In Our Time: Science

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5 de 54

The Evolution of Lungs
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.
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48:24
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48:24
Heisenberg's Uncertainty Principle
Melvyn Bragg and guests discuss the German physicist who, at the age of 23 and while still a student, effectively created quantum mechanics for which he later won the Nobel Prize. Werner Heisenberg made this breakthrough in a paper in 1925 when, rather than starting with an idea of where atomic particles were at any one time, he worked backwards from what he observed of atoms and their particles and the light they emitted, doing away with the idea of their continuous orbit of the nucleus and replacing this with equations. This was momentous and from this flowed what’s known as his Uncertainty Principle, the idea that, for example, you can accurately measure the position of an atomic particle or its momentum, but not both.With Fay Dowker Professor of Theoretical Physics at Imperial College LondonHarry Cliff Research Fellow in Particle Physics at the University of CambridgeAnd Frank Close Professor Emeritus of Theoretical Physics and Fellow Emeritus at Exeter College at the University of OxfordProducer: Simon TillotsonReading list:Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different (Vintage, 2018)John Bell, ‘Against 'measurement'’ (Physics World, Vol 3, No 8, 1990)Mara Beller, Quantum Dialogue: The Making of a Revolution (University of Chicago Press, 2001)David C. Cassidy, Beyond Uncertainty: Heisenberg, Quantum Physics, And The Bomb (Bellevue Literary Press, 2010) Werner Heisenberg, Physics and Philosophy (first published 1958; Penguin Classics, 2000)Carlo Rovelli, Helgoland: The Strange and Beautiful Story of Quantum Physics (Penguin, 2022)
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58:02
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58:02
The Evolution of Horses
Melvyn Bragg and guests discuss the origins of horses, from their dog sized ancestors to their proliferation in the New World until hunted to extinction, their domestication in Asia and their development since. The genetics of the modern horse are the most studied of any animal, after humans, yet it is still uncertain why they only have one toe on each foot when their wider family had more, or whether speed or stamina has been more important in their evolution. What is clear, though, is that when humans first chose to ride horses, as well as eat them, the future of both species changed immeasurably.With Alan Outram Professor of Archaeological Science at the University of ExeterChristine Janis Honorary Professor in Palaeobiology at the University of Bristol and Professor Emerita in Ecology and Evolutionary Biology at Brown UniversityAnd John Hutchinson Professor in Evolutionary Biomechanics at the Royal Veterinary CollegeProducer: Simon Tillotson
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50:10
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50:10
The Science of Glass
While glass items have been made for at least 5,000 years, scientists are yet to explain, conclusively, what happens when the substance it's made from moves from a molten state to its hard, transparent phase. It is said to be one of the great unsolved problems in physics. While apparently solid, the glass retains certain properties of a liquid. At times, ways of making glass have been highly confidential; in Venice in the Middle Ages, disclosure of manufacturing techniques was a capital offence. Despite the complexity and mystery of the science of glass, glass technology has continued to advance from sheet glass to crystal glass, optical glass and prisms, to float glasses, chemical glassware, fibre optics and metal glasses.With:Dame Athene Donald Professor of Experimental Physics at the University of Cambridge and Master of Churchill College, CambridgeJim Bennett Former Director of the Museum of the History of Science at the University of Oxford and Keeper Emeritus at the Science MuseumPaul McMillan Professor of Chemistry at University College LondonProducer: Simon Tillotson.
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45:57
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45:57
The Earth's Core
Melvyn Bragg and his guests discuss the Earth's Core. The inner core is an extremely dense, solid ball of iron and nickel, the size of the Moon, while the outer core is a flowing liquid, the size of Mars. Thanks to the magnetic fields produced within the core, life on Earth is possible. The magnetosphere protects the Earth from much of the Sun's radiation and the flow of particles which would otherwise strip away the atmosphere. The precise structure of the core and its properties have been fascinating scientists from the Renaissance. Recent seismographs show the picture is even more complex than we might have imagined, with suggestions that the core is spinning at a different speed and on a different axis from the surface.WithStephen Blundell Professor of Physics and Fellow of Mansfield College at the University of OxfordArwen Deuss Associate Professor in Seismology at Utrecht UniversityandSimon Redfern Professor of Mineral Physics at the University of CambridgeProducer: Simon Tillotson.
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46:41
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46:41