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Is Elon Musk's vision for the future a libertarian fantasy or scientific imperative?The question of human settlement on Mars is, for many people, not if" but when". Elon Musk's SpaceX company began speaking of the Mars Colonial Transporter around 2012. Its latest incarnation, the prototype for a massive spaceship called Starship that can house up to 100 passengers and crew, took off from Texas in April but exploded before reaching Earth's orbit. Whether that counts as a success or not depends on who you ask, but it testifies to Musk's determination to see a human presence on Mars in the next decade.His view that colonising the cosmos is humankind's ultimate and inevitable destiny is widely shared. The moon, lacking an atmosphere, short on water, and with weak gravity, is not a very attractive stepping stone, but Mars has none of those drawbacks and is considered a much more viable place to build the first off-world settlement. Once the exclusive province of science fiction stories and films," according to Nasa, the subject of space colonisation has rapidly moved several steps closer to becoming a reality thanks to major advances in rocket propulsion and design, astronautics and astrophysics, robotics and medicine." Continue reading...

The actor has called out double standards for ageing stars in the movie industryCharlize Theron has said she wants to fight against" what she perceives as unjust double standards for female actors over 40 in Hollywood.The actor, 48, said she despise[s] the concept" that while men age like fine wines" women do so like cut flowers". Continue reading...

Chandrayaan-3 moves into prelanding orbit amid failure of Russian missionAs it was announced that Russia's first lunar mission in 47 years had crashed on to the moon, India's own mission, the Chandrayaan-3 lander, moved into prelanding orbit.News on Sunday of the Russian failure was met with excitement and nervousness in India: excitement that India was now poised to win the race to become the first country to land a craft on the moon's south pole; nervousness that its mission could also go horribly wrong at the last moment. Continue reading...

Curators at National Railway Museum at Shildon say they are delighted and proud to get Gaunless bridge backIt may not look like it helped change the world but the 200-year-old Gaunless Bridge did just that, its supporters say, and its name deserves to be shouted from the rafters.Locomotion, the National Railway Museum at Shildon in County Durham, is preparing to welcome home what is the world's oldest surviving iron railway bridge. Continue reading...

Retrograde analysis of the classic board gameUPDATE: The solutions can be read hereThe retrograde analysis of a game is the analysis of what happened in order to reach a particular state of play. There's a large literature about this sort of problem in chess.Today's first puzzle is retrograde analysis of snakes and ladders.The game starts with each player putting their marker on 1.Each player roles a single die. If you roll a 6, you get an extra throw.The players take turns in a fixed order.You go up ladders, and down snakes. It is possible to go up two ladders, or down two snakes, or up a ladder and down a snake on the same turn.The winner is the player who lands exactly on 100. (If you are on 98 and roll a 3, you bounce back' and land on 99.)If a player lands on a square occupied by another player, the player is not sent back to square 1. Continue reading...

Using drones and acoustic equipment, hundreds of volunteers from around the world take part in the surface watchIt was 90 years ago that Aldie Mackay, manager of the Drumnadrochit hotel, burst into the bar one evening to tell dumbfounded patrons she had just witnessed a water beast" in Loch Ness.It was this sighting - zealously reported in the Inverness Courier - that began the modern myth-making around an elusive monster surviving in the depths of the Highland loch - and next weekend hundreds of Nessie enthusiasts are expected to take part in the biggest organised hunt for the mysterious creature in 50 years. Continue reading...

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Observers will need a clear eastern horizon to see planet rise in the dawn twilight

Medications with semaglutide such as Ozempic and Wegovy are being studied to see if they can help other conditionsThey have taken the celebrity world by storm as a slimming jab and become a vital tool for managing type 2 diabetes. Now drugs such as Ozempic are being researched to look at whether they could help conditions ranging from alcohol misuse to dementia.Ozempic, a type 2 diabetes medication, and Wegovy, which is licensed for weight loss, contain the drug semaglutide, while a similar drug, liraglutide, is available for both purposes under different brand names. Continue reading...

All you need is some standard kitchen equipment, says Dr Ken VinesIt's not as difficult to estimate the weight of a human hand as John Pye thinks - and can be accomplished in the average kitchen (Letters, 17 August).Take a transparent jug that is tall enough to take the outstretched hand, although a loose fist could be used with a shorter jug. Weigh the jug. Put in a measured amount of water that is sufficient to cover the hand without spilling over when the hand is put in. This is best done using kitchen scales that are accurate to one or two grams. Continue reading...

It's often healthier to embrace the possibility of a new family dynamic and let go of punishing old patternsAfter several years of trying to salvage her long relationship with Rosa through couple's counselling and other efforts, Kara eventually made the difficult decision to end it. After the separation, Kara found herself estranged and isolated from Rosa's extended family, whom she had shared close ties with for more than 30 years.The enduring pain of being excluded from family gatherings and communications made her wonder if she was being punished for her choice to leave. Caught in a constant struggle, Kara oscillated between attempts to reconnect and repair, or avoidance because the rejections were far too painful. Continue reading...

Craft spun into unpredictable' orbit before planned touchdown could take place, Russia's state space corporation saysRussia's first moon mission in 47 years has failed after its Luna-25 spacecraft spun out of control and crashed into the moon, dealing a significant setback to the embattled Russian space programme's attempt to revive its Soviet-era prestige.The state space corporation Roscosmos said it had lost contact with the craft at 1157 GMT on Saturday after a problem as the craft was shunted into pre-landing orbit. A soft landing had been planned for Monday. Continue reading...

In rural Somerset, I gained new understanding of gardening - and the Caribbean islandsHome. It is a word heavy with meaning. One definition refers to the place of your belonging, the place that you are from. I grew up in Trinidad and Tobago, a former British colony whose peoples have come to or been forcibly brought from many places to mix more or less uneasily on these two small land masses joined together for political expediency. I grew up in my grandmother's and my mother's gardens, lush spaces filled with plants brought from many places, with the backdrop of the hills of the Northern Range rising green beyond them both.As a child, I did not know many of the stories of the people I came from. I still don't know as much as I would like, but I have learned that, like the plants, they came from many places, places such as Portugal, China, Africa (but where in Africa is still unclear), Scotland, and Ireland, explaining my last name. The stories seemed to come from everywhere except the actual place of my birth, making the notions of home and belonging difficult to take root. Continue reading...

Roscosmos says spacecraft got in trouble while attempting to enter a pre-landing orbit targeting south poleRussia has reported an abnormal situation" on its moon-bound Luna-25 spacecraft, which launched earlier this month.The country's space agency, Roscosmos, said on Saturday that the spacecraft ran into unspecified trouble while trying to enter a pre-landing orbit and that its specialists were analysing the situation. Continue reading...

As the medicinal use of psychedelics gains mainstream attention, fears remain over their effect on mental health and the need for safe administrationIn June 2021, 32-year-old actor Kate Hyatt travelled to a farmhouse near Great Malvern in Worcerstershire for a plant medicine retreat that she hoped would improve her mental health after a difficult time during the pandemic lockdowns. While there, she is believed to have taken a substance called wachuma, or San Pedro cactus, a powerful hallucinogen used by Indigenous people in the Andes for thousands of years.But Hyatt did not experience relief; instead, her mental health worsened. Three months later, she described being in some sort of psychotic break" and feeling as if her brain was going to explode. Later that autumn she took her own life. At the subsequent inquest, the coroner's report linked her worsening symptoms to the hallucinogens she had consumed. Continue reading...

This exploration of where, why and how we sleep (or don't) is as intelligent as it is eccentricAll our body wants is to sleep, it wants to leave us, head back to the stable, a worn-out horse," writes Marie Darrieussecq, at which I, a worn-out human, think yes. In a recent interview, Darrieussecq reflected on how much of her work is concerned with inhabiting. Who has a right to inhabit this planet, she asks, and who doesn't? Though she was talking about her novel Crossed Lines, in which a Parisian woman finds her life becoming bound up with that of a young Nigerian refugee, she could just as well be referring to Sleepless (Pas Dormir in the original French), a book that is - what? A memoir/interrogation/painting/song of insomnia, her own and that of others. It's a book about where, why, how we sleep and don't sleep; about how to find a place in the world where sleep can happen, a stable for the worn-out horse.Sleepless isn't a book that's straightforward to convey, at least not briefly. On the page it's fragmentary, footnoted and studded with photos and illustrations. It's panoramic in its survey of insomniac literature, and also softly intimate where it touches on the author's own life. In its range and genre it's unpindownable. Darrieussecq is one of the most prolific and distinguished living writers in France with a truly impressive body of work. All her familiar acuity, humour, humility and intensity are evident in Sleepless. Continue reading...

It is unclear whether BA.2.86 causes more severe disease but its detection in several countries has put scientists on alertA new Covid variant that is causing concern among scientists due to its large number of mutations has been detected in London.The variant, named BA.2.86, has been detected through genetic sequencing, although only a handful of such sequences have so far been reported. The first was reported in Israel, with the variant since being detected in Denmark and the US. Continue reading...

Doctors say test may diagnose childhood illnesses in less than an hour, helping quickly identify life-threatening infectionsA new blood test that would enable the commonest childhood illnesses to be diagnosed in less than an hour could transform" medical care, doctors say.Currently it can take doctors hours, days or even weeks to identify which of 18 infectious and inflammatory diseases a child with a worryingly high temperature is suffering from. Continue reading...

Loss of sea ice and rising temperatures in the ocean around Antarctica have a huge effect on the Earth's climate, but the ability to track them is laggingA chronic shortage of observations of the vast ocean surrounding Antarctica is hindering more accurate forecasts of the consequences of the climate crisis, a meeting of 300 scientists has concluded.The Southern Ocean has an outsized influence on the Earth's climate, absorbing masses of the extra heat and carbon dioxide caused by human activities. Continue reading...

De-aged image offers likelife image of how prince may have looked during unsuccessful Jacobite rising of 1745The face of Bonnie Prince Charlie has been recreated using death masks that depict him as he would have looked during the Jacobite rising of 1745.The prince, who was renowned for his good looks, has captivated a new generation of interest through the TV show Outlander. Continue reading...

Outbreaks may be addressed sooner by avoiding need for sending stool samples abroadPolio could be detected in wastewater in half the time using a new technique, helping public health authorities to respond quickly to deadly outbreaks, a study has found.The research in the Democratic Republic of the Congo (DRC), supported by the UK's Medicines and Healthcare Products Regulatory Agency (MHRA), represents the first time that (DDNS) has been used to detect polio, reducing the average testing time from 42 to 23 days, with an accuracy rate exceeding 99%. Continue reading...

In this special Age of Extinction mini-series from Science Weekly, Guardian biodiversity reporter Phoebe Weston explores the illegal killing of birds of prey on grouse moors, and asks why it is so difficult to solve these crimes. In the third and final episode, Phoebe finds out more about the pressures that drive people to commit raptor persecution, discovers how the police investigation into the case of Susie's crushed chicks unfolded, and how Susie is doing nowListen to episode one here Continue reading...

People not eligible for autumn booster programme should have option to pay for jab, experts argue, amid new wave concernsCovid vaccines should be made available for people to buy privately in Britain, leading scientists have urged, amid concerns over a new wave of the virus which could worsen in autumn and winter.Unlike flu jabs, which individuals or employers can buy for about 15 from high street pharmacies, Covid jabs are only available on the NHS in the UK. Continue reading...

We look at the current levels of the coronavirus and who will be offered a booster jabWith Covid in the UK on the rise once more, we take a look at the current situation and what the plans are for vaccination. Continue reading...

Medical breakthrough marks longest pig kidney has functioned in a human, setting stage for operations in living patientsA pig's kidney transplanted by surgeons into a brain-dead man has continued to function normally for more than a month - a critical step toward an operation the New York team hopes to eventually try in living patients.The latest experiment, announced on Wednesday by New York University Langone Health, marks the longest a pig kidney has functioned in a person, albeit a deceased one, and it's not over. Researchers will track the kidney's performance for a second month. Continue reading...

Giving women painkiller piroxicam alongside levonorgestrel found to prevent 95% of pregnanciesWomen who take a painkilling tablet alongside the world's most widely used morning-after pill have a far smaller risk of becoming pregnant than those who rely on emergency contraception alone.Sexual health experts have hailed the finding, reported on Thursday in the Lancet (paywall), as a significant and very exciting" potential breakthrough that could make it easier to prevent pregnancy after unprotected sex. Continue reading...

The Asia native was found in Georgia, prompting concern that it could devastate important pollinators including the honeybeeA yellow-legged hornet has been found in the US for the first time, prompting concerns among experts about the agricultural threat the invasive Asian species poses, not least to honeybees and other pollinators.The Georgia department of agriculture (GDA) said a beekeeper in Savannah spotted the insect on his property and reported it to authorities. It was subsequently confirmed as a yellow-legged hornet. Continue reading...

Genome analysis reveals new physical details of mummified corpse found in ice of Italian AlpsDark eyes, receding black hair, few or no freckles and a darker skin tone. This is how Otzi the iceman, the mummified corpse found trapped in the ice of the Italian Alps, would have looked while living.Researchers who conducted a higher-coverage analysis of the genome to learn more about Otzi's genetic history and the mummified man's physical appearance have found genes associated with male-pattern baldness and darker skin tone. Continue reading...

Urban gulls are often treated as nuisances but humans could learn a lot from the screeching snack-snatchersThey tear open rubbish bags looking for food, swoop down on passersby and steal their sandwiches, and even swallow rats and squirrels whole.Many people complain about the menace of urban gulls, but with the wild populations of some species in severe decline, our parks and high streets are increasingly the only places where gulls are thriving. Continue reading...

Some of the ancient plants have curious pouches that can trap tiny creaturesLiverworts are ancient green land plants that look like flattened liver-shaped pads, or they have stems and leaves and often get mistaken for mosses, their distant cousins.

Stanhope, Weardale, County Durham: Out on a walk, I dust off my identification skills for some tricky grassland toadstoolsThe grassland toadstool season started early this year. These inkcaps weren't here last week and they'll soon vanish, leaving just a dark stain on the lawn. I think they must be the glistening inkcap but it's hard to be certain. Heavy rain has washed away the diagnostic powdery scales that normally cover the cap. Earlier torrential downpours softened the earth, hard-baked by early summer drought, allowing these smooth, conical caps to shoulder it aside on their way to the surface. Now they are ragged around their rim, a sign of impending deliquescence into inky, spore-laden goo that will stick to flies' feet, to be carried away to pastures new.Every year, I struggle to refresh my identification skills for tricky brown grassland toadstools, without ever acquiring enough confidence for a fungal foray with a meal in mind; sitting on the edge of uncertainty isn't conducive to comfortable eating. Scientific advances based on DNA analysis, renaming and reordering species have not helped, rendering some of my old field guides obsolete. They've renamed this one, learned in my youth as Coprinus, meaning of dung", as a Coprinellus. A misnomer either way: it doesn't digest dung. This troop of toadstools is probably growing on decayed tree roots under the neatly mown grass. Continue reading...

In this special Age of Extinction mini-series from Science Weekly, Guardian biodiversity reporter Phoebe Weston explores the murky world of the illegal killing of birds of prey on grouse moors, and asks why it is so difficult to solve these crimes. In episode two, Phoebe speaks to the people trying to protect these rare birds, but as she digs deeper encounters a surprising silence around the killing of Susie's chicksRead more reporting from the Age of Extinction team Continue reading...

Researchers conclude there is potential value' in testing heart patients' urine for substances such as marijuana, ecstasy and cocaineMore than one in 10 patients admitted to cardiac intensive care have taken recreational drugs, research has found.Researchers in France tested the urine samples of all patients admitted to cardiac intensive care in 39 French hospitals during a fortnight in April 2021. They found 11% had taken drugs such as marijuana, ecstasy and cocaine. Continue reading...

Breakthrough raises hopes that musicality of natural speech can be restored in patients with disabling neurological conditionsScientists have reconstructed Pink Floyd's Another Brick in the Wall by eavesdropping on people's brainwaves - the first time a recognisable song has been decoded from recordings of electrical brain activity.The hope is that doing so could ultimately help to restore the musicality of natural speech in patients who struggle to communicate because of disabling neurological conditions such as stroke or amyotrophic lateral sclerosis - the neurodegenerative disease that Stephen Hawking was diagnosed with. Continue reading...

Researchers in Italy uncover inscribed sections of marble chronicle linked to previous finds at Ostia Antica archaeological parkSome of the daily activities of the Roman emperor Hadrian, who built monuments including the Pantheon during his more than two-decade reign, have been revealed after the discovery of fragments of marble slabs in Ostia Antica, an archaeological park close to Rome that was once the city's harbour.The details were inscribed on fasti ostienses, a type of calendar chronicling events involving emperors and other officials in ancient Rome which were drafted by the pontifex Volcani, the highest local religious authority. Continue reading...

According to a study of more than 3,000 people, heterosexual women take longer than men to make a verbal commitment to a new romanceName: I love you.Well, this is all very sudden. You're supposed to ask my age and appearance here. Continue reading...

Family and friends delight in telling me tall tales about rodents and now my unfortunate phobia has been passed on to my childrenWhile I couldn't spontaneously name them, I feel sure there were good qualities I wanted to pass on to my children. But all I've managed to transmit is a violent fear of rodents, and even that, to only one of them. I didn't realise how successful I'd been until a couple of years ago, when we saw a mouse in my son's bedroom. I screamed; he screamed. I jumped on the bed; he jumped on a chair - but it was a revolving one, so he started spinning round, screaming, and I screamed more. Mr Z ran in expecting an intruder, though I notice he didn't bring anything to use as a weapon. As much as I reviled it, I felt a bit sorry for the mouse. It was all so ultra.Consequent to this very noisy, melodramatic phobia, it pleases my associates to tell me stories about mice and rats, which, generally speaking, aren't true. My brother-in-law told me that, if they have a rat problem on a building site, they contain all the rats in a zone where the only food source is each other, until finally they have one giant rat, and they shoot it in the head. It stalks my dreams, this mutant rat cannibal, even though it makes no sense. On holiday, my friend told me there was a rat in the kitchen, and while I could recognise this at 50 paces as the title of a popular song, I nevertheless believed that there was also a real rat, in the kitchen. Continue reading...

Study of skills suggests practicalities of living among branches was precursor to advanced abilitiesWhether it's drumming a steady beat against a tree to attract a mate, weaving an intricate nest or just lifting food to their beaks, some birds engage in some truly fancy footwork.Now researchers say the evolution of such dexterity may have been driven by the creatures taking up residence in trees. Continue reading...

US research linked to dopamine release finds macaques decreased consumption by up to 90% after treatmentA form of gene therapy that is already being trialled in patients with Parkinson's disease might provide a one-off treatment for severe alcohol addiction.A study in macaque monkeys that were predisposed to heavy drinking found that it dramatically curbed their alcohol consumption. Drinking went down to almost zero," said Prof Kathleen Grant, at Oregon Health and Science University's National Primate Research Centre in Beaverton, US, who co-led the research. For months on end, these animals would choose to drink water and just avoid drinking alcohol altogether." Continue reading...

Michigan State discovery of building demolished in 1920s provides rare on-campus experience for archaeology studentsConstruction workers at Michigan State University hit something hard earlier this summer while installing hammock poles into the ground outside a residence hall.A closer inspection then revealed it was the foundation of a 140-year-old observatory that was demolished in the 1920s and - over the course of a century - became buried underground. Continue reading...

While the ultra-wealthy spend millions on bizarre elixirs, the rest of us can follow these simple steps to enjoy a better lifeIn the words of Taylor Swift, I might be feeling 22" but the reality is that my 39th birthday approaches and with that the slow creep to 40: official midlife territory. The desire to stay young feels like a universal pursuit, whether you are Swift, Madonna or Jeff Bezos. Indeed, it is an obsession that transcends the centuries: in 1513, explorer Juan Ponce de Leon discovered Florida while searching for the fountain of youth and eternal life.Fast forward just more than 500 years and American tech centimillionaire Bryan Johnson is on his own voyage of discovery. Johnson reportedly spends $2m (1.6m) a year on an intensive regime designed to reduce his biological age from 45 to 18. He recently made headlines for injecting himself with his 17-year-old son's plasma, after studies in mice showed young blood can rejuvenate old tissue.Prof Devi Sridhar is chair of global public health at the University of Edinburgh Continue reading...

All of us will experience pain and stress, but the brain has some smart ways to protect us. Here is how to get prepared for periods of adversityOur minds are more resilient than we know. According to a growing body of research, first popularised by psychologists Daniel Gilbert and Tim Wilson in the early 2000s, the brain has a remarkable capacity to make the best of bad events: when we encounter negative situations we subconsciously activate what is known as our psychological immune system.A self-protective mechanism analogous to the body's own immune system, the psychological immune system is a series of processes that our brain initiates to help us make sense of the adverse environment we might be in, assign meaning to what is happening, and ultimately find positives for the future. If we fail to land a job we had wanted, for instance, our brain might reason that the interviewer was rude and biased, therefore it wasn't the role for us. Or, we will speak to a friend and gain a new perspective on the benefits of our existing job. Continue reading...

Physicist Samuel Peralta's Lunar Codex project has seen the work of 30,000 artists from 158 countries carried on into space - and the effect on them has been profoundBefore the age of space exploration, all artists could do was look up and gaze, sketch and write about a moon they could never reach. But Samuel Peralta, a semi-retired physicist living in Canada, has changed all that with the launch of the Lunar Codex, a project that sends art to the moon, converted into Nanofiche files (think microfiche but smaller) and left on the surface in time capsules.The whole thing started with the realisation that Nasa was going to privatise lunar landers," he tells me on a video call. This enabled him to buy payload space - room on a rocket - for an artwork he created called Moonstone, which was etched on a metal disc. Continue reading...

Erin Patterson tells police she bought the fungi from a supermarket chain and an Asian grocery store

After reading that they are far heavier than you think, I abandoned the housework, the dog - and my grip on reality - and got out the kitchen scalesSummer makes me go a bit odd. A case in point - I spotted a headline recently that read: Your hands are probably about twice as heavy as you think they are", and I became instantly obsessed. How heavy are mine, and how could I weigh them? If I estimated their weight, would I mentally factor in this bombshell headline, skewing the result? I mean, have you ever thought about the weight of your hands? Go on: how heavy do you think they are?Then I found myself wondering whether heavy hands were bad, like heavy legs are in France. Every pharmacy there will offer you a selection of products at varying prices to deal with what is, I believe, a fictional condition, and if you tell a medical professional that your legs are heavy, they will take this entirely seriously and may even prescribe a trip to walk around in some knee-high seawater, like a racehorse, in a coastal spa somewhere. I've seen (and envied) it. Has the scourge spread? What is happening to our hands?Emma Beddington is a Guardian columnist Continue reading...

In today's newsletter: The Eris' strain of Covid is a reminder that the virus has never fully gone away - but what will it mean for Britain? Sign up here for our daily newsletter, First EditionGood morning. Covid has become a polarising topic that many people just want to forget about. Earlier this year, the World Health Organization officially declared an end to the global public health emergency. Cases, hospitalisations and deaths are at their lowest levels, though infections have undoubtedly become more difficult to track as monitoring systems are dismantled. But even so, experts have made it clear that Covid will be with us for many years to come even though the acute phase of the health emergency is over.Like an unwelcome guest that does not know when the party is over, Covid has continued to mutate and shape shift, creating a viral, ever expanding family tree through its numerous variants and sub-variants, with Eris the latest of interest to the WHO. Many thousands of vulnerable people are still shielding in the UK - poorly protected by a government that would rather ignore the problem. And with record waiting lists in the NHS, is the country any better prepared for a future pandemic than it was in 2020? Continue reading...

One of the finest constellations on show in the northern sky, Cygnus's body lies right along the Milky WayFrom the northern hemisphere, summer is the time for Cygnus, the swan, to fly high in our skies. A large constellation, it is definitely one of the finest on show in the northern sky.Cygnus is shaped like a cross but it doesn't take much imagination to see it as a swan. The central star in the constellation is Sadr. From this point, the swan's great neck stretches out towards the star Albireo, and the body back towards Deneb, which is Arabic for tail. The wings reach out to either side along a line of fainter stars. The body and neck of Cygnus lie right along the Milky Way, the misty band of light that can be seen from more rural locations and is the combined light from the billions of stars that make up our galaxy. Continue reading...

Evidence is mounting on the health costs of these products. The real culprit is financialised growth, not inadequate individual willpowerIf we are what we eat, then we are increasingly composed from substances including synthetic emulsifiers, flavour compounds, bulking agents and stabilising gums (one of the most common being a slime produced by bacteria). Well over half of the average diet in the UK and US now consists of ultraprocessed food (UPF) - or, as one scientist prefers to put it, industrially produced edible substances. Though defining it technically is complex, the simple explanation is that it contains items you wouldn't normally find in a kitchen.Sometimes UPF looks like junk food - obviously artificial and high in salt, fat and sugar. But it often comes in reassuring forms such as soup, muesli or yoghurt. Almost every food that comes with a health claim on the packet is a UPF," notes Dr Chris van Tulleken drily in Ultra-Processed People, one of several recent books on the subject. Continue reading...

Three people have died and a man remains in hospital after attending a lunch in Leongatha, Victoria, more than two weeks ago.Police say mushrooms are the suspected cause of death and are investigating.Jane Lee speaks to Guardian Australia science reporter Donna Lu about the case Continue reading...

The long-running series in which readers answer other readers' questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical conceptsWhy are human eyes different colours? Gabrielle Kuper, aged 5, LondonSend new questions to nq@theguardian.com. Continue reading...