Melvyn Bragg and guests discuss the evolution of lungs and of the first breaths, which can be traced back 400 million years to when animal life spread from rock pools and swamps onto land, as some fish found an evolutionary advantage in getting their oxygen from air rather than water. Breathing with lungs may have started with fish filling their mouths with air and forcing it down into sacs in their chests, like the buccal pumping that frogs do now, and slowly their swimming muscles adapted to work their lungs like bellows. While lungs developed in different ways, there are astonishing continuities: for example, the distinct breathing system that helps tiny birds fly thousands of miles now is also the one that once allowed some dinosaurs to become huge; our hiccups are vestiges of the flight reaction in fish needing more oxygen; and we still breathe through our skins, just not enough to meet our needs.With:Steve Brusatte Professor of Palaeontology and Evolution at the University of EdinburghEmily Rayfield Professor of Palaeobiology at the University of BristolAndJonathan Codd Professor of Integrative Zoology at the University of ManchesterProducer: Simon Tillotson Reading list:Roger B. J. Benson, Richard J. Butler, Matthew T. Carrano and Patrick M. O'Connor, ‘Air-filled postcranial bones in theropod dinosaurs: physiological implications and the ‘reptile’–bird transition’ (Biological Reviews: Cambridge Philosophical Society, July 2011)Steve Brusatte, The Rise and Fall of the Dinosaurs: A New History of a Lost World (Mariner Books, 2018)Jennifer A. Clack, Gaining Ground: The Origin and Evolution of Tetrapods (2nd edition, Indiana University Press, 2012)Camila Cupello et al, ‘Lung Evolution in vertebrates and the water-to-land transition’ (eLife, July 2022)Andrew Davies and Carl Moore, The Respiratory System (Elsevier, 2010) Kenneth Kardong, Vertebrates: Comparative Anatomy, Function, Evolution (8th edition, McGraw-Hill Education, 2018)Ye Li et al, ‘Origin and stepwise evolution of vertebrate lungs’ (Nature Ecology & Evolution, Feb 2025) P. Martin Sander and Marcus Clauss, ‘Sauropod Gigantism’ (Science, Oct 2008)Goran Nilsson, Respiratory Physiology of Vertebrates: Life With and Without Oxygen (Cambridge University Press, 2010)Steven F. Perry et al, ‘What came first, the lung or the breath?’ (Comparative Biochemistry and Physiology, Part A: Molecular & Integrative Biology, May 2001)Michael J. Stephen, Breath Taking: The Power, Fragility, and Future of Our Extraordinary Lungs (Grove/Atlantic, 2022)Mathew J. Wedel, ‘The evolution of vertebral pneumaticity in sauropod dinosaurs’ (Journal of Vertebrate Paleontology, Aug 2010)In Our Time is a BBC Studios Audio ProductionSpanning history, religion, culture, science and philosophy, In Our Time from BBC Radio 4 is essential listening for the intellectually curious. In each episode, host Melvyn Bragg and expert guests explore the characters, events and discoveries that have shaped our world.

Melvyn Bragg and guests discuss the decisive role of one of the great 20th Century physicists in solving the question of nuclear fission. It is said that Meitner (1878-1968) made this breakthrough over Christmas 1938 while she was sitting on a log in Sweden during a snowy walk with her nephew Otto Frisch (1904-79). Both were Jewish-Austrian refugees who had only recently escaped from Nazi Germany. Others had already broken uranium into the smaller atom barium, but could not explain what they found; was the larger atom bursting, or the smaller atom being chipped off or was something else happening? They turned to Meitner. She, with Frisch, deduced the nucleus really was splitting like a drop of water into a dumbbell shape, with the electrical charges at each end forcing the divide, something previously thought impossible, and they named this ‘fission’. This was a crucial breakthrough for which Meitner was eventually widely recognised if not at first.WithJess Wade A Royal Society University Research Fellow and Lecturer in Functional Materials at Imperial College, LondonFrank Close Professor Emeritus of Theoretical Physics and Fellow Emeritus at Exeter College, University of OxfordAnd Steven Bramwell Director of the London Centre for Nanotechnology and Professor of Physics at University College LondonProducer: Simon TillotsonReading list:Frank Close, Destroyer of Worlds: The Deep History of the Nuclear Age, 1895-1965 (Allen Lane, 2025)Ruth Lewin Sime, Lise Meitner: A Life in Physics (University of California Press, 1996)Marissa Moss, The Woman Who Split the Atom: The Life of Lise Meitner (Abrams Books, 2022)Patricia Rife, Lise Meitner and the Dawn of the Nuclear Age (Birkhauser Verlag, 1999) In Our Time is a BBC Studios Audio Production

Since plants have to mate and produce offspring while rooted to the spot, they have to be pollinated – by wind, water, or animals – most commonly insects. They use a surprising array of tricks to attract pollinators: striking colours, iridescent light effects, and enticing scents, to name but a few. Insects, on the other hand, do not seek to pollinate plants – they are looking for food; so plants make sure it’s worth their while. Insects are also remarkably sophisticated in their ability to find, recognise and find their way inside flowers. So pollination has evolved as a complex dance between plants and pollinators that is essential for life on earth to continue. With Beverley Glover, Director of the Cambridge University Botanic GardenJane Memmott, Professor of Ecology at the University of BristolAndLars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary, University of London.Producer: Eliane GlaserReading list:Stephen L Buchmann and Gary Paul Nabhan, The Forgotten Pollinators (Island Press, 1997)Lars Chittka, The Mind of a Bee (Princeton University Press, 2023)Steven Falk, Field Guide to the Bees of Britain and Ireland (British Wildlife Publishing, 2015)Francis S. Gilbert (illustrated by Steven J. Falk), Hoverflies: Naturalists' Handbooks vol. 5 (Pelagic Publishing, 2015)Dave Goulson, A Sting in the Tale: My Adventures with Bumblebees (Vintage, 2014)Edwige Moyroud and Beverley J. Glover, ‘The evolution of diverse floral morphologies’ (Current Biology vol 11, 2017)Jeff Ollerton, Birds and Flowers: An Intimate 50 Million Year Relationship (Pelagic Publishing, 2024) Alan E. Stubbs and Steven J. Falk, British Hoverflies (‎British Entomological & Natural History Society, 2002)Timothy Walker, Pollination: The Enduring Relationship Between Plant and Pollinator (Princeton University Press, 2020)In Our Time is a BBC Studios Audio Production

Melvyn Bragg and guests discuss slime mould, a basic organism that grows on logs, cowpats and compost heaps. Scientists have found difficult to categorise slime mould: in 1868, the biologist Thomas Huxley asked: ‘Is this a plant, or is it an animal? Is it both or is it neither?’ and there is a great deal scientists still don’t know about it. But despite not having a brain, slime mould can solve complex problems: it can find the most efficient way round a maze and has been used to map Tokyo’s rail network. Researchers are using it to help find treatments for cancer, Parkinson's and Alzheimer's disease, and computer scientists have designed an algorithm based on slime mould behaviour to learn about dark matter. It’s even been sent to the international space station to help study the effects of weightlessness. WithJonathan Chubb Professor of Quantitative Cell Biology at University College, LondonElinor Thompson Reader in microbiology and plant science at the University of GreenwichAndMerlin Sheldrake Biologist and writerProducer: Eliane Glaser In Our Time is a BBC Studios Audio production

Melvyn Bragg and guests discuss some of the great unanswered questions in science: how and where did life on Earth begin, what did it need to thrive and could it be found elsewhere? Charles Darwin speculated that we might look for the cradle of life here in 'some warm little pond'; more recently the focus moved to ocean depths, while new observations in outer space and in laboratories raise fresh questions about the potential for lifeforms to develop and thrive, or 'habitability' as it is termed. What was the chemistry needed for life to begin and is it different from the chemistry we have now? With that in mind, what signs of life should we be looking for in the universe to learn if we are alone?With Jayne Birkby Associate Professor of Exoplanetary Sciences at the University of Oxford and Tutorial Fellow in Physics at Brasenose CollegeSaidul Islam Assistant Professor of Chemistry at Kings College, LondonAnd Oliver Shorttle Professor of Natural Philosophy at the University of Cambridge and Fellow of Clare CollegeProducer: Simon TillotsonReading list: David Grinspoon, Venus Revealed: A New Look Below the Clouds of Our Mysterious Twin Planet (Basic Books, 1998)Lisa Kaltenegger, Alien Earths: Planet Hunting in the Cosmos (Allen Lane, 2024)Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth (‎Princeton University Press, 2004)Charles H. Langmuir and Wallace Broecker, How to Build a Habitable Planet: The Story of Earth from the Big Bang to Humankind (Princeton University Press, 2012)Joshua Winn, The Little Book of Exoplanets (Princeton University Press, 2023)In Our Time is a BBC Studios Audio Production

Melvyn Bragg and guests discuss the 2000-year-old device which transformed our understanding of astronomy in ancient Greece. In 1900 a group of sponge divers found the wreck of a ship off the coast of the Greek island of Antikythera. Among the items salvaged was a corroded bronze object, the purpose of which was not at first clear. It turned out to be one of the most important discoveries in marine archaeology. Over time, researchers worked out that it was some kind of astronomical analogue computer, the only one to survive from this period as bronze objects were so often melted down for other uses. In recent decades, detailed examination of the Antikythera Mechanism using the latest scientific techniques indicates that it is a particularly intricate tool for showing the positions of planets, the sun and moon, with a complexity and precision not surpassed for over a thousand years.With Mike Edmunds Emeritus Professor of Astrophysics at Cardiff UniversityJo Marchant Science journalist and author of 'Decoding the Heavens' on the Antikythera MechanismAnd Liba Taub Professor Emerita in the Department of History and Philosophy of Science at the University of Cambridge and Visiting Scholar at the Deutsches Museum, MunichProducer: Simon Tillotson In Our Time is a BBC Studios Audio ProductionReading list:Derek de Solla Price, Gears from the Greeks: The Antikythera Mechanism (American Philosophical Society Press, 1974)M. G. Edmunds, ‘The Antikythera mechanism and the mechanical universe’ (Contemp. Phys. 55, 2014) M.G. Edmunds, ’The Mechanical Universe’ (Astronomy & Geophysics, 64, 2023)James Evans and J. Lennart Berggren, Geminos's Introduction to the Phenomena: A Translation and Study of a Hellenistic Survey of Astronomy (Princeton University Press, 2006)T. Freeth et al., ‘Calendars with Olympiad display and eclipse prediction on the Antikythera mechanism’ (Nature 454, 2008)Alexander Jones, A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World (Oxford University Press, 2017)Jo Marchant, Decoding the Heavens: Solving the Mystery of the World’s First Computer (Windmill Books, 2009)J.H. Seiradakis and M.G. Edmunds, ‘Our current knowledge of the Antikythera Mechanism’ (Nature Astronomy 2, 2018)Liba Taub, Ancient Greek and Roman Science: A Very Short Introduction (Oxford University Press, 2022)

Melvyn Bragg and guests discuss the tantalising idea that there are shortcuts between distant galaxies, somewhere out there in the universe. The idea emerged in the context of Einstein's theories and the challenge has been not so much to prove their unlikely existence as to show why they ought to be impossible. The universe would have to folded back on itself in places, and there would have to be something to make the wormholes and then to keep them open. But is there anywhere in the vast universe like that? Could there be holes that we or more advanced civilisations might travel through, from one galaxy to another and, if not, why not? With Toby Wiseman Professor of Theoretical Physics at Imperial College LondonKaty Clough Senior Lecturer in Mathematics at Queen Mary, University of LondonAnd Andrew Pontzen Professor of Cosmology at Durham UniversityProducer: Simon TillotsonReading list:Jim Al-Khalili, Black Holes, Wormholes and Time Machines (Taylor & Francis, 1999)Andrew Pontzen, The Universe in a Box: Simulations and the Quest to Code the Cosmos (Riverhead Books, 2023)Claudia de Rham, The Beauty of Falling: A Life in Pursuit of Gravity (Princeton University Press, 2024)Carl Sagan, Contact (Simon and Schuster, 1985)Kip Thorne, Black Holes & Time Warps: Einstein's Outrageous Legacy (W. W. Norton & Company, 1994)Kip Thorne, Science of Interstellar (W. W. Norton & Company, 2014)Matt Visser, Lorentzian Wormholes: From Einstein to Hawking (American Institute of Physics Melville, NY, 1996) In Our Time is a BBC Studios Audio Production

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 LeicesterJames Ebdon Professor of Environmental Microbiology at the University of BrightonAnd Claas Kirchhelle Historian and Chargé de Recherche at the French National Institute of Health and Medical Research’s CERMES3 Unit in Paris.Producer: Simon TillotsonIn Our Time is a BBC Studios Audio ProductionReading 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. WithEmma Bunce Professor of Planetary Plasma Physics and Director of the Institute for Space at the University of LeicesterDavid Rothery Professor of Planetary Geosciences at the Open UniversityAnd Carolin Crawford Emeritus Fellow of Emmanuel College, University of Cambridge, and Emeritus Member of the Institute of Astronomy, CambridgeProducer: Simon Tillotson In Our Time is a BBC Studios Audio productionReading 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)

Melvyn Bragg and guests discuss the Serbian-American inventor Nikola Tesla (1856-1943) and his role in the development of electrical systems towards the end of the nineteenth century. He made his name in New York in the contest over which current should flow into homes and factories in America. Some such as Edison backed direct current or DC while others such as Westinghouse backed alternating current or AC and Nikola Tesla’s invention of a motor that worked on AC swung it for the alternating system that went on to power the modern age. He ensured his reputation and ideas burnt brightly for the next decades, making him synonymous with the lone, genius inventor of the new science fiction. With Simon Schaffer Emeritus Fellow of Darwin College, University of CambridgeJill Jonnes Historian and author of “Empires of Light: Edison, Tesla, Westinghouse and the Race to Electrify the World”And Iwan Morus Professor of History at Aberystwyth UniversityProducer: Simon TillotsonReading list: W. Bernard Carlson, Tesla: Inventor of the Electrical Age (Princeton University Press, 2013)Margaret Cheney and Robert Uth, Tesla: Master of Lightning (Barnes & Noble Books, 1999) Thomas P. Hughes, Networks of Power: Electrification in Western Society, 1880-1930 (Johns Hopkins University Press, 1983)Carolyn Marvin, When Old Technologies Were New (Open University Press, 1988)Iwan Rhys Morus, Nikola Tesla and the Electrical Future (Icon Books, 2019)Iwan Rhys Morus, How The Victorians Took Us To The Moon (Icon, 2022)David E. Nye, Electrifying America: Social Meanings of a New Technology (MIT Press, 1991)John J. O’Neill, Prodigal Genius: The Life of Nikola Tesla (first published 1944; Cosimo Classics, 2006)Marc J. Seifer, Wizard: The Life and Times of Nikola Tesla, Biography of a Genius (first published 1996; Citadel Press, 2016)Nikola Tesla, My Inventions: The Autobiography of Nikola Tesla (first published 1919; Martino Fine Books, 2011)Nikola Tesla, My Inventions and other Writings (Penguin, 2012)In Our Time is a BBC Studios Audio production