Sommaire pour July 2018 de BBC Science Focus Magazine

Bigger than a bus, daft as a brush: that’s the T. rex I remember. A monstrous predator made friendly by a pair of drumsticks for arms and a walnut for a brain. Of course, in its element, T. rex would have been terrifying, with its monstrous maw and blood-curdling roar. But if cinema’s taught me anything it’s that if I’m unlucky enough to stumble across one, then I can easily outwit it by standing still. It turns out, the films were wrong (thanks, Spielberg!). As with most apex predators, the T. rex didn’t just muscle its way to the top of the food chain, it used cunning to get there. And this story, of how a tyrannosaur became king, is one that scientists are beginning to piece together. Turn to…

Today’s music-lover has never had it so good: the vinyl revival, internet radio, plus the growing popularity of music streaming, like Spotify, Amazon Music and Google Play Music services. We’re even able to enjoy recording studio sound quality (better than CD) with the right equipment. Most of today’s music is digital and there’s one crucial piece of electronics that determines how good that music can ultimately sound: a DAC (digital to analogue convertor). The chances are, you’ve already used a DAC in the past 24 hours: that smartphone call, TV news catch-up or internet surf; DACs are essential circuit board devices embedded into everyday gadgets converting digital signals into analogue ones, so you can hear them. Most are tiny chips, costing no more than a few pounds, machine-soldered into circuit…

The microbiome seems to return to normal two weeks after a long-haul flight, but frequent flyers could find the disruptions become chronic. Michael is a science writer and broadcaster, who presents Trust Me, I’m A Doctor on BBC Two. His latest book is The Clever Guts Diet (£8.99, Short Books). This summer, lots of people will be jetting off to exotic countries and passing through multiple time zones. I’ll be one of them. The trouble is, I spend far too much of my life doing this, mainly while making documentaries. So I am, naturally, obsessed with jet lag. Jet lag is caused by a mismatch between external time cues (the Sun is rising, it must be morning) and our internal, circadian clock. The circadian clock plays a vital role in…

…It comes down to the fact that, in Einstein’s theory, time is not absolute, ticked off by a universal clock with which everyone agrees, but instead is relative. “I can’t talk to you in terms of time – your time and my time are different,” wrote the English novelist Graham Greene. According to Einstein, the rate at which time flows for someone depends on how fast they’re moving relative to you and the strength of the gravity they’re experiencing. If you can find a way to jump from a region where time flows at one rate to a region where it flows at slower rate, you can go back in time – you’ll have made a time machine. The recognition that time is not what you think it is goes…

1: IT’S FINE TO KEEP GOLDFISH IN SMALL BOWLS Nope. While goldfish cansurvive in cramped conditions, it’s not good for them. To live to their full lifespan and size (they can reach 45cm), they need properly aerated, treated and filtered water. 2: EACH VARIETY OF GOLDFISH IS A DIFFERENT SPECIES Wrong again. All goldfish are the same species, Carassius auratus, a type of carp originally from East Asia that’s been selectively bred for hundreds of years. 3: YOU CAN’T TRAIN A GOLDFISH TO DO TRICKS Yes you can! Like training a dog with food rewards, you can teach goldfish to swim through hoops, slalom between posts and even push a mini football into a net. 4: GOLDFISH HAVE A THREE-SECOND MEMORY Wrong! Goldfish remember things for months. Feed your pet…

There has been a lot of recent discussion about blue light and sleep. Blue light is the type of light that we can see outside on a stunning summer’s day, and is also emitted by many phones and tablets. This type of light has been given particular attention because it can suppress the hormone melatonin, which our bodies produce when the Sun goes down to make us feel sleepy (for more on melatonin, turn to p25). Therefore, if we look at the blue light of our tablets late at night, our bodies might be missing a cue that it is time to sleep. The upside of blue light is that it can be helpful at certain times of day, increasing arousal and alertness when needed and helping to set the…

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1. ANIMAL SANCTUARIES Veganism seeks to exclude all cruelty to animals. Simply opening the farm gates to the existing stock of 3.5 billion grazing animals and 19 billion chickens wouldn’t work. Most would starve to death or be eaten by predators. Instead, farms would need to be converted into sanctuaries for the remaining natural lives of the animals. 2. EMISSIONS Food production is responsible for a quarter of all greenhouse gas emissions, mostly from cows burping methane. Methane is such a potent greenhouse gas that a global switch to plant-based diets would cut emissions from food production by 28 per cent – that’s the equivalent of India going carbon neutral. 3. LAND USE Currently, 68 per cent of farmland is used for livestock. Planting a fifth of this with crops…

“MOVE MORE. IT’S THAT SIMPLE” Have you always loved sport? It’s been a lifelong obsession. My passion at school was swimming, then when I was 14 there was a scandal that transformed my life. It was 1976, the height of the Cold War. The British pentathlon team was fencing the Russians in the Montreal Olympics. The British captain got hit by a Russian fencer, but he complained. They checked the Russian’s sword and found it had a secret button. The Russians were thrown out for cheating and Britain went on to win. It raised the profile of British modern pentathlon. So you took up pentathlon? It became the next 15 years of my life. It took me to the Olympics, and European and World Championships. I had an incredible career.…

STEPHEN BRUSATTE We’ve got a lot wrong about dinosaurs over the years, especially when it comes to their intelligence. Palaeontologist Stephen sets us straight. ALICE GREGORY The latest research says that getting enough sleep is about more than simply recharging your batteries. Sleep expert Alice investigates HELEN SCALES Fish have a reputation for having short memories and little brainpower. This couldn’t be further from the truth. Marine biologist Helen plunges in…

If our Universe is one of many making up a much larger multiverse, life could be common in countless other parallel universes, according to researchers from the University of Sydney, the University of Western Sydney, the University of Western Australia, and Durham University. According to the multiverse theory, life arose in our Universe thanks to the amount of dark energy being just right. The theory states that if the amount of dark energy in a universe is too large, it causes such a rapid expansion that it prevents any stars, planets or life from forming. If it is too small, then the universe collapses again before anything interesting forms. Dark energy is the mysterious force that is accelerating the expansion of the Universe that started with the Big Bang. “FOR…

8 The age, in weeks, that puppies reach peak cuteness, as estimated by a team at Arizona State University. This is the age at which they are weaned by their mothers. 120 The age, in years, of a sourdough starter (a yeast culture used to make bread) owned by 84-year-old Ione Christensen who lives in the Yukon, Canada. 73 The speed, in kilometres per second, of the new figure for the Hubble constant – the speed at galaxies are moving away from the Earth. This was calculated by researchers at the Space Telescope Science Institute in Baltimore, Maryland.…

CHESS PLAYERS Chess grandmasters live longer than the general population, researchers at the University of Queensland have found. It’s not yet clear why, but it’s likely to be due to social and economic factors and a reduced risk of developing dementia, they say. MUSICIANS Learning an instrument can make your brain more efficient, so it’s able to perform a certain task with less effort than the brain of a non-musician, researchers at the Baycrest Centre for Geriatric Care, Canada, have found.…

Meet the Solar System’s first-known permanent immigrant. A team of international researchers have located an asteroid nestled in Jupiter’s orbit that started life in another solar system. Dubbed (514107) 2015 BZ509, or BZ for short, the asteroid was found in a retrograde orbit, meaning that it moves around the Sun in the opposite direction to the other planets. When the team ran simulations to trace the location of BZ back to the birth of our Solar System, 4.5 billion years ago when the era of planet formation ended, they found the asteroid has always moved in this way. This means that BZ could not have been there originally and must have been captured from another system. “Asteroid immigration from other star systems occurs because the Sun initially formed in a…

ADAPTIVE XBOX Gaming controllers can be a barrier for many players, so Microsoft has developed the Xbox Adaptive Controller, a highly customisable solution for gamers with a broad range of disabilities. The new controller features two large programmable buttons and 19 jacks that can be connected to a range of joysticks, buttons, switches and mounts, allowing gamers to personalise their setup. Microsoft claims it’s the most flexible adaptive controller ever made by a major gaming company. Currently, it can be used to play Xbox One and Windows 10 PC games, and gamers can set up three profiles on their controllers, so they don’t need to re-program the set up for every new game. Microsoft is considering rolling out several of the controller’s new features in its other products. For example,…

MOO-TOOTH TRACKERS Livestock Labs have implanted bio-monitors, called EmbediVets, under the skin of cows to help farmers spot disease. CEO Tim Cannon knows how it feels: he tested the tech by embedding one under his own skin before they were inserted in cows. CALIFORNIA HOMES MUST HAVE SOLAR The California Energy Commission now requires that all new homes built from 2020 onwards must have solar panels installed. It’s part of state law that requires California to generate half its power from renewables by 2030, a target they’re likely to hit well ahead of schedule. WOMEN’S WORK Research shows that jobs typically held by women are less likely to be taken over by robots. Women are overrepresented in roles that require high levels of social skills and empathy, and these are…

There was remarkably little to fault with all four sets. Tech companies are getting smarter and making sure all your content looks great – no matter what the quality of the source. In all four sets, the image standard was high. For us, the best balance between price and image fidelity was Sony’s XF90, but that’s based on the idea that’d we’d be using it with a set-top box and games console in place of its built-in interface. LG’s OLED shows how good Ultra HD can be, the Hisense demonstrates that affordable doesn’t meaning missing out on quality, and Samsung leads the way in terms of its smart package. Bring out the popcorn.…

- Black hole A region of space-time with such immense gravity that nothing can escape. - Cosmic strings Hypothetical thin ‘cracks’ in space-time, left over from the Universe’s formation. - Photon A particle of light. - Space-time The fusion of three-dimensional space (length, width, height) with time, to make four-dimensional space-time. It is warped in the presence of matter, such as stars and planets. - Tachyon A hypothetical particle that travels faster than the speed of light. - General Relativity This 1915 theory built on Special Relativity by adding gravitational effects and proposing that space-time is curved. - Special Relativity Einstein’s first theory of the structure of space-time, introduced in 1905. It’s based on the postulates that the laws of physics are the same for all observers in uniform motion…

Everyone knows that Isaac Newton came up with the law of gravity after seeing an apple fall from a tree in his mother’s garden. Newton himself told the story to several contemporaries, who recorded it for posterity. Ever since, Newton has been credited with discovering the law, describing how “All celestial bodies whatsoever have an attraction or gravitating power towards their own centres”. But these words are not Newton’s. They were penned by his scientific rival Robert Hooke in 1670, decades before Newton started telling people the apple story. This has led some historians to suspect Newton deliberately made up the story of the apple to back his claim to priority. While Hooke is best known today for a dull law about springs, he was one of the most brilliant…

In the otherwise fabulous Q&A section in the May issue, you use a photo of two British bulldogs to illustrate the question ‘Do dogs recognise their own breeds?’ (p82). I’m not sure if you’re aware, but the British Veterinary Association (BVA) is keen to discourage the media from using extreme conformation breeds – those bred for particularly acute physical characteristics – in their publications, especially in adverts. The British bulldog is classed as an extreme conformation breed. Their identifying traits – the flattened noses, narrowed nostrils, severely reduced nasal chambers and excessively saggy flesh in the pharynx – all contribute to brachycephalic obstructive airway syndrome (BOAS), which is the huffing and puffing that people expect from bulldogs and pugs. And don’t get me started on the skin, eye and thermoregulatory…

Somebody put the kettle on: nanoparticles extracted from tea leaves can inhibit the growth of lung cancer cells, killing up to 80 per cent of them, researchers at Swansea University have found. The team made the discovery by accident when testing out a new method of creating quantum dots – tiny semi-conducting particles measuring less than 10 nanometres in size that display a wide range of unique properties. Quantum dots have shown promise in several different applications, including computers, solar cells, healthcare and tumour imaging. However, they are complicated and expensive to manufacture and create toxic by-products. After attempting to create a method of producing non-toxic nanoparticles using extracts from tea leaves for use in the imaging of tumours, the team noticed something astounding: the quantum dots they had created…

Meet your cosmic neighbours: images assembled by an international team of researchers using data from NASA’s Hubble Space Telescope show the closest galaxies to Earth in unprecedented detail. Dubbed the Legacy ExtraGalactic UV Survey (LEGUS), the project combined data from observations in visible and UV light of 50 star-forming spiral and dwarf galaxies in the local Universe, ranging from 11 to 58 million light-years away. The resulting catalogue will provide researchers with a large and extensive resource for understanding the complexities of star formation and galaxy evolution, the team said. “Much of the light we get from the Universe comes from stars, and yet we still don’t understand many aspects of how stars form,” said team member Elena Sabbi of the Space Telescope Science Institute in Baltimore, Maryland. “This is…

What did they do? A team of researchers from Ruhr University Bochum in Germany put year-old Nile crocodiles into an MRI scanner and played them Bach’s Brandenburg Concerto No. 4. Why did they do that? Crocodiles originated over 200 million years ago, and their brains have barely changed since, making them a good modern-day representative of ancient brains. Scientists study crocodiles to understand at which point certain brain structures and behaviours first emerged. The point of the study was to examine how the crocodile brains respond to complex sounds, and see how those compared to the patterns seen in more recently evolved mammals and birds. What did they find? Different areas of the crocodilian brain were activated by complex music, such as Bach, compared to those activated by basic notes.…

MANUAL WORKERS Men working in physically demanding jobs, such as builders, are at greater risk of an early death despite getting a significant amount of exercise, Dutch researchers have found. The effect, which is thought to be down to the intense demands put on their cardiovascular systems, was not seen in women. CLASS CLOWNS This is no joke. Getting up to hijinks in the classroom can make young kids more popular with their classmates. Yet by the time they reach eight years old, classroom jokers are viewed as disruptive annoyances and are less desirable as playmates, a study at the University of Illinois has found.…

CHIMPANZEES’ BEDS ARE CLEANER THAN OURS This may not come as a surprise to parents of teenagers, but a study by North Carolina State University has found that the treetop beds that chimpanzees make each evening have far fewer bacteria, parasites and faecal particles than human beds. WEEKEND LIE-INS CAN HELP YOU LIVE LONGER Sleepy heads rejoice! Having a weekend lie-in to catch up on sleep could extend our lifetimes, researchers at the University of Oxford have found. Zzz. SHARKS LIKE JAZZ Researchers in Sydney who trained baby Port Jackson sharks to go to a feeding station each time they heard music have found they respond more positively to jazz than classical. Nice.…

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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 For how long can a chicken survive without its head? KANIKA AHUJA, WINCHESTER In the 1940s in the US, a chicken called Mike lived for 18 months without a head. He had been almost completely beheaded with an axe, but crucially the jugular vein and most of the brainstem were left intact. This left just enough brain function for essential functions, like…

1. Until bacteria were discovered in the 17th Century, infectious diseases were thought to be caused by noxious smells. The word ‘malaria’ comes from the Latin for ‘bad air’. 2. During the Black Death in Europe in the 14th Century, towns and cities would build bonfires of scented wood to try and purify the air and drive away the disease. 3. For more portable protection, the rich carried their own vials, filled with strong-smelling plant essential oils. The word ‘perfume’ comes from the same root as the word ‘fumigate’. 4. As perfume became associated with wealth, an industry grew up in Europe to cater to changing fashions. The original citrus recipe of Eau de Cologne dates back to 1709.…

THIS IS YOUR BRAIN ON MUSIC: UNDERSTANDING A HUMAN OBSESSION BY DANIEL LEVITIN (£7.99, DUTTON PENGUIN) My favourite book that explores the neuroscience of music. MUSICOPHILIA: TALES OF MUSIC AND THE BRAIN BY OLIVER SACKS (£8.99, KNOPF) Case studies of people struggling with neurological conditions reveal how the brain works. PERFECTING SOUND FOREVER: AN AURAL HISTORY OF RECORDED MUSIC BY GREG MILNER (£9.99, GRANTA BOOKS) Reading Greg’s account of early sound recording inspired me to research how the voice is changed by technology. SWEARING IS GOOD FOR YOU: THE AMAZING SCIENCE OF BAD LANGUAGE BY EMMA BYRNE (£12.99, PROFILE BOOKS) For all connoisseurs of potty-mouthed speaking. THE EVOLUTION OF LANGUAGE BY W. TECUMSEH FITCH (£40.99, CAMBRIDGE UNIVERSITY PRESS) A comprehensive account of language evolution, including drawing on Fitch’s fascinating research.…