Sommaire pour January 2024 de BBC Science Focus Magazine

If you click ‘reject all cookies’ whenever you visit a new website, you may be revealing more about yourself than you think, says new research. Cookies are pieces of data stored on your devices for various purposes, such as remembering your login details. They can also track your online behaviour so that companies can tailor adverts to you. Many people don't like this, whether because they want to keep their personal information private or because they don't want companies using it to sell them things. But new research, announced at NeurlPS 2023 (an AI conference that took place in December 2023), revealed there's a particular demographic that rejects cookies more than other people - and the advertisers know this. So cookierejectors may not really be keeping their information private after…

In our short history of space exploration, humans have already changed the Moon significantly. From the cultural heritage of our first footprints to the damage caused by the crash landings of our spacecraft, our presence is practically frozen in time in the Moon's dusty regolith. The Moon has been in its current epoch, the Copernican, for the last 1.1 billion years. Now, researchers are arguing for the formalisation of a new epoch: the lunar Anthropocene. This epoch, the researchers argue, began in 1959 when Russia's Luna 2 spacecraft became the first craft from Earth to land on the Moon. We spoke to one of those researchers, space archaeologist Dr Justin Holcomb at the University of Kansas in the US, to learn more. WHAT MARKERS SUGGEST THAT A NEW EPOCH HAS…

Imagine getting ready for bed, brushing your teeth, setting your alarm and then putting a device on your head that will enable you to control your dreams. It might sound like something out of a Christopher Nolan movie, but it's also the real-life promise of a new headband called Halo that's being developed by Prophetic, an American tech company. Halo is slated for release in 2025. The idea behind it is that the headband will allow you to have more lucid dreams and enjoy greater control over their content in ways that will benefit your waking life, from solving problems to practising guitar. The defining feature of a lucid dream is your awareness of being in a dream. In some cases, you might also be able to exert a degree…

It's no surprise that the rise of time poverty is largely down to changes in our work lives. But not in the rise of work hours: there's some evidence that hours per week have actually dramatically and nearly consistently fallen over the past 100 years. According to one study, the average employee in the UK works 514 fewer hours per year – the equivalent of 64 working days – than 70 years ago. However, while our work hours have fallen, the intensity and speed of that work has rocketed. After all, in the pre-digital era, the absence of email, video calls and instant messages created a naturally slower work environment. Just imagine it: how many letters would you send each day if they had to be handwritten and posted? How…

Perhaps the most surprising scientific discovery of the last decade is that the Universe is teeming with black holes. They've been detected in a surprising variety of sizes: some with masses only a bit larger than the Sun, others that are billions of times larger. And they've been detected in a variety of different ways: by radio emissions from the matter falling towards the hole; by their effect on the stars orbiting them; by the gravitational waves emitted as they merge; and by the extremely peculiar distortion of light they cause (think back to the ‘Einstein ring’, seen in the photos of Sagittarius A*, the supermassive black hole at the centre of the Milky Way, that graced the front pages of the world's newspapers not so long ago). The space…

Most of us strive for self-respect – to see ourselves in a positive light, to be proud of who we are. Any comments or experiences that undermine those feelings of self-worth can be uncomfortable and it's only natural to want to avoid them. But the thing is, whether your self-worth really is being undermined is, to a large degree, subjective. Much of it comes down to your perception of what someone said or did. When you take things personally, you're interpreting these situations as saying something significant and negative about you as a person. Say your boss picks holes in your sales report, and you come away feeling like this means she thinks you're a poor member of staff. Or, two of your friends cancel your planned get together at…

ACROSS 1 Happy to be told not to start (6) 5 Musical game (5) 9 Zero about strange lab being sweet (7) 10 Villain in Cairo, guessing (5) 11 Peculiar, losing American trinket (5) 12 Resentment one controlled in ship (7) 13 Group has right to my last drink (6) 15 Crime making one fly in a panic (6) 18 Walks with small monsters (7) 20 Quiet chat about material reinforcement (5) 23 Insinuate – like a rascal? (5) 24 Choose diamonds first, then mountaineering gear (3,4) 25 Sodium, sulphur and aluminium in one's nose (5) 26 Festival involved a steer (6) DOWN 2 Unending regalia for an organ (5) 3 Old bait used daily (7) 4 Dig up doctor by the border (6) 5 She's often heard at Christmas (5) 6 Artist's unrestrained glee acquiring registered company (2,5) 7 In a severe way at the back? (7) 8…

Despite a good night's sleep, many people still find themselves feeling drowsy and fatigued throughout the day. According to a study published in December, this could be explained by a sleep disorder that might be more common than previously thought. Idiopathic hypersomnia is a neurological disorder that can cause people to feel very tired during the day, sleep for excessive periods of time, have difficulty waking up and even wake up disorientated. While similar in nature, idiopathic hypersomnia is different to the more common narcolepsy. Narcolepsy can also cause people to feel tired throughout the day, but sufferers tend not to sleep excessively and can wake up feeling refreshed from naps. “It has been difficult to determine the prevalence of idiopathic hypersomnia because expensive and time-consuming sleep testing is required…

There are countless methods and devices that claim to improve the taste of your coffee, but scientists have discovered a trick that involves a few drops of water. The process of grinding coffee beans creates friction, which generates static electricity that can cause the particles of coffee to stick together. But scientists report that coffee beans holding a higher internal moisture level produce less static electricity. This, according to their findings published in the journal Matter, makes for a more reliable and intense espresso. All you need to do to raise the moisture content is simply add a splash of water to the beans before grinding them. “The central material benefit of adding water during grinding is that you can pack [your coffee machine] more densely because there's less clumping,”…

SF | REALITY CHECK | REVIEW THE SCIENCE BEHIND THE HEADLINES COVID inquiry | Dengue fever | Dream tech “That the UK didn't maintain its stocks of PPE was one of the main drivers of the high mortality rates in health and social care workers” For more fact-checking news, visit the BBC's Verify website at bit.ly/BBCVerify One of the hard lessons we learnt over the past four years is that public health relies on us balancing the benefits and harms of any action we might take to reduce the impact of disease. The recent COVID inquiry reminded us of that. But balancing those benefits and harms is difficult when you're not sure what they may be. Getting a clearer understanding of what works and what doesn't was one of the aims…

The giants of the tech world seem dead set on making virtual reality (VR) a daily part of our lives. No matter how many times it fails, they just keep coming back to insist the next headset, the next upgrade or the next iteration of it will be the key to a whole new experience. I've become pretty sceptical about these claims. Having yet to encounter a truly viable at-home VR experience, Mark Zuckerberg's regular claims that he hasn't wasted billions on his huge Meta project are falling on deaf ears here. But with the Meta Quest 3, he might finally be on to something. It launched in the UK in October and, dare I say it, might represent enough of an improvement to actually make me like virtual reality.…

TYRANNOSAURUS REX In 1902, in the desolate badlands of Hell Creek, Montana, the palaeontologist Barnum Brown spotted a jumble of enormous bones. They were from a muscular animal that stood several meters tall and walked on its hindlegs. The skull and jaws had the snarly grin of a fierce predator. Brown shipped the bones back to New York, where they were displayed at the American Museum of Natural History in 1905. Crowds were aghast. The monster — a dinosaur christened Tyrannosaurus rex — was described by the New York Times as “the most formidable fighting animal of which there is any record whatever.” In the 120 years since Brown's discovery, dozens of T. rex skeletons have been found in the 66-million-year-old Cretaceous rocks of North America. Scientists still regard T.…

HOW TO SEE THE HYADES STAR CLUSTER WHEN: JANUARY-FEBRUARY Go outside on a clear, dark night and look towards the south to locate the three stars of similar brightness in a line forming Orion's Belt. This distinctive arrangement is an excellent signpost for finding other sky targets. Follow the line it makes down and left as seen from the UK, to arrive at bright Sirius, the Dog Star, the brightest star in the night sky. Follow the belt line in the opposite direction to arrive at Aldebaran, a star marking the red eye of Taurus, the Bull. The bull's face is represented by the sideways V-shaped pattern of stars next to Aldebaran: the Hyades open cluster. The Hyades is the closest open cluster to Earth, an open cluster being a…

During Dry January in 2023, the World Health Organization (WHO) issued a statement about alcohol that poured warm, stale lager on the idea that any amount of booze is good for you. There's no such thing as a safe drink, it said. Issued in The Lancet Public Health, the statement reminded us that “alcohol is a toxic, psychoactive and dependence-producing substance and [was] classified as a Group 1 carcinogen by the International Agency for Research on Cancer decades ago.” Sobering stuff, and a surprise for those of us who toast our health with the occasional tipple. Everyone knows that drinking to excess is linked to a cocktail of ill health effects: damaged livers, hearts and mental health, plus increased risk of cancer. But most drinkers have also heard that, in…

SF | EYE OPENER BRITISH COLUMBIA, CANADA Nature photography requires patience to get that perfect shot. Patience paid off for Shane Gross, who captured this image of a family of tadpoles in a lake in British Columbia. Tadpoles tend to hide in deeper water at night in orderto avoid predators like water bugs and leeches. But during the warmer parts of the day they swim to the more oxygen-rich shallows to feed on plants and algae. This process is repeated daily for six to eight weeks before they finally metamorphose into Western toads, a common species in Canadaand the United States. “It was a real spectacle to behold,” says Gross. “But it was very challenging, photographically. I wanted to capture the whole scene, showing the tadpoles1 habitatas they swam among…

SF | DISCOVERIES MEDICINE Not sure whether hearing aids are worth getting? Well, scientists at the University of Southern California (USC) investigated their benefits and the results are loud and clear: hearing aids can reduce your risk of death by almost 25 per cent. Despite there being 40 million adults in the US who suffer from hearing loss, only one in ten people who need hearing aids actually uses them. In the UK, only three in ten people who need the devices use them, though 11 million are affected by hearing loss. The USC scientists hope the findings of their study will encourage people to use hearing aids. “Personally, as someone who uses a hearing aid, I find this result exciting,” Dr Janet Choi (opposite), lead researcher of the study…

Scientists have pinned down the characteristics of a unique type of genius dog, and it all comes down to how well they know their toys. These dogs are known as Gifted Word Learners (GWLs), as they know the names of many of their toys and can retrieve them on command. Published in Nature Scientific Reports, the study confirmed that these canine geniuses are incredibly rare. In fact, it's one of the first studies to investigate the characteristics of these dogs in depth, with a sample size of 41 rather than just one or two dogs. “By the time the study had finished, 50 per cent of the pups observed knew the names of over 100 toys” The researchers found that, on average, the genius dogs knew 29 toy names. However,…

We may not (yet) be able to see the future, but scientists can now predict which of your organs will fail first, according to a new study. But rather than a morbid window on your fate, the discovery could allow doctors to target these ageing organs early, before the symptoms of disease appear. The study, published in Nature, reveals that one in five healthy adults aged over 50 has at least one organ that's ageing too fast. This means they have a heightened risk of developing a disease in that organ over the next 15 years. But how can ageing happen at different rates within the same body? Everyone has two ages. There's your chronological age, the one you celebrate every year on your birthday that (unless you lie about…

Half of the global population is at risk of dengue, which is currently endemic in 100 countries. Between 2000 and 2019 there has been a 10-fold increase in dengue cases and 2023 saw the highest number of cases on record. The past year saw record-breaking outbreaks in Bangladesh, Peru and Burkina Faso. Climate change is fuelling the increase in this mosquito-borne viral disease, leading to larger outbreaks, quicker time between outbreaks and longer transmission seasons. Climate modelling studies forecast dengue spreading to more temperate parts of the world and putting even more people at risk. Now, the people behind a project named The World Mosquito Program are trying to solve the problem using a bacteria. You may think of dengue as a ‘tropical disease’, but ominously there are now reported…

THE AVERAGE HUMAN DAY How the average person aged 16-64 in OECD countries spends their time on various activities SOURCE: DECD Ruth is professor of the psychology of time, and a lecturer at Liverpool John Moores University. HOW DOES EACH COUNTRY SPEND ITS TIME? The average time (in minutes) people aged 16-64 spend on various activities SOURCE: OECD HOW MANY HOURS DO WE WORK COMPARED TO THE PAST? The average annual working hours for employees in OECD countries during the past 50 years SOURCE: OECD/HUBERMAN & MINNS…

BODY DYSMORPHIA FEATURE | SF A new year typically turns our minds to change. And if you've made a resolution around changing your appearance, you're not alone. Around 43 per cent of adults in the UK set a goal to lose weight last year. For many, these aims of ‘new year, new me’ may also extend to more extreme methods of appearance alteration, such as cosmetic procedures or plastic surgeries. But when does this common, widespread desire for self-improvement or enhancement become something more sinister? For around three per cent of the general population, the drive to fix or change one's physical appearance becomes a constant - a condition known as body dysmorphic disorder (BDD). Individuals with BDD see themselves as having serious defects or flaws in their bodies, that…

Lightning is one of the most spectacular displays that nature has to offer. But while it may be enjoyable to watch, it's something that you would never want to be struck by. To understand why, you need to know what lightning is and what causes it. Inside a thunderstorm (cumulonimbus) cloud, ice crystals and hail bounce around and collide with each other. This leads to the bottom of the cloud having a negative charge. But the top of the cloud and the ground it below both have a positive charge. Eventually, the negative and positive charges build up so much, that a huge spark of electricity – lightning – is released, and hits either other clouds nearby or something on the ground. The charge carried by a bolt of lightning…