BBC Science Focus MagazineSeptember 2017的目錄

Peering through a hole in a poplar leaf, these two damselflies look ready to invite us in for a cup of tea. The pair, who appear to be holding hands, were spotted close to the river Po in northern Italy. “Damselflies are often sexually dimorphic,” says Prof Adam Hart, an entomologist at the University of Gloucestershire. “This means that the males and females differ, typically in size and colouration, with males often more colourful and smaller than females.” Here, the larger, green damselfly on the right is more likely to be the female, and she’s probably been wooed by an elaborate courtship display. “The males will hover, flap, bob, flicker and display their wing spots in order to show themselves off,” says Hart. “They’ll also engage other males in ‘flights…

The largest remaining ice shelf on the Antarctic Peninsula lost roughly 10 per cent of its area on 12 July. This is when an iceberg dubbed A68, which has an area around four times that of London, broke free. Since then, researchers from the University of Leeds and the British Antarctic Survey (BAS) have been tracking the iceberg’s journey using the European Space Agency’s Copernicus Sentinel-1 satellite. They hope the event will offer them a unique opportunity to study the implications of the future loss of huge shelves of ice from the Antarctic. So far the iceberg has drifted 5km away from the Larsen-C ice shelf, shedding 11 smaller chunks of ice around 10km long as it went. “The satellite images reveal a lot of continuing action. We can see…

Proving that medical researchers can be softhearted too, a team at the Swiss Federal Institute of Technology in Zurich has used malleable silicone and 3D printing to create the most human-like artificial heart to date. It’s just 60 years since the first heart patients were given pacemakers, and 50 since the first human heart transplant took place. So while these procedures are almost considered routine, the technology involved is still in its relative infancy. The artificial hearts currently given to patients awaiting a transplant use mechanical pumps, which can seize up or fail; they also leave the patient without a natural pulse, which can affect other bodily functions. The new heart, in contrast, replaces the mechanical pump with an additional chamber that is inflated and deflated by pressurised air, mimicking…

In December 2015, the Paris Agreement, which has been signed by 195 countries, pledged to take action on global warming. The Agreement aimed to limit worldwide temperature rises to less than 2°C above pre-industrial levels by 2100, and to endeavour to keep it below 1.5°C. But new research from the University of Colorado suggests that hitting those targets may be much harder than previously thought. “The window of opportunity on a 1.5°C target is closing,” said lead researcher Dr Robert Pincus. The team used no computer modelling in their research, instead relying entirely on real-world measures of climate change. They discovered that even if we cut fossil fuel emissions to zero tomorrow, we are already committed to warming of around 1.3°C by 2100. If we fail to act, and emissions…

TRITON 7500/3 PRICE: $6.3m (£4.8m approx) tritonsubs.com Intended as leisure vehicles for superyacht owners, Triton Submarines’ mini submersibles have proved a surprise success with marine researchers and wildlife film-makers. So Triton is now building tougher subs that can dive deeper than ever. Building submersibles that can reach great depths isn’t that hard; the tricky part is designing one that can withstand the huge pressures involved, yet still has a screen that you can see out of. Accordingly, Triton’s latest machines feature a viewing dome made from a 261mm-thick globe of acrylic glass, which means the current two-seater 7500/2 and three-seater 7500/3 subs can descend to around 2,300m, compared to the few hundred metres earlier subs could manage. Triton hopes eventually to produce a submersible, complete with viewing dome, that can…

With ‘secondary ticketing’ a major bone of contention in the entertainment industry right now – the practice has even been the subject of questions in Parliament – online ticket agency Ticketmaster has come up with a novel solution involving your smartphone and ultrasonic audio. Ticket touts (or ‘scalpers’ if you’re in the US) have been around forever, buying tickets for concerts or sporting events early and then selling them on at a markup nearer the time. The dawn of the internet era, however, means ‘secondary ticketing’ is no longer the preserve of a few scruffy chancers standing in the rain outside your nearest arena, but rather a multimillion-dollar industry that’s making it hard to get event tickets at face value at all. Ticketmaster’s solution involves replacing the paper ticket with…

With the need to generate power without burning fossil fuels growing ever more urgent, news that researchers at George Washington University (GWU) in Washington, DC have invented a new type of solar panel that is almost twice as efficient as existing panels is very welcome. Funded by a $900,000 grant from the Advanced Research Projects Agency’s energy division and led by Matthew Lumb from GWU’s School of Engineering and Applied Science (as well as the Naval Research Laboratory), the team’s new panels can convert sunlight energy into electricity with an efficiency of 44.5 per cent, compared to 25 per cent for existing panels. They do this partly by using a type of technology that allows multiple solar receivers to be stacked one on top of another within a single cell,…

FORMATION OF STARS AND GALAXIES By studying what matter there is in the interstellar medium, scientists hope to learn more about how stars are born Space is called ‘space’ for a reason. The gaps between the stars are incredibly empty – far more sparsely populated than any vacuum we can create here on Earth. Astronomers call this area the interstellar medium (ISM). And though it may be diffuse, it’s thought to make up at least 10 per cent of the visible mass of our Galaxy. Stars sit embedded in the ISM, but are not isolated from it. “Stars are born inside the interstellar medium,” says Mikako Matsuura from the University of Cardiff. “It’s like an ecosystem.” The Voyagers have been able to study the birth of stars by recording the…

Almost anyone can have an OBE but certain characteristics make it more likely. One is ‘psychological absorption’. Scoring high on this measure means you are easily engrossed in films, books or music, ignoring everything else around you. You may be susceptible to hypnosis, have a rich fantasy life and remember having imaginary playmates as a child. Another is ‘positive schizotypy’. This sounds as though it’s related to schizophrenia and in a way it is. The idea is that everyone lies on a continuum from low to high schizotypy. High schizotypes have unusual dissociative experiences, disorganised thoughts, flat emotions and unstable moods, but are more imaginative and creative too. They include many writers, artists and poets, as well as OBErs. A third indication is ‘temporal lobe lability’, meaning the brain’s temporal…

FACT Polar bears are top carnivores that bioaccumulate the vitamin A produced by marine algae lower down the food chain. Because vitamin A isn’t water-soluble, it can’t be easily flushed from the body and is stored in the liver instead. Bears and seals have generally high levels of vitamin A in their livers but polar bears have the most of any animal. The recommended daily allowance (RDA) for vitamin A in humans is 0.9mg, and you can get that from eating just one-tenth of a gram of the liver from a well-fed polar bear. The entire liver contains enough vitamin A to kill as many as 52 adults! If you spread it out and ate just enough to get your RDA every day, that liver would last you 143 years!…

Visit the Robots exhibition at London’s Science Museum and you’ll be greeted by this little whippersnapper. The realistic, wall-mounted robot baby was built by UK animatronics company John Nolan Studio, and is based on the puppet babies they make for use on film sets. The puppets are usually operated remotely, but this one’s been automated so that it runs through a routine of movements and expressions throughout the day – which is what the cables sticking out of the back are for. Creepy near-realism aside, then, the baby is actually a low-tech affair. But that’s the point: it’s the first thing you see on a journey through 500 years of robot history, while thelastthing you see will be an all-singing, all-dancing, high-tech AI robot toddler – symbolising both how far…

It’s official: ageing is all in the mind. But when we say ‘the mind’, we mean ‘the brain’ – and specifically the hypothalamus, a region of the brain that is involved in growth, reproduction and metabolism. In 2013, researchers at the Albert Einstein College of Medicine in New York proved that this region of the brain also governs the entire body’s ageing process – and now the same team has identified the precise mechanism involved. The mechanism lies in a small cluster of neural stem cells, which were already known to be responsible for the formation of new brain neurons. The number of these stem cells declines as we get older, but the team has shown that by injecting fresh stem cells into the brains of adult mice, the ageing…

It seems we are all intergalactic travellers. Around 50 per cent of all matter in the Milky Way originated in a different galaxy, new research has revealed. It has long been believed that once galaxies start to form, they keep to themselves, with the matter that coalesced to form a galaxy in the first place essentially staying in it forever. But a new study carried out at Northwestern University in Illinois suggests that matter is, in fact, regularly transferred from one galaxy to another. “Given how much of the matter out of which we are formed may have come from other galaxies, we could all consider ourselves space travellers, or extragalactic immigrants,” said study co-author Daniel Anglés-Alcázar. The Northwestern team used computer models to study the evolution of the Universe…

As some of nature’s toughest critters, despite measuring less than 0.5mm long when fully grown, tardigrades can survive dehydration, extreme temperatures, the vacuum of outer space and doses of radiation hundreds of times stronger than that required to kill a human. Now, a team from the University of Edinburgh has sequenced the genomes of two species of tardigrade in an attempt to understand exactly how they are capable of such feats. By exploring the animals’ DNA, the team identified the genes that enable tardigrades to resist the effects of dehydration. These genes activate as the animals dry out, triggering the production of proteins that replace the water in their cells and preserve the microscopic structure. Other proteins analysed appear to protect the tardigrades’ DNA from damage, and may explain why…

Busy bees I beg to differ with Luis Villazon, who says “bees don’t fly in particularly straight lines, either” (Summer, p80). A bee foraging for nectar and pollen will fly from flower to flower until they have a full load, but the fully laden bee will then fly back to the hive as straight as possible, in order to conserve energy – hence the saying ‘making a beeline’. As children in Texas in the 1940s, we used to watch bees buzzing around flowers, and when we saw one fly off in a straight line we’d follow it back to the ‘bee tree’ where the honey was! Samuel Walker, North Yorkshire Facebooks I was interested in your article on face recognition research done on rhesus monkeys (Summer, p16). Having been a…

1. EXPLORE CRYSTAL CAVES INSIDE A GLACIER Drive along Iceland’s iconic Ring Road and you’ll pass many enormous glaciers. Inside some of them are glorious ice caves with translucent walls that produce weird light in hundreds of shades of blue. It’s a photographer’s dream. “Most of them [the caves] are formed by water running either through tunnels in the ice, or on the ground underneath the glacier,” says landscape photographer Iurie Belegurschi at Iceland Photo Tours, who takes groups into the ice caves within the vast Vatnajökull glacier in southeastern Iceland. Although there are many ice caves in Iceland, Vatnajökull’s are the most accessible. Safety is still important, though. “It’s safe to visit ice caves from November to March when it’s coldest outside and they’re stable,” says Belegurschi. “But always…

“It may turn out that OBEs are linked with the important social skill of being able to understand someone else’s perspective” Can you imagine becoming convinced that a pink, rubber hand is your own? Unlikely as it seems, this is the famous ‘rubber hand illusion’. The person’s own hand, lying next to a rubber hand, is concealed from view by a screen. If both hands are stroked simultaneously, people start to feel the touch as though it is on the rubber hand. Bigna Lenggenhager, at the University of Zurich, has managed to create a ‘whole body illusion’ using virtual reality. She places a camera two metres behind a participant and gives them a head-mounted display to wear, so they are looking at their own back. When the experimenter gently strokes…

1. THE RADIATION Nuclear bombs release 35 per cent of their energy as thermal radiation. A 1.2 megaton device, such as the B83 bomb in the US arsenal, will release two million gigajoules of energy. This will cause third-degree burns to exposed skin, at a distance of 10km. If you are already standing next to a wall or a car, duck behind it. Otherwise throw yourself on the floor, feet facing towards the blast, and cover your head with your arms. The thermal pulse will last around 10 seconds for a ground burst explosion. The initial gamma radiation is less dangerous than the heat pulse. 2. THE BLAST Once that ends, you have a brief lull before the blast wave hits you with 50 per cent of the bomb’s energy.…

Why save moving pictures of a galloping horse in DNA? We’re trying to create a living ‘molecular recorder’ – a cell that would capture information and store it in the DNA bases [the letters A, C, G and T] of the cell’s own genome, and get that information back again by sequencing the cell [reading its DNA]. We did all this in E.coli. How do you encode images as DNA letters? You have a bunch of pixels, and each pixel has a different value on a greyscale of black or grey or white. We came up with a code that says each pixel value would be a combination of three DNA bases, in one case, ‘CTG’ might encode a medium grey. We used three bases instead of a single base…

DRIVE To the uninitiated van driver, the Marco Polo is reassuringly simple to pilot, despite being almost 2m tall and 5m long. The soft suspension takes most of the roll out of the roads and soaks up sharp bends – to a point. The most prescient reminder you’ll get that you’ve brought the kitchen sink with you is if you have to test the brakes at the traffic lights. Otherwise the 2.5-litre engine does a stoic job of tugging your home from home to your holiday destination. You can fearlessly point the Marco Polo to the other side of Europe, and take on all the motorways, mountain climbs and switchbacks the continent might throw at you, albeit at a leisurely pace. And once you arrive, sensors and cameras make light…

If you’re visiting Dubai from 2018 onwards, behave yourself – because autonomous police vehicles will be watching your every move. Dubai Police recently purchased an REEM robot from Spain’s PAL Robotics that acts as a kind of automated police officer, but now they’re going one step further with the introduction of a fleet of O-R3 robotic police vehicles from Singapore-based OTSAW Robotics. While the REEM robot is built to handle mundane tasks, such as allowing people to report low-level crimes or pay their traffic fines, the O-R3 cars will actually patrol the streets to look out for criminal behaviour and keep an eye on known wrongdoers. Each car is accompanied by its own aerial drone, and between them the two pieces of hardware are kitted out with an impressive array…

1 Eatup! This unusual image demonstrates how we lick, eat and drink. You drink like this too, right? 2 Wonderful wildlife Pictures of our planet’s animals include dolphins, an eagle, a crocodile, an elephant, and this cute toad. 3 Solar spectrum The disc features the Sun’s spectrum of light in visible colours, perhaps to help aliens identify the Sun. 4 Engineering marvel The Great Wall of China is one of our most famous structures. Despite rumours, it is not visible from space. 5 Human athleticism Sporting activities feature in several images – also included are photos of runners and a mountain climber. Bolted to the underside of each of the Voyager probes is a 12-inch gold-plated copper disc, the Golden Record. It’s a time capsule of Earth as it was…

Have you ever felt as though you were lifting up out of your body, floating near the ceiling and looking down on the world and your own body below? If so, by definition, you’ve had an out-of-body experience, or OBE. This definition is important because it describes the OBE purely as an experience. This opens the question: does anything actuallyleave the body in an OBE? If it doesn’t, we have to find out why OBEs happen and what’s going on in the brain when one takes place. If it does, the implications are profound. If someone could truly leave their body, then mind or consciousness must be able to exist beyond the brain and even potentially survive death. If this were the case, much of science as we know it…

A worker bee spends three weeks as an egg, larva and pupa. When she emerges as an adult, she spends nearly three weeks in the hive, working her way up the ranks as she does different jobs. She’ll then spend four days guarding the hive entrance before flying off for the remaining three to four weeks of her life, to gather nectar and pollen. She will fly 800km and make one-twelfth of a teaspoon of honey. 1 Eyes Two compound eyes, plus three simple ‘ocelli’ that measure light intensity. Drones have 50 per cent more facets in their compound eyes than workers. 2 Wings Bees have two pairs of wings but they are connected together by a row of wing hooks that keep them synchronised. 3 Hairs Pick up tiny…

Why isn’t thorium used for nuclear power? DUNCAN WHERRETT, BERWICK-UPON-TWEED Uranium and plutonium have long been at the heart of nuclear power, but many experts see thorium as a better option. It’s more abundant, comes from more politically stable sources like India and Australia, and is harder to weaponise. The reactor design is also simpler, arguably safer, and produces less radioactive waste. Ironically, it’s the difficulty of making weapons that explains why thorium designs have yet to become commercially viable. The roots of nuclear power lie in the race to make atomic bombs, prompting many countries to adopt uranium- and plutonium-based designs. With so much investment and expertise already committed to them, they will be around for decades yet. Even so, there is growing interest in thorium designs, especially in…

01 SEE THE LIGHT INSIGHT ASTRONOMY PHOTOGRAPHER OF THE YEAR 2017 ROYAL GREENWICH OBSERVATORY, FREE, FROM 16 SEPTEMBER. The Northern Lights shimmer green and purple over the coal-mining settlement of Svea, in the Svalbard archipelago, in this shortlisted entry to the Insight Astronomy Photographer Of The Year 2017 contest. Now in their ninth year, the awards received over 3,800 entries from amateur and professional photographers this time around, including the first images of Uranus and asteroids that have ever been submitted to the competition. Other moments captured include a shooting star over the craggy landscape of Portland in Dorset, the International Space Station whizzing past the face of the Moon, and spectacular noctilucent clouds stretching across a moody Swedish sky. The winners are set to be announced on 14 September,…