Episode 343

The task of growing human brains in a lab has taken a step forward. Scientists have been creating brain organoids since 2013, but have now grown blood vessels in them for the first time. These mini brains resemble the developing cortex - the area of the brain that thinks, feels and stores memories. These advancements will help us learn more about the brain and conditions like dementia. But what if we go too far and they become conscious?

Geoengineering is being talked about more and more as countries fail to hit emissions targets. Without reductions we are on course to hit 4.5°C of warming by 2100, so new solutions are needed. But will artificially cooling the climate really help, or do even more damage? One popular method is solar radiation management - but that would require at least 100 aircraft working for hundreds of years. And new research shows that while it could work, the moment we stop doing temperatures would rebound rapidly. So is it worth even trying?

An incredible trove of ancient fossils have been discovered in a quarry in China, dating from 512 million years ago, just after Earth’s first mass extinction event. More than 8000 fossils have been analysed and nearly 60 per cent of the species are new to science. This group of arthropods, molluscs and brachiopods contain some very weird and wonderful creatures - including one which looks remarkably like a penis with long branching tentacles growing out of the end.

Hosted by Rowan Hooper and Penny Sarchet, with guests Carissa Wong, Alec Luhn and Sam Wong.

To read more about these stories, visit https://www.newscientist.com/

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Episode 342

Social media began with the best intentions - but it soon went sour. Platforms that once fostered connection are now driven by an endless desire to monopolise our time. From the endless scroll to ragebait content, social media is no longer designed to connect us with friends and family - but to profit from our attention. And that’s not to mention the damaging political influence it can have. As countries and governments move to act against it, is there a good solution to these problems?

Bitcoin is one big disaster for the environment. Mining bitcoin requires an inordinate amount of energy - and that cost only increases as more bitcoin is mined. It’s also a terrible investment these days, with some experts suggesting you’d be better off buying a load of Pokémon cards. Adding to that its role in fuelling crime on the dark web - and it becomes a strong contender for worst idea of the 21st century.

Carbon off-sets - another well intentioned solution to the climate crisis that’s gone horribly wrong. The idea is you can lessen the environmental impact of your actions, by off-setting the damage. Maybe you take a long-haul flight, but you plant a tree in return. The trouble is, not only does this give people permission to keep polluting the environment, it’s not even clear if offsetting actually works. But perhaps it’s not all bad?

Effective altruism is a surprising addition to the list, given that it’s meant to be a way of ensuring money goes to only the best causes. But judging which charities deserve donations above others is much more difficult than it seems. And part of the effective altruism movement suggests people should earn as much money as possible so they can one day give it away - which can obviously end badly. And then there are those who have taken it too far - ruining their life.

One seemingly good fix for environmental damage is the promise of alternative fuels, like natural gases, hydrogen and biofuels. But it turns out they probably do a lot more damage than good. Biofuels in particular require massive amounts of farmland to produce, which alone is highly polluting. Add to that the fact they’re driving up prices at the supermarket - perhaps there’s a better way to stop the climate from warming?

Hosted by Rowan Hooper and Abby Beall, with guests Matt Sparkes, Leah Crane, Michael Le Page and Joshua Howgego.
To read more about these stories, visit https://www.newscientist.com/

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Episode 341

"The best minds of my generation are thinking about how to make people click ads. That sucks." A compelling quote that sums up the thesis of Rutger Bregman’s new book. In Moral Ambition, the Dutch historian and the best-selling author argues that smart people need to stop wasting their lives in “BS” jobs - and turn their skills to causes that benefit humanity. By reflecting on the history of the abolitionist and women’s rights movements, he explains why it’s never too late to take action on major issues - like climate change or the exploitation of animals. He also explores how AI experts are preparing for a massive shift in the way we live, that we need to pay attention to.

Same-sex sexual behaviour in primates is incredibly common - despite seemingly having no evolutionary advantage. But scientists have now noticed something counterintuitive. This behaviour happens more often in high-stress environments, where food is scarce, suggesting it may aid with social cohesion. It may even improve the success of straight sex - increasing the number of offspring in a group.

If you want to live a longer, healthier life - it may be way easier than you think. Most modern longevity advice is about optimising every aspect of your life - and can feel overwhelming for many people. But a new study shows you can add a full year to your life, just by making very minor tweaks to things like sleep and exercise. Find out how.

For three years in a row, average global temperatures have exceeded 1.5 degrees Celsius above preindustrial temperatures. As we fail to get a handle on rising global heating, scientists are exploring a new - slightly odd - way of managing carbon levels. The idea is to protect Earth’s climate from future wildfires, but cutting down vast swathes of forest and sinking the trees in the Arctic ocean. But will it work - or make things worse?

Hosted by Rowan Hooper with guests Rutger Bregman, Michael Le Page, Carissa Wong and Alec Luhn.

To read more about these stories, visit https://www.newscientist.com/

Learn about New Scientist CoLab and ViiV Healthcare’s roundtable discussion here: [email protected]

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Episode 340

Acquiring Greenland has been deemed a national security priority by America. President Trump wants to use the country to deter adversaries in the Arctic, have control over its rare minerals and oil - and maybe even build experimental cities. But with the challenges of a changing climate, difficulty actually extracting any natural resources and the fact that Greenland isn’t free to occupy, how realistic are Trump's goals? 

Human-plant hybrid cells are being used to answer the mystery of “dark DNA”. Also known as “junk DNA”, this refers to the fact that much of the human genome seems to be inactive. And this new experiment may have proven this claim, showing that only about 10 per cent of our DNA is useful…the rest is just rubbish. What does that mean for the story of evolution, or the future of genetic modification? The team explores two major ways to interpret the results.

And two diet-related stories this week. First, that fibre seems to have a beneficial effect on sleep quality, according to a large observational study review. And second, how people who stop taking GLP-1 weight-loss drugs, like Ozempic and Wegovy, tend to regain the weight they lost within less than two years.

Hosted by Rowan Hooper and Penny Sarchet, with guests Michael Le Page, Alexandra Thompson, Anna Merril, Ruth Mottram and Martin Stendel.
To read more about these stories, visit https://www.newscientist.com/

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Episode 339

Humans are finally going back to the moon. NASA’s Artemis II mission is set to launch in April, taking four astronauts in a loop around the moon. If it goes well, it’ll set the stage for a lunar landing by Artemis III - bringing us closer to creating permanent settlements on the surface. And that’s not all - SpaceX is planning to visit Mars this year as part of its plans to colonise the Red Planet. Plus, in May we might see the launch of a new American space station. Will these missions mark 2026 as the year that kick-started our spread off planet?

GLP-1 weight loss drugs are set to get cheaper this year. The patent on semaglutide - the active ingredient in drugs like Ozempic - is about to run out, meaning more people will be able to access these hugely impactful medications. A pill version is also on the horizon, plus one upcoming drug that can cut body weight by a whopping 24 per cent.

The first phase 3 trials of LSD are taking place this year. 55 years after being banned, the psychedelic drug is being tested once again for its ability to reduce anxiety and treat mental health conditions. Research suggests LSD can rewire your brain and relieve moderate to severe anxiety for at least three months. But will the trials prove its benefits outweigh any side effects?

A carbon border tariff is being imposed by the EU - taxing imports of materials like steel from countries that aren’t doing enough to keep their emissions down. The policy is a positive step for climate action and will help to make EU industries more competitive. And it looks like countries around the world are soon to follow suit.

Hosted by Rowan Hooper and Penny Sarchet, with guests Jacob Aron, Michael Le Page and Alexandra Thompson.

To read more about these stories, visit https://www.newscientist.com/

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Episode 336

Looking for something great to read or watch on TV over the festive period? We’ve got you covered. In a special edition of the podcast, we share our favourite books, TV and films of 2025 - for those moments when you need a break from the festivities.

From pure science fiction to books exploring climate change and the history of our early ancestors, we have something for everyone. Below is a list of our top picks.

Films and TV

Ocean with David Attenborough

Andor Season 2

The White House Effect

Human with Ella al-Shamahi

Pluribus

My Husband the Cyborg

Severance Season 2

Books

Every Version of You by Grace Chan

The Story of CO2 is the Story of Everything by Peter Brannen

Clearing the Air by Hannah Ritchie

Positive Tipping Points by Tim Lenton

The Last Neanderthal by Ludovic Slimak

Hello Cruel World by Melinda Moyer

Hosted by Rowan Hooper with guests Bethan Ackerley and Alison Flood.

Sign up to our book club for more recommendations, discussion and author interviews https://www.newscientist.com/bookclub/ 

To read more about these stories, visit https://www.newscientist.com/

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Episode 337

As we reach the end of the year, catch up on some of New Scientist’s most exciting and thought-provoking features of the past twelve months. 

For decades we’ve got autism in girls all wrong. Symptoms present quite differently in girls to boys, meaning they often go undiagnosed. So why have we failed to see the differences - and why are girls so often neglected by autism research? We review a feature written by Gina Rippon - one of the scientists studying autism who admits to getting it wrong for years.

If you’re interested in living a longer life, you may have heard the name Bryan Johnson. He’s the tech millionaire who’s doing everything in his power to live as long as possible. From a 6.5 hour morning routine, to experimental gene treatments and hypoxia therapy - we dig into the life of the man whose slogan is “Don’t Die”.

There is no space, no time, no particles. This is the radical new quantum vision of reality proposed by physicist Vlatko Vedral. He argues that our current lens for looking at reality is full of problems, especially concerning observers - this idea that reality is somehow contingent on us looking at it. So what really lies beyond quantum theory?

Over tens of thousands of years, waves of Homo sapiens set out across Europe and Asia, only for their societies and cultures to mysteriously vanish. At last, ancient DNA from fossils is revealing why. We shed light on the lives of the LRJ people, a group of a few hundred ancient humans who roamed across Europe 43,000 years ago.

There are new hints that the fabric of space-time may be made of "memory cells" that record the whole history of the universe. If true, it could explain the nature of dark matter and much more. But how could pure emptiness ever remember, or store information? We discuss how Florian Neukart, the feature writer, has tested this theory inside a quantum computer.

Most of us see body fat as something we need to attack or get rid of. But we’re beginning to figure out just how important fat is for shaping our health and mind. The fat in our bodies is a communicative organ with a role in everything from bone health to mood. And it isn’t just one thing - it comes in various forms and colours, each with distinct functions and found in different locations. So do we need to respect fat a bit more?

A whole library’s worth of papyri owned by Julius Caesar’s father-in-law were turned to charcoal by the eruption of Vesuvius. But nearly 2000 years later, we can at last read these lost treasures. Discover how a particle accelerator is being used to decode messages once thought completely lost.

Our emotions can often get the better of us, taking control over our feelings and actions. But what if there were a way to harness your emotions for a happier, calmer life? Researcher Ethan Kross has found ways to do just that. Based on his own experience of his Grandmother’s resilience, who endured the trauma of Nazi occupation, he’s developed an actionable guide for anyone to master how they feel.

Hosted by Penny Sarchet, with guests Cat de Lange, Joshua Howgego and Claudia Canavan.

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Episode 336

In an unlikely turn of events, orcas and dolphins have been observed teaming up - to hunt and kill massive chinook salmon in the pacific. Given that orcas sometimes prey on dolphins, what’s going on? Despite the promising signs of cooperation between these two species, there may be something less heartwarming at play. We dig into the findings and discuss other surprising ways animals cooperate with each other.

From schizophrenia to bipolar disease, autism to OCD, many mental conditions are classified into different categories. But in the largest study of its kind, it’s been discovered that 14 different disorders fall into just five genetic groups. The finding could explain why people are often diagnosed with multiple psychiatric conditions at once - and bring comfort to those who are. Could it also help us find better treatments?

Exploding stars might be to thank for our very existence. It’s thought that supernovae may spew out the heavy elements required for the creation of planets and the emergence of life. A new model shows this is possible - and may help us figure out where to look next for alien life. Could this open up a new field of cosmic ecology? Plus, news of a strange new kind of star from the James Webb Telescope. Black hole stars may explain a running mystery about odd galaxies spotted by the telescope, called little red dots. 

Hosted by Rowan Hooper and Penny Sarchet, with guests Alec Luhn, Michael Le Page and Alex Wilkins.

To read more about these stories, visit https://www.newscientist.com/

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Episode 335

Exercise has been shown to shrink tumours by 60 per cent. A new study shows another link between regular exercise and cancer prevention, this time revealing that muscle cells may outcompete cancer cells for energy - basically starving them. We explore the links between metabolism and glucose - with the caveat that so far this has only been demonstrated in mice, in a small study.

The interstellar object 3I/ATLAS may be even weirder than we thought. Ever since we spotted this comet from another star system, scientists have been studying every inch of it. And no - it’s not an alien spacecraft. But it does seem to be home to surprising amounts of chemicals like carbon dioxide and methanol - essential ingredients for life. Could this shed light on the origin of life in the universe?

A 100-year-old debate between two titans of physics has finally been settled. In the 1920s, Albert Einstein and Niels Bohr butted heads about the nature of light. Einstein said light is a particle. Bohr said it’s both a particle and a wave. They came up with an experiment to settle the argument - the trouble is, they had no way to run it. Now, 100 years later, we finally have the technology to perform the test - and the winner is…

Hosted by Rowan Hooper and Penny Sarchet, with guests Alexandra Thompson, Alex Wilkins and Jacob Aron.

To read more about these stories, visit https://www.newscientist.com/

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Episode 334

Which sperm is the oldest sperm - the ancestor sperm that came before all others? Well, you might think it links back to an ancient animal that came before us, but the oldest sperm may actually predate animals altogether. We explore this plus the enduring mystery of the scrotum - and why a male’s most important body part is so delicate and…exposed. The team hears about the variation in scrotum morphology across mammals, and the evolution of “non-scrotality”.

Our brains undergo four major turning points throughout our lives. New research suggests the way our brains are wired shifts at key stages as we get older - and your adolescent years may last longer than you realised. We explore what is happening at each brain stage, how long they last and why this research could prove useful in figuring out conditions like depression or dementia.

Politicians, scientists, celebrities and climate activists gathered at the National Emergency Briefing in London this week and the message was clear: environmental breakdown is escalating faster than expected. One report highlighted that the biggest health risk of the 21st century is climate change, and other scientists described scenarios of starvation, wars and ungovernable societies. But there were messages of empowerment and hope too. Hear from some of the scientists - and a British army general - at the event.

Hosted by Rowan Hooper and Penny Sarchet, with guests Sam Wong, Carissa Wong, Michael Le Page, Lt General Richard Nugee, Paul Behrens and Kevin Anderson.

To read more about these stories, visit https://www.newscientist.com/

Sign the National Emergency Briefing open letter here: https://www.nebriefing.org/open-letter-keir

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Episode 333

It’s not often you get to see or hear someone playing music on a conch shell. So prepare yourself for a musical treat with musician and podcaster Steve Pretty, who brings into the studio a trumpet and a collection of his favourite conches, rigged up to some modern electronics.

Steve is best known as the bandleader of the Hackney Colliery Band, and also hosts the Steve Pretty On the Origin of the Pieces podcast.

Performing live on the show and recreating the acoustics of prehistoric cave gatherings (a rave in a cave!) Steve explains the science behind how conches and brass instruments can achieve so many different notes by manipulating air pressure and flow. He explores the evolution and origin of music - which may have evolved before language. And he explains the evocative nature of music, the different functions that it has in society and how it allows us to tap into different emotional states. 

Hosted by Rowan Hooper and Penny Sarchet.

To read more about these stories, visit https://www.newscientist.com/

Learn about Steve’s conch playing here: https://www.shellectronica.com/ 

And find his podcast here: https://www.originofthepieces.com/

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