BBC Science Focus MagazineNovember 2017的目錄

I never really ‘got’ gravity at school. I knew gravity was what made apples fall to the ground and planets loop around the Sun, but I could never satisfactorily get my head around how it actually worked. It wasn’t until university, when I walked into a classroom with nylon stretched out between some tables like a badly made trampoline, that I really understood. The nylon, my friend explained, was space-time, the fabric of the Universe. The weight in the centre, stretching the fabric towards the floor, was the Sun. This was what huge objects like stars did to space-time: they warped it, only in three dimensions rather than just two. Throw some marbles in and they became recognisable as small planets orbiting a large sun. Throw in dozens, and you…

According to the Office of National Statistics, anxiety or depression affects almost one in five adults in the UK. Currently, counselling therapies and antidepressant drugs are the most common form of treatment, but it can take weeks or months until positive effects are seen. Now, a meta-analysis carried out at the University of Pennsylvania has found that medically supervised periods of sleep deprivation can temporarily reduce symptoms in as little as 24 hours. “FURTHER STUDY IS NOW NEEDED TO DETERMINE PRECISELY HOW SLEEP DEPRIVATION BRINGS AROUND A REDUCTION IN SYMPTOMS” +VoU›DGGP›MPQYP›HQT›UQOG›VKOG›VJCV›UNGGR› FGRTKXCVKQP›JCU›RQVGPVKCN›CPVKFGRTGUUKXG›GHHGEVU›› DWV›GZCEVN[›JQY›GHHGEVKXG›KV›KU›CPF›JQY›KV›YQTMU› JCU›TGOCKPGF›C›O[UVGT[››6Q›KPXGUVKICVG›VJKU› HWTVJGT››VJG›VGCO›EQORKNGF›FCVC›HTQO›C›ECTGHWNN[› UGNGEVGF›ITQWR›QH››››UVWFKGU›FCVKPI›DCEM›UQOG›››› [GCTU››UGNGEVKPI›VJGUG›HTQO›CP›KPKVKCN›nNQPI›NKUVo›QH› OQTG›VJCP›››››››RKGEGU›QH›TGUGCTEJ› 6JG[›HQWPF›RQUKVKXG›TGUWNVU›KP›CTQWPF››››RGT› EGPV›QH›RCVKGPVU››TGICTFNGUU›QH›VJGKT›CIG››IGPFGT›› EQPFKVKQP››HQT›GZCORNG››DKRQNCT›FKUQTFGT›QT› RQUVRCTVWO›FGRTGUUKQP››QT›VJG›V[RG›QH›OGFKECVKQP› VJG[›YGTG›VCMKPI››KH›CP[››(WTVJGTOQTG››RCTVKCN› UNGGR›FGRTKXCVKQP›s›UNGGRKPI›HQT›VJTGG›VQ›HQWT› JQWTU›HQNNQYGF›D[›HQTEGF›YCMGHWNPGUU›HQT›CTQWPF› ›››JQWTU›s›YCU›LWUV›CU›GHHGEVKXG›CU›DGKPI›FGRTKXGF› QH›UNGGR›HQT››››JQWTU›KP›C›UKPING›UKVVKPI› p6JGUG›UVWFKGU›KP›QWT›CPCN[UKU›UJQY›VJCV›UNGGR› FGRTKXCVKQP›KU›GHHGEVKXG›HQT›OCP[›RQRWNCVKQPU›q› UCKF›&T›'NCKPG›$QNCPF››NGCF›CWVJQT›QH›VJG›RCRGT› RWDNKUJGF›KP›6JG›,QWTPCN›1H›%NKPKECN›2U[EJKCVT[›› p4GICTFNGUU›QH›JQY›VJG›TGURQPUG›YCU›SWCPVKHKGF›› JQY›VJG›UNGGR›FGRTKXCVKQP›YCU›FGNKXGTGF››QT›VJG› V[RG›QH›FGRTGUUKQP›VJG›UWDLGEV›YCU›GZRGTKGPEKPI›› YG›HQWPF›C›PGCTN[›GSWKXCNGPV›TGURQPUG›TCVG›q (WTVJGT›UVWF[›KU›PQY›PGGFGF›VQ›FGVGTOKPG› RTGEKUGN[›JQY›UNGGR›FGRTKXCVKQP›DTKPIU›CTQWPF›C› TGFWEVKQP›KP›VJG›U[ORVQOU›QH›FGRTGUUKQP›CPF›VQ› KFGPVKH[›VJQUG›YJQ›EQWNF›RQVGPVKCNN[›DGPGHKV›VJG› OQUV›HTQO›VJG›VTGCVOGPV››TGUGCTEJGTU›UC[›…

“IT TAKES AROUND 20 YEARS FOR PEOPLE TO PARK THEIR CONCERNS ABOUT A REPEAT OF A PREVIOUS DISASTER” What would you think if a nuclear-tipped missile zoomed through space and nearly hit a satellite or two? That’s pretty close to what actually happened on 12 October this year – except that the ‘missile’ was under no one’s control. Travelling at over 25,000 km/h, the house-sized chunk of rock known as asteroid 2012 TC4 packed the punch of a few dozen atomic bombs as it flew overhead, at a similar altitude to many communications satellites. Yet after a bit of media coverage, the event soon went the way of all such ‘cosmic close shave’ stories, and disappeared off the news radar entirely. Even when one of these objects actually does make…

GARMIN VIVOACTIVE 3 Garmin is best known for fitness devices these days, but the latest model in its Vivoactive range reaches out to the broader consumer market, too. So yes, it’ll monitor your heart rate and save all your run metrics, but it’ll also let you make contactless payments via the company’s all-new Garmin Pay technology. Meanwhile its battery life – up to seven days between charges – will put most other smartwatches to shame. £279.99, garmin.com SAMSUNG GEAR SPORT Aimed at the fitness-conscious, Samsung’s latest smartwatch has calorie counting/tracking and training apps, the latter guiding you through over 60 workouts and even streaming them to your TV if you’re exercising at home. More importantly, it’s waterproof to 50m and works with Speedo’s Swim Tracking app,…

1 CARBON DIOXIDE AND SUGAR As plastics tend to be made using fossil fuels, the search for alternatives is part of the journey towards a more sustainable future. Currently, 4 per cent of global oil production goes into plastic, but scientists are exploring ways to bring this down to zero. A sugar- and carbon dioxide-based substitute for the plastic polycarbonate (used for spectacles lenses, DVDs and greenhouses) has been developed by a team at the University of Bath. Not only does their method bypass fossil fuels, but the resulting material is transparent, strong and biodegradable. 2 AGAR Easily extracted by boiling red algae, agar is used to make confectionery in Japan. In a project called Agar Plasticity, the Tokyo-based design collective AMAM suggested that this gelatinous substance could be a…

SHINE A LIGHT ON MEMORY Optogenetics, a branch of science in which neurons are genetically modified to respond to light, is helping scientists to discover more about the brain, mental disorders and memory. Without memories, we’d be lost. They’re the threads that hold our lives together, connecting who we were to who we are. But we’ve only recently pieced together the extraordinary brain science behind them – a story that takes in amnesiacs, mind palaces and ghostly carnivals. One of our first analogies for understanding memory comes from Ancient Greece, where Plato likened memories to etchings on a wax tablet, and his favourite student, Aristotle, continued to use this in his own writings. Forgetfulness, said Aristotle, occurred in childhood because the wax was too soft, and in the elderly because…

1970s AARON This computer, invented by professor and artist Harold Cohen, created paintings autonomously, starting in the early 1970s until Cohen’s death last year. 2006 The Painting Fool The brainchild of British computer scientist Simon Colton, this complex tool is capable of setting its mood and generating paintings based on JQY›KV›HGGNU››+V›ECP›CNUQ›TGƃGEV› on the quality of its work and learn from its mistakes. 2010 DARCI Developed by Dan Ventura, a computer scientist at Brigham Young University in Utah, DARCI can make sense of things like colour and texture in pictures and use them as inspiration for its own original painting-like images. 2015 Deep Dream Generator Google’s free program can take simple, everyday pictures and transform them into quirky, psychedelic ones. The tool inspired an entire generation of artists to experiment with…

“This month sees a milestone as we finish sequencing the genetic codes of all living kākāpō” Have you always been interested in science? Always. My mum was a laboratory chemist at a brewer’s in Norwich. She encouraged me and my brothers to take an interest in science when we were kids. I loved going to local nature reserves and watching the sky at night. I also recorded the weather every day for seven years: rainfall, temperature, wind speed, that sort of thing. If we went on holiday, I’d get the neighbours to do it so there weren’t any gaps in my data. How did your scientific career begin?? My PhD in astronomy led to a post-doc with NASA. We built an instrument that looks for planets in distant solar systems…

DUNCAN GEERE Thirty years on from the Great Storm, Duncan asks why we failed to predict it, and why we still have trouble forecasting the weather today. p61 DINSA SACHAN Dinsa is a science and culture journalist based in New Delhi. This month she wonders: “Will artificial intelligence ever be able to create art?” p73 HELEN THOMSON As the author of an upcoming book on the human brain, science writer Helen is the ideal person to unravel the mysteries of memory. p66…

Got a bit of excess baggage around your mid-section you’d like to lose? Help may be on the way. A team at Columbia University has created a medicated skin patch that has successfully ‘melted’ excess fat in overweight mice. We all have two kinds of fat – white and brown. White fat stores extra energy in large globular deposits, while brown fat is stored in smaller deposits and can be easily burned to produce heat. Babies have lots of brown fat to help keep them warm but as we age it is gradually lost. “There are several clinically available drugs that promote browning, but all must be given as pills or injections,” said study co-leader Dr Li Qiang. “This exposes the whole body to the drugs, which can lead to…

Science still can’t fully explain why we need sleep, but many current theories involve clearing the brain of waste chemicals. A rethink maybe required, however, because research at California Institute of Technology (Caltech) shows that Cassiopeajellyfish, which have no brain at all, exhibit similar sleep behaviour to humans and other mammals. Cassiopea, the upside-down jellyfish, are known for sitting on the ocean floor and pulsating. So how can you tell if they’re snoozing? Scientists use three criteria to define ‘sleep’ across the animal kingdom. Is the creature less active? Is it less responsive to external stimuli? And if you deprive it of ‘sleep’, is it more prone to such a state afterwards? The Caltech team monitored the jellyfish 24 hours a day and found that they pulsate about 39 times…

This may look like a VR headset, but it’s actually your own personal 3D cinema. The Royole Moon’s 1080p AMOLED visor and integrated noise-cancelling headphones are said to recreate the experience of sitting in front of a curved 20.3m screen, giving an IMAX-like level of immersiveness from the comfort of your sofa. It can also be used to play games from your smartphone, PC or console, while its MoonOS gives access to content from streaming services. £849.99, royole.com…

1 RICOH THETA V Ricoh Theta’s new 360° camera is the first to be certified by Google as ‘Street View mobile-ready’, and is also the first to offer playback of your 360° pictures direct to a television. It’s controlled via an iOS/Android app, and can shoot 4K video as well as still images. $430 (£315 approx), theta360.com 2 LOMO’INSTANT SQUARE Aimed at Instagram addicts, this all-analogue instant camera uses Fujifilm’s widely available Instax film to shoot square, Polaroid-style pics. The modern world gets a look-in too, though, with a ‘full auto’ mode and remote shutter release. $199 (£145 approx), lomography.com 3 INSTA360 ONE This consumer 360° camera from Insta360 retails for under £250, yet can shoot 4K 360° video and 24MP RAW…

Let’s get one thing clear: there isn’t a duffer in sight here, and all three turntables offer impressive value for money. So which one you should buy comes down to personal taste and listening habits. If sonic fidelity is all that matters, then on sound alone the Rega Planar 2 just nudges it, though if you listen to a lot of dance music, hip-hop, reggae or heavy rock you may find it doesn’t pack the bottom-end welly you’re after. It’s also a nuisance having to remove the platter to change speeds, and you’ll need a separate phono stage if your amp doesn’t have one. The Pro-Ject Essential III fares a little better at the low end and packs in more features, but loses points for that low torque, which rules…

ENTROPY Central to the second law of thermodynamics, entropy is a measure of the disorder in a system. It reflects the number of different ways the components of a system can be rearranged. The letters making up the words on this page have low entropy – there’s only one way to arrange them (assuming each individual a, b, c, etc. is unique) to produce the text you’re reading. But if you scramble the letters, it will have higher entropy, as there are lots of ways to arrange them jumbled up. The second law of thermodynamics reflects that it’s easier to go from an ordered page to scrambled letters than it is to go from a pile of letters to the contents of this magazine. Similarly, it’s easier to break an…

For many, the defining image of the Great Storm of 1987 was weather forecaster Michael Fish standing before the nation, promising there would be no hurricane. Someone had phoned the BBC earlier, he told viewers, with fears that one was on the way. “Well, if you’re watching, don’t worry, there isn’t,” he cheerfully said. A few hours later, the south-east of England was hit by the worst weather it had seen in almost 300 years In subsequent days, as the damage was assessed, newspapers were filled with vitriol for Fish and the Met Office’s perceived failure to get the forecast right. The Met Office admitted that its radio and TV bulletins had predominantly warned of rainfall rather than strong winds, and conducted an internal investigation which resulted in improved weather…

500BC Ancient Greek poet Simonides of Ceos develops what is now known as the method of loci: a memory technique that world memory champions can use to remember pi to 70,000 digits. 300BC Philosophers Plato and Aristotle put forward the first theories of memory, describing it as something akin to etchings on a wax tablet. HERMANN EBBINGHAUS (1850-1909) Created a series of nonsense words that provided a way of testing different aspects of memory and forgetting, leading to early definitions of sensory, short-term and long-term memory. DONALD HEBB (1904-1985) The Canadian psychologist proposed that brain cells that are active at the same time form new and stronger connections – a theory that is now known to underlie our ability to create long-term memories. 1906 Physicians Santiago Ramón y Cajal and…

“HE FISHED OUT AN AXE, HACKED INTO A GLACIAL PIMPLE, AND OUT CAME ICE FILLED WITH RAINBOWS” We love it when a gift that we’ve carefully chosen makes someone happy. But when the recipient of the present is a small child we have to accept that the real source of joy is often the packaging rather than its contents. Physicists have a similar streak, and can often be left in a corner happily playing with something that isn’t meant to be the main attraction. This time, the culprit was one particular chunk of ice, on a day that had been filled with the stuff. The star of the show was a cave in the side of a glacier, and we had spent an afternoon working there, filming for a BBC…

Michael Fish’s famous 1987 ‘no hurricane’ prediction was technically correct p63 Sleep deprivation could help treat depression p15 Jellyfish go to sleep p26 People who eat shellfish may be ingesting 11,000 pieces of microplastic per year p57 Chin dimples are a dominant genetic trait p101 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+…

INVISIBLE ILLNESS I would like to commend James Lloyd for his article about his personal battle with OCD (October, p60). I myself struggled with ‘intrusive thoughts’ similar to those described by James (internal rather than physically visible OCD) for four to five years before being diagnosed with anxiety back in 2005. It led to depression and the worse period of my life to date. However, back then, even after being diagnosed with anxiety, I had never heard the term ‘intrusive thoughts’ and until reading James’ article thought they were just a side effect of the anxiety. Everything James describes is exactly what I experienced and I would never have thought to class it as OCD. It really does show that there is still a lot that needs to be done…

What’s that – BMW’s snazzy new hatchback? Miles off. It’s the designation that’s been given to the grave of a 10th-Century Viking warrior found in Birka in south-east Sweden. Cool. So why are we talking about it? When the grave was first unearthed in the 1870s, the shields, swords, axes and remnants of horses buried alongside the body led researchers to believe it belonged to a male Viking warrior. But they were wrong? Yep. A new DNA analysis has found the skeleton only has X chromosomes, and no Y chromosomes. This means it must have belonged to a woman. Wow! Does that mean this was the grave of a real-life shield-maiden? Well, there’s a bit of disagreement among researchers. Some say that there is still no solid proof the Viking…

BABIES CAN LEARN THE VALUE OF HARD WORK A study at MIT showed that babies as young as 15 months old persevered more with tasks they were attempting if they had previously seen an adult struggling hard to achieve something. FISH HAVE PERSONALITIES University of Exeter researchers studying Trinidadian guppies found that particular guppies were consistently more cautious, curious or aggressive than others across a range of situations and environments. MOODS ARE CONTAGIOUS, DEPRESSION ISN’T A US study has found that teenagers whose friends are in a good or bad mood are more likely to feel the same way – although this doesn’t apply if their friends are severely depressed. GIRAFFES’ LONG NECKS MAY BE A COOLING MECHANISM Giraffes’ necks are an evolutionary mystery, but a new study suggests that…

AN AMPLIFIER This strengthens the weak electronic signal from your hi-fi components to a level that’s powerful enough to drive a pair of speakers, as well as modifying the tone via bass and treble controls. For use with a turntable, you’d ideally want one with a dedicated Phono channel (see below). We like: Onkyo A-9010 (£200); Marantz PM-6006 (£279); Pioneer A-30 (£249) A PHONO STAGE The electronic signals mentioned above come in two flavours: line- and phono-level. Turntables produce the weaker phono-level signal, which needs to be boosted to line-level by a phono stage (or ‘phono preamp’) for your amplifier to process it. On amps with a Phono channel this is built-in, while many modern turntables (such as the Audio-Technica AT-LP5) have one onboard. Otherwise, you’ll need this extra piece…

There are over five trillion pieces of plastic in the world’s QEGCPU››6JG› floating island of rubbish that’s supposedly found at the centre of the Pacific Ocean, dubbed the ‘Great Pacific Garbage Patch’, has captured the public’s imagination, but even this doesn’t FQ›LWUVKEG›VQ›VJG›RTQDNGO››+P› reality, if you stood on a boat at that site you would see no enormous plastic island, but rather endless tiny fragments floating on the surface of the QEGCP››#EEQTFKPI›VQ›QPG›GUVKOCVG›› this plastic soup covers an area twice the size of the continental 7PKVGF›5VCVGU›› #U›RNCUVKE›OQXGU›VJTQWIJ›QWT› seas it breaks down into smaller pieces – the kind of pieces that can GCUKN[›DG›UYCNNQYGF›D[›OCTKPG›NKHG›› #PF›VJG›RTQDNGOU›EQPVKPWG› DGPGCVJ›VJG›UWTHCEG››5EKGPVKUVU›CTG› increasingly finding deposits of plastic at the bottom of the oceans, even as far down as the 10km-deep /CTKCPC›6TGPEJ›KP›VJG›2CEKHKE› 6JG›HCEVU›CTG›JQTTKH[KPI››DWV› many of the impacts that plastic will have…

1 AVOID SINGLE-USE PLASTICS The culprits here should be familiar to everyone: carrier bags, bottles and drinking straws. Purchase a ‘bag for life’, carry a reusable bottle, and sip drinks straight from the glass. 2 GIVE UP CHEWING GUM Chewing gum is made from synthetic rubber – a plastic – and shockingly around 100,000 tonnes of the stuff is discarded every year. Is minty-fresh breath really worth that? 3 GO ON A BEACH CLEAN Organisations like the Marine Conservation Society conduct cleans up and down the country, removing rubbish from the beaches and raising awareness of the ocean environment. 4 RECYCLE! We’ve all heard this one by now, but currently only a third of recyclable plastic used by UK consumers is recycled. So swot up on your local rules and…

In the Atlantic basin, the hurricane season normally lasts from June to November, peaking in September. The fact that we’ve seen eight hurricanes so far this year [as of 25 September] is markedly out of the ordinary – the average per season is six. However, perhaps more profound is the sheer number of strong hurricanes: this year was the first time in recorded US history that three Category 4+ hurricanes had made landfall in a single season. But whatever the remainder of the season brings, it’s unlikely to be as active as the famous 2005 season. This saw Katrina, one of 15 hurricanes that year, devastate the US coastline and left much of New Orleans underwater. Is there a link with climate change? We know that a warmer atmosphere can…

How do butterflies manage to fly in the wind? BRIAN MCHALE, LONDON Scientists have studied this by tethering individual insects in wind tunnels and training them to fly towards flowers, while filming them in slow motion. They have found that the lightweight insects use a range of flying styles to combat the challenges of staying airborne on windy days. They might clap their wings behind their backs to push themselves forward or ‘waggle’ by twisting their flapping wings, therefore creating miniature whirlwinds that roll off the wing and lift it up. Good posture is important, as is warming up the flight muscles before flight. But windy days can be useful. With help of tailwinds, migrating butterflies can travel at 100km/h at an altitude of several hundred metres! CC Why does…

1. Princess Leia was brought up in a noble household in a galaxy far, far away. But she dedicated herself to the downfall of the established regime, by force if necessary. 2. To most of us she is most famous for her iconic hair style. The twin ‘cinnamon bun’ look is handy for keeping your ears warm on chilly planets like Hoth. 3. In 1977, George Lucas was on the hunt for a distinctive look for Leia. He was inspired by Mexican fashions in the early 20th Century, but women there mostly wore their hair long. 4. Except for Clara de la Rocha. She was a revolutionary hero and guerilla fighter who became a colonel during the 1910 Mexican Revolution and fought in several battles.…