BBC Science Focus MagazineApril 2020的目錄

WIND WIN The UK government has lifted its opposition to subsidies for onshore wind power after a four-year ban. The next round of clean energy auctions, set to be held in 2021, will allow both onshore wind and solar to compete for subsidies once more, it said. Local communities will have a “definitive say” on whether projects are allowed to proceed, the government said. Despite the fact that there is strong support from the public for wind power, the number of new onshore wind farms dropped dramatically when the ban was implemented in 2016. Solar and onshore wind power are now the cheapest sources of new electricity in the UK. LOW CARBON SHIPS Nearly half of container ship voyages between China and the US could be made using hydrogen-powered ships…

In mid-March, as coronavirus spread across the UK, Sir Patrick Vallance – the UK government’s chief scientific advisor – said that, to control the impact of the virus, the country would need to build up “some degree of herd immunity” and that about 60 per cent of the population would need to become infected for this to happen. His comments soon came under fire. Over 500 scientists from UK universities wrote to the government, saying that going for herd immunity would risk more lives than necessary. COVID-19 has an estimated fatality rate of around 1 per cent. If 60 per cent of the UK population became infected – some 40 million people – that could equate to hundreds of thousands of deaths. The Department of Health and Social Care has…

Best for… photography and other professionals › Dell U2720Q, £628.80, dell.com This professional grade monitor from Dell is an unassuming workhorse. It’s fitted with a special anti-glare coating and is remarkably clear from a wide range of viewing angles. These features, paired with a soft brightness, made the screen exceptionally easy on the eyes. At 27 inches it’s at the smaller end of what’s necessary for 4K, but the display is remarkably crisp. Wildlife photography especially felt rich in detail, picking up on the diverse hues of green and blue in a photo of a kingfisher. It leaves the factory fully calibrated too, so you can get straight to work. The design allows for height, swivel and pivot adjustments, with a slim frame and a minimal footprint. There’s every port…

The Solar System is our cosmic back garden. It should be one of the best-known parts of our corner of the Universe. Yet when Hubble launched in 1990 our planetary neighbourhood was still deeply shrouded in mystery. Looking up from Earth, the ever-shifting atmosphere blurred our view of the planets, making it difficult to see their features. Above the turbulent air, Hubble could watch these worlds in peace and has been doing so for the last three decades. This long life has been one of Hubble’s greatest assets, making it possible to reveal the weather and climate patterns of changing seasons on our sister worlds as they make their journeys around the Sun. The Hubble science team has taken advantage of this unique long view by undertaking a project called…

HOW IS HUBBLE DOING? It’s performing at the peak of its capabilities and functioning marvellously. There aren’t as many available backups as there were some years ago. For instance, Hubble has six gyros to keep itself orientated, but only three are active and we need three to do our best science. Our engineers are coming up with clever ways to combat ageing. Things dim, they fade, one side of the detector has a greater sensitivity than the other. But they’ve kept the observations really at the forefront of what anyone can do on the ground or in space, and that’s pretty remarkable. “WE HAVE VERY FINE GUIDANCE SENSORS. IT’S LIKE KEEPING A LASER POINTER ON A DIME 330KM AWAY FOR 24 HOURS” WHAT SETS HUBBLE APART? It’s a one-stop shop…

1. Crime enforcement agency (police department, sheriff’s office) contracts a DNA investigation company to help them crack a cold case. 2. The company analyses crime scene DNA and converts it into a file representing its unique sequence of bases (adenine, cytosine, guanine, and thymine). 3. Around 700,000 single nucleotide polymorphisms (SNPs) – the most common points of genetic variation between people’s DNA – in the data are examined. An Excel spreadsheet showing the information about these points (loci) would be 26 columns wide and 851,000 rows long. 4. SNP DNA analysis is also used by online genealogy services to find distant relatives, while police DNA databases use a more basic short tandem repeat (STR) analysis, which allows identification of only close relatives. 5. The company uploads the data file to…

I DRINK FRUIT JUICE BY THE BUCKETLOAD. IS IT REALLY AS BAD FOR ME AS FIZZY DRINKS? The amount of sugars in fruit juice can be equivalent to, or even higher than, that found in fizzy drinks. That’s bad news – too much sugar puts us at risk of health problems including obesity and type 2 diabetes, as well as tooth decay. With research highlighting these potential health risks, and public awareness increasing, the reputation and popularity of fruit juice have fallen in recent years. It’s not all bad news. Pure fruit juice does contain vitamins, minerals and antioxidants, which are not generally found in fizzy drinks, and these can boost the immune system and help ward off infection and inflammation. So fruit juices are marginally better for you than…

WHAT CAUSES AN EARTHQUAKE? As the Earth’s tectonic plates push and pull each other, they generate strain that accumulates on lines of weakness in the crust known as faults. When this strain reaches a critical level, a fault will break and the rock masses on either side scrape past one another, releasing a huge amount of energy that causes the ground to shake. Every year, there are more than three million earthquakes; California alone experiences more than 10,000. Most are too small to detect, except by seismometers, but around 15 a year are major shocks of magnitude seven and above, capable of causing major damage and loss of life. WHY ARE EARTHQUAKES SO DIFFICULT TO PREDICT? The problem with earthquakes is that – unlike volcanic blasts – they typically happen…

GET THOSE MILES IN A current trend is to do high intensity gym training to get fit quickly. That won’t help with a marathon. You have to get mileage into your legs because the key to success is having what I call an ‘aerobic base’. That doesn’t mean you need to covervastdistances. For those who are new to marathons, you need to build up to 45km (28 miles) a week on average, with that distance split over several runs. PLAN A BIG (-ISH) RUN You need to experience a long run before the marathon itself. Less experienced runners tend to do a longest run of about 29km (18 miles). You want to do that about three to four weeks before the marathon. If you are new to…

PLAYING VIDEO GAMES DURING MEALTIMES MAY MAKE US EAT LESS Playing video games, or being distracted by technology during mealtimes may make us eat less, a study from the University of Illinois suggests. The team took a group of 119 young adults who hadn’t eaten for 10 hours and gave them a meal of mini quiches to eat while they played a simple memory and attention video game for 15 minutes. They found playing the game while eating made the participants eat significantly less than they did when eating the same meal without distractions. WHEN A BEE CAN’T SEE, THE BUMBLE MAKES DO WITH A FUMBLE Blindfold a bee and it’ll still be able to recognise a familiar object by touch alone. That’s the finding of experiments carried out by…

“It’s common to find loggerhead turtles with their digestive systems blocked because they’ve eaten plastic materials” While we know that some marine animals seem to eat plastic because it looks like jellyfish or some other food source, less research has been carried out into what plastic smells like to these creatures. But now a study from the University of North Carolina at Chapel Hill has found that the coating of algae and microbes that naturally builds up on ocean plastic causes it to give off the aroma of food. The researchers took 15 captive-reared loggerhead turtles, each around five months old, and placed them in a laboratory aquarium. They then piped in aromas of clean water, clean plastic, turtle food, and plastic that had been soaking in the marine environment…

PETROL CARS Electric cars produce less carbon emissions than petrol cars in 95 per cent of the world’s countries, even when taking into account the energy used for production and battery charging, a study by the University of Exeter has found. The only exception are countries that are still heavily reliant on coal power, such as Poland. BURGER LOVERS Next time you tuck into that bacon double cheeseburger it might be worth thinking about the impact meat production is having on fresh water supplies. The irrigation of feed crops for cattle accounts for one-third of all water use in the western US, and is depleting rivers and hurting fisheries, according to a study carried out in Virginia.…

The white, eyeless fish was found deep inside a network of limestone caves by subterranean explorers in Meghalaya, northeast India, in January this year. At 40cm long, it’s the largest cave-dwelling fish ever discovered...…

At the Bristol Hi-Fi Show earlier this year, one announcement stood out. French music-streaming service Qobuz was ditching MP3 and making its high resolution (hi-res) audio streaming cheaper. It’s the first streaming service to drop formats that compromise on quality. We caught up with Benoit Rebus, head of partnerships at Qobuz, to find out whether MP3 was on its way out... Why make the change? We [Qobuz] have been around in the UK since 2014. At the time we launched, we only had CD quality. Later on, we introduced studio quality. Our pricing plans and packages diversified over the years, but now we want to simplify our service and make it clear what we’re about. There’s no longer an entry-level service for MP3s, but you can switch to CD or…

A tablet that can replace my laptop Apple’s new iPad Pro blurs the line between laptop and tablet. The Magic Keyboard now comes with a trackpad at the bottom, and the hardware inside is virtually on a par with the tech inside a Macbook Air. The operating system will still be iOS (rather than OSX, which you usually find on Macs), but increasingly apps are becoming just as sophisticated as full-scale Mac software. It now includes a LiDAR scanner, which means it can scan and see the world around it, empowering some incredible augmented reality experiences. iPad Pro 2020, from £769, apple.com A console that likes your old games Microsoft is rewriting the book when it comes to console design with this monolith that we rather like. The Xbox Series…

SEASONS ON URANUS When Voyager 2 flew past Uranus in 1986, the ice giant appeared to be a placid marble with little weather. But Hubble has revealed the planet is now more active, suggesting that seasons have changed. It’s found several dark patches, which are believed to be storms blowing up on the planet. DEMOTING PLUTO In 2005, Mike Brown uncovered a large body in the outer Kuiper Belt, now known as Eris. It was over 2,300km wide, around the same size as Pluto. The discovery triggered a debate, and ultimately led to Pluto being demoted to dwarf planet. JUPITER’S AURORAE In 1997, Hubble was upgraded with a more sensitive Space Telescope Imaging Spectrograph, which revealed Jupiter’s ultraviolet aurorae. Astronomers found it formed curtains just like Earth’s, extending several hundred…

Look at a packet of Quorn mince and you’ll discover that a 75g serving contains 10.9g of protein, 3.4g of carbohydrates and 0.4g of saturated fat. Later this year, a glance at the packet will tell you something else: that producing the 75g serving released the equivalent of 0.16kg of carbon dioxide into the atmosphere. Since 2011, Quorn Foods has been working with researchers at Sheffield Hallam University and Innovate UK, a nondepartmental public body, to calculate the carbon footprint of its meatless products. Now it has had the information certified by the Carbon Trust, and plans to add it to product packets later this year. Doing so should, says Quorn Foods, “better [inform] people who want to understand the environmental impact of the foods they buy”. But will the…

HOW DO I SEE THE SUPERMOON? WHEN: 8 APRIL AND 7 MAY 2020 This year, April and May are especially good months for moongazers, because we have two supermoons in a row (three if you count the March supermoon). A full moon ‘supermoon’ is defined as a full moon that coincides with the Moon being at (or within 90 per cent of) its closest point to the Earth (its ‘perigee’) as it follows its elliptical orbit around us. A supermoon can be up to 14 per cent bigger and 30 per cent brighter than a normal full moon. Technically, a new moon can also be a supermoon, but we don’t tend to mark these because we can’t see them! The next full moon supermoon after these will be in April…

NATURAL ALAN LEVINOVITZ £20, PROFILE BOOKS, OUT NOW As fears about coronavirus and climate change intensify, it’s easy to feel like we are being punished by nature for our unnatural activities. Dense urban centres, an interconnected globe, high population, overconsumption… isn’t the problem that we are drifting too far from how nature wants us to live? But framing our problems, and their solutions, as natural vs unnatural is counterproductive and dangerous, just as it has always been. In Natural, readers will see how this approach is religious, not scientific, by substituting nature for God and ‘natural’ for ‘holy’. The anti-vaccination movement, condemnation of unnatural sexuality, deadly pursuit of natural cancer cures, the belief that a race or a gender can be naturally inferior – all are justified by appealing to…

If the world’s astronomers ever came together and held a competition to name the most metal planet, chances are WASP-76b would be the clear winner. It’s a planet with an atmosphere so extreme, that it rains molten iron. The gas giant exoplanet is located 390 light-years away from Earth, in the constellation Pisces. It was observed using a new instrument – dubbed ESPRESSO – built by a team at the University of Geneva and fitted to the Very Large Telescope (VLT), based at the European Southern Observatory (ESO). WASP-76b is tidally locked, meaning it takes as long to rotate around its axis as it does to go around its parent star. This results in the planet only ever showing one side to the star, leaving its colder night side in…

In mid-February this year, Storm Dennis brought a highly unusual visitor to the coastline of County Cork: a 77-metre long ‘ghost ship’, called the MV Alta . The cargo vessel had been drifting around on the Atlantic Ocean since it was abandoned near Bermuda in 2018, partway through a voyage from Greece to Haiti. The ship’s 10 crew members were rescued and taken to Puerto Rico by the coastguard, after a power outage left it stranded at sea. It is unclear exactly what happened to the vessel afterwards, but it was next spotted adrift in the mid-Atlantic in September 2019 by the British Royal Navy ship, HMS Protector . Once abandoned, ships are simply left to drift freely on the many ocean currents, some of which can flow for many…

A mysterious bone circle made from the remains of dozens of mammoths has been dated as being 20,000 years old, by researchers at the University of Exeter. It’s the oldest of its type ever found. The 10m x 10m structure is situated just outside the modern village of Kostenki, roughly 500km south of Moscow, and is one of about 70 scattered across Ukraine and the western Russian Plain. It contains 51 mammoth jawbones and 64 mammoth skulls, along with small numbers of reindeer, horse, bear, wolf, red fox and arctic fox bones. The researchers also found the remains of charred wood and other soft non-woody plants within the circular structure. This indicates that ice age humans may have been burning wood as well as bones for fuel, and that the…

PLANT FOR BUTTERFLIES From red admirals to hummingbird hawkmoths, people love to spot butterflies and moths in their gardens. Sadly, many of the UK’s species are in decline. To help tackle this, the Wildlife Trusts and the Royal Horticultural Society (RHS) are asking people to provide support in their gardens. Making nectar-rich flowers available throughout the year and delaying cutting back borders until late winter is a good start. Keeping an open area for wildflowers and grasses will attract egg-laying females, while hops, holly and nettles are a good food source for caterpillars. Visit bit.ly/garden-butterfly…

WHY ARE WE BEING ADVISED TO WASH OUR HANDS? Coronavirus is a respiratory illness, meaning it is mostly spread through virus-laden droplets from coughs and sneezes. If you don’t catch coughs and sneezes in a tissue and dispose of it, the virus can end up on surfaces. If someone touches that contaminated surface, the virus can transfer onto their hand. If you have the virus on your hands, you can infect yourself by touching your eyes, mouth or nose. You might think that you don’t touch your face very often, but a 2015 study found that people touch their faces an average of 23 times an hour. While washing your hands is useful in preventing yourself from getting infected, this is not the main reason the government recommends it. “It’s…

Both Google and Facebook are reported to be talking with governments about how to use the location data they collect from our phones to help track the spread of coronavirus across the UK, US, and presumably other countries too. If you’ve never checked your privacy settings on Google or Facebook, then the chances are that both are gathering large amounts of surprisingly accurate data on your movements. Taken across a population, this information can paint an unprecedented picture of how people are gathering and moving, and therefore how the virus might spreading. The work is in its early stages, according to an anonymous source speaking to The Washington Post . Both companies have confirmed they’ve spoken with government officials but stress they haven’t handed over any private data. Governments are…

The 50th Glastonbury Festival, the Eurovision Song Contest and The Rolling Stones’ tour dates are just a few musical casualties to the coronavirus pandemic. Large gatherings have been postponed or cancelled entirely to try to stop the spread, but some musicians aren’t letting the lack of a physical audience prevent a performance. “INSTEAD OF CANCELLING, JAMES BLUNT AND THE ORGANISER DECIDED TO RECORD THE SHOW IN THE EMPTY CONCERT HOUSE AND LIVESTREAM IT TO VIEWERS” Singer James Blunt – of You’re Beautiful fame, that one song we all hate but can’t help singing along to – was booked to perform in Hamburg in March, to a crowd of more than 2,000 people. Instead of cancelling, Blunt and the organiser, MagentaMusik360, decided to record the show in the empty Elbphilharmonie concert…

LIFTING THE VEIL VEIL NEBULA Stars that reach a violent end and explode in a supernova will often leave behind a scar on the sky – a brightly coloured cloud of gas, known as a supernova remnant. The Veil Nebula is one such remnant, stretching out over 110 light-years. Hubble took a look at the Veil Nebula back in 1997, only to return in 2015 when this image was taken. In the intervening years, astronauts had visited Hubble using the Space Shuttle and upgraded the main widefield and planetary camera for a second time. The improved resolution revealed the nebula’s delicate gas filaments in a new level of detail. The original supernova appears to have exploded just 8,000 years ago (practically yesterday in astronomy terms) and is still expanding. In…

EXTREME DEEP FIELD In 2012, the Hubble team released the eXtreme Deep Field. The image covered just 2x2.3 arcminutes, around 1/32,000,000ths of the sky, yet had an exposure time of around 23 days. It looks back through 13.2 billion years, showing one galaxy when it was just 450 million years old. CONFIRMING PRIMORDIAL HELIUM In 1995, Hubble finally confirmed the presence of primordial helium. Theory had predicted that after the Big Bang, the cooling Universe formed both helium and hydrogen, but the former had never been seen before. GAMMA RAY BURSTS GRBs are the most powerful explosions in the known Universe, but their origins are a mystery. In 2019, Hubble found a GRB that had come from the dense environment of a bright galaxy around five billion light-years away –…

It is surprisingly difficult to work out the carbon footprint associated with our diets: it depends as much on where and how the food we buy was grown as what we actually eat. For instance, some beef comes from calves raised within dairy herds, while other beef comes from calves raised in non-dairy herds. Researchers argue the ‘dairy beef’ carries a significantly lower carbon footprint because the herd is effectively growing two products – milk and beef – lowering the carbon footprint of both. The following is a very rough guide of the carbon cost of food, using the same data that Dr Graham Horgan at Biomathematics and Statistics Scotland and his colleagues are using in their algorithm. HIGH FOOTPRINT BREAKFAST Two rashers of bacon (0.6kg CO2e) Two small sausages…

Eighteen-year-old Angie Dodge from Idaho Falls was raped and murdered on 13 June 1996, and in 1998 Chris Tapp was imprisoned for the crime for 20 years. It wasn’t until May 2019 that genetic genealogy provided the leads that not only found the true culprit – Brian Leigh Dripps Sr – but also exonerated Tapp. CeCe Moore, the chief genetic genealogist of DNA analysis and genetic genealogy company Parabon, remembers it as her most satisfying case. But the path to Dripps was not an easy one. The crime scene DNA was badly degraded, and not obviously suitable for analysis. But enough was decoded for it to come up with several links on GEDmatch and for Moore to begin studying family trees. In total, she worked on the case for 100…

Since the mid-20th Century, plastic production has increased exponentially, and the resulting pollution has become a global environmental issue. Little by little, we are replacing plastics with more environmentally friendly options, but what about the plastic that’s already out there? Maybe Mother Nature can help out. Meet the waxworm: traditionally thought of as a pest, its love of beeswax may have a surprising benefit.…

Many of us spend large chunks of our lives staring at computer screens, smartphones and tablets. Long periods of screen time can cause headaches, eyestrain and blurred vision – all symptoms of a condition that’s been termed ‘computer vision syndrome’. This is caused by our eyes having to constantly work to keep focused over the short distance to the screen. We also blink three times less frequently when using a screen – just 5 times a minute – which makes our eyes dry and itchy. However, studies have so far failed to find any link between screen use and long-term eye health conditions, such as short-sightedness or cataracts. One 20-year study at the Ohio State University found that children who spent long periods in front of a computer screen or…