I was sitting in a conference in August, drifting as I so often do between listening to what was on stage and pretending to be doing important work on my laptop (by which I mean sending memes on WhatsApp).

All of a sudden, from the stage, the renowned biologist came out with a sentence that made every single person in the room sit up and pay attention: 鈥淥f course,鈥� she said, 鈥渨e now know that 础濒锄丑别颈尘别谤鈥檚 starts in the nose.鈥�

I鈥檓 sorry, what? Starts in the nose? I didn鈥檛 know 础濒锄丑别颈尘别谤鈥檚 starts in the nose.

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My own lovely dad died from 础濒锄丑别颈尘别谤鈥檚 last year, and ever since his diagnosis, I鈥檝e done an incredible amount of digging into the disease, trying to understand what was happening to him. I was astonished I鈥檇 never come across this idea.

And perhaps you haven鈥檛 either. Which is why I want to share my astonishment at discovering that Aviv Regev was right 鈥� not only is 础濒锄丑别颈尘别谤鈥檚 closely associated with our sense of smell, but there is a growing body of research suggesting that our noses might have something to do with why the disease develops in the first place.

The first bit you might already know: people with 础濒锄丑别颈尘别谤鈥檚 tend to lose their sense of smell, sometimes years before any symptoms of memory loss start to show up. But it turns out that our ability to smell is a surprisingly good indicator of our overall health (looking at you, covid-19). One study from 2014 found that of whether they would be dead within five years than a cancer diagnosis.

It鈥檚 not that losing your sense of smell itself will kill you. More that the olfactory nerves are deeply intertwined with some of the most important memory structures in the brain, so when they start to deteriorate, it can be an early warning that something much more serious is going on.

And this connection seems to work in both directions. One intriguing study (admittedly with quite a small sample size) , thus exposing them to all kinds of wonderful scents while they slept. After six months, the people who had the olfactory enrichment performed better on memory tests than those in a control group.

All very interesting. But not what Regev had been suggesting. Her words seemed to imply that noses are actually responsible for the trouble in the first place.

It turns out that the reason scientists are even entertaining this possibility is because of how fiercely our brains are protected from the outside world. Our skulls are like an actual fortress: even our blood isn鈥檛 allowed in without passing a particularly fussy bouncer called the blood-brain barrier.

Can we harness the brain鈥檚 deep-cleaning system to prevent 础濒锄丑别颈尘别谤鈥檚?

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One of the only real exceptions is a little bit of bone right at the top of your nose that is riddled with holes. It鈥檚 called the cribriform, and it鈥檚 where the olfactory fibres dangle down into your nose to give you your sense of smell 鈥� a bit like if you pushed some Play-Doh through a sieve.

And that means that, despite all the elaborate defences protecting your brain, there is a potential route in, sitting right in the middle of your face.

So, here鈥檚 the idea. Maybe the beta-amyloid plaques, the sticky little protein fragments that appear to play such a key role in the cascade of 础濒锄丑别颈尘别谤鈥檚 in the brain, are what鈥檚 left over after the brain has fought an infection. And maybe the nose is how the infection arrives.

To see if this held any water, in 2022, a group of scientists of some mice.

(I should add, for the sake of the mice鈥檚 reputation, that it was actually Chlamydia pneumoniae, a cousin of the bacterium that causes the STI. But I hope you鈥檒l forgive me the less scientifically accurate version. In a long career, you get very few chances to write sentences that good, and I wasn鈥檛 about to waste mine.)

The remarkable thing, though, was that within 72 hours, the bacteria had travelled up the nerves in the nasal cavity and got through to the brain. What鈥檚 more, the infection triggered the accumulation of beta-amyloid. Now that鈥檚 not definitive proof of how 础濒锄丑别颈尘别谤鈥檚 starts in humans. But there is some other, rather unsettling evidence that infections aren鈥檛 the only unwelcome visitors that manage to get in that way.

A group in Mexico . Inside the dogs鈥� brains, they found microscopic particles of metals 鈥� that seem to have entered through the nose 鈥� wrapped in pockets of inflammation and that same beta-amyloid protein. You don鈥檛 see the same thing in dogs that lived in cleaner, more rural environments.

Now these studies have been extended to who died from gun violence or car accidents 鈥� and they find something similar. Tiny, metal鈥搑ich particles, thought to originate from exhausts and brake dust, turned up in their brain tissue, alongside inflammation and accumulations of beta-amyloid. The very sorts of changes associated with 础濒锄丑别颈尘别谤鈥檚, appearing in brains that were sometimes only a few years old. Put together, it implies that the disease might have an environmental cause, one that begins much much earlier than we thought.

础濒锄丑别颈尘别谤鈥檚, stroke, depression: The preventative power of sauna

Sustained heat stress is bad for our health and can be deadly. But we鈥檙e discovering that heat therapies like sauna, when used in the right way, have surprisingly wide-reaching benefits for health

So, where does 础濒锄丑别颈尘别谤鈥檚 start? The answer is no one nose (pun very much intended). There is still a great deal we don鈥檛 understand, but the implications from all this research are rather extraordinary. What if the beta-amyloid plaques we鈥檝e spent so long trying to get rid of are, at least sometimes, the aftermath of the brain trying to protect itself? And what if, rather than focusing entirely on clearing up the damage, we could work out what set it off in the first place?

But more than anything, I can鈥檛 help but laugh as I think about all this in the context of my dad, who had many wonderful qualities, but a discreet nose wasn鈥檛 one of them. We used to say that his nose would enter a room 15 minutes before he did. He would have found it very funny indeed if it turned out to have been the cause of his downfall.

Hannah Fry: How OpenAI has caused an existential crisis in mathematics

OpenAI has been throwing everything at solving long-standing maths problems. This should have been a glorious moment for mathematicians 鈥� but instead we're having a massive collective wobble, says New Scientist's new columnist, Professor Hannah Fry

A few years ago, when I first started talking about mathematics in public, a professor of algebraic number theory pulled me to one side and gave me some sharp words of warning: 鈥淭he world fears mathematicians, Hannah. Let鈥檚 keep it that way.鈥�

He was being, to put it mildly, a bit of a snob. Maths had an intimidating mystique to maintain, and I was apparently jeopardising it by titting around on the internet making videos and podcasts, rather than focusing on a perfectly respectable research career.

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I have thought a lot about that comment since. Partly because I have spent the intervening years doing everything I can to completely ignore him (and getting a New Scientist column feels like a rather lovely reward for doing so).

But buried beneath his snobbery, I have come around to the idea that he was right about something. And I have never felt that more than in the past few weeks, since a swarm of AI agents have been busy solving our most famous long-standing problems.

I鈥檓 talking, of course, about OpenAI鈥檚 announcements over the past few weeks that it has found proofs for hundreds of mathematics problems that had previously resisted human attempts to solve them.

The furore began, most notably, with a proof (by way of finding a counterexample) that the Navier-Stokes equations can break apart. This particular gem was such a big deal to the mathematical community that at the turn of the millennium, the Clay Mathematics Institute promised they鈥檇 give $1 million to whoever managed to solve it.

Those Navier-Stokes equations are what I did my PhD on. They are basically Isaac Newton鈥檚 second law of motion: F=ma, but applied to fluids. They are, in my not entirely unbiased opinion, staggeringly beautiful, able to articulate everything from the drip of a water droplet on a leaf and the churn of an entire atmosphere to the gases swirling around in a galaxy in the sky.

The thing is, these equations have a tricky little bit that pops out of the acceleration part, which contains a feedback loop within it. The faster fluid flows, the faster the gradient can get between two adjacent streams, and so the faster fluid flows. It鈥檚 a bit like the fluid version of putting a microphone next to a speaker. The feedback loop can get louder and louder until everything ends up breaking. Or, in the case of the Navier-Stokes equations, the speed of the flow heads off to infinity.

To be clear: no one was ever worried about fluid dynamics tearing open a black hole when you stir your tea or anything. It was just that the weird behaviour of this little term left the possibility that the equations themselves would break.

On the flip side, there鈥檚 another term in the equation 鈥� the viscosity 鈥� that acts as a brake and calms everything down, stopping the flow from getting completely out of control. So, the question was: does the brake always kick in?

If you have been following the story, then by now you will know what happened. Various groups of mathematicians had been using AI to circle in on this problem, finding special cases where the feedback loop goes crazy, without quite getting to the full Navier-Stokes.

But supposedly, once OpenAI heard that others were getting close, they threw everything at it: 10,000 AI agents, sending each other 3 million messages over 88 hours, costing millions of dollars in tokens, to find a single example where everything blows up. The Navier-Stokes equations do indeed fall. And an AI proved it.

This should have been a glorious moment of scientific exposition, but instead, mathematicians have spent the last few weeks having a massive collective wobble.

Part of the reason is that nobody yet understands the answer. The OpenAI solution is almost hilariously ugly. It is a proof that鈥檚 166 pages long, accompanied by hundreds of thousands of lines of formal code 鈥� almost impenetrable symbols 鈥� slapped down on the table and left for the mathematicians to pick apart, while the AI labs move on to the next thing. They came for the glory without giving much back.

So, we are left with a proof that almost no one wants to read, a $1 million prize that no one will want to , and no one who can stand at a blackboard and explain why this particular vortex makes everything break, when nothing else we tried ever did.

And now, to top it off, the new tranche of proofs that landed last week claim to have polished off hundreds of other important, unsolved mathematical problems, including a big result in the biggest trophy in all of mathematics: the Riemann Hypothesis. All tipped onto the code-sharing website GitHub for someone else to check.

So, mathematicians are having their own existential crisis about their role and purpose, like Lee Sedol did after AlphaGo, Gary Kasparov before him with Deep Blue and probably every literature graduate, musician and artist since ChatGPT was launched.

Please don鈥檛 get me wrong. I want to use this column, at least in part, to talk about the incredible, world-changing things that are happening with AI in science. I know that there is some inevitability to machines outpacing the humans, and I know that at its best, AI has a great deal to offer.

But at its worst, AI is an engine of extraction. Not just text, or images or equations. The real sting in the tail is that OpenAI set its sights on mathematics because the prestige, the respect and the glory was just another thing that could be mined.

It didn鈥檛 need to be that way.

They so easily could have been open and collaborative. But the moment when one of humanity鈥檚 greatest intellectual traditions became vulnerable, they chose conquest over stewardship.

And so, I am left thinking about that professor again. He was right that there is a special mystique to mathematics, but wrong about who would puncture it. And I鈥檓 sorry to say that, while the world might fear mathematicians, the machines certainly don鈥檛.

(UK: Channel 4; US: not available)

In 2015, an amateur trophy hunter from the US shot and killed the largest lion in Africa. The vitriol unleashed after Cecil鈥檚 death isn鈥檛 surprising (or entirely unwarranted), but what is remarkable is how this delicately-crafted film uses the case as a locus for all sorts of arguments about conservation. A symbol in life and in death, Cecil and other large, charismatic animals exist in a complex balance with humans who, one way or another, invariably stake a claim on them.

听

(UK: BBC iPlayer; US: not currently available)

Almost everyone in the world now needs to have some knowledge of how AI technologies work, from all the chatbots they encounter to driverless cars and more. Mathematician Hannah Fry is an excellent person to impart such knowledge: across three episodes, she guides us through recent cases where AI has become entangled with very human problems. The series breaks down complicated topics through clear metaphors, and it benefits from Fry鈥檚 warmth, humour and complete lack of judgement towards those at the sharp end of this ultimate technological revolution.

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(UK: BBC iPlayer; US: Discovery+)

While we eagerly await Artemis III in 2027, why not revisit this year鈥檚 Artemis II mission, which returned humans on a flyby of the moon for the first time in more than 50 years? This all-too-brief film is the product of three and a half years of filming with the Artemis programme, and it鈥檚 the story of countless humans 鈥� all those behind-the-scenes engineers and designers who worked on the mission alongside the four astronauts who travelled further from Earth than anyone before them.

听

(UK: BBC iPlayer; US: PBS)

The best of the many, many documentaries released to celebrate David Attenborough鈥檚 centenary was this behind-the-scenes look at the most iconic natural history series ever made. Released in 1979, the structure and tone of Life on Earth became the blueprint for almost every nature documentary that has been made ever since, and consequently has helped to define how we view the world around us. Making Life on Earth is crammed full of fascinating details from the production process, from a terrifying near-miss with armed guards in Rwanda, to Attenborough discovering that he has an allergy to donkey fur while riding the animals to the bottom of the Grand Canyon 鈥� and how it ended up ruining a close-up.

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(UK: for rent; US: HBO Max)

Fifteen years ago, a devastating earthquake and subsequent tsunami killed 20,000 people across northern Japan and caused vital cooling systems at the Fukushima nuclear power plant to fail. Told through the most stomach-churning footage and eye-witness accounts, this film sets out exactly what went wrong and charts how a natural disaster turned into a nuclear emergency. Amid the grim details, one bright spot is the bravery of the so-called Fukushima 50, who remained onsite and risked their lives to prevent a full-scale meltdown that would have rendered vast swathes of Japan uninhabitable. Because of their actions, only one person has so far died as a result of the accident.

For mathematician Hannah Fry, the definition of artificial general intelligence (AGI) is somewhat hazy. But, she says, if we鈥檙e taking AGI to mean at least as good as most humans on any task that involves a computer, then we鈥檙e almost there. “I think AGI is really not far away at all. I really think that in the next five to 10 years, we鈥檙e going to see seismic changes.” New Scientist spoke to Fry about her love and fears for AI, and why we shouldn’t treat it as god-like, with untouchable knowledge.

AI Confidential with Hannah Fry airs in the UK on 23 Feb on BBC Two, with a wider release to be announced

Netflix
Bryan Johnson is an unusual fellow by anyone鈥檚 standards. A millionaire venture capitalist and anti-ageing evangelist, he wants to push his lifespan and 鈥渉ealthspan鈥� to the very limits by taking a daily cocktail of nearly 100 drugs and following a strict fitness regimen. The real miracle of Don鈥檛 Die is how it manages to wrench any sympathy for Johnson from the audience. His lifestyle is based on a deeply flawed approach to science, but his mindset is far more interesting than those of his tech bro contemporaries.

Disney+
There is a sequence in Ocean with David Attenborough that is as horrifying as anything I have watched all year: a bottom trawler鈥檚 mechanical teeth puncture the seabed, churning through sediment as fish are swept into an enormous net. Attenborough鈥檚 most political project to date is a disaster film, warning of the catastrophic environmental consequences of industrial fishing practices. If this is indeed some of the 99-year-old鈥檚 final work, as he hints at in the documentary, it will do his lengthy career justice.

BBC iPlayer/NBC
Who is the US equivalent of David Attenborough, a man whose voice is synonymous with the finest British programming? Your best bet may be the silver-screen credentials of two-time Oscar-winner Tom Hanks. He narrates this 10-part natural history series all about the incredible biodiversity of the Americas, lending it a glossy, cinematic sheen. Expect little insight into the climate crisis here, but what it lacks in real-world relevance, it (almost) makes up for with its gorgeous cinematography.

BBC iPlayer
Twenty years ago, Bruce Parry spent months living among Indigenous communities as part of the anthropology series Tribe. Now, the programme returns, but in a very different world. With deforestation and displacement even greater threats now than they were in the early 2000s, Parry must do even more to gain the trust of the groups that host him, none of which has permitted outsiders to visit before. There are so many fascinating scenes in Tribe 鈥� from piranha fishing and political meetings to yag茅(ayahuasca) rituals 鈥� that you only wish we could spend more time observing. The brief access we are granted via Parry feels like a gift.

Netflix
We have long leveraged the innocence of children for entertainment 鈥� child actors of the 1920s and 30s were forced to work long hours, given amphetamines and even pushed into near-death experiences. The 21st-century variant of this horrendous practice is 鈥渒idfluencing鈥�, when families build financial empires off the online antics of their precocious children. Bad Influence follows child pageant star and dancer Piper Rockelle, who was allegedly exploited by her 鈥渕omager鈥� after rising to fame at age 9. Warning: this is a truly grim look at the darkest side of social media.

The best science fiction TV shows to look forward in 2025

From Doctor Who and Severance to Apple Cider Vinegar, there are plenty of great sci-fi and science-inflected TV shows coming up this year, says Bethan Ackerley

BBC iPlayer/CNN
While the early days of Facebook are infamous thanks to the David Fincher film听The Social Network, Twitter鈥檚 origins aren鈥檛 so well-known.听Twitter: Breaking the Bird听traces the company鈥檚 history all the way back to when it was a simple platform for posting status updates. The film is most interesting when covering the internecine power struggles between Jack Dorsey and his fellow founders; it also delves into the technical issues that have plagued the social media platform since its inception. And did you know that Twitter (or X, as it鈥檚 now known) could have started off with the name Ketchup or Friend Stalker? But its later chapters are also a welcome reminder that the myriad problems at Twitter didn鈥檛 begin with the volatile presence of Elon Musk 鈥� the cracks were there from the very start.

BBC iPlayer
Last year, naturalist Chris Packham presented听Inside Our Autistic Minds, a two-part documentary that saw autistic people make films to try to express how their minds work to their loved ones. The follow-up season focuses on ADHD and dyslexia, two other highly misunderstood conditions. While the series largely focuses on the social challenges that can come with ADHD and dyslexia, there is good science to back things up, with some great insights into the neurological underpinnings of these conditions. There is also a welcome focus on the positives of ADHD and dyslexia, such as the enlightening fact that many people with dyslexia have above-average pattern-recognition abilities.

Netflix
From the makers of听My Octopus Teacher听comes听Pangolin: Kulu鈥檚 Journey, the story of a baby pangolin saved from the illegal wildlife trade. Underweight and traumatised when he was rescued, Kulu must be rehabilitated by his handler Gareth before he can be released into the wild. Gareth describes himself as a helicopter parent 鈥� he certainly spends a lot of time hauling Kulu out of warthog burrows before nightfall approaches. It is all unbearably cute, and while it is fair to say that听Pangolin: Kulu鈥檚 Journey听is a touch too sentimental, it鈥檚 also hard not to feel an intense affection for this strange, sensitive creature and his brethren. As the world鈥檚 most trafficked wild mammals, pangolins will need plenty of goodwill from humans if they are to survive.

BBC iPlayer
Season three of Hannah Fry鈥檚 guide to the everyday technologies we rely on is as enchantingly informative as always. This time round, she investigates rollercoasters, motorways and (inevitably) air fryers. This is highly detailed stuff, and delving into the nitty-gritty of this taken-for-granted tech results in some surprising discoveries. How did the inventor of the theremin influence the doorbells on our homes today? Why were frisky chickens key to the creation of fridges? And what, exactly, is an air fryer鈥檚 starfish? If you鈥檝e ever been tempted to take apart your appliances to learn how they work, let this charmingly small-scale series will save you from violating their warranties.

Amazon Prime Video
We have got to know individual octopuses in quirky roles: psychics, escapologists and unlikely teachers. How wonderful, then, to have this two-part series about our tentacled friends and their extraordinary abilities. Our beautifully animated guide to the life cycle of these creatures is Doris, a giant Pacific octopus that beats the odds by surviving her dangerous childhood and going on to reproduce, dying shortly afterwards. Despite that unhappy ending, Octopus! is a light-hearted documentary full of curiosity and humour.

NOW
Science fiction is our most potent means of imagining the future 鈥� and that future is often bleak. The primary aim of this four-part documentary is to chart how sci-fi dreamed up the atomic bomb, then taught us how to relate to it, with fear and fascination that would go on to poison humanity鈥檚 relationship with everything else on the planet. Beyond that, though, Wonderland is a thoughtful, rigorous consideration of the past 80 years of sci-fi in all its forms, not just the most apocalyptic or traditional. This is a welcome salve for all those wounded by the surface-level analysis too often afforded to the genre.

Netflix
In 2023, the world was gripped by the four-day search for the missing OceanGate Titan submersible, which had disappeared on a trip to see the wreck of the Titanic. We would eventually learn that the five people on board, including OceanGate co-founder Stockton Rush, had been killed almost instantly after a fatal implosion. This feature-length documentary reveals how ego and negligence led to those tragic deaths. One particularly chilling sequence sees Rush on an early test dive, listening to an acoustic monitoring system that signalled when the carbon-fibre hull was cracking under deep-sea pressures to a dangerous extent. The company later abandoned this vital safeguard.

Disney+/NatGeo
In 1983, Sally Ride was NASA鈥檚 golden girl: the first US woman to go to space, she was among the most famous people in the world, even appearing on Sesame Street. But she and her fellow female astronauts were subject to institutional sexism and invasive media attention. This feature-length documentary is framed around the personal life Ride fought to keep private, including her 27-year relationship with Tam O鈥橲haughnessy during a deeply homophobic period in US history. There are plenty of fascinating details about Ride鈥檚 career too, such as how the hand-eye coordination she honed in her former tennis career gave her the edge over colleague Judy Resnik, who would be placed on a later mission that ended in the Challenger disaster.

BBC iPlayer
Back in 1999,听Walking with Dinosaurs was a TV sensation, transporting viewers to our prehistoric planet through some cutting-edge-at-the-time visual effects. Those visuals have dated a little since the show first aired, so the time was ripe for a reboot. In each episode of the 2025 series, researchers play detective, uncovering ancient remains and then extrapolating a wealth of information from the bones and the surrounding environment. These imagined stories are charming and moving by turns, whether we鈥檙e watching a baby Triceratops chase a dragonfly through the jungle or an Albertosaurus pack听cornering their prey. Take it all with a pinch of salt, of course: there is much about dinosaurs鈥� lives that we do not and cannot know.

(BBC iPlayer)

This big-budget series from David Attenborough and the BBC Studios Natural History Unit takes a closer look at the flora and fauna of the UK and Ireland. Warring capercaillie and the sex lives of ash-black slugs are two highlights.

(Netflix)

In 2016, 10-year-old Maya Kowalski was admitted to hospital with severe pain. The tragedy that ensued lays bare the failings of a US hospital.

(BBC iPlayer)

Each episode of听Earth听delves deep into the history of our planet, from the worst-ever mass extinction to the rise of humans, and is replete with cutting-edge scientific research.

(Apple TV+)

Michael J. Fox, best known as the star of the听Back to the Future听films, was diagnosed with early-onset Parkinson鈥檚 disease at just 29 years old. His documentary about living with the condition is moving but never mawkish.

(BBC iPlayer)

Mathematician Hannah Fry presents this addictively interesting series, which returned in 2023 to teach us all about the innovations underpinning everyday life, from passports to vacuum cleaners.

(Netflix)

It can be difficult to look the world of emergency medicine straight in the eye, but this unflinching documentary about New York鈥檚 frontline healthcare workers is must-see viewing.

(Apple TV+)

Another entry from David Attenborough, this beautifully animated series explores the weirder, wilder side of dinosaurs and their contemporaries. With its emphasis on recreating the feel of a classic nature documentary, you will feel like you are really inhabiting the prehistoric world.

(Netflix)

Foodborne illnesses affect 48 million people in the US every year. This documentary takes aim at the industries fuelling these outbreaks, with shocking revelations.

(BFI Player)

Ella Glendining, who was born with no hip joints and short femurs, had never met anyone with the same rare condition she has. The community she finds throws the discrimination she faces elsewhere in life into sharp relief.

(Netflix)听

When it comes to mainstream nature documentaries, too few are bold enough to explicitly connect Earth鈥檚 natural beauty to the threats it faces from climate change.听Our Planet II听is a refreshing deviation.

(NASA+ and YouTube)

Only one episode of The Color of Space, NASA鈥檚 seven-part series about Black astronauts at the agency, has been released, but it is already a highlight of the new streaming service NASA+. Episode one is about Charlie Bolden, who became NASA鈥檚 first Black administrator.

(Netflix)

This eclectic four-part series tackles drone warfare, the James Webb Space Telescope,听Homo naledi and an ancient necropolis 鈥� perfect for mystery fans who are seeking variety.