Misha Glenny and guests discuss one of the wonders of the natural world. In 1875 in the western Pacific, the crew of HMS Challenger discovered the Mariana Trench which turned out to be deeper than Everest is high, by two kilometres. Trenches like Mariana form when one tectonic plate slips under another and heads down and there are around fifty of them globally. While at one time some thought it was too dark and deep for life there and others wildly imagined monsters, the truth has turned out to be much more surprising.

With

Heather Stewart,

Jon Copley

And

Alan Jamieson

Producer: Simon Tillotson

Reading list:

Susan Casey, The Underworld: Journeys to the Depths of the Ocean (Doubleday, 2023)

Jon Copley, Deep Sea: 10 Things You Should Know (Orion Books, 2023)

Hali Felt, Soundings: The Story of the Remarkable Woman Who Mapped the Ocean Floor (Henry Holt & Co, 2012)

M.E. Gerringer, ‘Pseudoliparis swirei: A newly-discovered hadal liparid (Scorpaeniformes: Liparidae) from the Mariana Trench’ (Zootaxa 4358 (1), 161-177, 2017)

A.J. Jamieson, The Hadal Zone: Life in the Deepest Oceans (Cambridge University Press, 2015)

A.J. Jamieson et al., ‘A global assessment of fishes at lower abyssal and upper hadal depths (5000 to 8000 m)’ (Deep-Sea Research Part 1. 178: 103642, 2021)

A.J. Jamieson et al., ‘Fear and loathing of the deep ocean: Why don’t people care about the deep sea?’ (ICES Journal of Marine Science. 78: 797-809, 2020)

A.J. Jamieson et al., ‘Microplastic and synthetic fibers ingested by deep-sea amphipods in six of the deepest marine environments on Earth’ (Royal Society Open Science, 6, 180667, 2019)

A.J. Jamieson et al., ‘Bioaccumulation of persistent organic pollutants in the deepest ocean fauna’ (Nature Ecology and Evolution. 1, 0051, 2017)

V.L. Vescovo et al., ‘Safety and conservation at the deepest place on Earth: A call for prohibiting the deliberate discarding of nondegradable umbilicals from deep-sea exploration vehicles’ (Marine Policy. 128, 104463, 2021)

J.N.J. Weston et al., ‘New species of Eurythenes from hadal depths of the Mariana Trench, Pacific Ocean (Crustacea: Amphipoda)’ (Zootaxa. 4748(1): 163-181, 2020)

In Our Time is a BBC Studios Production

Spanning history, religion, culture, science and philosophy, In Our Time from BBC Radio 4 is essential listening for the intellectually curious. In each episode, host Misha Glenny and expert guests explore the characters, events and discoveries that have shaped our world.

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

Emily Rayfield

And

Jonathan Codd

Producer: 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 Production

Spanning 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.

With

Jess Wade

Frank Close

And

Steven Bramwell

Producer: Simon Tillotson

Reading 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 Garden

Jane Memmott, Professor of Ecology at the University of Bristol

And

Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary, University of London.

Producer: Eliane Glaser

Reading 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)

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.

Jonathan Chubb

Elinor Thompson

And

Merlin Sheldrake

Producer: 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

Saidul Islam

And

Oliver Shorttle

Producer: Simon Tillotson

Reading 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

Jo Marchant

And

Liba Taub

Producer: Simon Tillotson

Reading 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

Katy Clough

And

Andrew Pontzen

Producer: Simon Tillotson

Reading 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

James Ebdon

And

Claas Kirchhelle

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

David Rothery

And

Carolin Crawford

Producer: Simon Tillotson

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)