Tabla de contenidos para 25 October 2025 en New Scientist

Tackling climate change is an inherently collectivist endeavour. We only have one planet, with one atmosphere, and whenever anyone in the world emits greenhouse gases, we all feel the effects. But some people have an outsized influence. Globally, the wealthiest 1 per cent are responsible for one-fifth of all emissions since 1990. If the richest people and nations voluntarily cut their carbon footprint, the entire world would benefit. Of course, anyone with a passing grasp of reality knows this isn’t going to happen. But what if the wealthiest instead try to fix their carbon imbalance by funding geoengineering efforts that aim to cool the planet back down? Here, the promise of global benefit is less certain. As we report in our exclusive survey of climate scientists (see page 6), the…

MODERN humans may indeed have wiped out Neanderthals – but not through war or murder alone. A new study suggests that when the two species interbred, a slow-acting genetic incompatibility increased the risk of pregnancy failure in hybrid mothers. A similar mismatch between mothers and fetuses may also help explain a subset of pregnancies that fail today. We know from genetic studies that there was sustained interbreeding between Homo sapiens and Neanderthals between approximately 50,000 and 45,000 years ago. Neanderthals went extinct around 41,000 years ago, but some of their DNA has persisted in modern humans with non-African ancestry, making up around 1 to 2 per cent of the genome. But mysteriously, none of the mitochondrial DNA in modern humans is derived from Neanderthals. This form of DNA is carried…

Book The Climate Diplomat Peter Betts Profile Editions CLIMATE negotiators, lobbyists and world leaders will descend on the Brazilian rainforest city of Belém next month for this year’s UN climate summit, COP30. For anyone who has been to a COP summit, or tried to follow one from afar, the meetings can feel completely bewildering. Dozens of parallel negotiating tracks take place at the same time, replete with cryptic agendas and buzzword-y labels, ranging from “dialogues” and “consultations” to “informal informal” discussions. To an observer, it can feel like a vast talking shop, wrapped up in its own conventions and with little relevance to the outside world. Thankfully, we have the wisdom of Peter Betts, a legendary figure in COP circles, to set us straight. Outsiders are unlikely to have heard…

Film The White House Effect Directed by Bonni Cohen, Pedro Kos and Jon Shenk Streaming on Netflix from 31 October THE opening sequence of The White House Effect, a harrowing new climate documentary, transports you to the great drought of 1988. Picture the scene: a sweltering summer across North America brings the worst drought to the US since the Dust Bowl of the 1930s. There is no respite. The heat is inescapable. These extreme conditions set the agenda for that year’s presidential race between Democrat Michael Dukakis and Republican George H. W. Bush. The latter would win in a landslide with a platform promising greater environmental protections. “Some say these problems are too big,” Bush said on the campaign trail in Michigan, in reference to climate change. “My response is…

THINK of pollution and your mind’s eye might conjure up images of smoke spewing chimneys, car exhausts and those sewer outflows you see on beaches. What probably doesn’t spring to mind is the mesosphere, a slice of sky far above the height any aeroplane flies. And yet a growing chorus of scientists are sounding the alarm that this could be the site of a worrying new form of pollution. There are currently more than 15,000 satellites zooming around our planet, and almost all are destined to be de-orbited, a euphemistic way of saying they will burn up in the atmosphere. In doing so, they will release clouds of metals, soot and reactive chemicals that could have worrying effects, including damaging our protective ozone layer. “It is like a mini geoengineering…

GROWING up, I avoided team sports at all costs. Eye-hand coordination just isn’t my strong suit. Plus, I have a pernicious competitive streak. Pair the two together and sport became a source of frustration rather than fun. But recent studies are making me rethink that attitude. It turns out that group exercise, especially team sports, may be better for our health than working out alone. A 2023 analysis found that participating in sport, either recreationally or competitively, is linked with lower stress, less anxiety and better mental health, such as higher self-esteem. And these effects were especially pronounced in team sports. In fact, such sports seem to improve mental well-being more than other forms of exercise, regardless of the amount of physical activity. The social aspect may also enhance sport’s…

HUMANITY will attempt large-scale efforts to block radiation from the sun before the end of the century, according to leading climate scientists surveyed by New Scientist, in a last-ditch bid to shield Earth’s inhabitants from the worsening impacts of climate change. “The concept of solar geoengineering worries me greatly, but I can see it is becoming more attractive as the world fails to address the problem of reducing greenhouse gas emissions,” says survey respondent James Renwick at the Victoria University of Wellington in New Zealand. Two-thirds of respondents predict we will see risky interventions to tweak the atmosphere before 2100. Worryingly, 52 per cent say this will probably be driven by a “rogue actor” – such as a private company, billionaire or nation state – highlighting widespread concern that the…

STRANGE behaviour at the centre of our galaxy may be down to dark matter. In 2009, observations from the Fermi Gamma-ray Space Telescope revealed a surprisingly high concentration of gamma rays coming from the middle of the Milky Way, a phenomenon that has been dubbed the galactic centre gamma-ray excess (GCE). Now, simulations hint those gamma rays could come from the annihilation of dark matter particles. The debate over what could cause the GCE has been raging since it was first spotted, with two main explanations emerging over the years. The first is it could come from an as-yet-unseen population of pulsars, which are rapidly rotating neutron stars that blast out beams of powerful radiation. The second explanation is it could come from weakly interacting massive particles (WIMPs), which have…

USING low-calorie sweeteners in place of sugar seems to give beneficial gut microbes a boost and help people maintain weight loss. The finding, from one of the longest trials of sweeteners to date, indicates these products may not be as harmful as we thought. Research has found low-calorie sweeteners may stoke hunger, increase blood sugar or raise the risk of heart attacks and strokes. But long-term studies of sweeteners, especially in the context of a healthy diet, have been lacking. So Ellen Blaak at Maastricht University in the Netherlands tracked their effects in people who used them as a sugar substitute. She and her colleagues recruited 341 adults in Europe who were overweight or had obesity and placed them on a low-calorie diet for two months, leading to an average…

IN THE 2020s, the US was spending an eye-watering $182 billion a year on locking up its citizens. No other country imprisoned as many people or spent as much in doing so. And the US wasn’t alone: prisons in many countries around the world were overcrowded, inhumane and expensive. So why not just get rid of them? This became possible when technology was developed so that people could be monitored and detained at home – and when society caught up to the benefits. The HomeGuard scheme, which replaced traditional prisons, comprised three elements. The first was an ankle bracelet that monitored the prisoner’s precise location. The second was a harness containing sensors that recorded what the person was doing and saying. If the terms of the sentence were broken –…

Book The Immortalists Aleks Krotoski Bodley Head, UK, out now; US, April 2026 IN ALL my years covering ageing research, I have paid little attention to the fringes, at which people (mostly rich white men) strive to cheat death, or at least add decades to life. Thankfully, journalist and social scientist Aleks Krotoski has, and her portrayal of “the immortalists”, as she calls them, is eye-opening, entertaining and disturbing. The quest for eternal life is as old as humans, of course, but recently it has taken on a new, sinister twist. In the driving seat are Silicon Valley “tech bros”, who see ageing and death as just another problem to solve. They have what Krotoski calls “engineer’s syndrome” – a hubristic belief that any complex problem can be cracked using…

Editor’s pick Going down a black (rabbit) hole 4 October, p 28 From Rachael Padman, Cambridge, UK In his article “What’s inside a black hole?”, Stuart Clark is troubled at the thought of conceding that “the universe is not entirely ruled by physics”. As a physicist, I am content to think that the universe is always ruled by physics, and in fact that is a tautologous statement. But I am happy – in fact quite excited – by the thought that we don’t yet know some of that physics. How desperately sad it would be if the only thing left to do was to apply our existing theories to yet more systems. The universe doesn’t need our theories or our permission to do what it does. I sometimes wonder whether…

1. Stratospheric aerosol injection This would involve releasing tiny particles of liquid called aerosols from planes high in the atmosphere, where they would reflect away sunlight. More than 60 per cent of survey respondents said this is the most likely method to be deployed. 2. Cirrus cloud thinning Aerosols such as nitric acid could thin cirrus clouds, resulting in them allowing more heat to escape back into space. However, injecting too much aerosol could thicken the clouds and have the opposite effect. Only a small fraction of survey respondents thought this or land-based approaches to increasing Earth’s albedo would be attempted. 3. Marine cloud brightening Tiny droplets of seawater are sprayed into clouds, brightening them and increasing the sunlight they reflect. This was tested in a small field trial in…

HIGH in the Argentinian Andes, a team of palaeontologists has found a small dinosaur fossil with the first hints of the extended neck that distinguishes sauropod dinosaurs like Diplodocus. Named Huayracursor jaguensis, the fossil is a partial skeleton from a dinosaur that lived in the Triassic Period, around 230 million years ago. It was around 2 metres long and weighed about 18 kilograms. Later, sauropods such as Brontosaurus and Patagotitan would become some of the largest and longest-necked animals ever to have lived, reaching lengths of over 35 metres and weights of more than 70 tonnes. Until recently, it was thought that sauropodomorphs, the precursors of these long-necked herbivorous dinosaurs, were small, short-necked and possibly omnivorous. Other sauropodomorphs living at the same time as H. jaguensis were much smaller, around a…

FOR the first time, astronomers are seeing a ring system form in real time. The rings in question encircle Chiron, a comet-like object that takes a path around the sun between the orbits of Saturn and Uranus. Chiron isn’t the first small object we have observed rings around: the asteroid Chariklo and dwarf planets Haumea and Quaoar also have small ring systems. All of these rings were spotted through a method called stellar occultation, which involves waiting for the object to pass in front of a distant star and then creating a map of how the star’s light is blocked by orbiting material. “There are only maybe 20 objects that have been observed through stellar occultations, so observing four of them with rings is high statistics,” says Bruno Sicardy at the…

THERE was a jam-packed programme of talks and exhibits on offer at this year’s New Scientist Live at Excel London, which took place from 18 to 20 October and attracted thousands of visitors of all ages. With topics including the search for dark matter, how gaming has transformed technology, how animals treat themselves with medicine and the future of human reproduction, there was a huge range to explore. Highlights included broadcaster and campaigner Chris Packham revealing the six species that have meant the most to his career, and GP Zoe Williams’s talk about the hormonal fluctuations that take place over the course of a menstrual cycle, and how understanding these can empower girls and women. After the talks, many people took the chance to meet with the speakers, from TikTok…

Obomate Briggs Video producer London As a lover of fashion, I was intrigued to visit Material World, the first festival at London’s Royal Botanic Gardens, Kew, devoted to fashion and textiles. Staged in the Temperate House until 2 November, the exhibition sees artists, designers and scientists explore plants, textiles and sustainability. One standout is Nnenna Okore’s Between Earth and Sky. Hanging 20 metres above the ground, this large-scale sculptural work turns simple materials into intricate, immersive forms, while the use of biodegradable materials, responsibly sourced fibres and natural dyes encourages us to ponder our own responsibilities. The focus on organic materials continues in the Growing the Next Era of Fashion section, with clothes made from plants and fungi. I especially loved a dress knitted from pineapple fibre and nettle leaves…

I PLACED the cold, jade rolling pin under my cheekbone and gently glided it to the edge of my face. To be honest, I felt a bit like a piece of pastry. But my grandma assured me that I was engaging in a serious traditional Chinese practice that would make my skin glow and my face less puffy. It would be more than a decade before face rolling became the next big beauty fad on social media – and several years more before I realised its supposed benefits may hinge on the lymphatic system, a network spanning the entire body, consisting largely of thread-like vessels and bean-shaped nodes. Despite having been described in the first known medical scientific paper, the lymphatic system remained a mystery for millennia afterwards. Being extremely…

1 Materialisms Consciousness is entirely physical, solely the product of biological brains and all mental states can be wholly explained by physical states – which are fundamental fields and particles deep down. 2 Non-reductive physicalism Consciousness is entirely physical, solely the product of biological brains, but mental states or properties can’t be reduced to physical states or entirely explained by physical laws. 3 Quantum and dimensional Fundamental physics – especially quantum mechanics – plays a necessary role in the generation of consciousness, beyond the widely accepted role of quantum mechanics in all physical entities. 4 Information Information is the basic “stuff” of reality and is more fundamental than matter, energy and space-time. Consciousness arises from or is identical to informational structures or processes. 5 Panpsychisms The essence of consciousness or proto-consciousness is a primitive,…

Speaking our truth The experienced science journalist soon learns to skim over certain sections of scientific papers: specifically, the sentences stating that the research represents “a significant advance” and “expands our understanding”. Not because they’re incorrect, but because literally any study that achieves anything at all can make these claims, and academics are incentivised (as we all are) to amplify the impact of their work. Except for the times when they don’t bother. Via a long sequence of events that started with reporter Matthew Sparkes and went via the social network Bluesky, Feedback discovered a paper on the arXiv preprint server from 2018 that should win a prize for its absolute refusal to make any big claims. In it, researchers Joseph Redmon and Ali Farhadi described their latest iteration of…