Sommaire pour September 2019 de BBC Science Focus Magazine

In astronomy, the horizons are changing all the time. Bigger, more sophisticated telescopes and increasingly inventive imaging techniques continually redefine how much of our Universe we can see. In recent years we’ve discovered hundreds of Earth-like planets nestled in distant galaxies, witnessed neutron stars crash into to each other and even got up close and personal with a black hole. In these terms, it seems odd to think there might be an undiscovered planet lurking beyond Pluto, let alone one that might be four times bigger than Earth. After all, Neptune was discovered in 1846, and Pluto, though it isn’t considered a planet, was identified in 1930. How is that this shadowy world has evaded our gaze for so long? Find out on p50, where Colin Stuart reports on the…

Drone down PARIS,FRANCE Looking rather like props from an action film, these NEROD F5 devices are actually high-tech drone jammers, designed to scramble the signal of an enemy unmanned air system (UAS). On 14 July, this demonstration of the NEROD F5 stunned crowds at the Bastille Day parade in Paris. When the trigger is pulled, the gun fires microwave-frequency signals towards the drone, which then disrupts any communication between the drone and its pilot. This means the pilot can no longer direct the drone. The rifle-style design of the NEROD F5 is unlike most drone scramblers, which usually require a large battery that is worn in a backpack by the operator. Other methods of bringing down drones include sending a false GPS signal to the drone, which confuses its sense…

EDITORIAL Editor Daniel Bennett Production editor Alice Lipscombe-Southwell Commissioning editor Jason Goodyer Staff writer James Lloyd Editorial assistant Amy Barrett Online editor Alexander McNamara Online assistant Sara Rigby Science consultant Robert Matthews ART Art editor Joe Eden Deputy art editor Steve Boswell Picture editor James Cutmore CONTRIBUTORS Abigail Beall, Peter Bentley, Dan Bright, Verity Burns, Charlotte Corney, Emma Davies, Alexandra Franklin-Cheung, Federica Fragapane, Helen Glenny, Alice Gregory, Hilary Guite, Alastair Gunn, John Holcroft, Jules Howard, Christian Jarrett, Minet Kin, Lalitha Krishnan, Aleks Krotoski, Tor McIntosh, Sergio Membrillas, Michael Mosley, Helen Pilcher, Emmanuel Polanco, Helen Scales, Gabriel Silvera, Victor Soma, Colin Stuart, Jocelyn Timperley, Luis Villazon. ADVERTISING & MARKETING Group advertising manager Tom Drew Advertising manager Neil Lloyd Senior sales executive Anastasia Jones Brand sales executive Sarah Smith Brand sales executive…

Times were hard for the Stone Age inhabitants of the Bale Mountains of Ethiopia. So hard, in fact, that the plummeting temperatures of the Ice Age forced them to exist on a diet of giant mole rats, which were plentiful. Excavations of the Finch Habrea shelter, located 3,350m above sea level, have discovered stone artefacts, bits of pottery, and piles of giant rat bones (pictured right). Carbon dating suggests the artefacts are between 47,000 and 31,000 years old making the site one of the oldest high altitude settlements ever discovered.…

#WorldLizardDay 14 August marked this year’s World Lizard Day – a global celebration of all things lizardy. Liam Russell @liam_agilis #WorldLizardDay #sandlizards are found in 3 areas of the UK, heathland in Surrey and Dorset and sand dunes in Merseyside. Dune animals differ in colour and pattern. ZSL London Zoo @zsllondonzoo Happy #WorldLizardDay from Ganas! #DYK, Komodo dragons are the largest living lizards in the world? #WildlifeWednesday #WildlifeFacts IOP Publishing @IOPPublishing Join us to celebrate #WorldLizardDay with research exploring the adhesive systems and load-sharing that occurs in gecko toes in the journal @BioinspBiomim by researchers from @StanfordEng and @TU_ Muenchen (bit.ly/lizard_toes) #GretaThunberg Climate change activist Greta Thunberg is heading across the North Atlantic on a boat to attend a climate change conference in New…

GAMERS Playing video games may be the best way to wind down, researchers at University College London have found. People who played a smartphone puzzle game for 15 minutes after work were more relaxed, more energetic, and less stressed than those who were given fidget spinners or mindfulness apps to use. OPTIMISTS Being a glass-half-full person may help us to sleep better, a study at the University of Illinois has found. A survey of more than 3,500 people aged 30 to 50 found that those who rated themselves as optimistic were 78 per cent more likely to report good sleep.…

There are currently around 850,000 people living with dementia in the UK, with estimates by the Alzheimer’s Society indicating this could soar to more than two million by 2051. There is currently no cure, but maintaining social links throughout middle age could help to lower the risks of developing the disease, a study at University College London suggests. The team analysed data collected between 1985 and 2013 about people’s frequency of contact with friends and relatives. They then checked the electronic health records of the same people up until 2017 to see if they’d ever received a dementia diagnosis. They found that those who saw friends and relatives almost daily at the age of 60 were around 12 per cent less likely to develop dementia than someone who only saw…

YOUR WORK FOCUSES ON FORGETTING… The majority of the public, and also many of my colleagues, think of forgetting from the perspective of memory failure. Forgetting is thus considered to be a glitch of memory. It is a relatively recent a fundamental function of the memory system, something that it needs to function properly. On one hand there is a system that constantly makes sure that structures that have been formed during memory formation are maintained, and, at the same time, there’s a process that tries to eliminate these structures. We now refer to this process as an ‘active forgetting mechanism’, a process that brains use to remove memories with the goal to keep memory optimally functional. SO FORGETTING IS A GOOD THING? I think there is indeed a bliss…

Within 50 years, there will be artificial intelligence that is indiscernible from a human being. Discuss. I’m not talking about a Turing test for a computer’s ability to deceive us; tech can already do that really well. Think of a real-life, embodied version of Scarlett Johansson’s character in the Spike Jonze film Her. A programmed artefact that, if we met it in the street, would be so convincing that we couldn’t tell the difference between us and it. Full disclosure: I don’t believe it’ll happen, and certainly not in the next half century (even if we could make convincing synthetic bodies). I’ve spent too long investigating the complexity of the mind to imagine a computer programmer has cracked our code so quickly. We have too many nuances and contradictions to…

HORMONES AND NEUROTRANSMITTERS IN THE BRAIN ECT increases the levels of some neurotransmitters (chemical messengers that transmit signals between neurons) and hormones in the brain. Serotonin and dopamine are two neurotransmitters that increase after ECT. Serotonin regulates anxiety and reduces depression, while dopamine affects mood and motivation. Antidepressants have similar effects on the brain, but as ECT is generally faster acting and more effective than antidepressants, experts believe these changes cannot entirely account for ECT’s benefits. INCREASES IN THE SIZE OF THE BRAIN’S EMOTIONAL PROCESSING AREAS A recent study in humans showed that ECT increases the amount of grey matter in the brain’s hippocampus and the amygdala. The hippocampus is involved in learning, memory and emotion, while the amygdala plays a role in the processing of emotions. However, this increase…

STEVE GRANTHAM, PRESTON WHAT’S THE MOST DANGEROUS SPORT? This is surprisingly hard to answer, as it depends both on how the risk is measured – per participant, say, or per event – and the availability of reliable data. But according to a 2014 analysis by Prof Sir David Spiegelhalter at Cambridge University, the UK’s leading authority on risk, mountaineering is probably the most dangerous sport, carrying a risk of death of around 1 per cent per climb. By comparison, running a marathon is around 1,000 times safer. RM NYE LEWIS-DAVIES WHAT DOES THE WORLD LOOK LIKE OUTSIDE OF OUR BRAINS? Your question has echoes of the American philosopher Thomas Nagel’s classic paper “What is it like to be a bat?” – a creature that is able to navigate using echolocation…

The science of epidemiology has saved the lives of millions by helping to reveal the causes of good and bad health. Using so-called cohort studies, researchers have made some crucial discoveries, showing the deadly link between smoking and cancer, for example, and the benefits of exercise for mental health. Yet the scientist who pioneered this type of study was forced to abandon research and died in obscurity – chiefly because she was a woman. Born in Lincolnshire in 1877, Janet Lane-Claypon was a brilliant medical student who became fascinated by epidemiology. In 1912, she published a pioneering study of two groups – ‘cohorts’ – of babies, fed breast milk and cow’s milk respectively. Using sophisticated techniques, she not only discovered the link between breastfeeding and better growth, but also ruled…

Hold onto your breath, dear readers, for this month we’re diving deep. Hundreds of metres beneath the surface of the world’s oceans, there lives a curious fish that waddles along the seafloor using its fins like four little legs. It has a pink complexion and a frog-like mouth. Upon its head is a unicorn-like dorsal fin which glows in the dark and entices inquisitive fish to their doom. This is the pink frogmouth, a deep-sea creature that looks to have been designed by a sugar-addled six-year-old. Still holding your breath? Good. You and the pink frogmouth have this in common. Earlier this year, scientists discovered that this fish (and other members of its taxonomic family) has the unique ability of holding its breath underwater, for as long as four minutes.…

RING VIDEO DOORBELL 2 Ring has the best smart doorbell, in my opinion. My favourite feature is the rechargeable battery, so you don’t have to wire it into the wall (although you can if you’d prefer), along with the ability to see and talk to any visitors through the mobile app. There’s motion detection too and, handily, infrared night vision. £179, EN-UK.RING.COM GOOGLE NEST CAM IQ INDOOR Google’s indoor smart home camera comes in a cheaper model, but the IQ is superior in that it’s smart enough to tell the difference between general motion and people. There’s two-way audio so you can scare off burglars, and a 4K sensor for a sharp picture. Pay a bit more for a Nest Aware subscription and it will even recognise faces. £299, STORE.GOOGLE.COM…

WHAT I’M WATCHING Amy Barrett EDITORIAL ASSISTANT HORIZON: CANNABIS – MIRACLE MEDICINE OR DANGEROUS DRUG? ON IPLAYER Cannabis. One of the world’s oldest and most controversial drugs. Even the word can conjure up that unmistakable whiff. Components of cannabis include tetrahydrocannabinol (THC), which is responsible for the high, and cannabidiol (CBD), a non-psychoactive ingredient that’s available as an oil in most pharmacies and health food shops. But what does scientific research say about the effects of cannabis on our brains and our bodies? In this Horizonprogramme, A&E doctor Javid Abdelmoneim joins a research group hoping to find an answer. Over a number of weeks, Javid inhales – supervised, of course – different quantities of THC and CBD. Sometimes, he is relaxed and good-humoured; other times, he becomes anxious,…

Eye opener ANTI-DRONE GUNS Watch a live-stream of the Paris Bastille Day parade, where the anti-drone guns were demonstrated in front of thousands. Skip ahead to 35:50 to see the guns in action. bit.ly/anti_drone_guns MELTING SEA ICE Climate scientist Steffen Olsen captured this incredible video of the dogs pulling him across the melting Inglefield Fjord sea ice. bit.ly/melting_sea_ice Reality check CAT SENSE BY JOHN BRADSHAW (£9.99, PENGUIN) Published in 2014, John Bradshaw’s insight into the domestic cat describes the challenges faced by felines, and their owners, in their lifetime. MAMMAL MAPPER APP FREE, AVAILABLE ON IOS AND ANDROID You can help The Mammal Society survey the UK’s wildlife populations by recording any sightings of mammals. The library created by users of the app will contribute to future scientific research and…

Your brain has its own box of memories. If you were to hold it in your hand, brush off the dust and open it up, you’d be able to pull out Polaroid snaps of your most treasured memories. Your graduation ceremony perhaps, wouldn’t want to forget. But how does your brain keep these memories in their crystal-clear clarity? The strength of a memory lies in its formation and upkeep. When we create a memory, the axons of nerve cells in the brain connect. The point at which two axons connect is called a synapse, and it is the strength of the synapse that determines if the memory is stored or allowed to fade away. Now, a study in mice carried out by Nobel Prize-winning researchers at Columbia University has shown…

FREQUENT FLYERS Planning a flight? Make sure you’re buckled up tight! Changes in the jet stream thanks to climate change are leading to more turbulence. Researchers at Reading University estimate that severe turbulence could rise threefold in the next 50 years. FAT CATS We’re not the only ones that are prone to middle aged spread. Researchers in Toronto have found that pet cats pile on the pounds as they age, peaking at eight years old. They suggest that cat owners regularly pop their moggies on the scales to make sure they are a healthy weight.…

Using gender-neutral pronouns instead of gender-specific ones such as ‘he’ or ‘she’ can promote equality, research suggests. More than 3,000 people took part in a survey in Sweden, where a gender-neutral pronoun (‘hen’) was adopted in 2015. Participants who were asked to use gender-neutral pronouns to describe a cartoon of a non-gendered figure were subsequently less likely to give a male name to a second fictional character than participants who were asked to use masculine pronouns, suggesting a reduction in mental bias towards males. The researchers also found that those who used gender-neutral pronouns expressed more positive and tolerant attitudes towards women and LGBT individuals.…

SEDNA Discovered by Mike Brown, Chad Trujillo and David Rabinowitz in 2003, Sedna was one of the objects that forced astronomers to re-evaluate Pluto’s planethood. It takes 11,400 years to orbit the Sun, crawling along at an average speed of just one kilometre per second. Sedna will make its closest approach to the Sun in 2075–2076, providing a once in an 11,400-year opportunity to get the best view of this world named after the Inuit goddess of the sea. 2012 VP113 This object is often nicknamed ‘Biden’ after Joe Biden, who was the US vice-president at the time of its discovery at the Cerro Tololo Inter-American Observatory in Chile. At 600 kilometres wide, astronomers believe its pink colouration is due to the way cosmic radiation has shaded its surface, which…

THIRTEEN YEARS AGO YOU PUBLISHED THE GOD DELUSION . WHAT WERE YOU HOPING TO ACHIEVE WITH YOUR NEW BOOK, OUTGROWING GOD ? I actually wanted it to be a children’s book, but the publishers weren’t keen so they pushed up the age scale of it. I think of it as a book for young people, but I would hope that anybody could read it. I’ve been aware that some people have asked for an easier version of The God Delusion . It isn’t that. I think it’s a bit easier, the language is a bit easier, but it doesn’t really overlap much. It’s not The God Delusion-lite – the chapters are about different things. Though I hope it is light. WHY DO YOU THINK WE WANT TO BELIEVE IN THE…

Ecologist Emma Olliff doesn’t want her own children. Not biological ones at least. She made the decision quite young, she says, but she only fully consolidated the reasons why in her early 20s. “I did a marine biology degree, and then a biological diversity masters,” she says. “And so was made very aware of human impacts on the environment, and how more of us is only going to make it worse.” She isn’t alone. The idea of reducing the number of children you choose to have – or even going child-free – for environmental reasons has had a surge of interest in the past few years, with a particular focus on the climate impact of adding another person into the world. Some also say they are concerned about bringing children…

DR ALASTAIR GUNN Astronomer, astrophysicist ALEX FRANKLINCHEUNG Environment/ climate expert ALOM SHAHA Science teacher, author PROF ALICE GREGORY Psychologist, sleep expert DR HILARY GUITE Former GP, science writer CHARLOTTE CORNEY Zoo director, conservationist DR HELEN SCALES Oceans expert, science writer DR CHRISTIAN JARRETT Neuroscientist, science writer DR EMMA DAVIES Chemistry expert, science writer LUIS VILLAZON Science/tech writer JULES HOWARD Zoologist, science writer PROF ROBERT MATTHEWS Physicist, science writer…

There are more bacterial cells in your body than human cells, but the ratio isn’t as extreme as once thought. A 2016 study at the Weizmann Institute of Science in Israel found that our total cell count is 56 per cent bacteria (compared with earlier estimates of 90 per cent). And because bacteria are much smaller, their total mass is only about 200g. So by weight, we are more than 99.7 per cent human. Even so, we shouldn’t underestimate the contribution bacteria make to our body, nor feel threatened by it. Most of our ‘human’ cells contain structures called mitochondria, which we rely on to convert glucose into compounds we can use for energy. These mitochondria probably began as free-living bacteria before they embarked on a symbiotic relationship with us.…

1. Although most famous for his work on evolution, Charles Darwin’s final scientific book was about earthworms. It sold more quickly in its first year than On The Origin Of Species! 2. Earthworms are the staple food of badgers, making up to 80 per cent of their diet. Earthworms aren’t very nutritious, though, so a single badger can eat several hundred of them in a night. 3. Badgers have a complex vocal repertoire of at least 16 different calls, ranging from low growls and grunts, to chitters, squeaks, yelps and even a sort of quacking sound. 4. When Ben Burtt, sound designer on the original Star Warsmovies, developed the voice of Chewbacca, he used recordings of badger calls, as well as bears, lions and a walrus.…

JOCELYN TIMPERLEY As the global population surges towards eight billion, climate and energy journalist Jocelyn looks at whether having fewer children can really make a difference. p74 ABIGAIL BEALL What will cities of the future look like? Science and tech journalist Abigail reveals the plans to move people into the trees, onto the oceans, and deep underground. p42 HELEN GLENNY Electroconvulsive therapy is shrouded in controversy and misunderstanding. Science writer Helen explains why it might be time to rethink this potentially life-saving therapy. p68 DARREN NAISH Everyone has a story about gulls eyeing up their lunch, but are the birds getting bolder? Zoologist and science writer Darren investigates whether they are really a menace. p38…

One of the great gender myths has, it seems, been busted for good: new research shows that men and women are equally good (or bad) at multitasking. Psychologists in Germany tested the multitasking prowess of 48 men and 48 women, using letter and number identification tasks to measure the participants’ ability to pay attention to two tasks at once (concurrent multitasking), or to switch attention between tasks (sequential multitasking). Multitasking had a negative effect on both the participants’ speed and their accuracy, but there was no difference in performance between the men and women.…

Walking past a smorgasbord of fast food outlets along your commute could make you fatter, according to research by Arizona State University. The study analysed data from 710 female elementary school employees in New Orleans. Commuters who passed within a kilometre of more supermarkets, grocers and restaurants offering fast food had higher BMIs than those passing by restaurants that offered slower, more formal table service. “The availability and variety of fast-food restaurants along our commute create endless opportunities for a quick, cheap, and unhealthy meal,” said Prof Adriana Dornelles, who carried out the research.…

An analysis of all suitable sites for onshore wind farms across mainland Europe suggests that the continent has the potential to supply enough energy for the whole world until 2050. The study, carried out by researchers based at the University of Sussex and Denmark’s Aarhus University claims that million square kilometres of Europe could generate 497 exajoules of energy: enough to comfortably meet the expected global energy demand in 2050. Turkey, Russia and Norway have the greatest potential for future wind power, the researcher say. “Our study suggests that the horizon is bright for the onshore wind sector and that European aspirations for a 100 per cent renewable energy grid are within our collective grasp technologically,” said co-author Benjamin Sovacool, professor of energy policy at the University of Sussex. “Obviously,…

One in four adults in the UK owns a cat, according to the UK’s leading vet charity. That adds up to 11.1 million cats, many of whom free-roam over great distances. With so many felines prowling the country and with British wildlife in a precarious state, it begs the question, how harmful are domestic cats to the species they prey on? The Mammal Society, a charitable organisation concerned with the welfare and conservation of mammals, surveyed cat owners to find out just that. Over the course of five months, on average a single cat brought home 11 prey items, which included all manner of animals from house sparrows to grass snakes. This may not seem like much, but with millions of cats in Britain, this could mean that some 274…

You’re sitting by the sea, eating lunch, when suddenly you spot a seagull eyeing up your chips. Perhaps you try to shoo it away or shelter your plate in case of a sudden attack. But researchers at the University of Exeter have found that the best way to protect your food is to stare the gull down. The team studied herring gulls’ thieving behaviour in Cornwall with the help of a clear bag filled with chips. Only a small number of gulls attempted to snatch the food, and those that did were more willing to make a move when the human was looking away. The gulls tried to grab the chips on average 21 seconds faster when they were unattended than when the human was staring at the bird. Whether…

One of my favourite foods is chocolate, especially the milky stuff, but I will eat dark chocolate. So this particular headline cheered me up no end: “People who eat dark chocolate are less likely to be depressed”. It was based on a study carried out by researchers from University College London, published in the journal Depression & Anxiety. They compared the chocolate-eating habits of more than 13,000 adults (based on dietary questionnaires), with their depression scores (based on something called the Patient Health Questionnaire). After adjusting for confounders such as height, weight, marital status, ethnicity, education, income, physical activity, smoking, etc, they found that eaters of dark chocolate had 70 per cent lower odds of being clinically depressed than those who reported not eating chocolate at all. Dr Sarah Jackson,…

I TOOK ONE OF MY WIFE’S CONTRACEPTIVE PILLS AS A DARE, BUT NOW I’M WORRIED. WILL ANYTHING HAPPEN? Nothing will happen if you only took one. There’s a one in four chance that the pill was a dummy anyway, as most packets include seven tablets with no drugs in them (meant to maintain the habit of taking the pill while the ‘withdrawal bleed’ happens). If you regularly took the ‘combined pill’, which contains oestrogen and progestogen hormones, it would have mild feminising effects, such as wider hips, softer skin and slight breast development. The oestrogen dose is about a tenth of that taken by transgender women, but it’s a form of oestrogen associated with higher risks of deep vein thrombosis, so it wouldn’t be a good idea for anyone wanting…

ELEANOR TEW, YORK HOW DO BABY BIRDS BREATHE INSIDE THEIR EGGS? It’s all down to some nifty engineering inside the eggshell. Early on in a chick’s development, it grows a hollow, sac-like structure from its gut, known as an ‘allantois’. This pouch fuses with a second membrane (‘chorion’) surrounding the chick and its yolk, which together form the ‘chorioallantoic membrane’. With one end attached to the chick, and one end close to the eggshell’s inner surface, this membrane effectively acts like lung tissue, connecting the chick’s circulatory system to the outside world. Oxygen diffuses through microscopic pores in the shell to the blood vessels in the chorioallantoic membrane, and then on to the chick’s bloodstream. Carbon dioxide, the gaseous waste product of respiration, passes in the opposite direction. EMAIL YOUR…

INVENTING OURSELVES SARAH-JAYNE BLAKEMORE (£8.99, BLACK SWAN) An engaging and informative overview of the processes happening in the brain during teenage development, written by one of the leaders in the field. COOKIE AND THE MOST ANNOYING BOY IN THE WORLD KONNIE HUQ (£10.99, PICCADILLY PRESS) Konnie’s new book for 8- to 12-year-olds is all about a determined girl with a passion for science and her dealings with the many problems life’s thrown at her. MR SHAHA’S RECIPES FOR WONDER ALOM SHAHA AND EMILY ROBERTSON (£8.99, SCRIBE) A brilliant and beautifully illustrated book that allows parents and children to explore the fun side of science in their own home.…

WHY WOULD I WANT A ‘SMART’ SECURITY SYSTEM? Home security no longer means slapping a big, ugly box to the side of your house, nor does it demand an expensive professional to hardwire your new system in place. The smart home has ushered in a DIY security revolution: you can now build a decent security system in less than 30 minutes, with your smartphone acting as the controller. Smart home security systems beat traditional ones not just by eliminating hefty installation fees and long-term contracts, but in sheer convenience too. WHAT DO I NEED TO GET STARTED? Smart home security encompasses a wide range of gadgets, from cameras to doorbells, sensors to smoke alarms – but don’t let it overwhelm you. Sure, maybe you want the full Fort Knox, but…