Science Weekly

Humans have been wondering why we sleep for thousands of years. Is sleep’s purpose rest and relaxation, memory consolidation or maybe cognitive processing? In the last 15 years, scientists have discovered another possible explanation – waste disposal. In 2012 neuroscientist Maiken Nedergaard’s lab discovered that the brain has its own cleaning process, the glymphatic system, which clears away unhelpful proteins and metabolic byproducts, and only switches on at night. Since that groundbreaking discovery we’ve learned more about what drives this system and, importantly, how it could be impacting dementia. To understand more, Ian Sample talks to Prof Nedergaard about how she made the original discovery and how subsequent work is building a picture of sleep as anything but a quiet and inactive state. Help support our independent journalism at theguardian.com/sciencepod

Last month at Beijing’s half marathon, a robot named Lightning beat the human world record by nearly seven minutes. It’s the latest in a string of AI-powered milestones that have got people wondering whether robots are about to enter our everyday lives, just as chatbots have. And the country leading the charge is China, where the government has pledged to invest more than £100bn in robotics over the next 20 years. To find out how robots are already entering the workforce, and what needs to happen to get them cleaning our homes and weeding our gardens, Ian Sample hears from the Guardian’s senior China correspondent, Amy Hawkins, and from Nathan Lepora, professor of robotics and AI at Bristol University, who researches how robots can achieve human-like dexterity. Help support our independent journalism at theguardian.com/sciencepod

Home red-light therapy devices have exploded in popularity as masks, body wraps and mittens promise to reduce wrinkles, redness and even acne. But do the claims stack up, and what other benefits are scientists investigating? Ian Sample hears from his co-host, Madeleine Finlay, and the consultant dermatologist Dr Jonathan Kentley. Kentley explains how the potential benefits of red light were discovered, how it is thought to interact with collagen in our skin, and what science has to say about its impact on our appearance. Help support our independent journalism at theguardian.com/sciencepod

The US supreme court has preserved nationwide access to mail-order abortion pills – for now. As Carter Sherman explains, the fight to protect this medication is far from over, as a nationwide, near-total abortion ban could be on the horizon. Carter speaks with Dr Angel Foster, co-founder of the Massachusetts Medication Abortion Access Project, who reveals how the legal battle over abortion pills has affected patients across the US – and what could happen next. Help support our independent journalism at theguardian.com/sciencepod

After more than a decade of global consultation, polycystic ovary syndrome – which affects as many as one in eight women – has been renamed. The condition is caused by high levels of androgens, which can lead to symptoms such as excess hair, weight gain and irregular periods. To understand why campaigners wanted it renamed, and what its new name – polyendocrine metabolic ovarian syndrome (PMOS) – could mean for patients, Madeleine Finlay hears from the Guardian’s science correspondent, Nicola Davis, and Rachel, a campaigner from the charity Verity. Help support our independent journalism at theguardian.com/sciencepod

An outbreak of Ebola has emerged in the Democratic Republic of Congo and Uganda, leading to nearly 400 confirmed cases and more than 100 deaths. To find out how the outbreak might have begun, what authorities can do to contain it and why this outbreak is causing particular concern, Ian Sample hears from Daniela Manno, a clinical epidemiologist at the London School of Hygiene and Tropical Medicine. Help support our independent journalism at theguardian.com/sciencepod

The US supreme court dealt a devastating blow to the 1965 Voting Rights Act when it ruled in Louisiana v Callais in April that states cannot consider race in redistricting. Southern states from Tennessee to Alabama have rushed to erase majority-Black districts, sparking chaos for the midterm elections. Kai Wright talks to Stacey Abrams, a voting rights activist and former Georgia house minority leader, about the fallout from the decision, and why, despite it all, she still believes the way forward lies in engaging more voters to participate in democracy. ‘They have fractured communities and said we’re going to scatter these seeds. Our job is to grow,’ she says. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay sits down with co-host and science editor Ian Sample to discuss three eyecatching stories from the week, including an update on hantavirus. Also on the agenda is the Pentagon’s release of a tranche of never before seen documents relating to UFOs, and a study looking at the link between taking part in cultural activities and slower biological ageing. Help support our independent journalism at theguardian.com/sciencepod

Last month President Trump signed an executive order designed to fast track both research and access to psychedelic drugs as treatments for mental health illnesses. The most prominent in the order was ibogaine, a drug derived from the root bark of a West African shrub, that has shown some promise in relieving the long term effects of traumatic brain injury. Madeleine Finlay talks to journalist Mattha Busby about podcaster Joe Rogan’s role in the story, what else is behind the President’s interest in psychedelic research, and what the order will change in practice for scientists and researchers. Help support our independent journalism at theguardian.com/sciencepod

To celebrate Sir David Attenborough’s centenary, Madeleine Finlay catches up with natural history writer Patrick Barkham, who has met the celebrated presenter. They explore how the natural world has changed in the century that Attenborough has been on Earth, and how his programming has reflected his growing commitment to highlighting the devastating impacts of the climate crisis on nature and biodiversity. Help support our independent journalism at theguardian.com/sciencepod

Three people have died after an outbreak of hantavirus onboard a cruise ship travelling from Argentina to Cape Verde. The World Health Organization says a total of seven cases – two confirmed by laboratory testing and five suspected – have been identified on the cruise ship so far. It is also investigating whether rare human-to-human transmission of the virus could be behind the cases. Madeleine Finlay talks to Prof Jonathan Ball from Liverpool School of Tropical Medicine to find out where the virus comes from, how it is transmitted to humans, and what health agencies will be doing to try to contain it. Help support our independent journalism at theguardian.com/sciencepod

The transition towards renewable energy received a boost last week when representatives from 57 countries met in Santa Marta, Colombia, for a world-first climate meeting aimed at bringing the fossil fuels era to an end. Madeleine Finlay hears from the Guardian’s global environment editor, Jon Watts, about how the landmark conference came about, who was missing, and whether the optimism can translate into real world action. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay sits down with co-host and Guardian science editor Ian Sample to talk through three eye-catching stories from the week, including the news that the number of years people in the UK are spending in good health has declined compared with a decade ago. Also on the agenda is the science, tech and nutrition behind two runners at this weekend’s London marathon breaking the two-hour threshold, and an answer to why some old houses feel particularly spooky. Help support our independent journalism at theguardian.com/sciencepod

Social media is awash with content about food intolerances and the symptoms to look out for. But figuring out whether you actually have one, and what’s triggering it, is surprisingly difficult. One avenue people are gravitating towards is at-home testing. Madeleine Finlay sits down with health and lifestyle journalist Rebecca Seal to unpick the science behind these tests. Rebecca explains how they purport to work, how accurate they actually are, and how we can all investigate what we might be intolerant to, without breaking the bank. Rebecca’s book Irritated: The Allergy Epidemic and What We Can Do About It, is out now.. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay sits down with science editor Ian Sample to hear about some of the winners of the Breakthrough Prize, which held its ceremony in LA last weekend. Each prize is worth $3m and they’re awarded in physics, maths and life sciences. Madeleine and Ian hear from molecular biologist Jean Bennett, who shared a life sciences prize for her work developing the world’s first FDA-approved gene augmented therapy for sight loss. She explains how a chance encounter while dissecting a brain in medical school led her on a 25-year journey to develop the treatment.. Help support our independent journalism at theguardian.com/sciencepod

Earlier this month the AI company Anthropic said it had created a model so powerful that, out of a sense of responsibility, it was not going to release it to the public. Anthropic says the model, Mythos Preview, excels at spotting and exploiting vulnerabilities in software, and could pose a severe risk to economies, public safety and national security. But is this the whole story? Some experts have expressed scepticism about the extent of the model’s capabilities. Ian Sample hears from Aisha Down, a reporter covering artificial intelligence for the Guardian, to find what the decision to limit access to Mythos reveals about Anthropic’s strategy, and whether the model might finally spur more regulation of the industry.. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay sits down with co-host and science editor Ian Sample to discuss three eye-catching stories from the week, including a review into the effectiveness of a new class of Alzheimer’s drug that was once hailed as a game-changer in slowing the progress of the disease. Also on the agenda is the news that the world could be heading for a ‘super El Niño’ this summer and a study exploring whether conversations about dull topics really are as boring as we expect them to be. Help support our independent journalism at theguardian.com/sciencepod

Alongside the oil and gas stranded in the strait of Hormuz is another commodity vital to today’s economy: helium. It is a critical element in all kinds of areas from MRI machines to the Large Hadron Collider, and even deep-sea diving. It is also integral to the AI boom. And this isn’t the first time its fragile global supply chain has been threatened. So why is helium so useful, and what will happen if the shortage continues? Ian Sample hears from co-host Madeleine Finlay, and from Sophia Hayes, professor of chemistry at Washington University in St. Louis. Help support our independent journalism at theguardian.com/sciencepod

This week Artemis II’s four-astronaut crew broke Apollo 13’s distance record, becoming the humans to travel the farthest from Earth. Now on their way home, the team has experienced tech malfunctions, views like no other and moments of intense emotion, all in under 10 days. To find out about all the highs and lows of the mission, Madeleine Finlay hears from the Guardian’s science editor, Ian Sample. Help support our independent journalism at theguardian.com/sciencepod

The number of human cases of guinea worm, a painful and debilitating tropical illness, fell to a record low of just 10 last year, according to the Carter Centre, the foundation set up by the late former US president Jimmy Carter. But despite years-long declines, it remains almost impossible to completely eradicate the parasite. Only one human illness has been entirely eradicated: smallpox. Why is it so difficult, and could guinea worm one day be the second? Ian Sample hears from co-host Madeleine Finlay, and David Molyneux, emeritus professor of tropical disease microbiology at the Liverpool School of Tropical Medicine. Help support our independent journalism at theguardian.com/sciencepod

Saunas and cold plunge pools are popping up everywhere in the UK, bringing fiery heat and icy cold to a beach, city farm or park near you. Their users will be ready with all the reasons why it’s good for both the mind and the body. But what’s the evidence for the benefits of sauna and cold plunge? Madeleine Finlay hears from Ian Sample and from Dr Heather Massey, associate professor at the University of Portsmouth’s extreme environments laboratory.. Help support our independent journalism at theguardian.com/sciencepod

If all goes to plan, Artemis II, Nasa’s mission to return humans to the moon, will launch this week. The mission will mark the farthest that humans have travelled from Earth, and the first return to the moon in more than 50 years. It will also pave the way for landing on the moon again as soon as 2028. But given the Apollo missions have already achieved that feat, does going back to the moon still matter today? To find out, Madeleine Finlay hears from the Guardian’s science editor, Ian Sample, the Atlantic journalist Ross Andersen, and Jan Wörner, a former director general of the European Space Agency. Help support our independent journalism at theguardian.com/sciencepod

A box the size of a filing cabinet was lifted by crane, slowly moved and placed very carefully in the back of an unassuming lorry earlier this week. What looked like a casual drive around the Cern campus was actually a world-first experiment in transporting antimatter, the most expensive and volatile substance on Earth. To find out why scientists wanted to achieve this milestone, and what happened on the journey, Madeleine Finlay hears from the Guardian’s science editor, Ian Sample, and the Cern physicist Dr Christian Smorra.. Help support our independent journalism at theguardian.com/sciencepod

Why is it like something to be ourselves and how do physical processes create our subjective experience? These questions get to the heart of the knotty problem of consciousness, and they provided the spark for the latest book from award-winning author and journalist Michael Pollan. In A World Appears, Pollan goes in search of answers about what we do and don’t know about consciousness, and why it has proven such an elusive phenomenon. He tells Ian Sample how thoughts and feelings shape our conscious experience, whether we can learn anything about human consciousness from AI, and why he thinks our minds need to be defended in today’s technology saturated world. Help support our independent journalism at theguardian.com/sciencepod

On the evening of 29 December 2011, police officer Clifton Lewis was moonlighting as a security guard at a Chicago minimart when two men walked in. They shot Lewis several times, then took off with his gun and police star. A week later, police had their suspects: four men affiliated with a gang called the Spanish Cobras. For hours, under intense police questioning, they all said they did not do it. But that did not seem to matter. This is episode one of Off Duty, an investigation by the Guardian’s Melissa Segura. Help support our independent journalism at theguardian.com/sciencepod

Over the weekend, news emerged of an outbreak of meningitis among university and school students in Kent in south-east England. The outbreak has killed two young people and left several others seriously ill. Health officials confirmed that the meningitis B strain has been identified in some of the cases. To find out what we know about the outbreak, who is most at risk and why questions are being asked about who has access to the meningitis B vaccine, Madeleine Finlay speaks to Eliza Gil, a clinical lecturer specialising in infectious disease at the London School of Hygiene and Tropical Medicine. Help support our independent journalism at theguardian.com/sciencepod

Grey-market injectable peptides – a category of substances with obscure, alphanumeric names such as BPC-157, GHK-Cu, or TB-500 – have developed a devoted following among biohackers and health optimisers. To understand how these unregulated substances have become mainstream and what they could be doing in our bodies, Madeleine Finlay hears from journalist Adrienne Matei and from Dr Anna Barnard, an associate professor at Imperial College London who researches peptides. 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 explores the link between exercise and brain health. Also on the agenda: the discovery that hedgehogs can hear high-frequency ultrasound and what this could mean for their conservation, and new research examining how biased AI autocomplete tools can influence the beliefs of users.. Help support our independent journalism at theguardian.com/sciencepod

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

More of us are turning to products containing mushroom extracts, with the medicinal fungi market worth billions of pounds. Promises of mental and physical health benefits have seen its popularity spill over from wellness influencers to the shelves of Marks & Spencer – but is there any scientific evidence behind these claims? In this episode from June, Ian Sample chats to Madeleine Finlay about the appeal of mushroom drinks and supplements, and hears from the mycologist Prof Nik Money on what we really know about how fungi can affect our minds and bodies. Help support our independent journalism at theguardian.com/sciencepod

Psychologists have typically believed that we become less curious as we age, but recent research has shown curiosity actually becomes more targeted and specific in our later years. In this episode from September, Madeleine Finlay hears from Dr Mary Whatley, an assistant professor of psychology at Western Carolina University, and Dr Matthias Gruber of Cardiff University’s Brain Research Imaging Centre to find out why we change in this way, and how maintaining broad curiosity into older age can help keep our brains young. Help support our independent journalism at theguardian.com/sciencepod