Nature Podcast

By the end of 2024 up to two billion people will have gone to the polls, in a pivotal year of elections around the globe. This is giving political scientists the chance to dive into each election in detail but also to compare the differing voting systems involved.They hope understanding the advantages and drawbacks of the systems will help highlight whether some are more likely to promote democratic resilience or to stave off corrosive partisanship.This is an audio version of our Feature: Which is the fairest electoral system? Mega-election year sparks debate

00:48 The hidden cities of UzbekistanResearchers have uncovered the scale of two ancient cities buried high in the mountains of Uzbekistan. The cities were thought to be there, but their extent was unknown, so the team used drone-mounted LiDAR equipment to reveal what was hidden beneath the ground. The survey surprised researchers by showing one of the cities was six times bigger than expected. The two cities, called Tashbulak and Tugunbulak, were nestled in the heart of Central Asia’s medieval Silk Road, suggesting that highland areas played an important role in trade of the era.Research Article: Frachetti et al.Video: Uncovering a lost mountain metropolis09:32 Research HighlightsHow children's’ movements resemble water vapour, and why coastal waters may be a lot dirtier than we thought.Research Highlight: Kids in the classroom flow like water vapourResearch Highlight: Sewage lurks in coastal waters — often unnoticed by widely used test12:06 Watermarking AI-generated textA team at Google Deepmind has demonstrated a way to add a digital watermark to AI-generated text that can be detected by computers. As AI-generated content becomes more pervasive, there are fears that it will be impossible to tell it apart from content made by humans. To tackle this, the new method subtly biases the word choices made by a Large Language Model in a statistically detectable pattern. Despite the changes to word choice, a test of 20 million live chat interactions revealed that users did not notice a drop in quality compared to unwatermarked text.Research Article: Dathathri et al.News: DeepMind deploys invisible ‘watermark’ on AI-written text22:38 Briefing ChatWhat one researcher found after repeatedly scanning her own brain to see how it responded to birth-control pills, and how high-altitude tree planting could offer refuge to an imperilled butterfly species.Nature: How does the brain react to birth control? A researcher scanned herself 75 times to find outNature: Mexican forest ‘relocated’ in attempt to save iconic monarch butterfliesSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.

In this episode:00:46 An unusual γ-ray producing microquasarA type of binary-system known as a microquasar has been found to be firing out γ-rays at high energy-levels, which may make it a candidate to be a long-theorized natural particle-accelerator known as a PeVatron. These objects are thought to be a source of galactic cosmic rays, the origins of which are currently a mystery.Understanding how this microquasar works could also help researchers learn more about full-sized quasars — monstrous objects centred around supermassive black holes, which are too distant to study easily.Research Article: Alfaro et al.News and Views: High-altitude particle detector spots a second Galactic microquasar09:27 Research HighlightsThe comb jellies caught fusing their bodies, and an ancient burial site reveals that Classical accounts of Scythian culture appear to be true.Research Highlight: Two comb jellies fuse their bodies and then act as oneResearch Highlight: Evidence of dead people posed on dead horses found in ancient tomb12:08 A ‘smart’ insulin-molecule that could lower hypoglycaemia riskResearchers have developed a modified insulin-molecule that varies its level of activity depending on blood-glucose levels. It’s hoped that this ‘smart’ insulin could one day help those with diabetes regulate their blood sugar more easily.Many people with diabetes rely on regular insulin injections, but because blood-sugar levels can be difficult to predict it can be hard to select the correct dose. This can lead to hypoglycaemia — a life-threateningly low level of glucose. To overcome this, a team created a modified form of insulin with a switch that activates the molecule when glucose levels are high, and deactivates it when levels are low. This insulin-molecule was effective at maintaining correct blood glucose in animal models, and may eventually help lessen diabetes-related complications in humans.Research Article: Hoeg-Jensen et al.News and Views: Smart insulin switches itself off in response to low blood sugar20:33 Briefing ChatAncient DNA confirms that infamous lions hunted humans and a variety of game, and a new technique can sequence a cell’s DNA and pinpoint its proteins, without cracking it open.Nature: Famed lions’ full diet revealed by DNA — and humans were among their preyNature: ‘Phenomenal’ tool sequences DNA and tracks proteins — without cracking cells open

00:55 Graphene TongueResearchers have developed a graphene ‘tongue’ that uses AI to tell the subtle differences between drinks. Graphene has long been sought after as a chemical sensor, but tiny variations between devices have meant that it couldn’t be used very reliably. The team behind the ‘tongue’ got around this problem by training an AI to tell the difference between similar liquids regardless of variations between graphene devices. They hope that their work shows that it’s possible to use ‘imperfect’ chemical sensors to get accurate readings and that the ‘tongue’ will be able to help detect problems with food.Research Article: Pannone et al.09:22 Research HighlightsA 3D-printed optical microscope that can image biological samples with ultrahigh resolution, and how newly-hatched sea turtles dig their way up to the beach.Research Highlight: A ‘Swiss army knife’ microscope that doesn’t break the bankResearch Highlight: Baby sea turtles ‘swim’ up from buried nests to the open air11:32 How migrating salmon move nutrients and contaminants at a continental scaleStudies of migrating Pacific salmon have revealed that these animals transport thousands of tonnes of nutrients and kilograms of contaminants from the ocean to freshwater ecosystems. It’s been known that as the fish return to their freshwater spawning grounds from the sea they bring with them both nutrients and contaminants, but the impact of each has largely been studied separately. A new study combines datasets to estimate that over 40 years, the levels of nutrients these fish carry have increased at a proportionally higher rate than the contaminants, but the toxins could nevertheless be present at concerning levels to the animals that eat them.Research Article: Brandt et al.News and Views: Salmon’s moveable feast of nutrients with a side order of contaminants23:19 Nobel NewsFlora Graham from the Nature Briefing joins us to talk about the winners of this year’s science Nobel Prizes.News: Medicine Nobel awarded for gene-regulating ‘microRNAs’News: Physics Nobel scooped by machine-learning pioneers News: Chemistry Nobel goes to developers of AlphaFold AI that predicts protein structuresSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.

00:46 Physicists spot new types of high-energy radiation in thunderstormsPhysicists have identified new forms of γ-ray radiation created inside thunderclouds, and shown that levels of γ-ray production are much higher on Earth than previously thought.Scientists already knew about two types of γ-ray phenomena in thunderclouds — glows that last as long as a minute and high-intensity flashes that come and go in only a few millionths of a second. Now, researchers have identified that these both occur more frequently than expected, and that previously undetected γ-ray types exist, including flickering flashes that share characteristics of the other two types of radiation.The researchers hope that understanding more about these mysterious phenomena could help explain what initiates lightning, which often follows these γ-ray events.Research Article: Østgaard et al. Research Article: Marisaldi et al. Nature: Mysterious form of high-energy radiation spotted in thunderstorms10:00 Research HighlightsAncient arrowheads reveal that Europe's oldest battle likely featured warriors from far afield, and why the dwarf planet Ceres’s frozen ocean has deep impurities.Research Highlight: Bronze Age clash was Europe’s oldest known interregional battle Research Highlight: A dwarf planet has dirty depths, model suggests12:09 A complete wiring diagram of the fruit fly brainResearchers have published the most complete wiring diagram, or ‘connectome’ of the fruit fly’s brain, which includes nearly 140,000 neurons and 54.5 million connections between nerve cells.The map, made from the brain of a single female fruit fly (Drosophila melanogaster), reveals over 8,400 neuron types in the brain, and has enabled scientists to learn more about the brain and how it controls aspects of fruit fly behaviour.The FlyWire connectome: neuronal wiring diagram of a complete fly brainNature: Largest brain map ever reveals fruit fly's neurons in exquisite detail22:16 Briefing ChatHow researchers created an elusive single-electron bond between carbon atoms, and why bigger chatbots get over-confident when answering questions.Nature: Carbon bond that uses only one electron seen for first time: ‘It will be in the textbooks’Nature: Bigger AI chatbots more inclined to spew nonsense — and people don't always realizeSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.

The world's fastest supercomputer, known as Frontier, is located at the Leadership Computing Facility at Oak Ridge National Laboratory in Tennessee. This machine churns through data at record speed, outpacing 100,000 laptops working simultaneously.With nearly 50,000 processors, Frontier was designed to push the bounds of human knowledge. It's being used to create open-source large language models to compete with commercial AI systems, simulate proteins for drug development, help improve aeroplane engine design, and more.This is an audio version of our Feature: A day in the life of the world’s fastest supercomputer

In this episode:00:46 Unravelling why children with Down’s syndrome are at a higher risk of leukaemiaChildren with Down’s syndrome have a 150-fold increased risk of developing leukaemia than those without the condition. Now, an in-depth investigation has revealed that changes to genome structures in fetal liver stem-cells appear to be playing a key role in this increase.Down’s syndrome is characterised by cells having an extra copy of chromosome 21. The team behind this work saw that in liver stem-cells — one of the main places blood is produced in a growing fetus — this extra copy results in changes in how DNA is packaged in a nucleus, opening up areas that are prone to mutation, including those known to be important in leukaemia development.The researchers hope their work will be an important step in understanding and reducing this risk in children with Down’s syndrome.Research Article: Marderstein et al. News and Views: Childhood leukaemia in Down’s syndrome primed by blood-cell bias11:47 Research HighlightsHow taking pints of beer off the table lowers alcohol consumption, and a small lizard’s ‘scuba gear’ helps it stay submerged.Research Highlight: A small fix to cut beer intake: downsize the pintResearch Highlight: This ‘scuba diving’ lizard has a self-made air supply14:12 Briefing ChatHow tiny crustaceans use ‘smell’ to find their home cave, and how atomic bomb X-rays could deflect an asteroid away from a deadly Earth impact.Science: In the dark ocean, these tiny creatures can smell their way homeNature: Scientists successfully ‘nuke asteroid’ — in a lab mock-upSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.

In this episode:00:45 The biggest black hole jets ever seenAstronomers have spotted a pair of enormous jets emanating from a supermassive black hole with a combined length of 23 million light years — the biggest ever discovered. Jets are formed when matter is ionized and flung out of a black hole, creating enormous and powerful structures in space. Thought to be unstable, physicists had theorized there was a limit to how large these jets could be, but the new discovery far exceeds this, suggesting there may be more of these monstrous jets yet to be discovered.Research Article: Oei et al. 09:44 Research HighlightsThe knitted fabrics designed to protect wearers from mosquito bites, and the role that islands play in fostering language diversity.Research Highlight: Plagued by mosquitoes? Try some bite-blocking fabricsResearch Highlight: Islands are rich with languages spoken nowhere else12:26 A sustainable, one-step method for alloy productionMaking metal alloys is typically a multi-step process that creates huge amounts of emissions. Now, a team demonstrates a way to create these materials in a single step, which they hope could significantly reduce the environmental burdens associated with their production. In a lab demonstration, they use their technique to create an alloy of nickel and iron called invar — a widely-used material that has a high carbon-footprint. The team show evidence that their method can produce invar to a quality that rivals that of conventional manufacturing, and suggest their technique is scalable to create alloys at an industrial scale.Research article: Wei et al.25:29 Briefing ChatHow AI-predicted protein structures have helped chart the evolution of a group of viruses, and the neurons that cause monkeys to ‘choke’ under pressure.Nature News: Where did viruses come from? AlphaFold and other AIs are finding answersNature News: Why do we crumble under pressure? Science has the answerSubscribe to the Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.