AI can't learn new things forever — an algorithm can fix that

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. Hosted on Acast. See acast.com/privacy for more information.

In this episode:00:45 What ancient DNA has revealed about Rapa Nui’s pastAncient DNA analysis has further demonstrated that the people of Rapa Nui did not cause their own population collapse, further refuting a controversial but popular claim. Rapa Nui, also known as Easter island, is famous for its giant Moai statues and the contested idea that the people mismanaged their natural resources leading to ‘ecological suicide’. Genomes sequenced from the remains of 15 ancient islanders showed no evidence of a sudden population crash, substantiating other research challenging the collapse idea.Research Article: Moreno-Mayar et al.News and Views: Rapa Nui’s population history rewritten using ancient DNANews article: Famed Pacific island’s population 'crash' debunked by ancient DNA17:03 Research HighlightsThe extinct bat-eating fish that bit off more than they could chew, and how manatee dung shapes an Amazonian ecosystem.Research Highlight: Ancient fish dined on bats — or died tryingResearch Highlight: The Amazon’s gargantuan gardeners: manatees19:29 A macabre parasite of adult fruit fliesDespite being a hugely-studied model organism, it seems that there’s still more to find out about the fruit fly Drosophila melanogaster, as researchers have discovered a new species of parasitoid wasp that infects the species. Unlike other parasitic wasps, this one lays its eggs in adult flies, with the developing larva devouring its host from the inside. The miniscule wasp was discovered by chance in an infected fruit fly collected in a Mississippi backyard and analysis suggests that despite having never been previously identified, it is widespread across parts of North America.Research article: Moore et al.32:04 Briefing ChatHow a dye that helps to give Doritos their orange hue can turn mouse tissues transparent, and an effective way to engage with climate-science sceptics.Nature News: Transparent mice made with light-absorbing dye reveal organs at workNature News: How to change people’s minds about climate change: what the science says Hosted on Acast. See acast.com/privacy for more information.

The often repeated claim that "80% of the world's biodiversity is found in the territories of Indigenous Peoples" appears widely in policy documents and reports, yet appears to have sprung out of nowhere. According to a group of researchers, including those from Indigenous groups, this baseless statistic could be undermining the conservation efforts of the Indigenous People it's meant to support and prevent further work to really understand how best to conserve biodiversity.Two of the authors joined us to discuss how this statistic gained traction, the harm it could cause, and how better to support the work of Indigenous Peoples.Read more in a Comment article from the authors: No basis for claim that 80% of biodiversity is found in Indigenous territories Hosted on Acast. See acast.com/privacy for more information.

In this episode:00:45 Why a 'nuclear clock' is now within researchers’ reachResearchers have made a big step towards the creation of the long theorized nuclear clock, by getting the most accurate measurement of the frequency of light required to push thorium nuclei into a higher energy state. Such a timekeeper would differ from the best current clocks as their ‘tick’ corresponds to the energy transitions of protons and neutrons, rather than electrons. Nuclear clocks have the potential to be more robust and accurate than current systems, and could offer researchers new insights into fundamental forces present within atomic nuclei.Research Article: Zhang et al.News and Views: Countdown to a nuclear clockNature News: ‘Nuclear clock’ breakthrough paves the way for super-precise timekeepingEditorial: Progress on nuclear clocks shows the benefits of escaping from scientific silos10:10 Research HighlightsThe star that got partially shredded by a supermassive black hole, not just once, but twice, and how heatwaves could mangle bumblebees’ sense of smell.Research Highlight: This unlucky star got mangled by a black hole — twiceResearch Highlight: Bumblebees’ sense of smell can’t take the heat12:11 How engineered immune cells could help limit damage after spinal injuryBy harnessing T cells to fine-tune the inflammation response, researchers have limited the damage caused by spinal injury in mice, an approach they hope might one day translate into a human therapy. Following injury to the central nervous system, immune cells rush to the scene, resulting in a complex array of effects, both good and bad. In this work researchers have identified the specific kind of T cells that amass at the site, and used them to create an immunotherapy that helps the mice recover more quickly from injuries by slowing damage to neurons.Research article: Gao et al.20:36 Briefing ChatHow unprecedented floods in Brazil have helped and hindered paleontologists, and the ‘AI scientist’ that does everything from literature review through to manuscript writing, to an extent.Nature News: The race to save fossils exposed by Brazil’s record-setting floodsNature News: Researchers built an ‘AI Scientist’ — what can it do?Subscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday. Hosted on Acast. See acast.com/privacy for more information.

The 'file-drawer problem', where findings with null or negative results gather dust and are left unpublished, is well known in science. There has been an overriding perception that studies with positive or significant findings are more important, but this bias can have real-world implications, skewing perceptions of drug efficacies, for example.Multiple efforts to get negative results published have been put forward or attempted, with some researchers saying that the incentive structures in academia, and the ‘publish or perish’ culture, need to be overturned in order to end this bias.This is an audio version of our Feature: So you got a null result. Will anyone publish it? Hosted on Acast. See acast.com/privacy for more information.

In this episode:00:31 Chatbots makes racist judgements on the basis of dialectResearch has shown that large language models, including those that power chatbots such as ChatGPT, make racist judgements on the basis of users’ dialect. If asked to describe a person, many AI systems responded with racist stereotypes when presented with text written in African American English — a dialect spoken by millions of people in the United States that is associated with the descendants of enslaved African Americans — compared with text written in Standardized American English. The findings show that such models harbour covert racism, even when they do not display overt racism, and that conventional fixes to try and address biases in these models had no effect on this issue.Research Article: Hoffman et al.News and Views: LLMs produce racist output when prompted in African American EnglishNature News: Chatbot AI makes racist judgements on the basis of dialect07:01 How ancient engineers built a megalithic structureThe 6,000-year-old Dolmen of Menga is a marvel of ancient engineering. New research reveals new insights into the structure and the technical abilities of the Neolithic builders who constructed it. The work shows that a setup of counterweights and ramps may have been used to correctly position the massive sandstone blocks that make up walls of the structure, which were each tilted at precise, millimetre-scale angles. The researchers suggest that this construction shows that the Neolithic people who built the dolmen had a working understanding of physics, geometry, geology and architectural principles.Nature News: Stone Age builders had engineering savvy, finds study of 6000-year-old monument12:28 Spider makes fireflies flash as baitOrb-weaving spiders (Araneus ventricosus) use ensnared male Absocondita terminalis fireflies to trick more insects into their web. A bite from the spider causes the flashing pattern of the trapped firefly to shift to one resembling a female looking to mate, leading others into an ambush. Exactly how this system works is unclear, but researchers say it is a rare example of a predator altering the behaviour of its prey to catch others.Science: Spiders force male fireflies to flash like females—luring more males to their death16:35 The physics of paper cutsBy combining experiments and theoretical work, a team has unraveled the mystery of why only certain types of paper can cut into human skin. Their work shows that paper that is too thin will buckle without cutting, while paper that’s too thick will distribute force over a relatively large area without inflicting damage. The research suggests that the sweet spot for slicing is paper with around 65 micrometres in thickness, which includes the kind used to print certain high-profile journals…Research Highlight: What Science and Nature are good for: causing paper cuts Hosted on Acast. See acast.com/privacy for more information.

For millennia, humanity has obsessed about halting ageing and, ultimately, preventing death. Yet while advances in medicine and public-health have seen human life-expectancy more than double, our maximum lifespan stubbornly remains around 120 years.On the latest episode of Nature hits the books, Nobel laureate Venki Ramakrishnan joins us to discuss what scientists have learnt about the molecular processes underlying ageing, whether they can be prevented, and why the quest for longevity also needs to consider the health-related issues associated with old age.Why We Die: The New Science of Ageing and the Quest for Immortality Venki Ramakrishnan Hodder (2024)Music supplied by Airae/Epidemic Sound/Getty images. Hosted on Acast. See acast.com/privacy for more information.

00:46 Old AIs can’t learn new tricksAn algorithm that reactivates dormant ‘neurons’ in deep learning based AIs could help them overcome their inability to learn new things and make future systems more flexible, research has shown. AIs based on deep learning struggle to learn how to tackle new tasks indefinitely, making them less adaptable to new situations. The reasons for this are unclear, but now a team has identified that ‘resetting’ parts of the neural networks underlying these systems can allow deep learning methods to keep learning continually.Research Article: Dohare et al.News and Views: Switching between tasks can cause AI to lose the ability to learn08:55 Research HighlightsTo stop crocodiles eating poisonous toads researchers have been making them sick, and a sacrificed child in ancient Mexico was the progeny of closely related parents.Research Highlight: How to train your crocodileResearch Highlight: DNA of child sacrificed in ancient city reveals surprising parentage11:20 Briefing ChatHow video games gave people a mental health boost during the pandemic, and where the dinosaur-destroying Chicxulub asteroid formed.Nature News: PlayStation is good for you: video games improved mental health during COVIDNature News: Dinosaur-killing Chicxulub asteroid formed in Solar System’s outer reachesSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday. Hosted on Acast. See acast.com/privacy for more information.

00:48 The mystery of Stonehenge’s Altar StoneStonehenge’s central stone came from Northern Scotland, more than 600 miles away from the monument, according to a new analysis of its geochemistry. It is commonly accepted that many of the rocks that make up the iconic neolithic monument came from Wales, 150 miles from the site. Previously, it had been thought that a central stone, called the Altar Stone, had also come from this area, known as the Preseli Hills. The new work suggests that the ancient Britons went much further, perhaps ferrying the Altar Stone hundreds of miles, to place the rock at the centre of Stonehenge.Research Article: Clarke et al.News: Stonehenge’s massive slabs came from as far as Scotland — 800 kilometres away12:12 Research HighlightsHow a parasite could help scientists break through the blood-brain barrier, and the physics of skateboard moves.Research Highlight: Engineered brain parasite ferries useful proteins into neuronsResearch Highlight: How expert skateboarders use physics on the half-pipe14:13 A new way to break bondsChemists have demonstrated a way to break Selenium-Selenium bonds unevenly, something they have been trying for decades. Chemical bonds have to be broken and reformed to create new compounds, but they often don’t break in a way that allows chemists to form new bonds in the ways they would like. Breaks are often ‘even’, with electrons shared equally between atoms. To prevent such an even split, a team used a specific solvent and a combination of light and heat to force the selenium bonds to break unevenly. This could potentially open up ways to create compounds that have never been made before.Research Article: Tiefel et al.News and Views: Innovative way to break chemical bonds broadens horizons for making moleculesSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday. Hosted on Acast. See acast.com/privacy for more information.

AIs built on Large Language Models have wowed by producing particularly fluent text. However, their ability to do this is limited in many languages. As the data and resources used to train a model in a specific language drops, so does the performance of the model, meaning that for some languages the AIs are effectively useless.Researchers are aware of this problem and are trying to find solutions, but the challenge extends far beyond just the technical, with moral and social questions to be answered. This podcast explores how Large Language Models could be improved in more languages and the issues that could be caused if they are not.Watch our related video of people trying out ChatGPT in different languages. Hosted on Acast. See acast.com/privacy for more information.