyn Bragg and guests discuss the planet which is closest to our Sun. We see it as an evening or a morning star, close to where the Sun has just set or is about to rise, and observations of Mercury helped Copernicus understand that Earth and the other planets orbit the Sun, so displacing Earth from the centre of our system. In the 20th century, further observations of Mercury helped Einstein prove his general theory of relativity. For the last 50 years we have been sending missions there to reveal something of Mercury's secrets and how those relate to the wider universe, and he latest, BepiColombo, is out there in space now.

With

Emma Bunce Professor of Planetary Plasma Physics and Director of the Institute for Space at the University of Leicester

David Rothery Professor of Planetary Geosciences at the Open University

And

Carolin Crawford Emeritus Fellow of Emmanuel College, University of Cambridge, and Emeritus Member of the Institute of Astronomy, Cambridge

Producer: Simon Tillotson In Our Time is a BBC Studios Audio production

Reading list:

Emma Bunce, ‘All (X-ray) eyes on Mercury’ (Astronomy & Geophysics, Volume 64, Issue 4, August 2023)

Emma Bunce et al, ‘The BepiColombo Mercury Imaging X-Ray Spectrometer: Science Goals, Instrument Performance and Operations’ (Space Science Reviews: SpringerLink, volume 216, article number 126, Nov 2020)

David A. Rothery, Planet Mercury: From Pale Pink Dot to Dynamic World (Springer, 2014)

Paul Erdős (1913 – 1996) is one of the most celebrated mathematicians of the 20th century. During his long career, he made a number of impressive advances in our understanding of maths and developed whole new fields in the subject.

He was born into a Jewish family in Hungary just before the outbreak of World War I, and his life was shaped by the rise of fascism in Europe, anti-Semitism and the Cold War. His reputation for mathematical problem solving is unrivalled and he was extraordinarily prolific. He produced more than 1,500 papers and collaborated with around 500 other academics.

He also had an unconventional lifestyle. Instead of having a long-term post at one university, he spent much of his life travelling around visiting other mathematicians, often staying for just a few days.

With

Colva Roney-Dougal Professor of Pure Mathematics at the University of St Andrews

Timothy Gowers Professor of Mathematics at the College de France in Paris and Fellow of Trinity College, Cambridge

and

Andrew Treglown Associate Professor in Mathematics at the University of Birmingham

The image above shows a graph occurring in Ramsey Theory. It was created by Dr Katherine Staden, lecturer in the School of Mathematics at the Open University.

Melvyn Bragg and his guests discuss one of the simplest and most remarkable of all molecules: water. Water is among the most abundant substances on Earth, covering more than two-thirds of the planet. Consisting of just three atoms, the water molecule is superficially simple in its structure but extraordinary in its properties. It is a rare example of a substance that can be found on Earth in gaseous, liquid and solid forms, and thanks to its unique chemical behaviour is the basis of all known life. Scientists are still discovering new things about it, such as the fact that there are at least fifteen different forms of ice.

Hasok Chang Hans Rausing Professor of History and Philosophy of Science at the University of Cambridge

Andrea Sella Professor of Chemistry at University College London

Patricia Hunt Senior Lecturer in Chemistry at Imperial College London.

Producer: Thomas Morris.

In a programme first broadcast in 2013, Melvyn Bragg and his guests discuss absolute zero, the lowest conceivable temperature.  In the early eighteenth century the French physicist Guillaume Amontons suggested that temperature had a lower limit.  The subject of low temperature became a fertile field of research in the nineteenth century, and today we know that this limit - known as absolute zero - is approximately minus 273 degrees Celsius.  It is impossible to produce a temperature exactly equal to absolute zero, but today scientists have come to within a billionth of a degree.  At such low temperatures physicists have discovered a number of strange new phenomena including superfluids, liquids capable of climbing a vertical surface.

With:

Simon Schaffer Professor of the History of Science at the University of Cambridge

Stephen Blundell Professor of Physics at the University of Oxford

Nicola Wilkin Lecturer in Theoretical Physics at the University of Birmingham

Producer: Thomas Morris

Melvyn Bragg and his guests discuss the life and work of the Victorian anthropologist and archaeologist Augustus Pitt-Rivers. Over many years he amassed thousands of ethnographic and archaeological objects, some of which formed the founding collection of the Pitt Rivers Museum at Oxford University. Inspired by the work of Charles Darwin, Pitt-Rivers believed that human technology evolved in the same way as living organisms, and devoted much of his life to exploring this theory. He was also a pioneering archaeologist whose meticulous records of major excavations provided a model for later scholars.

With:

Adam Kuper Visiting Professor of Anthropology at Boston University

Richard Bradley Professor in Archaeology at the University of Reading

Dan Hicks University Lecturer & Curator of Archaeology at the Pitt Rivers Museum at the University of Oxford.

Producer: Thomas Morris.

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 Professor of Planetary and Space Sciences at the Open University

Paul Murdin Senior Fellow at the Institute of Astronomy at the University of Cambridge

Don Pollacco Professor of Astronomy at the University of Warwick

Producer: Thomas Morris.

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 Director of the Biophysical Sciences Institute and Professor of Chemistry at the University of Durham

Chris Hammond Life Fellow in Material Science at the University of Leeds

Mike Glazer Emeritus Professor of Physics at the University of Oxford and Visiting Professor of Physics at the University of Warwick

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss Fermat's Last Theorem. In 1637 the French mathematician Pierre de Fermat scribbled a note in the margin of one of his books. He claimed to have proved a remarkable property of numbers, but gave no clue as to how he'd gone about it. "I have found a wonderful demonstration of this proposition," he wrote, "which this margin is too narrow to contain". Fermat's theorem became one of the most iconic problems in mathematics and for centuries mathematicians struggled in vain to work out what his proof had been. In the 19th century the French Academy of Sciences twice offered prize money and a gold medal to the person who could discover Fermat's proof; but it was not until 1995 that the puzzle was finally solved by the British mathematician Andrew Wiles.

With:

Marcus du Sautoy Professor of Mathematics & Simonyi Professor for the Public Understanding of Science at the University of Oxford

Vicky Neale Fellow and Director of Studies in Mathematics at Murray Edwards College at the University of Cambridge

Samir Siksek Professor at the Mathematics Institute at the University of Warwick.

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the cell, the fundamental building block of life. First observed by Robert Hooke in 1665, cells occur in nature in a bewildering variety of forms. Every organism alive today consists of one or more cells: a single human body contains up to a hundred trillion of them.

The first life on Earth was a single-celled organism which is thought to have appeared around three and a half billion years ago. That simple cell resembled today's bacteria. But eventually these microscopic entities evolved into something far more complex, and single-celled life gave rise to much larger, complex multicellular organisms. But how did the first cell appear, and how did that prototype evolve into the sophisticated, highly specialised cells of the human body?

With:

Steve Jones Professor of Genetics at University College London

Nick Lane Senior Lecturer in the Department of Genetics, Evolution and Environment, University College London

Cathie Martin Group Leader at the John Innes Centre and Professor in the School of Biological Sciences at the University of East Anglia

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss game theory, the mathematical study of decision-making. First formulated in the 1940s, the discipline entails devising 'games' to simulate situations of conflict or cooperation. It allows researchers to unravel decision-making strategies, and even to establish why certain types of behaviour emerge. Some of the games studied in game theory have become well known outside academia - they include the Prisoner's Dilemma, an intriguing scenario popularised in novels and films, and which has inspired television game shows. Today game theory is seen as a vital tool in such diverse fields as evolutionary biology, economics, computing and philosophy. With:Ian StewartEmeritus Professor of Mathematics at the University of WarwickAndrew ColmanProfessor of Psychology at the University of LeicesterRichard BradleyProfessor of Philosophy at the London School of Economics and Political Science.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the emergence of geology as a scientific discipline. A little over two hundred years ago a small group of friends founded the Geological Society of London. This organisation was the first devoted to furthering the discipline of geology - the study of the Earth, its history and composition. Although geology only emerged as a separate area of study in the late eighteenth century, many earlier thinkers had studied rocks, fossils and the materials from which the Earth is made. Ancient scholars in Egypt and Greece speculated about the Earth and its composition. And in the Renaissance the advent of mining brought further insight into the nature of objects found underground and how they got there. But how did such haphazard study of rocks and fossils develop into a rigorous scientific discipline?With:Stephen PumfreySenior Lecturer in the History of Science at Lancaster UniversityAndrew ScottProfessor of Applied Palaeobotany at Royal Holloway, University of LondonLeucha VeneerResearch Associate at the Centre for the History of Science, Technology and Medicine at the University of Manchester.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the measurement of time. Early civilisations used the movements of heavenly bodies to tell the time, but even in the ancient world more sophisticated timekeeping devices such as waterclocks were known. The development of mechanical clocks in Europe emerged in the medieval period when monks used such devices to sound an alarm to signal it was the hour to pray, although these clocks did not tell them the time. For hundreds of years clocks were inaccurate and it proved hard to remedy the problems, let alone settle on a standard time that the country should follow. It was with the advent of the railways that time finally became standardised in Britain in the mid-19th century and only in 1884 that Greenwich became the prime meridian of the world. Atomic clocks now mark the passing of the days, hours, and minutes and they are capable of keeping time to a second in 15 million years. With:Kristen LippincottFormer Director of the Royal Observatory, GreenwichJim BennettDirector of the Museum of the History of Science at the University of OxfordJonathan BettsSenior Curator of Horology at the Royal Observatory, GreenwichProducer: Natalia Fernandez.

Melvyn Bragg and guests discuss the pioneering Danish astronomer Tycho Brahe (1546 – 1601) whose charts offered an unprecedented level of accuracy.

In 1572 Brahe's observations of a new star challenged the idea, inherited from Aristotle, that the heavens were unchanging. He went on to create his own observatory complex on the Danish island of Hven, and there, working before the invention of the telescope, he developed innovative instruments and gathered a team of assistants, taking a highly systematic approach to observation. A second, smaller source of renown was his metal prosthetic nose, which he needed after a serious injury sustained in a duel.

The image above shows Brahe aged 40, from the Atlas Major by Johann Blaeu.

With

Ole Grell Emeritus Professor in Early Modern History at the Open University

Adam Mosley Associate Professor of History at Swansea University

and

Emma Perkins Affiliate Scholar in the Department of History and Philosophy of Science at the University of Cambridge.

Melvyn Bragg and his guests discuss the physics of electrical conduction. Although electricity has been known for several hundred years, it was only in the early twentieth century that physicists first satisfactorily explained the phenomenon. Electric current is the passage of charged particles through a medium - but a material will only conduct electricity if its atomic structure enables it to do so. In investigating electrical conduction scientists discovered two new classes of material. Semiconductors, first exploited commercially in the 1950s, have given us the transistor, the solar cell and the silicon chip, and have revolutionised telecommunications. And superconductors, remarkable materials first observed in 1911, are used in medical imaging and at the Large Hadron Collider in Geneva. With:Frank CloseProfessor of Physics at the University of OxfordJenny NelsonProfessor of Physics at Imperial College LondonLesley CohenProfessor of Solid State Physics at Imperial College LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the evolution of the Scientific Method, the systematic and analytical approach to scientific thought. In 1620 the great philosopher and scientist Francis Bacon published the Novum Organum, a work outlining a new system of thought which he believed should inform all enquiry into the laws of nature. Philosophers before him had given their attention to the reasoning that underlies scientific enquiry; but Bacon's emphasis on observation and experience is often seen today as giving rise to a new phenomenon: the scientific method.The scientific method, and the logical processes on which it is based, became a topic of intense debate in the seventeenth century, and thinkers including Isaac Newton, Thomas Huxley and Karl Popper all made important contributions. Some of the greatest discoveries of the modern age were informed by their work, although even today the term 'scientific method' remains difficult to define.With: Simon SchafferProfessor of the History of Science at the University of CambridgeJohn WorrallProfessor of the Philosophy of Science at the London School of Economics and Political ScienceMichela MassimiSenior Lecturer in the Philosophy of Science at University College London.Producer: Thomas Morris.

Melvyn Bragg and guests discuss the giant molecules that form the basis of all life. Macromolecules, also known as polymers, are long chains of atoms. They form the proteins that make up our bodies, as well as many of the materials of modern life. Man's ability to mimic the structure of macromolecules has led to the invention of plastics such as nylon, paints and adhesives. Most of our clothes are made of macromolecules, and our food is macromolecular. The medical sciences are making increasingly sophisticated use of macromolecules, from growing replacement skin and bone to their increasing use in drug delivery. One of the most famous macromolecules is DNA, an infinitely more complex polymer than man has ever managed to produce. We've only known about macromolecules for just over a century, so what is the story behind them and how might they change our lives in the future?With:Tony RyanPro-Vice Chancellor for the Faculty of Science at the University of SheffieldAthene DonaldProfessor of Experimental Physics at the University of Cambridge and a Fellow of Robinson CollegeCharlotte WilliamsReader in Polymer Chemistry and Catalysis at Imperial College, London Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Hippocratic Oath. The Greek physician Hippocrates, active in the fifth century BC, has been described as the father of medicine, although little is known about his life and some scholars even argue that he was not one person but several. A large body of work originally attributed to him, the Hippocratic Corpus, was disseminated widely in the ancient world, and contains treatises on a wide variety of subjects, from fractures to medical ethics.Today we know that the Hippocratic Corpus cannot have been written by a single author. But many of its texts shaped Western medicine for centuries. The best known is the Hippocratic Oath, an ethical code for doctors. Celebrated in the ancient world, and later referred to by Arabic scholars, it offers medics guidance on how they should behave. Although it has often been revised and adapted, the Hippocratic Oath remains one of the most significant and best known documents of medical science - but there is little evidence that it was routinely sworn by doctors until modern times. With:Vivian NuttonEmeritus Professor of the History of Medicine at University College LondonHelen KingProfessor of Classical Studies at the Open UniversityPeter PormannWellcome Trust Associate Professor in Classics and Ancient History at the University of WarwickProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the origins of infectious disease. Infectious disease has been with us for millennia. There are reports of ancient outbreaks of plague in the Bible, and in numerous historical sources from China, the Middle East and Europe. Other infections, including smallpox, tuberculosis and measles, have also been known for centuries. But some diseases made their first appearances only recently: HIV emerged around a century ago, while the Ebola virus was first recorded in the 1970s.But where do the agents of disease come from, and what determines where and when new viruses and bacteria appear? Modern techniques allow scientists to trace the histories of infective agents through their genomes; the story of disease provides a fascinating microcosm of the machinery of evolution.With:Steve JonesProfessor of Genetics at University College LondonSir Roy AndersonProfessor of Infectious Disease Epidemiology at Imperial College LondonMark PallenProfessor of Microbial Genomics at the University of Birmingham.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the neutrino.In 1930 the physicist Wolfgang Pauli proposed the existence of an as-yet undiscovered subatomic particle. He also bet his colleagues a case of champagne that it would never be detected. He lost his bet when in 1956 the particle, now known as the neutrino, was first observed in an American nuclear reactor. Neutrinos are some of the most mysterious particles in the Universe. The Sun produces trillions of them every second, and they constantly bombard the Earth and everything on it. Neutrinos can pass through solid rock, and even stars, at almost the speed of light without being impeded, and are almost impossible to detect. Today, experiments involving neutrinos are providing insights into the nature of matter, the contents of the Universe and the processes deep inside stars.With:Frank CloseProfessor of Physics at Exeter College at the University of OxfordSusan CartwrightSenior Lecturer in Particle Physics and Astrophysics at the University of SheffieldDavid WarkProfessor of Particle Physics at Imperial College, London, and the Rutherford Appleton Laboratory. Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the age of the Universe.Since the 18th century, when scientists first realised that the Universe had existed for more than a few thousand years, cosmologists have debated its likely age. The discovery that the Universe was expanding allowed the first informed estimates of its age to be made by the great astronomer Edwin Hubble in the early decades of the twentieth century. Hubble's estimate of the rate at which the Universe is expanding, the so-called Hubble Constant, has been progressively improved. Today cosmologists have a variety of other methods for ageing the Universe, most recently the detailed measurements of cosmic microwave background radiation - the afterglow of the Big Bang - made in the last decade. And all these methods seem to agree on one thing: the Universe has existed for around 13.75 billion years.With:Martin ReesAstronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of CambridgeCarolin CrawfordMember of the Institute of Astronomy and Fellow of Emmanuel College at the University of CambridgeCarlos FrenkDirector of the Institute for Computational Cosmology at the University of Durham.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the nervous system.

Most animals have a nervous system, a network of nerve tissues which allows parts of the body to communicate with each other. In humans the most significant parts of this network are the brain, spinal column and retinas, which together make up the central nervous system. But there is also a peripheral nervous system, which enables sensation, movement and the regulation of the major organs.

Scholars first described the nerves of the human body over two thousand years ago. For 1400 years it was believed that they were animated by 'animal spirits', mysterious powers which caused sensation and movement. In the eighteenth century scientists discovered that nerve fibres transmitted electrical impulses; it was not until the twentieth century that chemical agents - neurotransmitters - were first identified.

With:

Colin Blakemore Professor of Neuroscience at the University of Oxford

Vivian Nutton Emeritus Professor of the History of Medicine at University College, London

Tilli Tansey Professor of the History of Modern Medical Sciences at Queen Mary, University of London.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss randomness and pseudorandomness.Randomness is the mathematics of the unpredictable. Dice and roulette wheels produce random numbers: those which are unpredictable and display no pattern. But mathematicians also talk of 'pseudorandom' numbers - those which appear to be random but are not. In the last century random numbers have become enormously useful to statisticians, computer scientists and cryptographers. But true randomness is difficult to find, and mathematicians have devised many ingenious solutions to harness or simulate it. These range from the Premium Bonds computer ERNIE (whose name stands for Electronic Random Number Indicator Equipment) to new methods involving quantum physics.Digital computers are incapable of behaving in a truly random fashion - so instead mathematicians have taught them how to harness pseudorandomness. This technique is used daily by weather forecasters, statisticians, and computer chip designers - and it's thanks to pseudorandomness that secure credit card transactions are possible.With:Marcus du SautoyProfessor of Mathematics at the University of OxfordColva Roney-DougalSenior Lecturer in Pure Mathematics at the University of St AndrewsTimothy GowersRoyal Society Research Professor in Mathematics at the University of CambridgeProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the innovations and influence of Thomas Edison, one of the architects of the modern age.Edison is popularly remembered as the man who made cheap electric light possible. Born in 1847, he began his career working in the new industry of telegraphy, and while still in his early twenties made major improvements to the technology of the telegraph. Not long afterwards he invented a new type of microphone which was used in telephones for almost a century. In the space of three productive years, Edison developed the phonograph and the first commercially viable light bulb and power distribution system. Many more inventions were to follow: he also played a part in the birth of cinema in the 1890s. When he died in 1931 he had patented no fewer than 1093 devices - the most prolific inventor in history. As the creator of the world's first industrial research laboratory he forever changed the way in which innovation took place.With:Simon SchafferProfessor of the History of Science, University of CambridgeKathleen BurkProfessor of History, University College LondonIwan MorusReader in History, University of AberystwythProducer: Thomas Morris.

Melvyn Bragg and guests discuss the discovery made in 1911 by the Dutch physicist Heike Kamerlingh Onnes (1853-1926). He came to call it Superconductivity and it is a set of physical properties that nobody predicted and that none, since, have fully explained. When he lowered the temperature of mercury close to absolute zero and ran an electrical current through it, Kamerlingh Onnes found not that it had low resistance but that it had no resistance. Later, in addition, it was noticed that a superconductor expels its magnetic field. In the century or more that has followed, superconductors have already been used to make MRI scanners and to speed particles through the Large Hadron Collider and they may perhaps bring nuclear fusion a little closer (a step that could be world changing).

The image above is from a photograph taken by Stephen Blundell of a piece of superconductor levitating above a magnet.

With

Nigel Hussey Professor of Experimental Condensed Matter Physics at the University of Bristol and Radbout University

Suchitra Sebastian Professor of Physics at the Cavendish Laboratory at the University of Cambridge

And

Stephen Blundell Professor of Physics at the University of Oxford and Fellow of Mansfield College

Producer: Simon Tillotson

Melvyn Bragg and his guests discuss the role played by women in Enlightenment science. During the eighteenth century the opportunities for women to gain a knowledge of science were minimal. Universities and other institutions devoted to research were the preserve of men. Yet many important contributions to the science of the Enlightenment were made by women. These ranged from major breakthroughs like those of the British astronomer Caroline Herschel, the first woman to discover a comet, to important translations of scientific literature such as Emilie du Chatelet's French version of Newton's Principia - and all social classes were involved, from the aristocratic amateur botanists to the women artisans who worked in London's workshops manufacturing scientific instruments. The image above, of Emilie du Chatelet, is attributed to Maurice Quentin de La Tour.

With

Patricia Fara Senior Tutor at Clare College, University of Cambridge

Karen O'Brien Professor of English at the University of Warwick

Judith Hawley Professor of 18th Century Literature at Royal Holloway, University of London

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the history of logic. Logic, the study of reasoning and argument, first became a serious area of study in the 4th century BC through the work of Aristotle. He created a formal logical system, based on a type of argument called a syllogism, which remained in use for over two thousand years. In the nineteenth century the German philosopher and mathematician Gottlob Frege revolutionised logic, turning it into a discipline much like mathematics and capable of dealing with expressing and analysing nuanced arguments. His discoveries influenced the greatest mathematicians and philosophers of the twentieth century and considerably aided the development of the electronic computer. Today logic is a subtle system with applications in fields as diverse as mathematics, philosophy, linguistics and artificial intelligence.With:A.C. GraylingProfessor of Philosophy at Birkbeck, University of LondonPeter MillicanGilbert Ryle Fellow in Philosophy at Hertford College at the University of OxfordRosanna KeefeSenior Lecturer in Philosophy at the University of Sheffield.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss imaginary numbers. In the sixteenth century, a group of mathematicians in Bologna found a solution to a problem that had puzzled generations before them: a completely new kind of number. For more than a century this discovery was greeted with such scepticism that the great French thinker Rene Descartes dismissed it as an "imaginary" number.The name stuck - but so did the numbers. Long dismissed as useless or even fictitious, the imaginary number i and its properties were first explored seriously in the eighteenth century. Today the imaginary numbers are in daily use by engineers, and are vital to our understanding of phenomena including electricity and radio waves. With Marcus du SautoyProfessor of Mathematics at Oxford University Ian StewartEmeritus Professor of Mathematics at the University of WarwickCaroline SeriesProfessor of Mathematics at the University of WarwickProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Pliny's Natural History.Some time in the first century AD, the Roman scholar Pliny the Elder published his Naturalis Historia, or Natural History, an enormous reference work which attempted to bring together knowledge on every subject under the sun. The Natural History contains information on zoology, astronomy, geography, minerals and mining and - unusually for a work of this period - a detailed treatise on the history of classical art. It's a fascinating snapshot of the state of human knowledge almost two millennia ago.Pliny's 37-volume magnum opus is one of the most extensive works of classical scholarship to survive in its entirety, and was being consulted by scholars as late as the Renaissance. It had a significant influence on intellectual history, and has provided the template for every subsequent encyclopaedia.With:Serafina CuomoReader in Roman History at Birkbeck, University of LondonAude DoodyLecturer in Classics at University College, DublinLiba TaubReader in the History and Philosophy of Science, Cambridge UniversityProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the history of Antarctica.The most southerly of the continents is the bleakest and coldest place on Earth. Almost entirely covered in ice, Antarctica spends much of the winter in total darkness.Antarctica was first named in the second century AD by the geographer Marinus of Tyre, who was one of many early geographers to speculate about the existence of a huge southern landmass to balance the known lands of northern Europe. But it wasn't until the nineteenth century that modern man laid eyes on the continent.In the intervening two hundred years the continent has been the scene for some of the most famous - and tragic - events of human exploration. In 1959 an international treaty declared Antarctica a scientific reserve, set aside for peaceful use by any nation willing to subscribe to the terms of the agreement.With: Jane FrancisProfessor of Paleoclimatology at the University of LeedsJulian DowdeswellDirector of the Scott Polar Research Institute and Professor of Physical Geography at the University of CambridgeDavid WaltonEmeritus Professor at the British Antarctic Survey and Visiting Professor at the University of Liverpool.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Neanderthals.In 1856, quarry workers in Germany found bones in a cave which seemed to belong to a bear or other large mammal. They were later identified as being from a previously unknown species of hominid similar to a human. The specimen was named Homo neanderthalis after the valley in which the bones were found.This was the first identified remains of a Neanderthal, a species which inhabited parts of Europe and Central Asia from around 400,000 years ago. Often depicted as little more advanced than apes, Neanderthals were in fact sophisticated, highly-evolved hunters capable of making tools and even jewellery.Scholarship has established much about how and where the Neanderthals lived - but the reasons for their disappearance from the planet around 28,000 years ago remain unclear.With: Simon Conway MorrisProfessor of Evolutionary Palaeobiology at the University of CambridgeChris Stringer Research Leader in Human Origins at the Natural History Museum and Visiting Professor at Royal Holloway, University of LondonDanielle SchreveReader in Physical Geography at Royal Holloway, University of LondonProducer: Thomas Morris.

From the 1600s to the 1800s, scientific research in Britain was not yet a professional, publicly-funded career.So the wealth, status and freedom enjoyed by British aristocrats gave them the opportunity to play an important role in pushing science forwards - whether as patrons or practitioners.The Cavendish family produced a whole succession of such figures.In the 1600s, the mathematician Sir Charles Cavendish and his brother William collected telescopes and mathematical treatises, and promoted dialogue between British and Continental thinkers. They brought Margaret Cavendish, William's second wife, into their discussions and researches, and she went on to become a visionary, if eccentric, science writer, unafraid to take on towering figures of the day like Robert Hooke.In the 1700s, the brothers' cousin's great-grandson, Lord Charles Cavendish, emerged as a leading light of the Royal Society.Underpinned by his rich inheritance, Charles' son Henry became one of the great experimental scientists of the English Enlightenment.And in the 1800s, William Cavendish, Henry's cousin's grandson, personally funded the establishment of Cambridge University's Cavendish Laboratory. In subsequent decades, the Lab become the site of more great breakthroughs.With:Jim BennettDirector of the Museum of the History of Science at the University of OxfordPatricia FaraSenior Tutor of Clare College, University of CambridgeSimon SchafferProfessor of History of Science at the University of Cambridge and Fellow of Darwin College, CambridgeProducer - Phil Tinline.

The Cool Universe is the name astronomers give to the matter between the stars.These great clouds of dust and gas are not hot enough to be detected by optical telescopes.But over the last few decades, they have increasingly become the focus of infrared telescopy.Astronomers had long encountered dark, apparently starless patches in the night sky. When they discovered that these were actually areas obscured by dust, they found a way to see through these vexing barriers, using infrared telescopes, to the light beyond.However, more recently, the dust itself has become a source of fascination.The picture now being revealed by infrared astronomy is of a universe that is dynamic.In this dynamic universe, matter is recycled - and so the dust and gas of the Cool Universe play a vital role. They are the material from which the stars are created, and into which they finally disintegrate, enriching the reservoir of cool matter from which new stars will eventually be formed. As a result of the new research, we are now beginning to see first-hand the way our planet was formed when the solar system was born.With:Carolin CrawfordMember of the Institute of Astronomy, and Fellow of Emmanuel College, at the University of CambridgePaul MurdinVisiting Professor of Astronomy at Liverpool John Moores University's Astronomy Research InstituteMichael Rowan-RobinsonProfessor of Astrophysics at Imperial College, LondonProducer: Phil Tinline.

Melvyn Bragg and guests Usha Goswami, Annette Karmiloff-Smith and Denis Mareschal discuss what new research reveals about the infant brain.For obvious reasons, what happens in the minds of very young, pre-verbal children is elusive. But over the last century, the psychology of early childhood has become a major subject of study. Some scientists and researchers have argued that children develop skills only gradually, others that many of our mental attributes are innate. Sigmund Freud concluded that infants didn't differentiate themselves from their environment. The pioneering Swiss child psychologist Jean Piaget thought babies' perception of the world began as a 'blooming, buzzing confusion' of colour, light and sound, before they developed a more sophisticated worldview, first through the senses and later through symbol. More recent scholars such as the leading American theoretical linguist Noam Chomsky have argued that the fundamentals of language are there from birth. Chomsky has famously argued that all humans have an innate, universally applicable grammar.Over the last ten to twenty years, new research has shed fresh light on important aspects of the infant brain which have long been shrouded in mystery or mired in dispute, from the way we start to learn to speak to the earliest understanding that other people have their own minds. With:Usha Goswami, Professor of Education at the University of Cambridge and Director of its Centre for Neuroscience in Education Annette Karmiloff-Smith, Professorial Research Fellow at the Centre for Brain and Cognitive Development at the Department of Psychological Sciences, Birkbeck College, University of LondonDenis Mareschal, Professor of Psychology at the Centre for Brain and Cognitive Development at Birkbeck College, University of London.

Melvyn Bragg and guests John Barrow, Colva Roney-Dougal and Marcus du Sautoy explore the unintended consequences of mathematical discoveries, from the computer to online encryption, to alternating current and predicting the path of asteroids.In his book The Mathematician's Apology (1941), the Cambridge mathematician GH Hardy expressed his reverence for pure maths, and celebrated its uselessness in the real world. Yet one of the branches of pure mathematics in which Hardy excelled was number theory, and it was this field which played a major role in the work of his younger colleague, Alan Turing, as he worked first to crack Nazi codes at Bletchley Park and then on one of the first computers.Melvyn Bragg and guests explore the many surprising and completely unintended uses to which mathematical discoveries have been put. These include:The cubic equations which led, after 400 years, to the development of alternating current - and the electric chair.The centuries-old work on games of chance which eventually contributed to the birth of population statistics.The discovery of non-Euclidean geometry, which crucially provided an 'off-the-shelf' solution which helped Albert Einstein forge his theory of relativity.The 17th-century theorem which became the basis for credit card encryption.In the light of these stories, Melvyn and his guests discuss how and why pure mathematics has had such a range of unintended consequences.John Barrow is Professor of Mathematical Sciences at the University of Cambridge and Professor of Geometry at Gresham College, London; Colva Roney-Dougal is Lecturer in Pure Mathematics at the University of St Andrews; Marcus du Sautoy is Charles Simonyi Professor for the Public Understanding of Science and Professor of Mathematics at the University of Oxford.

Melvyn Bragg and guests discuss the voyage of HMS Challenger which set out from Portsmouth in 1872 with a mission a to explore the ocean depths around the world and search for new life. The scale of the enterprise was breath taking and, for its ambition, it has since been compared to the Apollo missions. The team onboard found thousands of new species, proved there was life on the deepest seabeds and plumbed the Mariana Trench five miles below the surface. Thanks to telegraphy and mailboats, its vast discoveries were shared around the world even while Challenger was at sea, and they are still being studied today, offering insights into the ever-changing oceans that cover so much of the globe and into the health of our planet.

The image above is from the journal of Pelham Aldrich R.N. who served on the Challenger Surveying Expedition from 1872-5.

With

Erika Jones Curator of Navigation and Oceanography at Royal Museums Greenwich

Sam Robinson Southampton Marine and Maritime Institute Research Fellow at the University of Southampton

And

Giles Miller Principal Curator of Micropalaeontology at the Natural History Museum London

Producer: Simon Tillotson

As part of the BBC's year of science programming, Melvyn Bragg looks at the history of the oldest scientific learned society of them all: the Royal Society. The horrors of the First World War were a shocking indictment of the power of science. Picking up the thread at this hiatus in scientific optimism, this programme, recorded in the current home of the Royal Society in Carlton House Terrace in London, looks at the more subtle, discreet role the Society played in the 20th century, such as secretly arranging for refugee scientists to flee Germany, co-ordinating international scientific missions during the Cold War and quietly distributing government grant money to fund the brightest young researchers in the land. As ever more important scientific issues face the world and Britain today, the programme asks how well placed the Royal Society is to take an important lead in the future.

As part of the BBC's year of science programming, Melvyn Bragg looks at the history of the oldest scientific learned society of them all: the Royal Society. The 19th century blooms scientifically with numerous alternative, specialist learned societies and associations, all threatening the Royal Society's pre-eminence. Attempts to reform the membership criteria - marking scientific leadership's painful transition from patronage to expertise - are troubled, and organisations such as the British Association for the Advancement of Science (now the BSA) excite and enliven scientific discourse outside of London. Science becomes a realistic career and a path of improvement, and by the time HG Wells writes science fiction at the end of the 19th century, there are sufficient numbers of interested, informed readers to suggest that Edwardian society contained the beginnings of a scientific society.

As part of the BBC's year of science programming, Melvyn Bragg looks at the history of the oldest scientific learned society of them all: the Royal Society. Programme two begins in the coffee house Isaac Newton and the fellows of the early 18th century frequented. At the Royal Observatory, Greenwich, we learn how Newton's feud with the Astronomer Royal John Flamsteed tested the lines between government-funded research and public access. In the age of exploration, senior fellows accompany naval expeditions, such as Cook's expedition to Tahiti and subsequent discovery of Australia. International relations are fostered between scientists such as Benjamin Franklin, whose house in London serves as live-in lab and de facto American embassy. By the end of the century the President, Sir Joseph Banks, successfully embeds the Royal Society in the imperial bureaucratic hub of the new Somerset House. But while senior fellows concentrated on foreign fields, a more radical, dissident science and manufacturing base wrought the Industrial Revolution right under their noses.

As part of the BBC's year of science programming, Melvyn Bragg looks at the history of the oldest scientific learned society of them all: the Royal Society. Melvyn travels to Wadham College, Oxford, where under the shadow of the English Civil War, the young Christopher Wren and friends experimented in the garden of their inspirational college warden, John Wilkins. Back in London, as Charles II is brought to the throne from exile, the new Society is formally founded one night in Gresham College. When London burns six years later, it is two of the key early Fellows of the Society who are charged with its rebuilding. And, as Melvyn finds out, in the secret observatory in The Monument to the fire, it is science which flavours their plans.

Melvyn Bragg and guests Serafina Cuomo, John O'Connor and Ian Stewart discuss the ideas and influence of the Greek mathematician Pythagoras and his followers, the Pythagoreans.The Ancient Greek mathematician Pythagoras is probably best known for the theorem concerning right-angled triangles that bears his name. However, it is not certain that he actually developed this idea; indeed, some scholars have questioned not only his true intellectual achievements, but whether he ever existed. We do know that a group of people who said they were followers of his - the Pythagoreans - emerged around the fifth century BC. Melvyn Bragg and his guests discuss what we do and don't know about this legendary figure and his followers, and explore the ideas associated with them. Some Pythagoreans, such as Philolaus and Archytas, were major mathematical figures in their own right. The central Pythagorean idea was that number had the capacity to explain the truths of the world. This was as much a mystical belief as a mathematical one, encompassing numerological notions about the 'character' of specific numbers. Moreover, the Pythagoreans lived in accordance with a bizarre code which dictated everything from what they could eat to how they should wash. Nonetheless, Pythagorean ideas, centred on their theory of number, have had a profound impact on Western science and philosophy, from Plato through astronomers like Copernicus to the present day.Serafina Cuomo is Reader in Roman History at Birkbeck College, University of London; John O'Connor is Senior Lecturer in Mathematics at the University of Saint Andrews; Ian Stewart is Emeritus Professor of Mathematics at the University of Warwick.

Melvyn Bragg and guests Jim Al-Khalili, Frank Close and Frank James discuss the history of the discovery of radiation.Today the word 'radiation' conjures up images of destruction. But in physics, it simply describes the emission, transmission and absorption of energy, and the discovery of how radiation works has allowed us to identify new chemical elements, treat cancer and work out what the stars are made of.Over the course of the 19th century, physicists from Thomas Young, through Michael Faraday to Henri Becquerel made discovery after discovery, gradually piecing together a radically new picture of reality. They explored the light beyond the visible spectrum, connected electricity and magnetism, and eventually showed that heat, light, radio and mysterious new phenomena like 'X-rays' were all forms of 'electromagnetic wave'. In the early 20th century, with the discovery of radioactivity, scientists like Max Planck and Ernest Rutherford completed the picture of the 'electromagnetic spectrum'. This was a cumulative achievement that transformed our vision of the physical world, and what we could do in it.Jim Al-Khalili is Professor of Theoretical Physics and Chair in the Public Engagement in Science at the University of Surrey; Frank Close is Professor of Physics at Exeter College, University of Oxford; Frank James is Professor of the History of Science at the Royal Institution.

Melvyn Bragg and guests Richard Corfield, Jane Francis and Sanjeev Gupta discuss the geological formation of Britain.Around 600 million years ago the island that we now call Britain was in two parts, far to the south of the Equator. Scotland and north-western Ireland were part of a continent (Laurentia) that also included what is now North America. To the south-east, near the Antarctic Circle, meanwhile, you would have found southern Ireland, England and Wales. They formed a mini-continent (Avalonia) with what is now Newfoundland.Over the course of hundreds of millions of years, as they inched their way north, the two parts came together - first as part of a vast unitary continent (Pangaea), later as a promontory on the edge of Europe, and eventually, as sea levels rose, as an island. The story of how Britain came to be where it is now, in its current shape - from the separation of North America and Europe to the carving out of the English Channel - is still being uncovered today.Richard Corfield is Visiting Senior Resarch Fellow at Oxford University; Jane Francis is Professor of Palaeoclimatology at the University of Leeds; Sanjeev Gupta is a Royal Society-Leverhulme Trust Research Fellow at Imperial College London.

Melvyn Bragg discusses the epic feud between Sir Isaac Newton and Gottfried Leibniz over who invented an astonishingly powerful new mathematical tool - calculus. Both claimed to have conceived it independently, but the argument soon descended into a bitter battle over priority, plagiarism and philosophy. Set against the backdrop of the Hanoverian succession to the English throne and the formation of the Royal Society, the fight pitted England against Europe, geometric notation against algebra. It was fundamental to the grounding of a mathematical system which is one of the keys to the modern world, allowing us to do everything from predicting the pressure building behind a dam to tracking the position of a space shuttle.Melvyn is joined by Simon Schaffer, Professor of History of Science at the University of Cambridge and Fellow of Darwin College; Patricia Fara, Senior Tutor at Clare College, University of Cambridge; and Jackie Stedall, Departmental Lecturer in History of Mathematics at the University of Oxford.

Melvyn Bragg and guests Martin Brasier, Richard Corfield and Rachel Wood discuss the Ediacara Biota, the Precambrian life forms which vanished 542 million years ago, and whose discovery proved Darwin right in a way he never imagined. Darwin was convinced that there must have been life before the Cambrian era, but he didn't think it was possible for fossils like the Ediacara to have been preserved. These sea-bed organisms were first unearthed in the 19th century, but were only recognised as Precambrian in the mid-20th century. This was an astonishing discovery. Ever since, scientists have been working to determine its significance. Were the Ediacara the earliest forms of animal life? Or were they a Darwinian dead end? Either way, it is argued, they reveal some of the secrets of the workings of evolution. Richard Corfield is Senior Lecturer in Earth Sciences at the Open University; Martin Brasier is Professor of Palaeobiology at the University of Oxford; Rachel Wood is Lecturer in Carbonate Geoscience at the University of Edinburgh.

Melvyn Bragg discusses Logical Positivism, the eye-wateringly radical early 20th century philosophical movement. The Logical Positivists argued that much previous philosophy was built on very shaky foundations, and they wanted to go right back to the drawing board. They insisted that philosophy - and science - had to be much more rigorous before it started making grand claims about the world. The movement began with the Vienna Circle, a group of philosophically-trained scientists and scientifically-trained philosophers, who met on Thursdays, in 'Red Vienna', in the years after the First World War. They were trying to remould philosophy in a world turned upside down not just by war, but by major advances in science. Their hero was not Descartes or Hegel but Albert Einstein. The group's new doctrine rejected great swathes of earlier philosophy, from meditations on the existence of God to declarations on the nature of History, as utterly meaningless. When the Nazis took power, they fled to England and America, where their ideas put down new roots, and went on to have a profound impact.Melvyn is joined by Barry Smith, Professor of Philosophy at the University of London; Nancy Cartwright, Professor of Philosophy at the London School of Economics; and Thomas Uebel, Professor of Philosophy at Manchester University.

Melvyn Bragg and guests discuss one of the greatest changes in the history of life on Earth. Around 400 million years ago some of our ancestors, the fish, started to become a little more like humans. At the swampy margins between land and water, some fish were turning their fins into limbs, their swim bladders into lungs and developed necks and eventually they became tetrapods, the group to which we and all animals with backbones and limbs belong. After millions of years of this transition, these tetrapod descendants of fish were now ready to leave the water for a new life of walking on land, and with that came an explosion in the diversity of life on Earth.

The image above is a representation of Tiktaalik Roseae, a fish with some features of a tetrapod but not one yet, based on a fossil collected in the Canadian Arctic.

With

Emily Rayfield Professor of Palaeobiology at the University of Bristol

Michael Coates Chair and Professor of Organismal Biology and Anatomy at the University of Chicago

And

Steve Brusatte Professor of Palaeontology and Evolution at the University of Edinburgh

Producer: Simon Tillotson

Melvyn Bragg and guests Steve Jones, Bill Amos and Eleanor Weston discuss the evolutionary history of the whale. The ancestor of all whales alive today was a small, land-based mammal with cloven hoofs, perhaps like a pig or a big mole. How this creature developed into the celebrated leviathan of the deep is one of the more extraordinary stories in the canon of evolution. The whale has undergone vast changes in size, has moved from land to water, lost its legs and developed specialised features such as filter feeding and echo location. How it achieved this is an exemplar of how evolution works and how natural selection can impose extreme changes on the body shape and abilities of living things. How the story of the whales was pieced together also reveals the various forms of evidence - from fossils to molecules - that we now use to understand the ancestry of life on Earth.Steve Jones is Professor of Genetics at University College London; Eleanor Weston is a mammalian palaeontologist at the Natural History Museum, London; Bill Amos is Professor of Evolutionary Genetics at Cambridge University.

Melvyn Bragg and guests Frank Close, Jocelyn Bell Burnell and Ruth Gregory discuss the Vacuum of Space. The idea that there is a nothingness at the heart of nature has exercised philosophers and scientists for millennia, from Thales's belief that all matter was water to Newton's concept of the Ether and Einstein's idea of Space-Time. Recently, physicists have realised that the vacuum is not as empty as we thought and that the various vacuums of nature vibrate with forces and energies, waves and particles and the mysterious phenomena of the Higgs field and dark energy.

Patricia Fara, Stephen Pumfrey and Rhodri Lewis join Melvyn Bragg to discuss the Jacobean lawyer, political fixer and alleged founder of modern science Francis Bacon.In the introduction to Thomas Spratt's History of the Royal Society, there is a poem about man called Francis Bacon which declares 'Bacon, like Moses, led us forth at last, The barren wilderness he past, Did on the very border stand Of the blest promis'd land, And from the mountain's top of his exalted wit, Saw it himself, and shew'd us it'.Francis Bacon was a lawyer and political schemer who climbed the greasy pole of Jacobean politics and then fell down it again. But he is most famous for developing an idea of how science should be done - a method that he hoped would slough off the husk of ancient thinking and usher in a new age. It is called Baconian Method and it has influenced and inspired scientists from Bacon's own time to the present day.