Sommaire pour Summer 2021 de BBC Science Focus Magazine

Everyone likes a fruity smoothie in the summer, but a mosquito smoothie might be more beneficial for your health. Scientists at Imperial College London have developed a new way of extracting malaria parasites from infected mosquitoes by processing the insects into a slurry, then filtering out the parasites to use in the vaccine. The method allows more parasites to be extracted faster with less contamination, and could lead to the development of better malaria vaccines. The malaria parasite, Plasmodium, is spread through the bites of infected female Anopheles mosquitoes. Plasmodium is becoming more resistant to antimalarial drugs, while mosquitoes are becoming more resistant to pesticides. Finding better ways of treating malaria is therefore a matter of urgency, as the disease claims 400,000 lives per year, 61 per cent of which…

Virtual reality can boost brain activity that may be crucial for learning, memory and even treating Alzheimer’s, ADHD and depression, a study on rats has found. After monitoring the animals’ brain activity with tiny electrodes, researchers from the University of California Los Angeles (UCLA) discovered electrical activity in a region known as the hippocampus differed depending on whether the rodents were placed in real-world or virtual reality (VR) environments. (Before you ask: no, the rats weren’t fitted with tiny VR headsets. They were placed on a small moving track surrounded by screens.) The new findings are significant as the hippocampus is a primary driver of learning and memory, including spatial navigation, in the brain. When rats walk around in real life, electrical activity in the hippocampus neurons appears synchronise, at…

Supermassive black holes (SMBHs) are thought to be lurking at the centre of every galaxy, but very little is known about their origins. Current thinking suggests that these cosmic behemoths, which can have masses millions of times that of the Sun, would grow relatively slowly as it would take a considerable amount of time for them to suck in the matter that surrounds them. There must be something else going on, however, as several supermassive black holes have been observed that date back to the early days of the Universe. Now, physicists at the University of California think they may have an explanation: seed black holes, or black holes in their initial stages, can be formed by the collapse of the dark matter halos that surround galaxies. “Physicists are puzzled…

“Life finds a way,” said Dr Ian Malcolm, Jeff Goldblum’s character in the original Jurassic Park movie. The statement is true, not only for the chaotic events that unfold in the film, but also for occurrences away from the silver screen, in the real world. Life seems to be capable of establishing a presence in every corner of the planet, no matter how hostile the conditions appear to be. Whether the immediate environment is blisteringly hot or bitingly cold, corrosively acidic, crushingly high pressure or radioactive, life adapts to tolerate it. Provided there’s liquid water, however little of it there may be, life springs up. That life comes in many varieties of microorganism, but if it can tolerate these sorts of extreme conditions it’s classed as an extremophile. On Earth,…

Britain is one of the most secular countries in the world. Belief in God has been declining, along with other indicators of religion, since polling began. In 1961, when a question about God was included in a survey by the National Opinion Polls, 91 per cent of Britons expressed belief. By 2018, according to the British Social Attitudes survey, that had fallen to 55 per cent of the population, with 26 per cent affirming that they’ve never believed. Nevertheless, these figures show that a majority of Britons still believe, whether confidently or tentatively. Belief in God has declined less sharply than other aspects of religion, like belonging to a church and taking part in its rituals. Organised religion has been losing followers quicker than God! “It’s not only that talk…

According to data from the company Statista, just 11 per cent of us consider death in our daily lives. Most of us are clearly busy with the subject of life, perhaps only considering the subject three or four times a year. We in the West are, in the words of one philosopher, masters of “burying existential anxieties under a mound of French fries”. But that’s understandable, right? Death is horrible. We live. We die. And then it ends. What possible reason could there be for thinking about death more? Plus, French fries are delicious. According to some scientists however, there are advantages to thinking about death more. Psychologists, in particular, point to a number of studies that suggest that thinking about death (‘mortality salience’) can raise people’s self-worth, encourage them…

In The Better Angels Of Our Nature, evolutionary psychologist Steven Pinker claims humans have become less violent. He thinks we’ve never been more peaceful and that this trend towards peace has been sustained over the long term. He finds evidence in declining rates of violent deaths per 100,000 of population, the elimination of customs such as human sacrifice, and the reduction of targeted violence such as lynching, pogroms, and spousal abuse. These changes arose from the rise of modern states, commerce, greater gender equality, cosmopolitanism and reason, despite the short-term setbacks of individual wars. It’s impossible, however, to reach back into the past and calculate the proportion of people who died violent deaths with any precision. For instance, we lack global and historical data for intimate partner violence – likely…

The last few years have seen a lot of discussion about a ‘replication crisis’ or ‘credibility crisis’ in psychology. Various scientific findings, it seems, don’t appear to be repeatable when other scientists run exactly the same experiments. Most of the focus in this crisis is on how scientists behave: were the original experiments biased? Was the work sloppy? Was someone gaming the system or even cheating? But perhaps a more pernicious problem is deeply rooted in how people think. Many people who practise, use and report on the science of psychology assume that thoughts, feelings, behaviours and other psychological outcomes are the result of one or two strong factors or causes. This is called a ‘mechanistic mindset’. Typical experiments attempt to isolate one or two variables, manipulate them and observe…

A theory of everything would do several things. Currently, we know the Universe is glued together by four fundamental forces. Thanks to Einstein, we have a theory of gravity, which views gravity as the curvature of space-time, and a ‘quantum’ theory of the other three fundamental forces (the electromagnetic, weak nuclear, and strong nuclear forces), which views them as arising from the exchange of force-carrying particles. Physicists believe the quantum picture is more fundamental and so the first thing they’d like for their theory of everything is a theory of quantum gravity. But this isn’t what all physicists want. Each of the three fundamental quantum forces is a consequence of a different underlying ‘symmetry’ and they’re stitched together into the patchwork theory of the ‘Standard Model’. Physicists would like to…

If by ‘Universe’ we mean ‘everything there is’, then the Universe clearly does not have an edge. If we thought it did, we would be guilty of not including everything! But people often ask the question in a slightly different way, which assumes there is an edge: “If the Universe is expanding,” they say, “what is it expanding into?” This, though, misunderstands what is meant by ‘expanding Universe’. In Berlin in 1915, at the height of WWI, Albert Einstein came up with a revolutionary theory of gravity, which supplanted Newton’s and, in 1916, he applied it to be the biggest source of gravitating mass he knew of: the Universe. What Einstein’s theory showed (it was others who spotted this, not Einstein) was that the Universe could not be still but…

IT’S COLD OUTSIDE. Lakes, rivers, the sea… if you live in the UK, any outdoor, non-heated swimming is cold-water swimming. I do it because I enjoy being outside and it’s something I’ve always done. LOTS OF PEOPLE REPORT POSITIVE EFFECTS FROM DOING IT. There’s lots of anecdotal evidence. People say cold-water swimming can help with depression, pain and migraines. Some menopausal women find a decrease in the severity or number of hot flushes. These personal experiences are important, but we lack the scientific studies to back them up. This is starting to change. We want to know who benefits from cold-water swimming, what the effects are and what the underlying mechanisms are. WHAT ELSE COULD IT HELP? One study, from Cambridge University, hinted that cold-water swimming might help stave off…

The Last Unicorn This one-hour documentary follows wildlife conservationists’ expedition to South Sudan, where they hope to find a population of northern white rhinos - a species officially declared extinct in 2018. BBC Two, check Radio Times for details Black Hill, Bleak Summer Twenty years after the UK’s biggest ever outbreak of foot and mouth disease, Dave Howard revisits the remote farming community where he grew up, to tell the story of its devastating impact there. BBC Radio 4 27 July, check Radio Times for details Animal Park Ben Fogle (pictured), Kate Humble and the team at Longleat Estate return to our screens for more behind-the-scenes adventures at the safari park. BBC One, check Radio Times for details…

Purrrrrfect physics Aaaah! An experiment to prove that cats like virtual boxes (June, p22). Yet another quantum effect. I’m surprised that Erwin Schrödinger didn’t capitalise on cats’ liking for imaginary boxes when conducting his famous ‘Schrödinger’s cat’ experiment. How much easier it would have been for him to see the kitty’s waveform collapsing (or not) if it had been in an illusory box! What box? Pooof! Err... what cat? Martin Kirby-Sykes…

Good month COFFEE DRINKERS Whether your go-to is a double decaf latte with mocha sprinkles or a plain old black Americano, drinking coffee can reduce your chances of developing liver disease by 20 per cent, a study at the University of Southampton has found. CHOCOHOLICS It turns out breakfast really is the most important meal of the day! Eating chocolate within an hour of waking may help us to burn more fat and lower glucose levels, according to research by a team at Brigham and Women’s Hospital in Boston, US. Bad month THE TONGUE-TIED According to a survey by the insights agency Perspectus Global, 61 per cent of Brits find it irritating when people mispronounce words. The top offenders were ‘pacifically’ instead of ‘specifically’, which 35 per cent said was…

WHAT DID THEY DO? A team at the University of Florida placed 20 crayfish into sheltered watery mazes with two exits, one spiked with food and the other laced with the scent of another crayfish. They then exposed half of them to selective serotonin inhibitors, a type of antidepressant, and compared the behaviour of the two groups. WHAT DID THEY FIND? The crayfish that were exposed to antidepressants emerged from the shelter sooner and spent three times as long in the food-scented area - this indicates that they were ‘bolder’ and may be more susceptible to predators. Though this may seem insignificant, over time it could have a noticeable effect on the ecosystem. WHY DID THEY DO THAT? Antidepressants frequently make their way into waterways, thanks to low levels of…

Up yours, kidney disease! That’s what we imagine researchers from the Keck School of Medicine of the University of Southern California bellowed after successfully growing parts of a kidney in the lab - a move that could lead to new patient treatments. Using stem cells, the team was able to create rudimentary cell structures, known as organoids, that mimic some functions of the real organ. Specifically, the new organoids resemble the collecting duct system that concentrates and transports urine, maintaining the body’s fluid and pH balance. With such an accurate model of the kidney, researchers could use it to screen potential therapeutic drugs. Furthermore, the organoids can be genetically engineered to harbour mutations that cause disease, providing scientists with a better idea of how to tackle such illnesses. In fact,…

Two astronauts from NASA and the European Space Agency have successfully installed the first of six new solar arrays on the International Space Station (ISS). The mission is the first step in a programme to increase the power-generation capacity of the ISS to meet future demands, including Artemis – NASA’s planned crewed mission to the Moon, currently scheduled for 2023. Some of original arrays have been in place for 20 years and are showing signs of age. The six new arrays will be installed directly on top of the existing ones and generate roughly the same amount of power, despite only being half the size. Once fully installed, the arrays will be able to supply power to the ISS until 2030. 1. The solar arrays were constructed by engineers at…

Are we alone?” is probably the question astronomers get asked most often by the general public. The search for extraterrestrial intelligence is surely worthwhile, despite the heavy odds against success, because the stakes are so high. That’s why we should welcome Breakthrough Listen – a 10-year commitment by Russian-Israeli investor Yuri Milner to buy time on some of the world’s best radio telescopes and develop instruments to scan the sky in a more comprehensive and sustained fashion. But even if the search succeeded (and few of us would bet more than 1 per cent on this), it’s unlikely that the ‘signal’ from aliens would be a decodable message. It would more likely constitute a by-product (or even a malfunction) of some supercomplex machine far beyond our comprehension that could trace…

Back in the 1990s, we debated the risks and benefits of genetically modified (GM) crops. Some found the idea of eating ‘non-natural’ foods unsavoury, while others saw the merits of crops with increased yields and resistance to pests, drought and disease. Today, as pressures on farming intensify under climate change, we’re seeing a new debate. The difference now is that scientists have better tools for editing genomes and we’re not just talking about using them in crops. Understanding how the old and the new tools differ is key to deciding whether you believe they should be used. The traditional technique of introducing foreign DNA to create transgenic organisms – as in insectresistant corn, which contains genetic material from bacteria – is slower, more expensive and less accurate than modern gene-editing…

Like giving birth, dying is a bodily process with stages and recognisable progression. Also like birth, the speed of the process can vary from person to person. Medical support is sometimes needed to make dying (or giving birth) as safe and comfortable as possible. As dying approaches, most people lose interest in eating and drinking. This is normal: spoonfuls of ‘tastes for pleasure’ may still be welcome when meals have become too much to manage. Dying people consistently lack energy. Many of us have experienced profound weariness caused by illness: the ‘can’t get out of bed’ state of severe flu, or overwhelming tiredness as we recover from surgery. Sleep usually recharges our energy and can be part of recovery but, at the end of life, sleep gradually makes less impact…

Anthropologists laud the common human practice of burying our dead as one of the hallmark traits that set us apart from other apes. Town-planners, on the other hand, must lament it. For these individuals face an impossible dilemma: most of the graveyards and cemeteries are nearly full, yet people have a nasty habit of continuing to die. In the UK, partly because of the surge in town-and city-living, the problem of where to put all these bodies is a particularly thorny one. According to research published earlier this year, a quarter of council-owned cemeteries will be full to capacity in 10 years and one-in-six will be full within five. How might we avoid the nightmarish situation? What might we do to avoid a serious crisis in the way that we…

The idea that ‘money can’t buy you happiness’ has prevailed for over a decade. Studies showed that earning above what we needed to cover our basic needs and keep us ‘comfortable’ was futile, and could even make us less happy. But sadly, those days are gone. Social scientists have now removed any rose-tinted spectacles to agree a new motto: the more the merrier. In 2020, researchers analysed data from the Office for National Statistics and Happy Planet Index to find out how much money the average Briton would need to live a happy life. The answer: £33,864 or more. And it’s the ‘more’ part that’s key. A study published this year by Matthew Killingsworth of the University of Pennsylvania suggests that the more money we have, the happier we are.…

Assuming you equate senses with their receptors, such as the retinas in your eyes and the cochlea in your ears, then the traditional answer to this question is five – seeing, hearing, touch, smell and taste. They’re called the ‘exteroceptive’ senses because they carry information about the external world. But your body also has receptors for events occurring inside you, such as your beating heart, expanding lungs, gurgling stomach and many other movements that you’re completely unaware of. They’re traditionally grouped together as another sense, called ‘interoception’. SIX, SEVEN, EIGHT… Yet a proper answer to this question is even more complex and interesting. For one thing, your body has receptors to carry other types of information, such as temperature, that we don’t usually consider to be senses. Also, some of your receptors…

Particles and antiparticles have opposite properties, such as electric charge. For instance, the antiparticle of the negative electron is the positive positron. Every physics process we know of creates equal amounts of matter and antimatter. When a particle meets its antiparticle however, it ‘annihilates’, ultimately into high-energy photons. As such, the Universe should contain no matter or antimatter, and just be a sea of photons. Instead, it contains enough matter to make about two trillion galaxies and, as far as we can tell, no antimatter. A clue to what happened to all the antimatter comes from the fact that the ‘afterglow’ of the Big Bang (the cosmic background radiation) contains about 10 billion photons for every particle of matter in today’s Universe. This tells us that, in the Big Bang,…

The mineral pyrite has another name: fool’s gold, as its metallic yellow crystals trick miners into thinking they’ve struck real gold. It’s not without its uses - the compound creates sparks when hit with steel, which can be used to start a fire - but it’s always been seen as worthless compared to its coveted cousin. Now, scientists have discovered that the mineral, made of iron and sulphur, actually contains a type of gold hidden within its crystal structure. Research suggests that extracting this gold could be a more sustainable method of getting the metal than current energy-intensive mining processes. Fool’s gold is found inside rocks beneath Earth’s surface, sometimes near real gold deposits. The mineral has a crystalline structure, which grows over the years and stretches within the rock.…

Heart failure affects over 10 million people in the US and Europe every year and the outlook for patients is often bleak. Medication can only control the condition for so long and most patients require a heart transplant. If your heart slowly failing isn’t scary enough, the number of donor hearts that become available each year is tiny compared to the number of people waiting for one. For some patients, their body size or blood type means the chances of finding a donor heart are virtually zero. Attempts have been made to design artificial hearts since the 1950s, with little success. Many tests of artificial hearts over the years have involved seeing how many days – and it was often days – some poor animal could survive with one installed…

In 2020, US and Chinese scientists found a way to enable worms to live five times longer than normal by manipulating their genes. Worms are often used in ageing research since we’ve inherited some of the same genetic circuitry during evolution. It’s suggested that targeting some of these conserved genes using drugs could be a way to extend the human lifespan. But since worms only live for a few weeks, extrapolating the US and Chinese scientists’ success to humans could be foolhardy. In short, we can’t expect to live to 500. But let’s not be greedy. We already live far longer than our hunter-gatherer ancestors, who invariably snuffed it before the age of 40. Should we, though, stop considering life as something that comes to its natural conclusion at 73…

Today’s computers are incredible. Nearly 50 years ago, we had Pong, one of the first computer games, which played ‘tennis’ using moving blocks on each side of the screen. Today we have photo-realistic virtual worlds filled with computer-generated characters that all seem to move and behave as they should. The advancement of computers is said to follow Moore’s Law, named after Gordon Moore, one of the founders of Intel. In the 1960s, Moore saw the rate of progress and predicted that the number of transistors on a chip would double every two years. By the mid 1970s there were 10,000 transistors on a chip. By 1986 it was more than a million. And by 2020 we had 2.6 trillion. Because of Moore’s Law, computer power has been doubling about every…

Good news! Through vaccines, healthy diets and a great swathe of medical innovations, human lifespans have roughly doubled in the last century or so, from an average of 35 years in 1900 to an average of more than 70 years today. But, wait… you want more? Perhaps understandably, you won’t find yourself alone in seeking to stretch your life out that bit further. In fact, one unrelenting ideal, frequently chased by Silicon Valley companies, sees us running upstairs well into our 90s and has our brains being as fresh as a child’s into the 12th decade of life. It also envisions a future where USB-enabled brains in jars live to see the extinction of the Sun. MAKE ROOM FOR THE NEW STOCK The truth is that ideas such as these…

We may not feel like it, but most of us have endured our first global pandemic surprisingly well, statistically speaking. According to the latest World Happiness Report, there’s been no overall change in ‘positive affect’ – our ability to experience positive emotions. But there has been a 10 per cent increase in the number of people who said they were worried or sad the previous day. And 22 per cent of us report that our mental health is worse than before COVID-19, with increases in depression and anxiety widespread. So while we may still be able to experience ‘the good stuff’, we’re getting more ‘sad’ too. One reason is that the physical distancing and isolation needed during the pandemic have compromised our social connections, which are vital for happiness. Many…

People often describe the brain as a computer, as if neurons are like hardware and the mind is software. But this metaphor is deeply flawed. A computer is built from static parts, whereas your brain constantly rewires itself as you age and learn. A computer stores information in files that are retrieved exactly, but brains don’t store information in any literal sense. Your memory is a constant construction of electrical pulses and swirling chemicals, and the same remembrance can be reassembled in different ways at different times. Brains also do something critical that computers today can’t. A computer can be trained with thousands of photographs to recognise a dandelion as a plant with green leaves and yellow petals. You, however, can look at a dandelion and understand that in different…

In 1905, Albert Einstein showed in his Special Theory of Relativity that space is intimately connected to time via the cosmic speed limit of light and so, strictly speaking, we live in a Universe with four dimensions of spacetime. For everyday purposes however, we think of the Universe in three dimensions of space (north-south, east-west, up-down) and one dimension of time (past-future). In that case, a fifth dimension would be an extra dimension of space. Such a dimension was proposed independently by physicists Oskar Klein and Theodor Kaluza in the 1920s. They were inspired by Einstein’s theory of gravity, which showed that energy, most commonly mass-energy, warped four-dimensional space-time. Since we’re unable to perceive these four dimensions, we attribute motion in the presence of a massive body, such as a…

DO WOMEN MAKE FOR BETTER ENDURANCE ATHLETES THAN MEN? You only need to think of any marathon you’ve watched to assume that men tend to outperform women in sport. But an interesting recent review published in the journal Sports Medicine has reignited the discussion. It highlighted that the male-female performance gap in ultra-endurance competitions (events typically more than six hours) is as low as 4 per cent, while it’s around 10 per cent in traditional endurance sport. And the difference seems to reduce the longer the event becomes, to the point that women even outperform men when it comes to events like ultra-distance swimming. Just look at the finishing times for the 45.8km Manhattan Island marathon swim. On average over the past 30 years, the best women have been 12…

ACROSS 1 Where you may acquire education and elegance (5) 4 A hundred and one took in performance, and they’re prickly (5) 8 Roam around after a scent (5) 9 Uncontrolled sheep puts pressure on worker (7) 10 Peg is a character, by the sound of it (3) 11 Handle a nice surprise (5) 12 Clear problem with current cake (6) 14 Wave weapon at English article written by bard (13) 17 Leave ship with Greek character, returning chat (6) 19 Putin’s unusual contribution (5) 22 Compendium includes its own writer (3) 23 Soldier unwilling to share (7) 24 Furious buccaneer loses head (5) 25 Intrigued elves have to investigate (5) 26 Background player is surplus (5) DOWN 1 Berate pursuit – it’s back in (8) 2 Sailor takes poem…