In Our Time: Science

Melvyn Bragg and his guests discuss the Sun. The object that gives the Earth its light and heat is a massive ball of gas and plasma 93 million miles away. Thanks to the nuclear fusion reactions taking place at its core, the Sun has been shining for four and a half billion years. Its structure, and the processes that keep it burning, have fascinated astronomers for centuries. After the invention of the telescope it became apparent that the Sun is not a placid, steadily shining body but is subject to periodic changes in its appearance and eruptions of dramatic violence, some of which can affect us here on Earth. Recent space missions have revealed fascinating new insights into our nearest star.With:Carolin Crawford Gresham Professor of Astronomy and Fellow of Emmanuel College, CambridgeYvonne Elsworth Poynting Professor of Physics at the University of BirminghamLouise Harra Professor of Solar Physics at UCL Mullard Space Science LaboratoryProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and work of Robert Boyle, a pioneering scientist and a founder member of the Royal Society. Born in Ireland in 1627, Boyle was one of the first natural philosophers to conduct rigorous experiments, laid the foundations of modern chemistry and derived Boyle's Law, describing the physical properties of gases. In addition to his experimental work he left a substantial body of writings about philosophy and religion; his piety was one of the most important factors in his intellectual activities, prompting a celebrated dispute with his contemporary Thomas Hobbes.With:Simon Schaffer Professor of the History of Science at the University of CambridgeMichael Hunter Emeritus Professor of History at Birkbeck College, University of LondonAnna Marie Roos Senior Lecturer in the History of Science and Medicine at the University of LincolnProducer: Thomas Morris.

Melvyn Bragg and his guests discuss photosynthesis, the process by which green plants and many other organisms use sunlight to synthesise organic molecules. Photosynthesis arose very early in evolutionary history and has been a crucial driver of life on Earth. In addition to providing most of the food consumed by organisms on the planet, it is also responsible for maintaining atmospheric oxygen levels, and is thus almost certainly the most important chemical process ever discovered.With:Nick Lane Reader in Evolutionary Biochemistry at University College LondonSandra Knapp Botanist at the Natural History MuseumJohn Allen Professor of Biochemistry at Queen Mary, University of London.Producer: Thomas Morris

Melvyn Bragg and his guests discuss the science of matter and the states in which it can exist. Most people are familiar with the idea that a substance like water can exist in solid, liquid and gaseous forms. But as much as 99% of the matter in the universe is now believed to exist in a fourth state, plasma. Today scientists recognise a number of other exotic states or phases, such as glasses, gels and liquid crystals - many of them with useful properties that can be exploited.With:Andrea Sella Professor of Chemistry at University College LondonAthene Donald Professor of Experimental Physics at the University of CambridgeJustin Wark Professor of Physics and Fellow of Trinity College at the University of OxfordProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the eye. Humans have been attempting to understand the workings and significance of the organ for at least 2500 years. Some ancient philosophers believed that the eye enabled creatures to see by emitting its own light. The function and structures of the eye became an area of particular interest to doctors in the Islamic Golden Age. In Renaissance Europe the work of thinkers including Kepler and Descartes revolutionised thinking about how the organ worked, but it took several hundred years for the eye to be thoroughly understood. Eyes have long attracted more than purely scientific interest, known even today as the 'windows on the soul'.With:Patricia Fara Senior Tutor of Clare College, University of CambridgeWilliam Ayliffe Gresham Professor of Physic at Gresham CollegeRobert Iliffe Professor of Intellectual History and History of Science at the University of SussexProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Social Darwinism. After the publication of Charles Darwin's masterpiece On the Origin of Species in 1859, some thinkers argued that Darwin's ideas about evolution could also be applied to human society. One thinker particularly associated with this movement was Darwin's near-contemporary Herbert Spencer, who coined the phrase 'survival of the fittest'. He argued that competition among humans was beneficial, because it ensured that only the healthiest and most intelligent individuals would succeed. Social Darwinism remained influential for several generations, although its association with eugenics and later adoption as an ideological position by Fascist regimes ensured its eventual downfall from intellectual respectability.With:Adam Kuper Centennial Professor of Anthropology at the LSE, University of LondonGregory Radick Professor of History and Philosophy of Science at the University of LeedsCharlotte Sleigh Reader in the History of Science at the University of Kent.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Catastrophism, the idea that natural disasters have had a significant influence in moulding the Earth's geological features. In 1822 William Buckland, the first reader of Geology at the University of Oxford, published his famous Reliquae Diluvianae, in which he ascribed most of the fossil record to the effects of Noah's flood. Charles Lyell in his Principles of Geology challenged these writings, arguing that geological change was slow and gradual, and that the processes responsible could still be seen at work today - a school of thought known as Uniformitarianism. But in the 1970s the idea that natural catastrophes were a major factor in the Earth's geology was revived and given new respectability by the discovery of evidence of a gigantic asteroid impact 65 million years ago, believed by many to have resulted in the extinction of the dinosaurs.With:Andrew Scott Leverhulme Emeritus Fellow in the Department of Earth Sciences at Royal Holloway, University of LondonJan Zalasiewicz Senior Lecturer in Geology at the University of LeicesterLeucha Veneer Visiting Scholar at the Faculty of Life Sciences at the University of ManchesterProducer: Thomas Morris.

The podcast explores complexity and its applications in various fields like biology and political science, discussing topics such as the behavior of societies, traffic flow prediction, and disease spread. It delves into the emergence of complexity as a separate discipline and highlights the application of mathematical models in understanding complex systems. The podcast also examines the concept of emergence in multilevel systems and emphasizes the need for iterative problem-solving approaches in addressing complexity.

Melvyn Bragg and his guests discuss the development of the microscope, an instrument which has revolutionised our knowledge of the world and the organisms that inhabit it. In the seventeenth century the pioneering work of two scientists, the Dutchman Antonie van Leeuwenhoek and Robert Hooke in England, revealed the teeming microscopic world that exists at scales beyond the capabilities of the naked eye. The microscope became an essential component of scientific enquiry by the nineteenth century, but in the 1930s a German physicist, Ernst Ruska, discovered that by using a beam of electrons he could view structures much tinier than was possible using visible light. Today light and electron microscopy are among the most powerful tools at the disposal of modern science, and new techniques are still being developed.With:Jim Bennett Visiting Keeper at the Science Museum in LondonSir Colin Humphreys Professor of Materials Science and Director of Research at the University of CambridgeMichelle Peckham Professor of Cell Biology at the University of LeedsProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Roman physician and medical theorist Galen. The most celebrated doctor in the ancient world, Galen was Greek by birth but spent most of his career in Rome, where he was personal physician to three Emperors. He was one of the most prolific authors of his age, and a sixth of all surviving ancient literature in Greek was written by him. Celebrated in his own lifetime, he was regarded as the preeminent medical authority for centuries after his death, both in the Arab world and in medieval Europe. It was only the discoveries of Renaissance science which removed Galen from his dominant position in the pantheon of medicine.With:Vivian Nutton Emeritus Professor of the History of Medicine at University College LondonHelen King Professor of Classical Studies at the Open UniversityCaroline Petit Wellcome Trust Senior Research Fellow in Classics at the University of WarwickProducer: Thomas Morris.