The scientist John Dalton was born in North England in 1766. Although he came from a relatively poor Quaker family, he managed to become one of the most celebrated scientists of his age. Through his work, he helped to establish Manchester as a place where not only products were made but ideas were born. His reputation during his lifetime was so high that unusually a statue was erected to him before he died. Among his interests were meteorology, gasses and colour blindness. However, he is most remembered today for his pioneering thinking in the field of atomic theory. With: Jim Bennett Former Director of the Museum of the History of Science at the University of Oxford and Keeper Emeritus at the Science MuseumAileen Fyfe Reader in British History at the University of St AndrewsJames Sumner Lecturer in the History of Technology at the Centre for the History of Science, Technology and Medicine at the University of ManchesterProducer: Victoria Brignell.

Melvyn Bragg and guests discuss plasma, the fourth state of matter after solid, liquid and gas. As over ninety-nine percent of all observable matter in the Universe is plasma, planets like ours, with so little plasma and so much solid, liquid and gas, appear all the more remarkable. On the grand scale, plasma is what the Sun is made from and, when we look into the night sky, almost everything we can see with the naked eye is made of plasma. On the smallest scale, here on Earth, scientists make plasma to etch the microchips on which we rely for so much. Plasma is in the fluorescent light bulbs above our heads and, in laboratories around the world, it is the subject of tests to create, one day, an inexhaustible and clean source of energy from nuclear fusion.With Justin Wark Professor of Physics and Fellow of Trinity College at the University of OxfordKate Lancaster Research Fellow for Innovation and Impact at the York Plasma Institute at the University of Yorkand Bill Graham Professor of Physics at Queens University, BelfastProducer: Simon Tillotson.

In a programme first broadcast in 2016, Melvyn Bragg and guests discuss Zeno of Elea, a pre-Socratic philosopher from c490-430 BC whose paradoxes were described by Bertrand Russell as "immeasurably subtle and profound." The best known argue against motion, such as that of an arrow in flight which is at a series of different points but moving at none of them, or that of Achilles who, despite being the faster runner, will never catch up with a tortoise with a head start. Aristotle and Aquinas engaged with these, as did Russell, yet it is still debatable whether Zeno's Paradoxes have been resolved.With Marcus du Sautoy Professor of Mathematics and Simonyi Professor for the Public Understanding of Science at the University of OxfordBarbara Sattler Lecturer in Philosophy at the University of St Andrewsand James Warren Reader in Ancient Philosophy at the University of CambridgeProducer: Simon Tillotson

Melvyn Bragg and guests discuss the development of photography in the 1830s, when techniques for 'drawing with light' evolved to the stage where, in 1839, both Louis Daguerre and William Henry Fox Talbot made claims for its invention. These followed the development of the camera obscura, and experiments by such as Thomas Wedgwood and Nicéphore Niépce, and led to rapid changes in the 1840s as more people captured images with the daguerreotype and calotype. These new techniques changed the aesthetics of the age and, before long, inspired claims that painting was now dead.WithSimon Schaffer Professor of the History of Science at the University of CambridgeElizabeth Edwards Emeritus Professor of Photographic History at De Montfort UniversityAndAlison Morrison-Low, Research Associate at National Museums ScotlandProducer: Simon Tillotson.

Melvyn Bragg and guests discuss penicillin, discovered by Alexander Fleming in 1928. It is said he noticed some blue-green penicillium mould on an uncovered petri dish at his hospital laboratory, and that this mould had inhibited bacterial growth around it. After further work, Fleming filtered a broth of the mould and called that penicillin, hoping it would be useful as a disinfectant. Howard Florey and Ernst Chain later shared a Nobel Prize in Medicine with Fleming, for their role in developing a way of mass-producing the life-saving drug. Evolutionary theory predicted the risk of resistance from the start and, almost from the beginning of this 'golden age' of antibacterials, scientists have been looking for ways to extend the lifespan of antibiotics.WithLaura Piddock Professor of Microbiology at the University of BirminghamChristoph Tang Professor of Cellular Pathology and Professorial Fellow at Exeter College at the University of OxfordAndSteve Jones Emeritus Professor of Genetics at University College, LondonProducer: Simon Tillotson.

Melvyn Bragg and guests discuss Euclid's Elements, a mathematical text book attributed to Euclid and in use from its appearance in Alexandria, Egypt around 300 BC until modern times, dealing with geometry and number theory. It has been described as the most influential text book ever written. Einstein had a copy as a child, which he treasured, later saying "If Euclid failed to kindle your youthful enthusiasm, then you were not born to be a scientific thinker."With Marcus du Sautoy Professor of Mathematics and Simonyi Professor for the Public Understanding of Science at the University of OxfordSerafina Cuomo Reader in Roman History at Birkbeck University of LondonAnd June Barrow-Green Professor of the History of Mathematics at the Open UniversityProducer: Simon Tillotson.

Exploring the devastating Mount Tambora eruption in 1815, leading to a year without summer. Topics include weather effects, global consequences, famine, mass migration, and poetry's response to extreme conditions. There is also a focus on the fascination with volcanoes and geology in the early 19th century.

Melvyn Bragg and guests discuss the neutron, one of the particles found in an atom's nucleus. Building on the work of Ernest Rutherford, the British physicist James Chadwick won the Nobel Prize for Physics for his discovery of the neutron in 1932. Neutrons play a fundamental role in the universe and their discovery was at the heart of developments in nuclear physics in the first half of the 20th century. With Val Gibson Professor of High Energy Physics at the University of Cambridge and fellow of Trinity CollegeAndrew Harrison Chief Executive Officer of Diamond Light Source and Professor in Chemistry at the University of EdinburghAndFrank Close Professor Emeritus of Physics at the University of Oxford.

Melvyn Bragg and guests discuss the life and work of Robert Hooke (1635-1703) who worked for Robert Boyle and was curator of experiments at the Royal Society. The engraving of a flea, above, is taken from his Micrographia which caused a sensation when published in 1665. Sometimes remembered for his disputes with Newton, he studied the planets with telescopes and snowflakes with microscopes. He was an early proposer of a theory of evolution, discovered light diffraction with a wave theory to explain it and felt he was rarely given due credit for his discoveries. WithDavid Wootton Anniversary Professor of History at the University of YorkPatricia Fara President Elect of the British Society for the History of ScienceAndRob Iliffe Professor of History of Science at Oxford UniversityProducer: Simon Tillotson.

Melvyn Bragg and guests discuss the origins, development and uses of chromatography. In its basic form, it is familiar to generations of schoolchildren who put a spot of ink at the bottom of a strip of paper, dip it in water and then watch the pigments spread upwards, revealing their separate colours. Chemists in the 19th Century started to find new ways to separate mixtures and their work was taken further by Mikhail Tsvet, a Russian-Italian scientist who is often credited with inventing chromatography in 1900. The technique has become so widely used, it is now an integral part of testing the quality of air and water, the levels of drugs in athletes, in forensics and in the preparation of pharmaceuticals.WithAndrea Sella Professor of Chemistry at University College LondonApryll Stalcup Professor of Chemical Sciences at Dublin City UniversityAndLeon Barron Senior Lecturer in Forensic Science at King's College London.