Indholdsfortegnelse for March 2023 i BBC Science Focus Magazine

Spaghettification. It's the term that describes what would happen if you fell feet-first into a black hole. You'd be stretched out and squeezed in at the same time, quickly turning you into something that resembles a human noodle. This happens because the difference in the strength of gravity between your feet and your head as you approach the black hole is so great. Its pull would be enough to yank your ankles out away from you, and its pressure would push your sides inwards, turning your body into the sort of shape you'd expect to find in a bowl of bolognese. Thankfully, it hasn't happened to a human yet (as far as we know), but we have seen it happen to stars as they get dragged into the all-consuming maw…

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EYE OPENER Ever wondered what it might be like if your TV was expanded to Sistine Chapel proportions? Probably not. But if you did, it might look something like this. What you're seeing here is the inside of the Now Building, a public atrium in London's Soho district that's been lined with 8K LED screens to create a giant digital canvas. How giant? Well, the atrium stands four storeys tall and is covered from floor to ceiling with 2,100m2 (23,000ft2) of HD TV screens. Outernet London, the company behind the Now Building, describes it as the “largest LED screen deployment by pixel density on the planet”. The hundreds of millions of pixels in these screens have been deployed to broadcast an immersive mix of digital artworks, entertainment and advertising. The…

The habit of male northern quolls to forgo sleep and food in favour of recklessly pursuing every possible mating opportunity may be killing them, researchers from the University of the Sunshine Coast, Australia, have found. Northern quolls (Dasyurus hallucatus) are carnivorous cat-sized marsupials that live across northern Australia. While the females can live and reproduce for up to four years, the males rarely make it beyond a single mating season. The reason for this has long puzzled researchers. Now, a new study suggests that this post-breeding die-off, known as semelparity, may be due to males travelling long distances and skipping sleep in order to mate with as many females as they can. “They cover large distances to mate as often as possible and it seems that their drive is so…

The worst kept secret in Hollywood!” shout the headlines. This particular badly-kept secret involves a pricey new weight-loss drug called Semaglutide. If you take the glossy celebrity magazines at face value, fans of these $1,200-a-month injections include Kim Kardashian and Elon Musk. But in mid-February, the weight-loss treatment moved beyond the A-list when UK high-street chemists announced they would be selling Semaglutide injections from spring 2023. At the time of writing, the UK price had not been disclosed. So what is Semaglutide? Is it safe? And could it be a game-changer for tackling the broader public health crisis of obesity? Semaglutide is manufactured by the Danish pharmaceutical giant Novo Nordisk, and sold under the names Ozempic and Wegovy. Ozempic, in particular, made inter national headlines last year after going viral…

INNOVATIONS …a comfier VR experience Among the many issues with virtual reality, one that comes up time and time again is just how uncomfortable the headsets can be, because of both their size and weight. Ironically, a company called Bigscreen has solved this problem with what they claim is the world's smallest VR headset. Weighing just 127g, this headset is incredibly light, and is custom-built for your face. Of course, to get the device this small, sacrifices will have had to be made, and only time will tell if this is the future… or yet another failure in virtual reality. Bigscreen Beyond £1,149, store.bigscreenvr.com …IKEA breaks into health tech IKEA is no longer just known for cheap furniture and complicated instructions that leave you sobbing on your living room floor.…

… COULD DINOSAURS HAVE HAD SYMBIOTIC RELATIONSHIPS WITH OTHER ANIMALS? … WHAT'S THE BEST WAY TO DRY CLOTHES INDOORS? … WHY DO COMPUTERS AND CONSOLES NEED TO RESTART TO INSTALL UPDATES? … HOW DOES DENDROCHRONOLOGY WORK? … ARE THERE REALLY DINOSAURS IN FOSSIL FUELS? … HOW DO ROBOT VACUUM CLEANERS NAVIGATE? … WHY DOES BAD NEWS MAKE ME FEEL SICK? … WHAT GIVES CLOUDS THEIR SHAPE? … DO WEIGHTED BLANKETS REALLY WORK FOR ANXIETY AND INSOMNIA? … HOW DO ROCKS STAY ON THE SURFACE OF DIMORPHOS? Email your questions to questions@sciencefocus.com or submit on Twitter at @sciencefocus OUR EXPERTS PETE LAWRENCE Astronomy expert AMY ARTHUR Science writer DR NISH MANEK GP and medical expert DR CLAIRE ASHER Science journalist DR HELEN PILCHER Biologist and science writer LUIS VILLAZON Science and tech…

Dendrochronology is a technique that involves calculating the age of a tree, or a piece of wood, by counting growth rings. As well as growing upwards, trees grow outwards each year by adding new woody tissue just underneath the bark, in an area known as the vascular cambium. In the spring, trees produce large, thin-walled cells under the bark, but as growth slows towards the end of the summer, they add denser, thicker-walled ‘latewood’ cells that appear darker in colour, leaving visible rings in the trunk that mark each year of growth. Dendrochronology has a wide range of applications, including dating archaeological remains and calibrating radiocarbon dating. As the width of each ring depends on how much new tissue was added during the growth season, which is influenced by the…

When you discover something bad has happened, it can trigger your body's ‘fight or flight’ response. It's governed by what's known as the sympathetic nervous system, which sends commands from your spinal cord to your body's major organs, including your heart and intestines, gearing you up to either fight or flee when faced with danger. A key part of the fight or flight response is to shut down digestion so that blood flow and energy can be sent to your limb muscles instead. In some people, this sudden effect on digestion can manifest as nausea, vomiting or diarrhoea. In short, the bad news has prompted you to feel threatened and your body has triggered your survival mode. The sympathetic nervous system is in constant opposition with the parasympathetic nervous system,…

EXPLAINER WHAT IS IT? The Amazon rainforest is the largest remaining tropical rainforest in the world. It's also the most biodiverse. One in ten of all known species are found here, including many that are endangered and found nowhere else. It's big and it's beautiful, and it's vitally important, not least because it stores vast amounts of carbon, influences rainfall patterns across South America, and affects climate on a much broader scale. In the last 40 years, around a fifth of the rainforest has been felled or burned to make way for cattle ranches and other activities. Now scientists fear it's on the verge of irreparable damage. We lose it at our peril. We need to act now to save one of the world's last true wonders. WHO LIVES THERE?…

A Documentary: By ChatGPT While teachers fret about an AI that can do students’ homework, the BBC Radio 4 producers have gone and got a machine to create a whole documentary… about itself. The lazy so-and-sos… Available now on BBC Sounds CrowdScience: Can A Robot Be Soft? The Terminator, Robocop, Optimus Prime… all the best robots are well hard. But what if they were a little less angular and a little more curvy, like an octopus or a fish, for example? The CrowdScience team dives into the world of soft robotics to look for Blobtimus Slime. Available now on BBC Sounds Wild Isles Sir David Attenborough explores the incredible wildlife here in Britain and Ireland. This six-part series will get up close and personal to some of the most dramatic…

EYE OPENER On 19 January, this weird, UFO-shaped cloud appeared over the city of Bursa at sunrise. This type of rare formation is a ‘lenticular cloud’ and tends to occur in the troposphere, which is the lowest layer of Earth's atmosphere. According to the Met Office, when moist, stable air blows across a large obstacle, such as a mountain range, a series of ripples can form. If conditions are right, the water vapour in the rippled air may condense to form lenticular clouds. Turbulence can accompany the clouds, so pilots tend to avoid them – unless they particularly enjoy bumpy conditions! As lenticular clouds do not generally form over flat ground, many people have never seen them. In fact, it's thought that a number of UFO sightings can be attributed…

reply@sciencefocus.com BBC Science Focus, Eagle House, Bristol, BS1 4ST @sciencefocus www.facebook.com/sciencefocus @bbcsciencefocus “THE FACT THAT MEASURABLE BRAIN DAMAGE CAN BE INDUCED BY JUST A FEW DAYS ON A DIET THAT MANY PEOPLE EAT HABITUALLY IS CONCERNING” KIMBERLEY WILSON, P66 LETTER OF THE MONTH Always 30 years… I have keenly followed nuclear fusion research for over 30 years and, as the old joke goes, it's always been just 30 years away, so I'd have hoped to have working fusion reactors by now! Therefore, I was thoroughly pleased when I heard about the breakthrough at the National Ignition Facility at the Lawrence Livermore National Laboratory in the US (January, p14), where ‘ignition’ has been achieved for the first time. The holy grail has been to get a net gain of energy and…

WEDDINGS Who needs a glamorous venue or a beautiful church when you can have your wedding in the metaverse? Strap on a headset and look into your partner's avatar's eyes as they unemotionally stare back at you at the digital altar. While it's still a new concept, there are already a few people who have done their wedding ceremonies via Meta's Horizon Worlds. BUY LAND In the real world, it's becoming harder and harder to get onto the property ladder, so perhaps we could all settle for a virtual plot of land instead? A number of websites have appeared recently, offering to sell users land, houses and furniture in the metaverse. These plots of land don't exactly come cheap, so this is more of an investment for the ‘more money…

…OVERPRICED LIMITED- EDITION HEADPHONES Bangs Olufsen's new earbuds offer the unique ability to be in an elite club, albeit a club of people who may have overpaid fora pair of earbuds.The Beoplay EX Atelier Editions are described as ‘ultra-rare’, and while Bang S Olufsen hasn't stated the exact number available, getting a pair requires a reservation and a high probability of beingturned down. So, what is so unique aboutthese headphones? Well, they're green… oh, and they cost €300 more than the same earbuds in any other colour. But hey, at least you'll be in that elite club! Bangs Olufsen's new earbuds offer the unique ability to be in an elite club, albeit a club of people who may have overpaid fora pair of earbuds.The Beoplay EX Atelier Editions are described…

CHARLOTTE EDWARDS, CHELTENHAM Centipedes are much faster. Precise figures are hard to come by, but common centipede species run at comparable speeds to a spider, whereas millipedes move more at the pace of an ant. The reason for this has nothing to do with their different numbers of legs – the leggiest centipede species have 384 legs, which is more than a typical garden millipede. But almost all centipedes are hunters and have evolved legs that splay out sideways from their body, which allows a rapid rowing motion as they chase prey. Millipedes have shorter legs tucked underneath their bodies to give them better traction as they push their way through soil and leaf litter.…

Software comprises lots of files and programs all interacting. When a computer is running software, it loads much of the program into its memory. If we managed to update that same software on the hard disk or SSD, then the program may panic as everything will be different – it won't be able to find the files that were there a moment ago. The version in memory will not be compatible with the version on the hard disk or SSD. Lots of errors will be thrown and your computer may crash. To prevent this, operating systems usually insist that when major updates are needed, we shut down the software being updated, then restart with the new software installed.…

GECKO-INSPIRED ROBOT TO BE RECRUITED TO THE OPERATING THEATRE A climbing robot inspired by geckos could assist surgeons with difficult operations. Dubbed GeiwBot, the robot was designed and built by engineers at the University of Waterloo, Canada. It is made from a smart material that allows users to remotely activate magnetic grippers on its surface that mimic how geckos use their feet to climb walls and trees. Currently, the bot can be moved into position by shining ultraviolet light onto a light-reactive strip on its back that causes it to crawl much like an inchworm. The researchers now plan to develop a system that allows it to be controlled by near-infrared radiation for potential use inside the body during surgery. BACTERIA COULD BE USED TO HARVEST RARE EARTH METALS FROM…

How would you respond if you were chatting with a stranger and they used hate speech, or told you they wanted to run over someone with their car? Some people might be agreeable. Some would deflect or change the subject. And some might ask questions or push back. Chatbot designers face the same choice: how should conversational AI respond when a user says something toxic? Interestingly, chatbots may be successful at encouraging people to do better. Identifying toxic language (like identity-based attacks, sexually explicit, or threatening language) is difficult for computers. Moderation tools struggle to account for context, sarcasm, or slang, and both human and AI-powered moderators are more likely to label a black person's comment as offensive compared to a white person's. But when a chatbot can correctly identify…

Philips Hue starter kit £134.99, philips-hue.com Philips Hue offers a huge range of lighting and accessories, from standard bulbs to lighting strips, chandeliers, outdoor lighting, motion sensors, switches, and decorative Edisonstyle bulbs. Until recently, every Hue bulb had to be connected wirelessly to a hub, called the Hue Bridge, which plugged into your Wi-Fi router. That is still an option – and is required to unlock full functionality – but the latest generation of Hue bulbs have Bluetooth, for direct control from the smartphone app. Whichever approach you take, the Hue system is easy to set up and use, with options for gathering lights into groups for simultaneous control, for setting timers and for having your lights simulate a sunrise. Hue's fullcolour bulbs can be any colour, brightness and temperature,…

Fermented foods Unpasteurised sauerkraut, kimchi, kefir, blue cheese, live yoghurt, miso, tempeh, fermented pickles and kombucha all help to boost the diversity of beneficial microbes in our gut. While we still have a lot to learn about the effect of the gut microbiome on the brain and mental health, animal studies indicate that the bugs in our guts can influence everything from anxiety to the structure of our brains, and a diverse gut microbiome is supportive of overall health. Tea, coffee and dark chocolate These are rich in polyphenols, which can enhance the elasticity of blood vessels, allowing blood to flow more freely. In the gut, polyphenols are converted into phenolic acids, which have a protective effect on brain cells. Tea has been shown to reduce anxiety and improve memory…

The harpy eagle is one of the largest and most powerful raptors on earth. Native to the rainforests of Central and South America, it is named after the harpies of Greek mythology; malevolent wind spirits with the face of a woman and the body of a vulture. The harpy eagle is an apex predator. Its broad and relatively short wings enable it to fly almost straight up, so it can navigate the understory of the forest, and attack from below as well as above. Monkeys, sloths and opossums beware; the harpy eagle can snatch prey weighing up to 8kg. Its curved black talons, which can grow up to 13cm long, can exert over 50kg of pressure, so it kills its victims by crushing them. Cloaked in demure shades of grey,…

The ideal way to dry wet laundry is to hang it outside on a warm, sunny day, but that's not always possible. When drying clothes indoors, three main factors determine drying time: temperature, humidity and airflow. The water molecules trapped in the fabric's fibres must evaporate by turning into water vapour. This happens as water molecules jostling within the fabric gain enough energy to turn into a gas, a process that is accelerated if the material is warmer. At the same time, water molecules in the air randomly condense onto the fabric. So, the drier the air, the higher the ratio of evaporation to condensation, and the faster clothes will dry. Warmer air holds more water, so higher temperatures reduce the relative humidity, which help clothes dry faster. A flow…

WHAT GIVES CLOUDS THEIR SHAPE? If you've ever tried to make out faces or animals in the contours of the clouds, you might have wondered why they come in such a variety of shapes. Moisture is always present in the air as water vapour, but when it condenses into liquid droplets or solid ice particles, these particles scatter light, making them visible as clouds. The shape of a cloud is determined by air temperature, density and movement. Differences in temperature and density prevent water-laden air from mixing with the surrounding air, giving clouds a distinct shape and creating crisp edges. Air movement pulls clouds into different formations. Although no two clouds are exactly the same, they can be grouped into categories. Cumulus clouds are puffy and cotton-like, forming low in…

Q & A Most of us have a friend that can eat whatever they want, whenever they want, and still somehow stay slim. They may say they've been blessed with a fast metabolism, but is that really the case? The metabolism is the process by which our bodies turns food and drink into the energy we need for life. Often, scientists talk about metabolism in the context of the body's energy use over the course of a day, which is called the metabolic rate. The more energy expended, the higher the metabolic rate. It follows, then, that people with fast metabolisms are those that burn through a lot of energy in one day. The majority of the energy we get from food is used by the body simply to keep…

Many small asteroids, such as Dimorphos, Ryugu and Bennu, have quite low densities compared to moons or terrestrial planets. Known as ‘rubble-pile’ asteroids, they appear to be composed of loose conglomerations of rocks, small grains and dust, and are not ‘solid’ at all. Planetary scientists believe that rubble-pile asteroids are formed by material coalescing after the destruction of larger asteroids. The Japanese spacecraft Hayabusa2 visited asteroid Ryugu in 2018 and revealed that about 50 per cent of its volume is empty space! Meanwhile, measurements have revealed that Bennu has a density only slightly greater than that of water. It is likely that Bennu has hollow cavities in its interior, some of which are probably filled with water. NASA's OSIRIS-REx probe, which collected a sample from Bennu in 2020, would almost…

Northern glass frog This tree frog has translucent skin on its belly, which makes its internal organs clearly visible from underneath. Elsewhere its skin is pale green, camouflaging it amidst the forest's foliage. Jesus Christ lizard Famed for its ability to run on water, when its hind feet slap the surface, they create air pockets which help to prevent it from sinking. It can reach speeds of up to two metres per second, for distances of up to four metres. Pink river dolphin This freshwater cetacean is the largest species of river dolphin. They are born grey and acquire their pink colour with age. Their final hue is influenced by many things, including behaviour, diet and how close their capillaries are to the skin. Hoatzin Hoatzins are surely the weirdest…

Hyperspace travel – the ability for spaceships to travel as fast as the speed of light – is an integral part of the Star Wars universe. The new series of The Mandalorian, for instance, would be quite a different show if Mando and Grogu had to wait 6,000 years to fly from one planet to the next. But it does raise the question of just how feasible such technology is. Will we ever attain the ability to travel vast distances across space without having to burn through generations of astronauts? Or are we just marooned in our corner of the Galaxy? To answer that, Prof Patrick Johnson, author of The Physics Of Star Wars, needs to be clear on what, exactly, hyperspace travel is. “If we're talking about the idea…