Sommaire pour August 2016 de BBC Science Focus Magazine

For the last three months, a cohort of scientists and engineers afloat off the coast of Mexico have been drilling night and day to dig out cylinders of rock buried beneath the seabed. In June, the team finally struck paydirt – a core of rubble taken from ground zero of the meteorite strike thought to have eradicated the dinosaurs. To find out what this core will tell us about the most cataclysmic event in Earth’s history, turn to p34. These days, humanity is becoming a victim of its own success. Improvements in road and car safety, for one, have meant that the number of organs available to transplant is in steady decline. One solution that scientists are looking at is xenotransplantation – the use of animal organs to replace our…

SUNSPOT ACTIVITY IS AT ITS WEAKEST SINCE 1906, WHICH IS A SIGN IT COULD BE HEADING TO A LONG-TERM LOW THE SUN IN NUMBERS DISTANCE TO EARTH 149,600,000km Light from the Sun takes eight minutes to reach Earth In June, something unusual happened: the Sun went blank; that is it lost its spots for the first time in four years. This is a sign that the Sun is approaching a solar minimum, a period where sunspots – darker, cooler areas on the visible surface of the Sun that are caused by intense magnetic activity – are at their least abundant. Every 11 years, the Sun goes through a cycle during which its magnetic activity fluctuates up and down, leading to changes in the number of sunspots and solar flares. The…

Does the Solar System have a dark secret? Researchers at the University of Edinburgh have found that ‘dark hydrogen’ may be hidden under the surface of gas giant planets such as Jupiter and Saturn. It is accepted that hydrogen exists as a gas on the surface of giant planets and as liquid metal at their core. But what lies in between? To investigate this, the team used a laser-heated diamond anvil to recreate conditions found in the interior of gas giants. They squeezed hydrogen to pressures up to 1.5 million times of that on the Earth’s surface and heated it up to 5,000°C. They found a point between the gas and liquid phases at which the hydrogen doesn’t absorb or reflect light, which they dubbed ‘dark hydrogen’. “A dark hydrogen…

Science Journal This research-friendly Google app helps you organise, collate and annotate data from your Android phone’s internal sensors, or any bolt-ons you’ve added. Free, Android PlantNet Gardeners and amateur botanists alike will love this app, which enables you to identify over 40,000 species of plant simply by pointing your phone’s camera at them. Free, iOS/Android Pry This game for iPhone and iPad seeks to recreate the troubling experience of living with post-traumatic stress disorder, as you toggle between ‘real’ and inner worlds. £2.99, iOS…

Don’t forget that BBC Focus is also available on all major digital platforms. We have versions for Android, Kindle Fire and Kindle e-reader, as well as an award-winning iOS app for the iPad and iPhone, so you can get your fix of science knowledge wherever you go. Can’t wait until next month to get your fix of science and tech? Brought to you from the team behind BBC Focusmagazine, the Science Focus website is packed with news, articles and Q&As to keep your brain satisfied. sciencefocus.com…

0m Seabed. 503m Coring begins. As the focus of the expedition is on the impact crater, the scientists race through the first 500m of limestone before beginning to pull up cores of rock, 3m at a time. 550m Algal blooms. Around 55 million years ago, some 10 million years after the asteroid impact, the Earth was around 5°C warmer than at present. Scientists are hoping to recover black shales, the geological remnants of carbon-rich algal blooms predicted to have thrived in the warmer conditions. 550-620m Approaching ground zero. As the drill reaches the top of the impact layer, the ecology is expected to thin out to just a few, rather simple species. By studying the chemical make-up of the very first foraminifera to colonise the site after the impact, it…

Reincarnation is highly unlikely. But in the event that it is possible, I know what I’m coming back as: a mouse. Hardly a week goes by without scientists announcing they’ve cured some of these furry cheese-eaters of yet another disease, from cancer and AIDS to Alzheimer’s. So how come we humans are still succumbing to these diseases? Aren’t animal experiments supposed to be reliable signposts towards the next miracle cure? They certainly have the backing of the Royal Society, Britain’s premier scientific academy, which insists that “virtually every medical achievement in the past century has depended directly or indirectly on research using animals”. And the Royal Society doesn’t make statements like that without evidence to back them up. Actually, its website doesn’t give the evidence, but there’s an obvious explanation:…

DR CHRISTIAN JARRETT Christian is a psychology and neuroscience writer. His latest book is Great Myths Of The Brain. DR ALASTAIR GUNN Alastair is an astronomer at the Jodrell Bank Centre for Astrophysics at the University of Manchester. PROF ROBERT MATTHEWS Robert is a physicist and science writer. He’s visiting professor in science at Aston University. DR PETER J BENTLEY Peter is a computer scientist and author who is based at University College London. His latest book is Digitized. LUIS VILLAZON Luis is a freelance science and tech writer with a BSc in computing and an MSc in zoology from Oxford University. Could global ice melt affect the Earth’s tilt? MAX JONES, USA The Earth’s axis isn’t perfectly upright relative to its orbit, but instead is tilted at an angle…

We are brought up with doe-eyed flying elephants, talking hippy bears and scat-singing orangutans, so it’s no surprise that we have a tendency to anthropomorphise. We don’t merely empathise with our own, but with other species too. We see our own visages in the faces of our dogs and cats. We bless or curse other animals with our own emotional palette. But can we really make friends with other species? The slow loris is a good example of our mistaken projections. We interpret the big-eyed creature’s outstretched arms while being tickled as a sign of joy. Actually, it’s scared, and it’s stretching out to try to gather the venom that’s found in its elbow patch. How can we overcome these communication breakdowns? Sometimes, like Dr Dolittle, we try to talk…

Empathisers (Type E) Have a strong interest in people’s thoughts and emotions Likely to listen to mellow music with low energy and sad emotions such as R&B and soft rock. Prefer unpretentious music like folk and country, and contemporary music such as electronica. Systemisers (Type S) Have a strong interest in analysing rules and patterns Likely to listen to more intense music, including hard rock, punk and metal. Also prefer music with depth and complexity such as avant-garde classical music and experimental jazz. Balanced (Type B) Score relatively equally on empathy and systemising Likely to listen to a broader range of different musical styles and genres than those people who are pure empathisers or systemisers. Take the test for yourself at musicaluniverse.org…

1 IT’S A NATURAL DRUG Music can help to control the release of certain chemicals in your brain and blood supply. Stressed people often have too much adrenaline and cortisol in their system, so they are perpetually in a fight-or-flight mode. Music inhibits the release of these substances and encourages the release of pleasure-related chemicals such as dopamine and serotonin. 2 IT ALTERS OUR BEHAVIOUR Background music can have a surprisingly large effect on your behaviour. Slow music makes you walk more slowly in shops, eat more slowly in restaurants and drink more with your meal. Supermarket music can even persuade you to buy particular products by suggesting a certain country or mood. 3 IT HELPS US BOND Music is ancient and exists across all of the world’s cultures, so…

ISABELLE DE GROOTE How would our ancient ancestors have fared at the modern Olympics? Biological anthropologist Isabelle assesses the anatomy and sporting prowess of Homo erectus, the Neanderthals and other hominins. p56 MICHAEL REISS Michael is a bioethicist and professor of science education at University College London. This month he looks at the controversial idea of using organs from animals to save human lives. p66 HELEN SCALES Antibiotics are losing their effectiveness, putting us at risk of diseases and infection. But according to marine biologist Helen, the rivers, lakes and oceans of the world could contain exciting new drugs. p58…

In 1987, virtually every nation in the world signed the Montreal Protocol. It was a concerted effort to ban the use of CFCs in order to repair the widening hole in Earth’s ozone layer. Now, almost 30 years later, it appears to have paid off as scientists at MIT have found evidence that the hole in the ozone layer over the Antarctic is closing. The team found that the ozone hole has shrunk by more than four million square km, or about half the area of the United States, since 2000, when ozone depletion was at its peak. “We can now be confident that the things we’ve done have put the planet on a path to heal,” says lead researcher Susan Solomon. “Which is pretty good for us, isn’t it?…

99. 999% The proportion of the Earth’s one trillion microbial species yet to be discovered, as estimated by a biologist at Indiana University. 89.5m The height of the world’s tallest tree: a yellow meranti discovered in the Malaysian rainforest by researchers at Cambridge University. 15 trillion The number of litres of helium found in a gas field in Tanzania. The discovery will help to combat the world shortage of the gas, which is used in everything from MRI scanners to deep-sea diving equipment.…

What’s that? The latest herbal tea infusion? Nope. It’s a small rodent that lived on the island of Bramble Cay, o the coast of Queensland, Australia. Tell me more. It’s thought to be the first known species of mammal to be wiped out by man-made climate change. The animals have not been seen since 2009 and have recently been declared extinct. It was considered the Great Barrier Reef’s only endemic mammal. How did that happen? Bramble Cay measures just 150m by 340m and sits three metres above sea level. Experts say that rising sea levels due to climate change are to blame. Are any others species at risk? Yes. A recent study at the University of Connecticut has estimated that up to one in six species of animals and plants…

SPRING COMES EARLY TO CITIES Light from street lamps causes trees to start producing leaves up to a week earlier in cities than in rural areas, biologists from the University of Exeter have found. THE UNIVERSE IS GETTING ‘TIDIER’ Images recorded using the Herschel space telescope have shown more and more cosmic dust is being mopped up thanks to the formation of stars. BUTTER ISN’T UNHEALTHY A review of nine studies involving more than 600,000 people has found that butter is not linked to cardiovascular disease. Its bad reputation may be due to people spreading it on unhealthy foods such as white bread. WE GET OUR BEST NIGHT’S SLEEP ON TUESDAY Data from 5,000 Brits has shown that we sleep soundest on Tuesdays. It is thought the effect is due…

IN THE PINK Pregnant women in South Korea are being given portable Bluetooth sensors that cause a pink light in train carriages to illuminate when they board, encouraging other passengers to offer them a seat. NOT SO BREEZY Hugh McNeal, head of RenewableUK (formerly the British Wind Energy Association), has said there isn’t enough wind in England to power any more turbines. Offshore wind farms, however, remain a viable option. MOVIES ON THE MOVE Virgin Trains is introducing its own Netflix-like streaming service called BEAM, which will enable passengers on its intercity services to watch films and TV, play games and read eBooks. EYES DOWN Busy junctions in Sydney, Australia are being fitted with traffic lights in the ground. The aim is to catch the attention of pedestrians engrossed by…

Power to the people In response to David Clubb’s letter in the July issue, I should like to make the following points. The UK’s Department of Energy and Climate Change has a target of generating electricity from the following sources by 2035: 50 per cent from renewable sources, 35 per cent from nuclear and 15 per cent from gas-fired power stations. This is probably a very optimistic target, but confirms its faith in renewable sources and nuclear power. It is important that we continue to investigate the many sources of power available to ensure a reliable and cost-effective electricity supply. At present it is almost impossible to establish the true cost of electricity to consumers because of the subsidies, guaranteed prices and government interference in the market. Electricity storage may…

HOURS Huge earthquakes, megatsunamis up to 300m high, winds of over 1,000km/h and rampant wildfires result in instant annihilation for many species. WEEKS Dust from the impact and soot from wildfires block out sunlight for many years. Plants that survived the impact soon struggle. Food webs start to unravel. YEARS Prior to the impact, non-avian dinosaurs are already in decline, but the impact seals their fate. If any species survive the impact, it’s not for long. Over 90 per cent of all mammal species also go extinct. The largest mammals are hardest hit; the survivors are all smaller than a cat. On land, forests and flowering plants struggle with the low light levels, resulting in a preponderance of species like ferns, algae and moss. 300,000 YEARS Because mammals from several…

“BANK TELLERS MOISTEN THEIR FINGERS FOR GRIP, BUT CLIMBERS USE CHALK. WHICH METHOD WORKS?” Humans spend a lot of time picking things up and putting them down again. We hardly ever think about it. but whatever we’re manipulating – pens, cake, keys, tennis balls or this magazine – it’s only possible because our fingers can grip. Wandering round a stationery shop the other day, I spotted one of those sponge pads that you sometimes see in post offices. Bank tellers use them to moisten their fingers and improve their grip when they’re counting banknotes. But then I remembered the years I’ve spent on climbing walls and on gymnastic equipment. In those environments, it’s exactly the opposite. You put chalk on your hands to improve your grip, because the chalk dries…

Microbes living in the ocean collectively weigh the equivalent of 35 African elephants for every person alive today. In the last 30 years, around half of all new medicines released have been based on molecules found in the natural world. By 2050, 10 million people could die per year (or roughly one every three seconds) if no action is taken to combat antibiotic resistance. That’s more than the death toll from cancer and diabetes combined. In a survey of 139 academic studies, 72 per cent showed a link between antibiotic use in farm animals and drug resistance in humans. In the US, between 1997 and 2010, 60 per cent of cases of sore throats were treated with antibiotics, even though only 10 per cent were caused by bacterial infection, at…

 Michael is professor of science education at University College London and a priest in the Church of England. He has advised the House of Lords on the use of animals in scientific procedures and was the ethicist on the Farm Animal Welfare Commi ee (FAWC) from 2004 to 2012. Pigs are easy to keep in captivity and their physiology is similar to ours, despite not being closely related to us Earlier this year it was announced that researchers at the National Institutes of Health (NIH) in the US had kept a genetically engineered pig’s heart beating in a baboon for three years. Though it was undoubtedly a headline-grabbing story, there are serious implications for the research. Every year, several million people die worldwide because of transplant shortages. There just aren’t…

1. Walrus* Weight: 1,200kg Diet: shellfish, occasionally seals *Walruses spend a third of their lives on land or ice. 2. Polar bear Weight: 700kg Diet: ringed and bearded seals 3. Brown bear Weight: 680kg Diet: salmon, berries, seaweed 4. Siberian tiger Weight: 318kg Diet: deer, pigs 5. African lion Weight: 250kg Diet: wildebeest, zebra, carrion 6. Burmese python* Weight: 183kg Diet: rats, deer, goats *Heaviest recorded specimen 7. Jaguar Weight: 158kg Diet: caiman, deer, capybaras 8. Green anaconda Weight: 97.5kg Diet: fish, birds, deer 9. Spotted hyena Weight: 90kg Diet: wildebeest, zebra 10. Grey wolf Weight: 80kg Diet: moose, deer…

Music is an integral part of our lives. We carry it in our pockets and blast it from the rooftops. It’s the stuff that memories are made of, soundtracking our weddings, funerals and first kisses. But it has an even greater effect than you might imagine, from alleviating stress and depression to helping us bond with others and boosting IQ scores. Over the following pages, we delve into the surprising psychology of music. Does music really have the power to affect our well-being? Your body contains its own ‘pharmacy’ for dispensing an array of chemicals to help you respond to different situations: calming you down when you need to sleep, or putting you on alert if you’re in danger. If your pharmaceutical system is working properly, the correct chemicals will…

Welcome to our new number puzzle column! Upon discovering I am a mathematician, many people feel the need to tell me how much they disliked maths at school. But for others, those same lessons were the beginning of a love affair with solving problems. Once you experience the high of successfully working through a difficult puzzle, you can be hooked for life. If you find yourself in the first group, but occasional indulge in the odd bit of ‘brain-training’, let me see if I can win you over. And if you find yourself in the latter, welcome home. Each month I will present the best new maths puzzles from around the world, and celebrate the occasional classic. I will be ably assisted by Katie Steckles, a modern master of puzzles.…

Edinburgh is a rare mix of modern city and rugged natural beauty. One moment you find yourself engrossed in the shops on Princes Street, the next you’re lost in its hills or peaceful shores, oblivious that a city even exists. Steeped in cultural and academic history, Edinburgh is vibrant and cosmopolitan. It is also just the right size for cycling from one end to the other with ‘nae bother’. Every time I pass the JAMES CLERK MAXWELL STATUE 1 on George Street, I’m reminded of his genius. When we think of great scientists, most people think of Newton and Einstein, but Maxwell’s name should also be on everyone’s lips – he developed the theory of electromagnetism and was a truly brilliant thinker. Another scientist from Edinburgh was John Napier, the…

I’m perhaps best known for my work on theme park rides and attractions. I’ve been a design engineer for most of my working life. The projects that I work on are challenging because each one is unique. There are no prototypes. You only get one chance to build them correctly and that’s what keeps me interested. I became interested in engineering while I was still at school. I spent a summer holiday working on a construction site, digging holes in the ground and measuring the density of the soil. I worked 12 hours a day, seven days a week and made enough money to buy myself a Mini Cooper S. I was pretty pleased with that. But then I looked at the engineer driving around the site in his big,…

It’s two birds in one stone. Two pairs of wings belonging to hatchlings that lived alongside dinosaurs 100 million years ago have been found in Myanmar by an international research team. The fossilised wings have been immaculately preserved in amber. Each is just two or three centimetres long and includes bones, long ‘fingers’ tipped with sharp claws, as well as individual feathers. “These fossil wings show amazing detail,” said researcher Mike Benton. “The individual feathers show every filament and whisker, whether they are flight feathers or down feathers, and there are even traces of colour – spots and stripes.” The anatomy of the hand indicates that the fossils come from enantiornithines, a major group of birds that died out at the same time as the dinosaurs, 66 million years ago.…

Resistance is futile I always read Helen’s articles with interest but I confess that in this instance I am puzzled. It is a fact that in a vacuum all objects fall at the same speed, regardless of size and weight. However, when air and wind are involved, the rate of descent can be influenced by size, but the pull of gravity will always be constant. Helen states that the bigger the drop, the faster the terminal velocity. Although I can accept that very small droplets will be blown about by the wind, there are other factors. A larger drop will have to displace more air, and that resistance will slow it down. A smaller but still significant drop will have less resistance. Both drops will be affected by wind, so…

100-METRE SPRINT Homo neanderthalensis vs Homo sapiens Male world record: 9.58s (Usain Bolt, Jamaica) Unlike Homo erectus, who hunted in the open woodland and grasslands of Africa, the Neanderthals hunted on Europe’s cold steppes. Their stocky, cold-adapted bodies may have made them less efficient at long-distance running, but their superior leg strength, used when hunting animals up close, may have given them a very quick start. Whether they would have had the ability to maintain their speed over an entire 100m sprint, however, is doubtful. Homo sapiens UNEVEN BARS Australopithecus afarensis vs Homo sapiens World record: Perfect 10 Although A. afarensis walked on two legs, they still had ape-like bodies, with long, strong arms and short legs. These early hominins lived between 3.85 and 2.95 million years ago, climbing trees…

HORSESHOE CRABS The blood of these arthropods is packed with amoebocyte cells that react to tiny traces of bacteria. Their blood has been used for the last 50 years to test equipment and vaccines for contamination. CONE SNAILS The stings of these molluscs contain conotoxins. There is already a conotoxinbased painkiller that’s more potent than morphine. There are also cancer and diabetes treatments on the horizon. SPINY STARFISH This starfish’s body is covered in slime consisting of 14 per cent carbohydrate and 86 per cent protein. The substance is being investigated as a treatment for arthritis and asthma. PUFFERFISH These fish contain tetrodotoxin (or TTX). This is what makes fugu (a delicacy made from pufferfish) a risky dinner. TTX is being developed as a treatment for the pain suffered during…

Adrenaline This chemical triggers the body’s fight-or-flight response. It causes your air passages to dilate so you can get more oxygen into your system, and directs blood to the major muscle groups. Cortisol This is another fight-or-flight chemical and backs up the adrenaline response. It also damps down your body’s response to injuries (so you can keep running or fighting even when hurt). Dopamine This neurotransmitter is responsible for your ability to focus and get things done. It also acts as a ‘good mood’ chemical. Neurotransmitter These chemicals communicate information throughout your brain and body. They tell your heart to beat, they control muscles and senses, but also influence your mood. Serotonin A neurotransmitter that’s involved in regulating appetite, sleep, memory and mood. The Mozart effect This is a controversial…