Indholdsfortegnelse for Summer 2018 i BBC Science Focus Magazine

Batteries not included Why did Jack Stewart’s otherwise excellent article on ‘How green are electric cars?’ (June, p87) not take into account the CO2 emissions of building and recycling the vehicles, in addition to the emissions of running them? These should also be considered, especially in respect of the batteries. Andrew Holt, via email The construction of both electric and conventional cars has significant environmental impacts, and you could make a career out of quantifying them. Luckily for us, someone has: the Union of Concerned Scientists. In a 2015 analysis, they found that emissions from manufacturing cars with batteries can be 15 to 68 per cent higher than a gasoline car. However, that’s soon offset when the cars hit the road, where lower emissions from motoring make up the deficit…

FLYING SOLO Here’s one for the Christmas list: a lightweight, single-person drone plane that you can pilot yourself after just a few hours of training. The ‘Flyer’, which has been created by the start-up company Kitty Hawk, has 10 battery-powered propellers and weighs 113kg. The pilot has two controls: a joystick for direction, and a slider for speed, with no other instruments or screens. An onboard computer takes care of the tough job: keeping the Flyer level. In the US, the Flyer falls into the Federal Aviation Authority’s ultralight category, which means it can be flown without a pilot’s licence, but only in uncontrolled airspaces (typically away from people and planes). Kitty Hawk, which was set up by Google co-founder Larry Page, has so far stuck to testing its flying…

The sloth is a candidate for nature’s most misunderstood animal. Saddled with a name that speaks of sin, the world’s slowest-moving mammal has been eternally damned for its lethargic lifestyle. “These sloths are the lowest forms of existence,” proclaimed the great French naturalist Georges-Louis Leclerc, Comte de Buffon. “One more defect would have made their lives impossible.” He couldn’t have been more wrong. The sloth is a supreme survivor that has graced our planet for some 64 million years. A survey of a Panama rainforest in the 1970s found that an incredible one-third of the total mammalian biomass was made up of sloths. The secret to the sloth’s success is its lackadaisical nature. They are energy-saving icons, performing about 10 per cent of the physiological work of a mammal of…

1. Don’t wash your clothes Or at least, not so often. A single load of laundry generates 600g of CO2 , even if you wash at 30°C and dry it on the washing line. Tumble drying triples this. But the United Nations Environment Program and Levi’s Jeans both agree that you can wear trousers and skirts at least five times before washing them. The same goes for wool and synthetic sweaters, jackets and sweatshirts. If every household in the UK saved a whole laundry load per week, we would slash CO2 emissions by 840,000 tonnes a year. For ordinary laundry, halving the amount of detergent will leave your clothes just as clean while reducing the phosphates that end up in our rivers. These cause algal blooms that kill fish and…

Until Neanderthals’ disappearance some 40,000 years ago, they were our closest relatives. But ever since we discovered this hominin species in 1856, we’ve tended to stereotype them as brutal, unsophisticated ‘cavemen’. This is a view that’s now looking increasingly outdated. As scientists reveal new insights into Neanderthals’ lives – from their use of plants, to their family life and their artistic skills – the notion that they were an inferior species is being debunked once and for all. THEY WERE GOURMETS Neanderthals lived across Eurasia, from North Wales to Palestine, and all the way into Siberia. With such a colossal range, it’s no wonder that they ate a variety of foods. They hunted cooperatively in groups to capture formidable creatures such as bears, rhinos, and giant camels (now extinct). They…

What is the Universe expanding into? TOBY GRAHAM, SHREWSBURY Presently we do not know (and may never know) whether the Universe is infinite or not. If the Universe is infinite, then it can simply keep expanding without getting any bigger (since you can’t get bigger than infinity). It’s therefore not expanding into anything. On the other hand, if the Universe is finite in extent, this question becomes impossible to answer, since – being part of the fabric of the Universe ourselves – we have no way of looking outside it. AGu WINNER! Toby Graham wins a Roku Streaming Stick+ (£79.99, roku.com). It streams films and shows to your TV, and gives access to more than 4,000 channels, including Netflix, Amazon Video, NOW TV, YouTube, iPlayer and ITV Hub. NEXT ISSUE:…

01 MARVEL AT THE INVISIBLE This summer, the Eden Project’s new permanent exhibition called Invisible Worlds examines the parts of the planet that exist beyond our senses. A centrepiece of Invisible Worlds is Infinity Blue, which is an immersive, 20-tonne sculpture that celebrates cyanobacteria. Why should we care about them? Well, they are the organisms that gave us a living, breathing world when they started to photosynthesise around 2.4 billion years ago, releasing free oxygen into Earth’s atmosphere and changing the nature of our planet. Infinity Blue features 32 cannons that project scented vapour rings, which were developed to represent the aromas of the primordial world. To create the smells, sculptors Studio Swine collaborated with Paris-based perfume house Givaudan. “Infinity Blue gives physicality to the invisible elements our existence depends…

The red handfish, found off the southeast coast of Tasmania, uses its ‘hands’, which are modified fins, to crawl across the bottom of the seafloor. It doesn’t travel very far or fast, which restricts populations to small areas. Classed as critically endangered, it faces threats from habitat degradation and low reproductive rates. Often called the world’s rarest fish, scientists only knew of one population, numbering between 20 and 40 fish, until divers discovered a second population earlier this year. “Finding this second population is a big relief as it essentially doubles the number of individuals we thought were left on Earth,” says diver Antonia Cooper. “It provides hope that other small populations may still exist and allows scientists to start discussing conservation options such as habitat protection and the viability…

Thankfully, trepanation – the act of scraping, cutting, or drilling an opening into a person’s cranium to treat everything from headaches, to seizures, or even supposed demonic possession – is a practice largely confined to the past. But if you were ever in need of such an operation, you could do a lot worse than seeking out an Incan surgeon. After analysing 800 ancient skulls found in Peru that had undergone trepanation, a team at the University of Miami found that the procedures were carried out so expertly that the survival rate was more than 75 per cent – almost double that of those who underwent similar procedures during the American Civil War hundreds of years later. “In Incan times, the mortality rate was between 17 and 25 per cent,…

Why do dolphins need echolocation? They use it for navigation, hunting for prey and possibly in social contexts. Dolphins always use acoustics as their primary sense. They generate short sound pulses, which bounce off surfaces and come back as echoes – the time it takes to return is a measure of how far away an object is. The beam is quite focused so the dolphins turn their heads to scan their environment. How do they produce acoustic beams? They have a structure below the blowhole called the phonic lips. Sounds come out through the melon, the rounded forehead – it’s one of the tissues responsible for the shape and formation of the beam. It’s basically an acoustic lens: the speed of sound is faster along the edges compared to the…

#MICROBIOME MICROBES HELP SOLVE CRIMES Researchers in Atlanta ‘solved’ staged crimes by analysing microbial signatures at the scene. The team collected samples from residents’ and non-residents’ nostrils and hands, and various surfaces in the residents’ homes prior to and following mock burglaries by non-residents. They then identified the bacteria belonging to each individual to pinpoint the perpetrators with an accuracy of 60 per cent. GUT BACTERIA INFLUENCE LIFESPAN The bacteria living in our intestines could have an influence on how well we age. Researchers at McGill University prolonged the life of fruit flies by 60 per cent by feeding them with a combination of probiotics and a herbal supplement called Triphala. HEALTHY MICROBIOME = HEALTHY ARTERIES Low diversity of the ‘good bacteria’ in our digestive systems is linked to the…

Drones may one day hover over crowds in public spaces and at large events, scanning for signs of violent behaviour, according to a team of researchers from the UK and India. The researchers developed a computer algorithm that maps human postures and attempts to match them to ‘violent’ archetypes: strangling, punching, kicking, shooting and stabbing. The team then trained this algorithm on recorded footage of fake fights and once it had become accurate they tested out on a live video of a group of actors to see whether the tech would work in real-time. The accuracy of the system wasn’t perfect. The researchers reported 94 per cent accuracy when it came to identifying ‘violent’ poses, which dropped depending on how many people were in the frame. More importantly, this new…

While addressing members of the US military at the White House recently, Donald Trump spoke of his desire to create a sixth branch of the United States Armed Forces – one dedicated to conflicts in space. “I was saying it the other day, because we’re doing a tremendous amount of work in space – maybe we need a new force, we’ll call it the Space Force,” he said. The comments may have drawn scepticism from some quarters, but many experts believe space war is indeed coming. According to the narrative, whatever conflicts start on Earth are going to quickly move into space. From there it’s easy to conjure up images of laser guns, exploding satellites and rockets arcing around Earth to take out orbiting targets. Better up there than down…

It sounds like the plot from a Hollywood blockbuster. Eight time zones east of Moscow, in a remote corner of Siberia accessible only by boat, two men are trying to save the world from calamitous global warming. One, Sergey Zimov, is a pony-tailed man with a ZZ Top beard and penchant for concocting grand theories and smoking roll-ups; the other is his long-suffering son, Nikita. Their plan is to create an Ice Age nature reserve full of Ice Age creatures that will act as climate change superheroes. Their only superpower is digestion. In a nod to the Stephen Spielberg classic, the Zimovs have decided to call their venture Pleistocene Park. Meanwhile, 9,000km away in a Harvard University laboratory, a bunch of scientists are working to bring back what could become…

There’s something about walking barefoot along a sandy beach, just above the line of the waves, that is always special. Being the first to step on newly smoothed sand is liberating, and it’s as though you’re making a fresh start with every step. But something odd is happening. As each foot presses on the damp sand, you see a circle of lighter coloured dry sand spread out around it, which shrinks back as your foot lifts off. It’s weird, because you might expect that pushing the sand downwards would allow water to flood in. If anything, you’d expect the sand near your foot to get wetter, not drier. But sand is strange stuff, and that dry layer is showing you one of its oddest properties. Look at a handful of…

Last year, a record 84 million passengers passed through Los Angeles International Airport, pictured here. That number is growing; the International Air Transport Association (IATA) predicts that global air passenger numbers will nearly double by 2036. This leads to concerns over aviation’s contribution to global carbon emissions, as it’s been estimated that 2 per cent of human-made CO2 emissions currently come from air travel. IATA aims to deliver carbon neutral growth from 2020, and provides an offset scheme in which member states can compensate for their emissions by financing a reduction elsewhere. Individually, the Civil Aviation Authority advises the best way to reduce your CO2 emissions from flying is to moderate your air travel where possible, choose more modern aircraft, purchase economy tickets and fly with airlines with lower CO2…

GLASSES WEARERS It seems people who wear glasses really are smarter than average. A study of the genetic data of 300,000 people has found that those who scored the highest in intelligence tests were 30 per cent more likely to have genes that suggest they need to wear glasses. COFFEE DRINKERS Want to boost the effectiveness of your team? Have a cup of Joe. Researchers at Ohio State University found that drinking a cup of coffee before a group activity made participants more talkative, more positive and more engaged when carrying it out.…

Psychedelic drugs, such as LSD, DMT and DOI, really can expand your mind… as long as you’re a rat or a fly. A study of the drugs’ effects on the rodents and insects showed neurons in their brains were more likely to branch out and make new connections. If the drugs have a similar effect on human brains, it’s thought they may have potential as a treatment for depression, anxiety, addiction and even post-traumatic stress disorder (PTSD). “These are some of the most powerful compounds known to affect brain function, it’s very obvious to me that we should understand how they work,” said the paper’s senior author Dr David Olson, of the University of California, Davis. Depression is widely believed to be a result of imbalanced brain chemistry, but recent…

Sucking carbon dioxide from the air was long touted as far too expensive to be realistic, but a new cost analysis is changing that idea. The study, published in the journal Joule, estimates that carbon capture could now cost between $94 and $232 per tonne of captured carbon dioxide. Previously, the technology was estimated to cost around $1,000 per ton. What’s more, the cheapest design outlined by the study involves using that captured CO2 to make carbon-neutral fuels that can be sold. The technology uses fans to draw ambient air through a liquid that reacts with CO2, which is then processed to create a purified stream of CO2 gas. The CO2 is then combined with hydrogen to make fuels. Most of the tweaks that have reduced the cost of this…

New technology from Facebook can replace closed eyes with convincing open ones, ringing in the end of untimely blinks ruining your group shots. It’s called ‘in-painting’, and it’s not new: software like Photoshop has the ability to fill in space with what the program thinks should be there – imagine removing a tree and filling the gap with the same blue sky that surrounded that tree. But eyes are a big leap forward. Facebook points out that we’re extremely sensitive to small errors in facial structure, especially on our own faces, or those of the people we know well. Then there’s the ‘uncanny valley’ effect: the feeling of eeriness or revulsion we get when we see a humanoid object that isn’t quite right. Eye ‘in-painting’ could already recognise and reconstruct…

SLOW DOWN AND IMPROVE YOUR HEALTH Taking time out from the daily grind can benefit both body and mind In a now-famous study carried out in 1999, psychologist Dr Robert Levine analysed the pace of life in cities in 31 countries, measuring things such as the speed at which people walk and the time it takes post office staff to hand out stamps. He found that the fastest pace of life was in Western Europe and Japan, and the fastest-living countries also had the highest rates of coronary heart disease. When British psychologist Prof Richard Wiseman repeated the experiment in 2006 by simply measuring walking speed, he found the pace of life had increased by 10 per cent. The bigger the city, the faster our pace of life, and we’re…

1 Harry Kane had better watch out – female meerkats are the animal kingdom’s ultimate team leaders. Matriarchal mobs form around an alpha female who directs the pack when it’s threatened. As excellent sentinels, they’d always have a watchful eye on what’s going on in the game, communicating through barks when opposition is on the attack. Meerkats live in large societies, so they’ve got teamwork nailed. 2 To get the ball out of the box at speed, you need a mantis shrimp. The peacock mantis shrimp seen here might only be 10cm long, but with its specialised ‘clubs’ it can punch through water with enough force to cause an explosion. Let’s see Jordan Pickford do that. But there might be a few issues: some species use their sharp forelimbs to…

1 Permafrost is made of frozen soil, rock, water and organic matter, including animal bones and plant roots from the Ice Age. 2 As the permafrost melts, the roots of grasses that grew in the Ice Age are being devoured by hungry microbes. If oxygen is present, carbon-based sugars locked inside the roots are broken down to form carbon dioxide, but if the soils lack oxygen then methane is made. Both methane and carbon dioxide are greenhouse gases with the potential to accelerate global warming. 3 In the winter, grazers trample through the snow exposing the earth to bitterly cold Arctic air. This helps keep the ground frozen and carbon locked away. 4 In the summer, grazers promote the formation of lush, biodiverse grasslands by eating weeds, dispersing seeds and…

1. WE’D STILL NEED TO EAT Photosynthesis is only 3 to 6 per cent efficient. If you stood naked outdoors all day, you would generate less than 240 calories – about three chocolate digestive biscuits’ worth. If you weren’t eating anything to supplement this, photosynthesis wouldn’t even be enough to offset the heat your naked body would lose. You’d die of hypothermia before you starved. 2. WE’D STILL NEED OXYGEN Plants generate all of the oxygen they need as a by-product of their own photosynthesis. But since you’d need to eat extra food to power your more active metabolism, you’d also need to breathe extra oxygen in order to convert all of that food into energy. Photosynthesis would let you lower your breathing rate by 10 per cent at most.…

Can you train your brain to like different music? You might always hate free jazz, but research by neurophysiologist Prof Alice Mado Proverbio has shown that the more we listen to complex music (Stravinsky’s The Rite Of Spring, for example), the more we start to appreciate it. Meanwhile, if you want to pass on your unconventional music taste to the next generation, the trick is to influence young minds. Prof David Hargreaves at the University of Roehampton uses the term ‘openearedness’ to describe how young children are more able to listen to unusual forms of music – a skill that drops off at around the age of 10 or 11. Why do people have such different music tastes? Across all cultures, we seem to like certain note combinations and respond…