Sommaire pour March 2018 de BBC Science Focus Magazine

When it comes to understanding loneliness, music’s pretty much got it covered. From The Beatles to Bill Withers, and Roy Orbison to Radiohead, some of the greatest songs in modern history were written to express and relieve the pain of being alone. Science, it seems, has a bit of catching up to do. We’ve known for a long time that isolation is bad for us. Accounts of prisoners placed in solitary confinement and questionable experiments revealed the strange ways that extreme loneliness warps the brain. Meanwhile, large-scale analysis of the impacts of loneliness have shown that the chronically lonely tend to have higher blood pressure, are more likely to suffer from dementia and have weakened immune systems. In the long term, being lonely is worse for you than smoking 15…

In a world first, researchers from Arizona State University and the Chinese Academy of Sciences in Beijing have used DNA ‘nanorobots’ to kill cancerous cells by cutting off their blood supply. “We have developed the first fully autonomous, DNA robotic system for a very precise drug design and targeted cancer therapy,” said Prof Hao Yan. “Moreover, this technology is a strategy that can be used for many types of cancer, since all solid tumour-feeding blood vessels are essentially the same.” “WE HAVE DEVELOPED THE FIRST FULLY AUTONOMOUS, DNA ROBOTIC SYSTEM FOR A VERY PRECISE DRUG DESIGN AND TARGETED CANCER THERAPY” The nanobots were made from flat, rectangular DNA sheets, 90 x 60nm in size. Thrombin, a blood-clotting enzyme, was attached to the surface. When delivered to the surface of a…

It seems like colouring in is a truly ancient pastime. An archaeological dig at a site near Scarborough, North Yorkshire, has unearthed what is believed to be a 10,000-year-old ‘crayon’ made from red ochre, a type of clay consisting mainly of ferric oxide. The area in which the dig took place was already known to be rich in Mesolithic art. A pendant dug up in nearby Star Carr in 2015 is the oldest such object ever discovered, while a large number of headdresses made from red deer antlers have also been found in the area. Now, a joint team from the University of York’s departments of archaeology and physics has been responsible for locating and unearthing the new object, found preserved in peat. It’s a naturally occurring pebble, measuring 22mm…

What did they do? A team of researchers at the University of St Andrews taught Wikie, an orca based at Marineland Aquarium in Antibes, France, to imitate human speech. What can she say? The researchers picked words that were initially unfamiliar to Wikie. But by copying a trainer, she was able to say “hello” and “bye bye”, and count to three. And she’s a fast learner too – she often spoke the words correctly on her first try. Why did they do it? It’s known that orcas in the wild have calls that are specific to their own pod, and when captive orcas are moved, they change their call to fit in with their new companions. The researchers wanted to show that the animals learn these new calls by imitating…

Guildford-based satellite imaging company Earth-i has just launched a satellite that will, for the first time, beam back full-colour, high-res video of Earth from space. High-quality still satellite images have been available for years, as have short video clips, but the new satellite – which was launched via an Indian rocket on 11 January – will be the first to supply high-resolution footage on a continual basis. It was, however, just a test-run. If successful, it will be like a live Google Earth. Earth-i’s long-term goal is to build a constellation of 15 satellites called Vivid-i that encircle the planet and, if the test goes well, it plans to launch five satellites a year from 2019 onwards.…

The obvious first step is to start an activity or group that brings people together, but there is one trap that people often fall into, says Dr Farhana Mann, a psychiatrist at University College London. “If you truly want to build a sense of community, you may need to go outside your comfort zone. We tend to associate with people who are similar to us because it’s familiar – one of the major challenges is bringing in people who are more marginalised,” she explains. So if you’re looking to set up a local group to create a sense of connection in the area where you live, you also need to think: how can I extend this to people with mental health problems, to people from less represented minorities, to people…

STRESS TURNS YOUR HAIR GREY This is probably true. After all, we’ve seen country leaders go grey within weeks of taking office. The subject hasn’t been studied much, but a paper published inNaturein 2013 did find that hormones produced in response to stress can cause the melanocyte stem cells that determine hair colour to leave our hair follicles. STRESS WILL GIVE YOU STOMACH ULCERS Nope. Common stomach ulcers are caused by an infection by Helicobacter pylori bacteria, not by stress. However, stress and other lifestyle factors like drinking alcohol and eating spicy food may make existing ulcers worse. STRESS GIVES YOU WRINKLES Probably true. At the end of our chromosomes is a protective cap of DNA called a telomere. Telomeres shorten as we age, and studies have shown that stress…

DR ALASTAIR GUNN Astronomer, astrophysicist ALEX FRANKLINCHEUNG Environment/ climate expert DR PETER J BENTLEY Computer scientist, author PROF ALICE GREGORY Psychologist, sleep expert PROF MARK LORCH Chemist, science writer CHARLOTTE CORNEY Zoo director, conservationist DR HELEN SCALES Oceans expert, science writer DR CHRISTIAN JARRETT Neuroscientist, science writer EMMA DAVIES Heath expert, science writer LUIS VILLAZON Science/tech writer DR AARATHI PRASAD Biologist, geneticist PROF ROBERT MATTHEWS Physicist, science writer Do caterpillars have a sex before they become butterflies? ADRIAN LEWIS, EXETER The sex of a caterpillar is fixed at the moment the egg is fertilised, but most species don’t show any sex-specific features until they turn into butterflies. The immature reproductive organs are still present in the larval stage though, and in a few species with translucent bodies, you can see…

Have you always wanted to be a doctor? When I was three years old my Jamaican grandma bought me a children’s doctor outfit. It came with a stethoscope. I put it on and I totally loved it. She asked if I wanted to be a midwife like her when I grew up. But I said, no, I want to be a doctor. You’re on telly a lot. Do you still get to be a GP? I’m a GP first and foremost. I do two or three sessions a week. Then I do bits of TV –TrustMe,I’mADoctor, ThisMorningandHorizon. I also work with Public Health England as 1 of 50 clinical champions for physical activity. It’s a scheme that I helped set up and I’m really proud of it. My role involves…

YOU WILL NEED: • A bike valve (we cut one out of an old inner tube) • A bike pump (ideally a foot pump with pressure gauge) • Surgical spirit or 90% isopropyl alcohol (rubbing alcohol) • Hand drill (needs a drill bit with a similar diameter to the valve) • Hot glue gun • Empty plastic drinks bottle (minimum two-litre volume) • Safety goggles There is nothing mystical about clouds. In fact, it is perfectly possible to make your own cloud in a used drinks bottle. It might not be as massive as a 500,000kg white cumulus cloud, but at least you won’t have to go paragliding to get up close and personal. WHAT’S GOING ON? As the Sun heats the ground, it warms the air above it, causing…

YOU WILL NEED: • PVA glue • Bicarbonate of soda • Contact lens solution (it must contain boric acid) • Gel food colouring • Glitter (optional) Ghostbusters made green goop a must-have plaything more than 30 years ago. Now, slime is all the rage once more. This time, however, it can be made with items easily available in your local supermarket. Slime is great fun to play with, and its properties are underpinned by some serious science… WHAT’S GOING ON? The base ingredient for this slime recipe is PVA (polyvinyl acetate), YJKEJ›KU›OCFG›WR›QH›NQPI››URCIJGVVK›NKMG›OQNGEWNGU›ECNNGF›RQN[OGTU››6JG› PVA molecules are surrounded by water that can slide past one another with ease. The boric acid in the contact lens solution reacts with the bicarbonate of soda to create sodium tetraborate. These sodium tetraborate molecules form bridges…

SIMON CROMPTON We’re all stressed these days. Simon, science journalist and former health editor forTheTimesandThe DailyTelegraph,shows us how to take control. p62 HELEN CZERSKI Physicist and BBC presenter Helen has been travelling the world investigating the science of temperature. This month, she reveals some of its surprising effects. p70 MOYA SARNER Health and science journalist Moya has been investigating why loneliness is on the rise, how it hurts us and what we can do to help those caught in its grip. p48…

More effective treatments for Alzheimer’s disease could be just around the corner, thanks to a technique called deep-brain stimulation (DBS), research just published in the Journal of Alzheimer’s Disease suggests. Deep-brain stimulation involves implanting electrodes inside a patient’s brain that stimulate key areas of the frontal lobe by means of a tiny electric current, provided by a ‘battery pack’ implanted in the patient’s chest. The technique has already proved successful in treating neurological conditions such as depression and Parkinson’s disease, while in 2016, studies found that it could help to stimulate brain cell growth and slow memory loss. Building on this research, a team at the Ohio State University led by Dr Douglas Scharre, gave three Alzheimer’s patients DBS implants then tracked their cognitive function over three years. All three…

1 HOME HELP Apple’s recent entry into the speaker-plus-voice-assistant market is this 172mm tall, Siri-enabled unit that packs seven tweeters and one four-inch bass/midrange speaker. It’s compatible with HomeKit, but multi-room audio won’t arrive till later. Apple HomePod £319, apple.com 2 SUPER SHARP SHOOTER Here’s a camera aimed at serious – ‘happy to spend over £43K on a camera’ – photographers. It’s medium-format and can shoot still pictures at up to 400 megapixels, plus capture 4K video. The hefty price tag doesn’t include lenses. Hasselblad H6D-400c £43,500, hasselblad.com 3 BETTER PUTTER Want to improve your performance on the green? TaylorMade’s new putter has a built-in Blast Motion golf sensor that will track backstroke velocity, impact stroke speed and face rotation, then relay…

Today, society is becoming ever more divided. But if there is one thing that’s bringing everyone together, it’s loneliness. Scientists, doctors, charity workers and politicians from across the political spectrum all agree that loneliness is a big problem. A report published in December 2017 by the Jo Cox Commission revealed the staggering extent of loneliness in the UK. Almost one-quarter of parents surveyed by the charity Action for Children said they were “always or often lonely”, more than one-third of people aged 75 and over told Independent Age that their “feelings of loneliness are out of their control”, and over the course of a year more than 4,000 children called Childline because they felt unbearably lonely – some as young as six years old. One recent study found that nine…

SOCIAL NETWORK “Having a social network around you can be helpful in practising social skills. Some people have been so isolated they don’t remember how to interact, or have lost confidence in their ability to do so,” says psychiatrist Dr Farhana Mann. MENTAL HEALTH “Depression tends to make people want to withdraw from others, which makes it very difficult to join social groups and develop a sense of belonging,” explains psychology lecturer Dr Juliet Wakefield. INSIGHT People can have more success beating loneliness if they seek help. “The fact that someone tells me they’re lonely allows us to have a conversation that may help; I don’t know exactly what will work, but we can talk about it and address it,” says Mann. DEPRIVATION “Poverty can make loneliness very difficult to…

Everyone gets stressed, but some people seem more susceptible to pressures getting on top of them. It’s not just a simple matter of genetics – although scientists have found genes that do seem to affect our ability to cope when the going gets tough. What’s becoming increasingly clear is that stress in childhood can affect the way genes express themselves, and these epigenetic changes seem to be linked with conditions such as depression. Studies in animals are showing that stress in early life makes it much more likely that stress will prompt mood problems in adulthood. Childhood stress seems to trigger biochemical changes that alter the way genes express themselves. Once they’ve happened, these ‘epigenetic’ changes can be passed down through the generations. So the stresses your parents or grandparents…

How involved were you in the creation of Ex Machina and Annihilation? For Ex Machina, Alex Garland [the director] described it as a sanity check. I was there to look at how scientifically plausible the dialogue was. We wanted to make sure that there weren’t any of what we would call ‘2012moments’. In the film2012, the Earth is being destroyed by some sort of cosmic event and there’s this key moment in it when your cookie cutter scientist looks at the screen and says something like “the neutrinos are mutating”. Of course, this is a hilariously meaningless phrase. Scientific verisimilitude is important to Alex, even more so than to me. In fact, there were lots of times during both films where I said, “I’m not sure this matters,” but he…

Hunger is a complex sensation that is only indirectly linked to the need for food. Humans are opportunistic omnivores that have evolved to take advantage of sustenance whenever it is present. The sight or smell of food can trigger hunger, and so can even just imagining it. Your body also needs time to prepare for digestion and many of the related hormone changes are driven by your body clock. So you’ll feel hungry at lunchtime, whether you need to eat or not. 1. Vagus nerve This sends signals to the brain about how full or empty your stomach is, as well as the different nutrients present in the intestines. 2. Stomach When your stomach has been empty for two hours, it begins contracting to sweep remaining food into the intestines.…

YOU WILL NEED: • Clear plastic tumblers • Iodine liquid or tincture (available online) • Sodium thiosulphate powder or crystals (available online) • Water • Safety goggles • Rubber gloves WHAT’S GOING ON? When mixed in water, iodine swims around as two KQFKPG›CVQOU›DQWPF›VKIJVN[›VQIGVJGT››+QFKPG›KU›DNWG› black in its solid form but when it is combined with water, the iodine pairs form loose links with water OQNGEWNGU››HQTOKPI›YJCV›CTG›ECNNGF›EJCTIG›VTCPUHGT› EQORNGZGU››6JGUG›YCVGT›KQFKPG›EQORNGZGU›JCXG›C› [GNNQY[›DTQYP›EQNQWT››5QFKWO›VJKQUWNRJCVG›KU› known as a ‘reducing agent’ and it forces a negatively charged electron into the iodine duo, causing the iodine atoms to break apart as two negatively charged entities (called iodine ions). The separated iodine no longer interacts with light and so the liquid loses all its colour. This demonstrates how chemical stain removers remove stains by breaking CRCTV›VJG›OQNGEWNGU›VJCV›CTG›ECWUKPI›VJG›WPYCPVGF›EQNQWTCVKQP››%QNQWT›EQPXG[KPI› molecules, termed chromophores, can often be…

A giraffe’s dark patches help it cool down p72 Stress doesn’t give you ulcers p67 Polar bears and grizzlies can mate to give birth to grolar bears p58 You can make a battery with 2p coins. Turn to our home experiments supplement between p74 and p75 Solar panels work better on cool days p93 CONTACT US Advertising neil.lloyd@immediate.co.uk 01173008276 Lettersforpublication reply@sciencefocus.com Editorialenquiries editorialenquiries@sciencefocus.com 01173147388 Subscriptions bbcfocus@buysubscriptions.com 03330162113* Othercontacts sciencefocus.com/contact WANT MORE ? FOLLOW SCIENCEFOCUS FACEBOOK TWITTER PINTEREST GOOGLE+…

I’m a 45-year-old fast eater. I always have been, and I suspect it was linked to having older brothers and ‘racing’ to finish. In the Christmas issue, a study showed a link between fast eating and heart issues (p21). Is this because of how the body’s digestive system works, or is it linked to fast eaters being ‘fast’ in other aspects of life, which has a negative impact, because of work, stress, anxiety, etc? For the record, while I am a fast eater, I’m generally pretty chilled in most other aspects of life! Pete Starr, via email Thank you for getting in touch and thanks for reading the magazine. The study in question was only preliminary, so there are not really any concrete conclusions yet. The team found that fast…

INTELLIGENT MEN Men that score higher on IQ tests – especially those testing verbal intelligence – are more likely to be in a happy marriage, a Finnish study has found. The effect could be down to more intelligent men being able charm the ladies – or outwit their rivals. THE BILINGUAL Parlez-vous français? A study at Montreal’s Concordia University has found that speaking a second language may help to protect you from age-related cognitive decline by boosting tissue density in brain areas associated with memory.…

“IS TURMERIC JUST A FOOD FAD, OR COULD THIS SPICE REALLY BE BENEFICIAL FOR YOUR HEALTH?” Until quite recently, the only place that you’d probably encounter turmeric would be in a chicken tikka masala. But it has now become incredibly trendy, thanks to claims that it can improve everything from allergies to depression. When it’s fresh, turmeric looks a little bit like ginger root (in fact, they belong to the same family), but when it’s ground down you get a distinctive yellowy-orange powder that’s very popular in South Asian cuisine. There are at least 200 different compounds in turmeric, but there’s one that scientists are particularly interested in. It’s called curcumin. Thousands of papers have been published looking at turmeric and curcumin in the lab, and some have had…

Scientists have long observed that physical and mental problems caused by stress have a strong association with immune system changes. This has given rise to a new wave of research, looking at whether modifying the immune system through vaccines might make us more resilient to stress. Neuroscientists at Columbia University, US, have transferred immune cells from chronically stressed mice to unstressed mice, and found that the unstressed mice became more resilient to stress, showing fewer depressive symptoms. Separately, neuroscientists from the University of Colorado have modulated the immune system of mice by injecting them with species of bacteria known to decrease anxiety. When these mice were placed in a cage with aggressive animals, they were less intimidated than unimmunised mice, and later displayed none of the stress-related gut problems that…

BLACK OR WHITE? On a hot day, we tend to think that white clothes will reflect sunlight and therefore keep us cool. Yet while black absorbs more heat, it also radiates it away more quickly. A famous paper in 1980 noted that the Bedouin wear black robes in astonishingly hot desert conditions, but found that the advantages and disadvantages pretty much cancelled each other out. It turns out that other factors matter much more than clothing colour: for example, loose garments are helpful for heat loss because the air that flows between you and the clothes will cool you down, and a breeze will help too. So wear whatever colour you like! INVERSE FREEZING We all know that freezing is the process of cooling down a liquid until it solidifies.…

Other ideas to stop natural disasters have had mixed results PROJECT STORMFURY Between 1962 and 1983, US scientists tried to weaken hurricanes by seeding them from aircraft using silver iodide. The chemical was supposed to freeze supercooled water in the hurricane, thereby disrupting its structure. Nice idea, but unfortunately there was not enough supercooled water for the silver iodide to act upon, so the project was a failure. NUKE A HURRICANE There is always someone out there for whom a nuclear blast is the solution, in this case for stopping a hurricane in its tracks. The problem is that the energy locked up in a hurricane dwarfs that of even the biggest nuclear bomb. In fact, an established hurricane releases as much heat energy every 20 minutes as a 10-megatonne…

Almost everyone loves a mug of hot chocolate. Yet this silky, elegant drink gets its delicious flavour from cocoa powder, which is a bitter, gritty and unpolished substance – a classic ugly duckling. The awkwardness of cocoa powder is most obvious when you try to stir it into liquid, such as milk or vanilla essence. It just doesn’t want to go. The powder somehow perches on top of the liquid without getting wet. You can stir for ages, but when you push a clump of powder into the liquid with a spoon, it disappears only briefly before cheerfully popping up to the surface, releasing a puff of dry cocoa just to prove its point. But get the mixing right and silky hot chocolate awaits. What’s the secret of the transformation?…

In 1929, one of the most astounding discoveries ever made was published by the American astronomer Edwin Hubble. Using observations of distant galaxies, he showed that the Universe is expanding. Not only that, but it is doing so in a specific way, with galaxies racing away from each other at speeds that grow with their increasing distance from each other. Now known as Hubble’s Law, his principles remain at the core of cosmology, allowing scientists to calculate the age of the Universe. Yet by rights it should really be known as Lemaître’s Law, after the Belgian priest, astronomer and academic who both predicted it and demonstrated its validity two years before the publication of Hubble’s work. Originally trained in mathematics and astronomy, Georges Lemaître was an expert in the cosmic…

How was The Man Engine born? In 2015, the Cornish Mining World Heritage Site put out a call for projects to celebrate 10 years since the local mining landscape was added to the list of UNESCO World Heritage Sites. The aim was to increase awareness of the region’s industrial past, and The Man Engine was selected as the flagship project. We took him through western Devon and Cornwall in the summer of 2016, and we had an amazing response. In Penzance, 28,000 people turned up – more than the town’s entire population! All the pasty shops had their best-ever days. What’s he made from? He’s mostly steel – the parts were all made from scratch, and we were inspired by the Victorian, cast iron aesthetic. He has a smoke machine…

This ‘ambiguous cylinder’ optical illusion was devised by mathematician Kokichi Sugihara (bit.ly/29isMcS), earning him second place in the Best Illusion of The Year Contest 2016. If you place it on a table, and look down at a 45° angle, the object appears CV›ƂTUV›VQ›DG›C›E[NKPFGT››4QVCVG›KV››››››CPF›KV›OQTRJU› into a open box shape. Place the same object in front of a mirror and it can be seen as both a cylinder and a box at the same time. There are no special effects in this illusion – it is a mere manipulation of the assumptions the brain makes. When viewed from directly above, the actual shape of the object is neither a square nor a circle, but an intermediate of the two. The tops of two of its sides are curved downwards and the other…