Science Weekly

Among the many justifications Donald Trump has presented for the US and Israel attacking Iran has been the supposedly imminent threat posed by its nuclear weapons programme. But how close was the country really to developing an atomic weapon? Ian Sample hears from Kelsey Davenport, the director of non-proliferation policy at the Arms Control Association. She sets out why many experts don’t believe the country even had a structured nuclear weapons programme, and explains what she thinks the impact of the war could be on nuclear proliferation around the world.. Help support our independent journalism at theguardian.com/sciencepod

The conflict in the Middle East has sent energy prices soaring, and for countries that import a high proportion of their fuel, it’s a reminder of the perils of energy dependence. As the recipient of almost 90% of Iran’s crude oil, China knows this only too well. Which partly explains why the country spent the last decade heavily investing in clean power. To find out what else could be driving the strategy, Madeleine Finlay speaks to senior China correspondent Amy Hawkins. And energy correspondent Jillian Ambrose reflects on how China’s ambitions could affect the rest of the world. Help support our independent journalism at theguardian.com/sciencepod

In the past three months, Donald Trump’s White House has reportedly used AI twice to effect regime change – once in its capture of Venezuela’s president, Nicolás Maduro, and more recently to help plan the strikes that killed Iran’s supreme leader, Ayatollah Ali Khamenei. The most recent strikes coincided with the end of the Pentagon’s relationship with the AI company Anthropic over concerns its AI tool Claude was being used for purposes the company had explicitly prohibited. The government swiftly signed a new contract with Open AI. To find out what this means for the use of AI in forthcoming conflicts, Madeleine Finlay speaks to technology journalist Chris Stokel-Walker. He explains why he thinks this moment represents a dangerous turning point.. Help support our independent journalism at theguardian.com/sciencepod

Since the 1960s, global GDP has been rapidly rising and living standards have reached record highs. But something else has been rocketing up too – carbon emissions. For years, scientists and economists have been asking: is it possible to grow without heating and polluting the Earth? And as the climate becomes more unstable, the issue is only becoming more urgent. Madeleine Finlay hears from two economists arguing for a change in how we measure a country’s success. Nick Stern is professor of economics and government at the London School of Economics and an advocate of green growth, an approach to growth that prioritises green industry. Jason Hickel is a political economist and professor at the Autonomous University of Barcelona who advocates degrowth, shrinking parts of the economy that do not advance our social and ecological goals.. Help support our independent journalism at theguardian.com/sciencepod

For a long time fat was seen simply as an inert yellow substance wrapping around our bodies, but now that’s changing. Scientists are beginning to understand that our fat is actually intricate and dynamic, constantly in conversation with the rest of the body. It’s now even considered by some to be an organ in its own right. To find out more about the complex role fat plays in our health, Ian Sample hears from co-host Madeleine Finlay and from Declan O’Regan, professor of cardiovascular AI at Imperial College London. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay sits down with science editor Ian Sample and science correspondent Nicola Davis to discuss three eye-catching stories, including the impact of a powerful psychedelic on depression, answers on the death of Russian opposition leader Alexei Navalny, and an explanation to the mystery of why humans have chins. Help support our independent journalism at theguardian.com/sciencepod

Testimonials about the beneficial health effects of magnesium supplements abound online, with influencers claiming that a daily pill can help with everything from anxiety to sleep and brain fog. But do any of these claims stack up? Ian Sample is joined by co-host Madeleine Finlay to find out where the science stands. They also hear from Katherine Tucker, the founder of the Center for Population Health at the University of Massachusetts Lowell. She explains what magnesium is doing in our bodies and the best approach we can take to ensure we are getting enough. Help support our independent journalism at theguardian.com/sciencepod

In late January a new social media site took a certain corner of the internet by storm. Moltbook was conceived as a space where AI assistants could let off steam, chat and compare notes on their bosses, but it quickly became the focus of breathless claims that the singularity had arrived as the bots started badmouthing their humans and plotting an uprising. So what’s the truth about Moltbook? Madeleine Finlay hears from Aisha Down about what it tells us about AI, and about us.. Help support our independent journalism at theguardian.com/sciencepod

The release of the latest batch of documents relating to the late child sex offender Jeffrey Epstein has shed further light on his close relationship with the world of science. To find out why he cultivated scientists and where his interests lay, Ian Sample hears from Dan Vergano, a senior editor at Scientific American.. Help support our independent journalism at theguardian.com/sciencepod

On a recent trip to Lake Geneva in Switzerland, biodiversity reporter Phoebe Weston witnessed the impact of one of the planet’s most potent invasive species, the quagga mussel. In just a decade the mollusc, originally from the Ponto-Caspian region of the Black Sea, has caused irreversible change beneath the surface of the picturesque lake. While ecologists believe invasive species play a major role in more than 60% of plant and animal extinctions, stopping them in their tracks is almost impossible. Phoebe tells Madeleine Finlay how invasive species spread, how conservationists are trying combat them and why some think a radical new approach is needed.. Help support our independent journalism at theguardian.com/sciencepod

Just like men, women are increasingly being told by online influencers that the classic symptoms of middle age could be down to low testosterone. In the second part of this miniseries exploring the hormone, Madeleine Finlay finds out what testosterone supplementation is doing for women. She hears from science journalist Linda Geddes, who is taking testosterone for low libido, and from prof Susan Davis, a consultant endocrinologist and head of the Monash University Women’s Health Research Programme. Susan explains what the evidence really shows about the benefits and risks of women taking testosterone. Help support our independent journalism at theguardian.com/sciencepod

If TikTok influencers are to be believed, testosterone, or T, is the answer to everything from fitness frustrations and fatigue to low libido. But doctors are warning that social media misinformation is driving men to seek testosterone therapy that they don’t need. This in turn comes with risks for health and fertility. In part one of a miniseries exploring the popularity of testosterone, Madeleine Finlay hears from Prof Channa Jayasena of Imperial College London, who is chair of the Society for Endocrinology, about how this craze is manifesting in NHS clinics, and from ‘Sam’ who tells Madeleine about his own journey with the hormone. Help support our independent journalism at theguardian.com/sciencepod

Last week, a UN report declared that the world has entered an era of ‘global water bankruptcy’ with many human water systems past the point at which they can be restored to former levels. To find out what this could look like, Madeleine Finlay speaks to the Guardian’s diplomatic editor, Patrick Wintour, who has been reporting on Iran’s severe water crisis. And Mohammad Shamsudduha, professor of water crisis and risk reduction in the department of risk and disaster reduction at University College London, explains how the present situation arose and what can be done to bring water supplies back from the brink. Help support our independent journalism at theguardian.com/sciencepod

The Guardian’s science editor, Ian Sample, talks to Madeleine Finlay about three eye-catching science stories from the week, including a study that suggests positive thinking can boost immune response. Also on the agenda is the mysterious rise of scabies in the UK, and the discovery that cows are more adept with tools than previously known. Help support our independent journalism at theguardian.com/sciencepod

Studies detecting microplastics throughout human bodies have made for alarming reading in recent years. But last week, the Guardian’s environment editor, Damian Carrington, reported on major doubts among a group of scientists about how some of this research has been conducted. Damian tells Ian Sample how he first heard about the concerns, why the scientists think the discoveries are probably the result of contamination and false positives, and where it leaves the field. He also reflects on how we should now think about our exposure to microplastics. Help support our independent journalism at theguardian.com/sciencepod

Ian Sample puts listeners’ questions on dreams and nightmares to Dr Michelle Carr, director of the Dream Engineering Laboratory in Montreal’s Centre for Advanced Research in Sleep Medicine, and author of the new book Into the Dream Lab. They look at why we dream, what we can learn by examining our dreams, and what we can do when dreams turn to nightmares. Dr Carr gives her top tips for taking charge of our dreams and trying to influence their content. Help support our independent journalism at theguardian.com/sciencepod

Ian Sample puts listeners’ questions on sleep to Dr Allie Hare, consultant physician in respiratory and sleep medicine at Guy’s and St Thomas’ hospitals and president of the British Sleep Society. They cover why women experience sleep disturbance during the menopause, why sleep paralysis affects some people more than others, and what scientists know about the link between sleep and dementia. Hare also gives her top tips for getting better sleep in 2026. Help support our independent journalism at theguardian.com/sciencepod

Last year was full of unexpected science news, from the discovery of a new colour, to the interstellar visitor 3I/Atlas passing by our solar system, and a world-first treatment with a personalised gene editing therapy. So what will this year bring? Ian Sample and science correspondent Hannah Devlin discuss the big stories likely to hit the headlines and share their predictions for 2026. Help support our independent journalism at theguardian.com/sciencepod

The US capture of Nicolás Maduro and his wife, Cilia Flores, on Saturday left many people wondering why? Donald Trump hinted at an answer when he claimed the Venezuelan regime had stolen US oil rights and that American oil companies would help to run Venezuela going forward. Jillian Ambrose, the Guardian energy correspondent, explains to Ian Sample the appeal of Venezuelan oil to the US, how easy it is to extract and what the latest action tells us about Trump’s energy strategy. Help support our independent journalism at theguardian.com/sciencepod

Kevin Hall spent 21 years at the US National Institutes of Health and became known globally for his pioneering work on ultra-processed foods. In April he unexpectedly took early retirement, citing censorship under the Trump administration. Now he has co-authored a book with the journalist Julia Belluz that aims to bust myths and challenge wellness orthodoxy on everything from weight loss and metabolism to supplements and wearables. In this episode from October, Hall tells Ian Sample what he wants us all to understand about diet, exercise and weight loss, and what led to his departure from the job he loved. Help support our independent journalism at theguardian.com/sciencepod