Sommaire pour September 2021 de BBC Science Focus Magazine

In 1988, the Intergovernmental Panel on Climate Change (IPCC) was formed. It is a body made up of the world’s leading climate scientists, with members from 195 countries. Back in 1990 it issued its first report warning of the potential dangers of rising greenhouse gas emissions. Here are the key points from its latest report, released in August this year. Human activity over the last 100 years is to blame for increases in temperature Human activities have changed the climate and led to a significant increase in heatwaves, floods, droughts and wildfire. The researchers estimate that emissions of greenhouse gases from our activities are responsible for raising global surface temperatures by around 1.1°C since 1850-1900, with the last five years being the hottest on record. If this is allowed to…

Students may complain that Pythagoras’ Theorem has no real-world uses, but a 3,700-year-old tablet demonstrates that the formula was being used long before Pythagoras even wrote it down. The artefact, named Si.427, shows how ancient land surveyors used geometry to draw boundaries accurately. First discovered in central Iraq in 1894, Si.427 sat in a museum in Istanbul for over a century. It was only when mathematician Dr Daniel Mansfield from the University of New South Wales, Australia, began to study the clay tablet that its meaning was uncovered. “Si.427 dates from the Old Babylonian (OB) period – 1900 to 1600 BCE,” said Mansfield. “It’s the only known example of a cadastral document from the OB period, which is a plan used by surveyors define land boundaries. “This is from a…

More time spent indoors during the COVID-19 pandemic may have caused a significant rise in childhood short-sightedness, according to a new Hong Kong study. Published in the British Journal Of Ophthalmology, the findings were based on the ongoing Hong Kong Children Eye Study, which continually researches the eye conditions of children aged six to eight. The study found that 19.5 per cent of the 709 children recruited at the start of the pandemic (between December 2019 to January 2020) developed short-sightedness over the course of eight months. The overall estimated one-year incidence of shortsightedness for COVID-era six-year-olds was 28 per cent – much higher than the 17 per cent found in children studied pre-pandemic. The researchers note that these changes coincided with a reduction in the time the children spent…

WHAT DID THEY DO? In a niche experiment, researchers at the University of Bonn designed a machine to throw beer mats and recorded their trajectories using a high-speed camera. WHAT DID THEY FIND? The action of gravity causes the beer mats to tip backwards shortly after being thrown. They unavoidably begin to drift off their course after 0.45 seconds, wending to the left if they are spinning clockwise, or to the right if they are spinning anticlockwise. Now you know. WHY DID THEY DO THAT? Erm... just for fun. “There is no application for the project,” said the University of Bonn’s Dr Carsten Urbach. “However, the problem is clear for laypeople and physicists alike. And it wonderfully illustrates the entire process by which the natural sciences acquire knowledge – from…

SCIENCE BEHIND THE HEADLINES Space junk | Billionaires in space | Athletes and mental health “Estimates suggest there are currently half a million pieces of debris the size of a marble or larger, and 100 million pieces of debris more than one millimetre across” Visit the BBC’s Reality Check website at bit.ly/reality_check. or follow them on Twitter @BBCRealityCheck This year, in May, a hole was found in a robotic arm aboard the International Space Station (ISS). The suspected culprit was a piece of space junk. While thankfully no astronauts were injured, it has re-focused attention on the growing problem of orbital debris. HOW DID WE GET HERE? It’s easy to forget that just seven decades ago the Moon was the only thing orbiting the Earth. On 1 January 2021 there were 6,542 satellites…

Recently, I made a 10-part Radio 4 podcast called Just One Thing where in each 15-minute episode I explored the science behind simple things you can add to your daily routine, like squats, eating more fermented food or going for brisk, early morning walks. It was an instant hit and was immediately recommissioned. You can find the original series on BBC Sounds, where you will also find the latest episodes of the second series. One of the most popular episodes from the first series explored the risks and benefits of cold water immersion. For this episode I started having cold showers every morning, starting with a brief burst of hot water, followed by 45 seconds or so of an icy cold blast. It certainly perks you up, but is there…

HOW CAN I SEE CYGNUS? SEPTEMBER-NOVEMBER September ushers in the autumn equinox mid-month, heralding the onset of rapidly darkening skies. It provides optimum viewing of the constellation Cygnus, which from dusk appears directly overhead in the night sky. Cygnus is the 16th largest constellation and is easily recognisable for its distinctive cross pattern that resembles a swan in diving flight. It sits in the plane of the Milky Way and is rich with sky objects. These include two open star clusters, M29 and M39, which are both easily seen with a decent pair of binoculars. Even without optical equipment, Cygnus offers some bright stars that are visible to the naked eye. The brightest is Deneb, a blue-white supergiant located around 1,400 light-years away. You may already be familiar with Deneb…

WHY CAN OLD DREAMS FEEL LIKE REAL MEMORIES? For some people, old dreams can feel like real memories and this experience is referred to as ‘dream reality confusion’. In two studies by researchers from Maastricht University in the Netherlands, difficulty distinguishing dreaming and reality was reported by a substantial minority of participants (12 per cent in one study and 26 per cent in another). It has been proposed by other teams of researchers that the experience is particularly common in certain participants (such as those with narcolepsy or borderline personality disorder). Although there is relatively little research in this area, there are many hypotheses as to why this might occur. One possibility is that the dreams that are confused with reality are different from other dreams (they could be more…

After 25 movies in 59 years, it’s time for James Bond to make an appointment with a doctor. After all, surely a lifetime of dodging bullets, fighting villains, jumping off buildings and regularly drinking more cocktails than a Blackpool hen night cannot be good for you? We asked Carl Heneghan – a GP and professor of evidence-based medicine at the University of Oxford – to sit Bond down for his check-up. THE NAME’S INJURY, HEAD INJURY James Bond has been knocked unconscious from hits to the head 14 times throughout his career. “These are serious head traumas that will affect brain function,” says Heneghan. “In the long term we’re talking chronic traumatic encephalopathy, a neurodegenerative disease that plagues contact sports like American football.” Symptoms could include early onset dementia, anxiety,…

Fallout A moving four-part documentary from Lights Out that lifts the mushroom-cloud of mystery surrounding the UK’s history of atmospheric nuclear weapons tests. BBC Radio 4 11pm, 6 September The Mating Game Find out more about the birds, the bees, and animals from all over the world in this new documentary series on mating and reproduction, narrated by Sir David Attenborough. Check Radio Times for details The Life Scientific Reality is an illusion. Neuroscientist Prof David Eagleman (pictured) tells Prof Jim Al-Khalili how our brains create their own truths. BBC Radio 4 9am, 14 September…

You may have been told that it’s rude to start eating before everyone is ready, or that you shouldn’t leave the table before your guests have finished. As it turns out, apes are no different. Like us, chimpanzees and bonobos make a common gesture that signifies the start and end of a social interaction – a mutual gaze or a vocal signal is enough to show they’re ready to play, for example. These signals could represent the start and end of a mutual agreement, which researchers say challenges the current idea that only humans make joint commitments. “Joint commitment is the driving force, the glue, of our joint actions, whether at large scale, like long-term projects, or small scale, such as lunch,” explained one of the study’s authors Dr Raphaela…

Whether it’s 5:2, 16:8 or Eat Stop Eat, intermittent fasting diets have skyrocketed in popularity in recent years. Proponents of the diets claim they bring all manner of health benefits, from simple weight loss to significant falls in blood pressure, blood sugar and cholesterol. Now, a study carried out in mice at the University of British Columbia in Canada suggests that fasting may also help to protect us from infection. When humans or animals develop an infection, they often lose their appetite. However, it has so far remained unclear as to whether fasting could protect a host from infection or increase their susceptibility to it. To test this, the researchers fasted a group of mice for 48 hours and orally infected them with Salmonella enterica serovar Typhimurium – a bacteria…

The contenders for the world’s largest astrophotography competition have been chosen. The winners will be announced at an online ceremony on 16 September. Following the ceremony, a selection of the winning and shortlisted images will be displayed at an exhibition at the National Maritime Museum, London, from 18 September. 1. Lunar halo by Göran Strand This lunar halo was taken in a temperature of –16°C. This optical phenomenon forms when moonlight is refracted by ice crystals hanging in the atmosphere. 2. The tumult of the Sun by Hassan Hatami This image was created from data collected by NASA’s Solar Dynamics Observatory. It shows the tumultuous currents that churn around the Sun’s surface. 3. Alien throne by Marcin Zajac Locals living in the Badlands of New Mexico refer to rock spires…

Space travel made international headlines in July as both Amazon founder Jeff Bezos and Virgin boss Richard Branson flew to space in craft made by their own companies. Not to be outdone, Elon Musk’s SpaceX plans to launch an all-civilian crew into orbit in September. Commercial space travel is clearly firing up, and is predicted to become big business. Branson’s Virgin Galactic plans to begin regular commercial services in 2022, and already has 600 reservations at around $250,000 a ticket. According to a recent analysis from Swiss finance firm UBS, the space tourism industry will be worth $4bn by 2030. Upon landing from his suborbital flight, Bezos said the experience reinforced his commitment to fighting climate change. But what impact could spaceflight have on the environment itself? Rockets burn through…

NASA, perhaps best known for its spacecraft, also has pretty sizeable fleet of aircraft under its belt. It has a venerable tradition of X-planes, where ‘X’ stands for experimental. It started back in 1946 with the X-1, which became the first aircraft to travel faster than sound. Three-quarters of a century on, its new plane, the X-59, also aims to break the sound barrier – but this time it’s going to do it quietly. The speed of sound has always caused headaches for aircraft designers. The reason lies in the nature of sound itself. When anything from a handclap to a rocket disturbs the air, it causes pressure changes that spread out like a wave. The speed of this wave depends on the properties of the air, but under normal…

A recent poll by Aviva suggested that 60 per cent of UK workers plan to make changes to their career. Some want to find work that helps others, or that creates an income from a hobby, or allows for more flexible working. Those in the 25 to 34 age group are most likely to want to retrain to pursue a completely different career path from their current one. These numbers have increased since the pandemic started. There was already turbulence in the workplace, with many people and organisations feeling the impact of new technology, demographic changes, political decisions and climate change. The pandemic has brought new disruption, creating further uncertainty as well as the opportunity to review career direction. Prof Herminia Ibarra, from the London Business School, asserts that the…

YOUR QUESTIONS ANSWERED … IS IT POSSIBLE TO MAKE A SHIP OUT OF ICE? … WERE THE DINOSAURS COLD-BLOODED? … WHY ARE SEEDS SUCH DIFFERENT SIZES? … WHY DO I KEEP HAVING RANDOM VIOLENT THOUGHTS IN PUBLIC? … WHY DO FLAMINGOS STAND ON ONE LEG? … WHAT’S THE CARBON FOOTPRINT OF STREAMING TV? … WHY IS FLASH PHOTOGRAPHY BANNED FROM MOST MUSEUMS? … HOW CAN I SEE THE CYGNUS CONSTELLATION? … WHY CAN OLD DREAMS FEEL LIKE REAL MEMORIES? Email your questions to questions@sciencefocus.com or submit on Twitter at @sciencefocus OUR EXPERTS DR CLAIRE ASHER Science journalist PROF ALICE GREGORY Psychology and sleep expert DR STEVE BRUSATTE Veteran palaeontologist DR ALASTAIR GUNN Astrophysics lecturer NISHA BEERIERAZ Science and astronomy writer DR HELEN PILCHER Biologist and science writer BRIAN CLEGG Science…

I read with interest Aleks Krotoski’s column about the marginalisation of some groups in society due to the diminishing role of cash (August, p64). A large group mentioned in the article were the underserved and unbanked. We have a solution available, in the form of cryptocurrencies. Literally designed to be digital cash, with no complicated application forms to fill in and no credit history needed, you don’t even need a physical or fixed abode. The tech offers more than just cash, it can also give you a digital identity, which for some people will be a major step up in their ability to interact. Steve There have been several approaches to using blockchain services for the underserved and unbanked, from providing a stable ID to access government and health services…

Scientists have used fitness tracker technology on a troop of wild olive baboons to uncover how they stick together as a group. The results of the research showed that travelling with a mix of ages and abilities requires compromise on the part of the long- and the short-legged – but it’s the littlest baboons that draw the shortest straw. “Anybody who has tried to walk with a toddler knows the challenges of moving with someone who has a different physical ability,” said first author Dr Roi Harel, an ecologist at the Max Planck Institute of Animal Behavior. “Small individuals pay disproportionate costs associated with maintaining group cohesion, and this might be because they have the most to gain from group membership.” The team worked with a troop of wild baboons…

PROF PENNY HOLLIDAY Oceanographer “The ocean has this capacity for storing heat. This movement of heat around the globe keeps our climate nice for us to live in” STUDIES HAVE FOUND THAT THE ATLANTIC MERIDIONAL OVERTURNING CIRCULATION (AMOC) IS SLOWING DOWN. WHAT EXACTLY IS THE AMOC ? Put simply, it is large-scale ocean currents in the upper 1,000 metres of the Atlantic. The currents transport warm, salty water northwards throughout the Atlantic. When the water reaches the subpolar North Atlantic, the water gets cold, becomes dense and it sinks down to below 1,000 metres and it flows back southwards. You can think of it as a global conveyor belt, like the ones you see in the supermarket. WHAT INFLUENCE DOES THIS CONVEYOR BELT SYSTEM HAVE? It’s all about heat, it’s like…

“Consider a gymnast with their sights set on Olympic gold, for example. One slip, or one lapse of concentration, and that ambition is gone in an instant” Recently, mental health in sports was thrust into the public spotlight when Olympic gymnast Simone Biles and tennis star Naomi Osaka both chose not to compete, citing concerns over their mental wellbeing due to the pressures of elite competition. Both athletes strongly expressed concerns over the ongoing effects of being in an intense competitive environment, and both argued that a deterioration in mental health is a legitimate reason for withdrawing from competition. Although some reporters have been less than sympathetic, arguing that these highly paid athletes should accept and deal with the pressure, we should not be so easy to dismiss the notion…

Listen to Dr Helen Scales talking about marine conservation on The Life Scientific bit.ly/LS_helenscales 1 DID LIFE BEGIN IN THE DEEP SEA? Life on Earth began about four billion years ago. Where and how those simple cells first sparked into life remain tantalising mysteries, but evidence is stacking up that they could have first emerged in the deep ocean. In 2017, palaeontologists identified microscopic tubes and filaments made of iron-rich haematite lodged within rocks formed between 3.77 and 4.28 billion years ago. The rocks are a rare fragment of primeval oceanic crust preserved on land (most of the seafloor gets dragged back into the Earth’s mantle, melted and recycled into new crust). The tiny formations have the characteristic shape of microbes that live today on deep-sea hydrothermal vents – the hot…

Understanding Einstein: The Special Theory of Relativity Stanford University coursera.org/learn/einstein-relativity Here you’ll learn what inspired Einstein and get expert insight into his theories. Led by Stanford science historian Larry Lagerstrom, it addresses problems such as whether time can run more slowly for one person than another. Over 100,000 students have enrolled to tackle the 81 hours of course content. Learn for free or get a certificate for £34. Conservation with Jane Goodall / Space Exploration with Chris Hadfield Masterclass masterclass.com/classes/jane-goodall-teaches-conservationmasterclass.com/classes/chris-hadfield-teaches-space-exploration Masterclass works differently to other online classes in that it’s subscription-based. For £170 a year, you get access to all its eclectic range of courses. Some of the experts are top-level – renowned chimp expert Jane Goodall teaches conservation, while the space class is led by ex-International Space Station commander,…

SARCASTIC FRINGEHEAD It has an awesome name, with an attitude to match. The sarcastic fringehead is a big-mouthed, bolshy blenny that lives in the temperate coastal waters of California and Mexico’s Baja California. These strange fish hang out in their ocean floor dens, which can be burrows, empty shells or even discarded plastic bottles. Males reverse in, bottom first, then defend their territories from other sarcastic fringeheads by dropping caustic one-liners. Only joking! Riled individuals actually face-off by slamming their huge, open mouths together. Laterally-splayed jawbones and sail-like cheek membranes reveal a purple tongue, a double row of teeth, and a fluorescent yellow mouth rim. They look part fish, part Demogorgon from Stranger Things. It’s basically a ‘who’s got the biggest mouth’ competition, where the victor bags the best den…

I’M A MONSTER! WHY DO I KEEP HAVING RANDOM VIOLENT THOUGHTS IN PUBLIC? Everyone has inappropriate, alarming thoughts that occur to them out of nowhere. Thoughts of violence, of sex, of both. Many people worry that such thoughts mean there’s something wrong with them. But the opposite is true; they actually mean your brain is working normally. Human brains don’t just learn about the world by observing, experiencing and remembering things that happen to us. They also speculate, anticipate and simulate actions and outcomes. Our brains are constantly churning out thoughts about hypotheticals and ‘what ifs’ regarding our decisions and actions, to give us the best possible chance of succeeding with whatever it is we’re doing. Most of these will be straightforward, uninteresting, and forgotten quickly. These are ‘mundane’ thoughts.…

ACROSS 7 Policemen point to some trees (5) 9 Unfair treatment when buying salad ingredients? (3,4) 10 Straighten a French religious sign (7) 11 Fat Greek character takes cover out (5) 12 Deceive first threesome by way of petty details (6) 13 Strong drink for morale (6) 16 Car test includes gag about bait (6) 17 Blamed criminal for causing scene of confusion (6) 19 Gem held between rubbery lips (5) 21 Baffle complete, wife missing burrow (7) 22 Expert note about being solvent (7) 23 Scandinavian food (5) DOWN 1 Get used to a cold habit (8) 2 Nice and poor, cooking cheese (8) 3 Search for loud hazard (5) 4 Initially, and not properly, missing (4) 5 Recreate label, promote brainy bit (8,4) 6 Walk like a policeman…