Secretary of Defence Pete Hegseth has announced that the US military will be screening military personnel aged 30 and older for testosterone deficiency. Those found with low testosterone levels will be offered voluntary hormone replacement therapy. The secretary says this is to ensure “a healthy, capable, and decisively dominant fighting force”. Tom Whipple is joined by Professor Joe Herbert from the University of Cambridge to discuss why jacking soldiers up with testosterone may or may not be the best idea. Marine Biologist Kathryn Ayres, from the non-profit organisation Beneath the Waves, describes a newly observed behaviour in orcas in which they collaboratively swim so hard into a dead sunfish it explodes. Is it a teachable moment for their young or is it just for fun?Finally, we have Kit Yates, our resident mathematician, to reassure Tom that although AI might one day actually kill us all, at least it can disprove an 87-year-old mathematics conjecture. Presenter: Tom Whipple Producer: Dan Welsh, Alex Mansfield, Imy Harper, Tabitha Taylor Buck Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

A few years ago a satellite speeding through the Van Allen belt in earth orbit raised concerns that it may include a nuclear weapon. An explosion in that orbit would take out much of our global space infrastructure. The Outer Space Treaty of 1967 specifically prohibits such a thing, but it has proven technologically impossible to verify and monitor over the decades. Tom Whipple is joined by Prof Areg Danagoulian, Associate Professor of Nuclear Science and Engineering at MIT to explore a clever concept to spot such a thermonuclear device in orbit that he has published in this month’s Nature journal.Also on the show, Professor of Science Communications Gareth Mitchell discusses how the way toddlers waddle can teach robots how to play football, and how to win. He also examines a new global database on food consumption which aims to help answer some of the world’s most pressing questions on our diets and the environment. Presenter: Tom Whipple Producer: Alex Mansfield & Tabitha Taylor Buck Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

Synthetic biologist Kate Adamal and her team at the University of Minnesota published their research into the lab-created ‘SpudCell’ in a significant step towards building life from scratch. Science journalist, Kai Kupferschmidt, joins us to discuss the implications of this research, as well as the controversies.Nature reporter Lizzie Gibney tells us how science has helped us better understand the route that the famous Carthaginian general, Hannibal – and not forgetting his elephants – took across the Alps.Plus, in this week’s scout of science stories behind the ‘beautiful game’ we learn of research carried out at a Tokyo football match, monitoring seismic waves made by the vigorous celebrations of thousands of fans.Presenter: Tom Whipple Producer: Kate White, Alex Mansfield, Katie Tomsett, Tabitha Taylor Buck Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

During this year’s visit to the Royal Society Summer Science Exhibition in London, Tom Whipple discovers how sea urchins are being used to develop techniques to digitally preserve natural history, why we haven’t got robot butlers just yet, and what it takes to bottle lightning. Plus, in his ongoing quest to assemble a World Cup squad of science Tom recruits health reporter James Gallagher to scout out the best football science from around the world. This week, we want to know if there is robust evidence for a home advantage. We speak with Associate Professor of Cell & Developmental Biology Laura Porro from University College London, Dr Alice Leavey and Dr Fernando Alvares from the University of Southampton, Professor Ingmar Posner who leads the Applied Artificial Intelligence Lab at the University of Oxford and Dr Daniel Mitchard who is co-lead of Cardiff University’s Lightning Laboratory. Presenter: Tom Whipple Producers: Katie Tomsett, Kate White & Tabby Taylor Buck Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

As the UK and Europe battles with extreme weather warnings, is it time for us to consider some more extreme tactics to tackle the heat? Tom Whipple is joined by Mark Maslin, Professor of Earth System Science at University College London, to explore if solar geoengineering can help.Also on the show, science journalist Lizzie Gibney discusses the "Salah effect", when exposure to celebrities from stigmatised groups can help increase tolerance. She also examines new research into how the atom nucleus contain energy which can be used for telling the time. Plus, how laughter in great apes may have paved the way for the evolution of complex human language. Presenter: Tom Whipple Producer: Katie Tomsett, Alex Mansfield & Kate White Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

After this week’s announcement that under-16s will be banned from major social media platforms, we delve into the evidence behind the ban with Professor Amy Orben, Programme Leader of the Digital Mental Health Group at the University of Cambridge, and Dr Catherine Sebastian, Head of Evidence at Wellcome. Also on the show, what can penalty shoot-outs teach us about international diplomacy? And how does the valuation of a football player impact the number of crashes seen after their team plays? Professor of Mathematical Sciences at Bath and football fan, Kit Yates, joins Tom to assemble their very own World Cup squad of science. Presenter: Tom Whipple Producers: Kate White, Katie Tomsett, Keiran Manetta-Jones Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

After 144 years the tallest tower on the Sagrada Familia is finally complete, but when Gaudi first designed it, the technology to build the tower didn’t exist. We’re joined by Tristram Carfrae, structural engineer and designer at Arup who was tasked with this impossible feat over a decade ago. With the reappearance of screwworm in North America, we ask – is it ever acceptable to intentionally drive a species to extinction? Tom is joined by Dr Gregory Kaebnick from the Hastings Center for Bioethics to dive into the science that could make it happen and the ethics stopping us. Four in five of us will check the weather daily, but do we really know what our apps are telling us? Meteorologist Simon King guides us through the complex models behind these forecasts that govern our daily decisions. Plus, science journalist Caroline Steel is in the studio bringing us the scientific discoveries the headlines missed, but that you need to know. Presenter: Tom Whipple Producer: Kate White Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

Are we moving away from science as a strictly human endeavour? This is the view of Pushmeet Kohli, head of AI for Science at Google DeepMind. He joins Tom Whipple to discuss the use of the AI tool Co-Scientist as a collaborator in the lab, and the challenges in making Artificial Intelligence that works in science. Clare Bryant from the University of Cambridge also joins the conversation. And Steve Brusatte, Professor of Palaeontology at the University of Edinburgh, joins the program to talk about his new book, The Story of Birds, tracing a 150‑million‑year journey from small, feathered dinosaurs to the birds of today. Plus, science journalist Caroline Steel joins us to discuss the latest scientific discoveries that you might have missed. Presenter: Tom Whipple Producers: Dan Welsh and Kate White Production co-ordinator: Jana Bennett-Holesworth Editor: Martin Smith

From Hay Festival 2026, a dive into a big year for our oceans, with plankton specialist Vincent Doumeizel and physicist turned oceanographer Helen Czerski.Vincent is author of the Power of Plankton, which describes the crucial history and future of plankton and planktonic life on our planet. Helen's book The Blue Machine looks at the physical oceanic processes that shape the world.Presented by Tom Whipple Produced by Alex Mansfield

With 2023’s El Niño – a recurring pattern of extreme weather across the pacific basin - still leaving a bad taste in people's mouth, 2026 sees an El Niño stirring in the Pacific Ocean and there are warnings that this will be one of the strongest yet.Roland Pease speaks with Amanda Maycock, a climatologist from Leeds University, to discuss what this climate phenomenon is and how it will impact the world from October to early next year. He also hears from Scott Evans from the American Museum of Natural History, who has been exploring the Mackenzie mountains of Canada’s Northwest Territory to better understand the biology and ecology of life on earth before anything we might recognize - from the Ediacara era. This was before the explosion of different animal types with hard shells and bones in the later, Cambrian, time. In certain places around the world, much older rocks from the ancient ocean floor reveal an ecosystem abounding with soft, squidgy animal wierdness. In Canada Scott has found a new trove of these fossils, but from far deeper below the surface of those ancient seas. Did animal life begin deep in the darkest depths rather than paddling in pools nearer the land?Today, over half a billion years later, bottom trawling, a common fishing method involving dragging heavy nets across the bottom of the seafloor, is an environmentally destructive process that rips up everything in its path to maximise catch. We talked to Amanda Vincent, a professor at the Institute for the Oceans and fisheries of the British Columbia university and founder of the international Project Seahorse conservation group, about what bottom-trawl bans can achieve, in the light of results published about a renaissance of biodiversity off the coast of Scotland in an area where trawling has been banned for several years.Plus, we talk to science journalist Gareth Mitchell, who explains how bottom trawling can also have negative consequences on technology, as well as other science news you may have missed, including updates on solar storms and robotic wolf shortages in Japan.Presenter: Roland Pease Producers: Alex Mansfield and Dan Welsh Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth