Indholdsfortegnelse for February 2021 i BBC Science Focus Magazine

Out with a bang The December issue was my favourite for some months, because it contained more physics than usual. However, I had a question regarding the Big Bang. In any explosion, all the exploding material, mass and energy, travels outwards from the origin, leaving a continuously expanding vacuum at the centre, which by now would add up to a mind-bogglingly enormous empty volume in interstellar space. So where is it? Unlike the Higgs boson, it shouldn’t be hard to spot, surely? Mark Farren The Big Bang is often likened to an explosion, in the sense that a lot of stuff moved apart quickly. But it wasn’t literally an explosion, and the metaphor rapidly falls apart. In an explosion, you have a centre where the combustion happens, and things move…

Glaciers that have remained on the surface of Mars for hundreds of millions of years are revealing secrets of the planet’s unique geological past. By analysing the patterns and structures of rocks in 45 of the Red Planet’s glaciers, researchers at Colgate University, New York, have found that Mars underwent between 6 and 20 separate ice ages over the last 300 to 800 million years. The team made the discovery after painstakingly poring over a series of high-resolution images collected by the Mars Reconnaissance Orbiter satellite, and measuring the size of around 60,000 rocks in the photos. If there was a single, long ice age event, they would’ve expected to find a steady progression of larger to smaller rocks as they gradually eroded over time. However, they found that rocks…

Snake venom can pack a serious punch. In some species it contains toxic substances that affect the nerves (neurotoxins), which can kill small mammals in minutes and in some cases can even dispatch other snakes. However, certain snake species are able to survive snake bites that would be deadly to others. A new study by researchers at the University of Queensland, Australia, has discovered that this phenomenon is down to genetic mutations that allow their nerve receptors to repel the neurotoxins, similarly to the way the two positive sides of a magnet repel each other. “It’s an inventive mutation that’s been completely missed until now” Snakes such as cobras (Naja species) and kraits (Bungarus species) that prey on other snakes possess neurotoxins with positively charged sites on their molecular surfaces.…

WHAT DID THEY DO? Researchers at the German Primate Center listened in on the low frequency grunts that male Guinea baboons use to communicate with one another and studied their acoustic structure. WHY DID THEY DO THAT? They wanted to study the evolution of vocal learning; essentially, the ability to imitate sounds that allows humans to learn new languages even into old age. WHAT DID THEY FIND? Baboons in different social groups shared similarities in their grunts, much like accents in human languages, suggesting a degree of a phenomenon known as ‘vocal accommodation’. “People do this also: they often involuntarily adjust the tempo or their pitch to be more similar to that of the person you are talking to,” said lead researcher Prof Julia Fischer. “Such effects seem to be…

This year, in early January, a consultation was launched that asks whether organisms produced by genetic engineering should continue to be classified as genetically modified, if the organisms could have been developed using traditional breeding methods. The consultation is especially focused on gene editing, also known as genome editing, a technology that allows scientists to add, remove or alter an organism’s DNA. Unlike older types of ‘transgenic’ genetic modification, this process doesn’t introduce foreign DNA into the gene. In a speech launching the consultation, Environment Secretary George Eustice said gene editing raises “far fewer ethical or biological concerns” than transgenic modification and “respects the rules of nature”. In 2018, the European Court of Justice ruled that gene-edited crops should be considered the same as other genetically modified crops under EU…

IN BLOOM The contents of your toilet is precious – to algae, anyway. Human waste is packed with phosphorus and nitrogen, nutrients that algae needs to grow. Researchers have developed bioreactors, like this machinery designed by ClearAS in Missoula, USA, that exploit the way that algae grows rapidly when exposed to human waste. The system is packed with algae that extracts nutrients from wastewater, therefore cleaning the water to ensure it meets industry standards. The algae is then used to make materials for bioplastics and bioenergy. A full-scale system is up and running at South Davis sewers in Utah, treating 18 million litres of water daily. SET IN STONE Geothermal power plants, which use heat from the Earth’s core to generate energy, may provide a steady stream of electricity, but…

I EAT SALAD LEAVES TO FEEL HEALTHY — BUT IS THERE REALLY ANY GOODNESS IN THEM? In short: yes, most definitely! Most salad leaves contain essential nutrients and micronutrients such as vitamins, minerals, water and fibre. Plus, they are low in calories and high in volume — they can fill your plate up without adding too many calories. Remember, 100g of spinach contains half the calories of 100g of apple. Guidelines recommend eating five portions of fruit or vegetables a day, and salad leaves definitely count. But you need about a cereal bowl of leaves to rack up one portion. And be sure to watch out for salad dressings, which can increase the calorie count significantly (a tablespoon of French dressing alone can add 73 calories — about a third…

1 ACTIVATION A tsunami begins far offshore, with an earthquake, volcanic eruption or landslide. The sudden movement on the seabed displaces the water above it. Although the vertical movement may initially be less than a metre, it covers a large area and the total volume of water displaced is huge. 2 BUILD In deep water, the wave spreads out rapidly. The wave may only be 30cm high at this point and hard to spot, but it travels at more than 800km per hour. Unlike normal, wind-driven waves, which are spaced about 100m apart, there can be up to 200km between successive tsunami wave crests. 3 FORMATION Each wave has a peak and a trough, and sometimes the trough of a tsunami reaches land before the peak. This causes a drawback…

And the award goes to…. Paratarsotomus macropalpis, a sesame-seed-sized mite that lives amidst the pavements and rocks of southern California. The athletic arachnid has been clocked reaching speeds of 322 body lengths per second, which is the equivalent of a human running at 1,300 miles per hour. It’s more than 20,000 times smaller and 40 times faster than Usain Bolt, and it leaves the world’s fastest land mammal, the cheetah, eating dust. If you think that’s fast, scientists suspect that the mite’s prey could be even speedier, but the elusive animal has yet to be identified or caught on camera. HP…

1. A favourite zombie apocalypse weapon, a chainsaw’s chain moves at a speed of 27 metres per second. The world’s biggest chainsaw, Big Gus, is 6.98 metres long. 2. The chainsaw was first invented to help during difficult childbirths. Really. The device was first designed to cut through flesh and bone if a baby was trapped in the birth canal. 3. While it’s untrue that newborns only see in black and white, their colour vision is extremely limited when under two months old. However, they can spot bright red objects when on a green background. 4. Although it’s debated whether wearing red can increase performance levels through better visibility or associations with aggression, Taekwondo judges have been shown to award more points to competitors dressed in red protective gear.…

Scientists estimate that the Earth gains about 40,000 tonnes of material each year from the accretion of meteoric dust and debris from space. They also estimate that about 95,000 tonnes of hydrogen gas are lost from the Earth’s atmosphere to outer space each year. Although there are other processes involved, such as the loss of mass due to radioactive decay within the Earth’s core (about 160 tonnes a year), and helium loss from the atmosphere (about 1,600 tonnes a year), these are small effects. Annually, the amount of mass launched into Earth orbit is negligible by comparison, of the order of a few hundred tonnes. A conservative estimate therefore implies the Earth is losing something like 50,000 tonnes of mass every year. That sounds like a lot. But, since the…

Life In Colour A new David Attenborough series feels like what we all need right now. This series reveals the ingenious ways that creatures rely on colour to navigate the perils of the natural world. BBC Two, 28 Feb The DNA Clinic What can our DNA reveal about our family tree? How far back can we trace our relatives using it? And how good are over-the-counter DNA tests? These questions and more will be answered by a new series this month. BBC Two, check Radio Times for details The Jump COVID-19 isn’t the first time a disease has jumped species. This three-part series explores how we might prevent another pandemic before it has a chance to start. BBC Radio 4, 10, 17 and 24 March…

Tim Saviour I KNEW IT! I used to be able to eat and drink anything, but since becoming menopausal I have struggled with my weight. So, I exercised like a maniac for four years (all differing types) and I watched what I ate. I would lose weight at first but then it would creep back up. Reading Prof Tim Spector’s article about diet myths (November, p56) gave me a sign of relief… I am not going mad, I am just getting older and my body doesn’t process food the way it used to! Thank you, Tim, for giving me my sanity back! Shamsi Pearson WRITE IN AND WIN! The writer of next issue’s Letter Of The Month wins a Let’s Explore Oceans mega pack. It comes with a set of…

Kombucha – the trendy fermented drink beloved by health freaks and hipsters alike – has inspired researchers to grow a ‘living material’ capable of carrying out a range of tasks, such as detecting pollutants or purifying water. Engineers from MIT and Imperial College London made the material using a SCOBY, or symbiotic culture of bacteria and yeast. Usually used as a mother culture for making fermented kombucha tea, in this instance it was used to produce cellulose embedded with enzymes that can perform a variety of functions. Dubbed Syn-SCOBY, the material was made by combining a strain of laboratory yeast called Saccharomyces cerevisiae with a type of bacteria called Komagataeibacter that the team had isolated from a kombucha mother. The Komagataeibacter bacteria in the culture produced large quantities of tough…

It’s not just the Avengers who work best as a team: it turns out that electric eels also assemble to defeat their foes. Or at least catch their next meal. While monitoring wildlife in the Amazon River, scientists from the Smithsonian National Museum of Natural History discovered groups of up to 10 eels may form a pack to attack tetras. After herding the small fish into a tightly packed ball, the eels then deliver a synchronised high-voltage strike. “This is an extraordinary discovery,” said Dr David de Santana, lead author of the new study. “Nothing like this has ever been documented in electric eels. Hunting in groups is pretty common among mammals, but it’s actually quite rare in fishes. There are only nine other species of fish known to do…

The year 2020 is likely to live in our memories as the year COVID-19 brought the world to a standstill. Many are hesitant to hope for a more normal 2021, choosing to tentatively take life one day at a time as our future remains uncertain. But how does the world appear if we cast our eyes forward to 2022? Although the world has experienced pandemics in the past, the closest example we have to a blueprint would be the severe acute respiratory syndrome (SARS) epidemic. This was a coronavirus that cost over 770 lives, largely in eastern Asia, during the early 2000s. But after complications cropped up in animal trials for a SARS vaccine and the virus died out in humans, research funding dried up. Little progress was made into…

WHY DO WE NEED URBAN AIR PORTS? As an architect and partner at Foster + Partners [an architectural firm], I spent a lot of time developing cutting-edge, innovative buildings and city masterplans, but I never had the scope to tackle the bigger issues involving the bits between the buildings – in other words, our mobility network. When I first started working on this, my commute was just six miles across London, but it was polluted, congested and took over an hour. So I was just driven by passion and a sense of responsibility that we ought to be developing smarter, cleaner and greener ways to move around our cities. The urban air-mobility piece came about when Airbus started their air-mobility programme around three years ago. They came to us and…

Since we live inside the Milky Way it is difficult to see its spiral form. There are some clues though. First, there is a concentration of stars along the galactic plane and particularly in the constellation of Sagittarius. This implies the Milky Way is disc-shaped with a central bulge, just as we see in other spiral galaxies. Second, measurements of the velocities of stars and clouds of gas reveal that their motion is not random but follows a rotational pattern - just like those we see in other spiral galaxies Most convincingly, measurements of the distances of these objects show clearly that they are concentrated along the arms of a spiral Conclusion: The Milky Way is a barred spiral galaxy with four arms. AGu…

Current theories of physics break down once the temperature of an object reaches the ‘Planck temperature’, which is about 1,000,000,000,000,000,000,00 0,000,000,000,000°C. At that temperature, an object would emit radiation with so much energy that every photon would create its own tiny black hole. The whole Universe was very briefly at this temperature, about 10-43s after the Big Bang. Overall, it’s a hundred trillion, trillion times hotter than the Sun. LV.…

Some fish, amphibians and reptiles have a simple third eye on top of the head. This patch of light-sensitive cells doesn’t add much to their vision, but it helps some animals to regulate their body temperature and navigate via the Sun’s light. Invertebrates often have more than two eyes. Most spiders, for example, have eight eyes that help them spot and hunt prey. A group of marine molluscs called chitons do even better - they have hundreds of eyes dotted all over the armoured plates that cover their bodies. This boosts their field of view and helps them detect predators. HP…

ACROSS 7 A couple of bishops with zero time for another cleric (5) 9 National symbol to raise that woman’s temperature (7) 10 Invalidate six - one is in gallery (7) 11 Reporters apply an amount of force (5) 12 Second obligation holding record (6) 13 Betting present is a ball (6) 16 Emphasise a state of nervous tension (6) 17 Reason for earth (6) 19 Object to night manoeuvre (5) 21 Husband - former husband in the past - acquires new shape (7) 22 Dog right for underground worker (7) 23 Terrible key included for sad song (5) DOWN 1 Sad, vocal composition shows spirit (8) 2 Book about tin, fashioned in fabled place (8) 3 Lavish reward includes dragon (5) 4 Instrument is out of tune - omit…

There are thought to be millions of people in the UK with irritable bowel syndrome (IBS), yet despite the large number of sufferers, little is known about the condition. According to the NHS, IBS is usually a lifelong problem and has no known cure, though changes in diet and some medicines can alleviate symptoms. Now, a team of researchers at KU Leuven in Belgium have uncovered a mechanism behind the stomach pain and discomfort felt by IBS sufferers that could lead to potential new treatments using antihistamines. The team’s previous research demonstrated that blocking histamine – the compound that’s produced by the body’s immune system in response to an allergen — seemed to improve IBS symptoms. It’s been established that people who have suffered with an gastrointestinal infection (GI) in…

It has long been noted that small doses of LSD (lysergic acid diethylamide), can promote empathy and produce a feeling of a greater connection to the world in those who take it. But until now, the reason why this happened was unknown. Now, researchers from McGill University in Canada have discovered one of the possible mechanisms that contributes to the drug’s ability to produce these effects. The breakthrough could pave the way towards using the drug to treat mental health problems such as anxiety and alcohol-use disorder. The researchers administered a low dose of LSD to a group of mice over a period of seven days and noticed that it led to an increase in their social interactions. Then, using optogenetics — a cutting-edge technique that allows specific areas of…

ONLINE DATERS Swiss researchers have found that couples who met through dating apps were more likely to move in together, and more likely to want to have children, than couples who hooked up in more traditional ways. THE SUPERFIT We all know we should be moving a bit more to improve our health. Now, a study at the University of Oxford has found that the benefits for the cardiovascular system keep piling up the more activity we get, with the most active people reaping the most gains. ANGRY GAMERS Prone to rage-quitting when gaming? Maybe rethink your approach. FIFA 19 players that were shown positive video clips before playing scored more goals than those shown negative, angry clips, Stanford University researchers have found. NAUGHTY CHILDREN Kids who are impulsive, aggressive…

Black holes that formed in the early moments of the Universe could explain dark matter, physicists claim. They also say that some of these black holes could contain ‘baby universes’ that will never know we exist. In the beginning, the Universe was incredibly hot and dense – so much so that a random local fluctuation that increased the density of an area by only 50 per cent would be enough to spark gravitational collapse into a black hole. Unlike the black holes we see in our modern Universe, the hypothetical ‘primordial’ black holes created at this time didn’t form from a collapsing star, which means they could have a wide range of masses, including extremely small ones. Shortly after the Big Bang, the expansion of the Universe accelerated. This phase…

SCIENCE BEHIND THE HEADLINES “If we separate our biases away from thinking that some features only belong to us, then we can move the field forward much faster” WHAT WAS THE EXPERIMENT? Researchers based at the Minimal Intelligence Lab at the University of Murcia, Spain, and the Rotman Institute of Philosophy in London, Canada, placed 20 potted French bean plants in the centre of cylindrical booths. The plants were either alone, or accompanied by a garden cane planted into the ground 30 centimetres away. The scientists then used time-lapse photography to track the movements of the plants until the tip of the shoots made contact with the canes. They found that the shoots would grow along more predictable paths in the presence of the canes, almost as if they could…

A see-through speaker… Apart from public toilets, there are few things in life that aren’t made better by being see-through. Case in point, this speaker that replaces its housing with tempered glass. Its creator, a Swedish design studio, says that its speakers use durable, recyclable materials. Each of the devices can be used alone as a Bluetooth speaker, paired together as a stereo sound system, or plugged into existing audio equipment. It’s upgradable too, with a compartment at the rear that can hold and power various modules – a voice assistant, for example, or new wireless tech. Transparent speakers From £900, transpa.rent A telescope for the social media age The notion of a telescope without an eyepiece to look through could inspire a few strongly worded letters from our readers,…

Look up at the sky after sunset and the familiar quilt of night is punctured with bright stars. These blazing furnaces are so vivid that we can see their light, despite the fact that even the nearest are quadrillions of kilometres away. It’s a sight most of us have seen on countless occasions, so you’d be forgiven for thinking that all stars must behave this way. After all, isn’t shining just what a star does? Yet if a flurry of recent findings is to be believed, there’s an entirely different class of stars lurking out there - stellar ghosts cloaked under a veil of darkness. These transparent, invisible stars give out no light whatsoever, meaning they skulk unseen in the celestial shadows. Astronomers already suspect that, unlike ordinary stars, most…

Nebulae are clouds of dust and gas that represent either end of a star’s life cycle. Some are places where stars have died, others where stars are forming. The Orion Nebula is the latter. At only 1,344 light-years away, the Orion Nebula is the closest and one of the brightest nebulae visible from Earth. This means it can be seen with the naked eye when viewed under dark skies. The brightness of objects in the night sky as seen from Earth are measured on a logarithmic scale: the lower the number, the brighter the object. This scale means an object with magnitude 1 will be 10 times brighter than a magnitude 2 object. The Sun has a magnitude of -26, while the brightest star in the night sky, Sirius, has…

WHAT ACTUALLY IS MEMORY? Memory, in short, is a process. It begins with an ‘encoding phase’ when experiences are represented in webs of interconnected neurons. Over the short term - imagine briefly memorising a phone number - this takes place at the front of the brain. If you process information deeply enough it will work its way through into longer-term storage, which involves the hippocampus in the brain’s medial temporal lobe (near the ears). Psychologists distinguish between memory for knowledge, which they call ‘semantic memory’, and memory documenting past experiences, known as ‘autobiographical memory’. These two kinds depend on somewhat different neural systems, meaning it’s possible for illness or injury to interfere with one while leaving the other relatively intact. Another distinction is between ‘explicit memory’ - memories you can…

THERE’S NO NEED TO GO THE GYM Everyone can exercise at home. During the pandemic, life has been different and lots of people have started doing online workouts. Joe Wicks has been popular, for example. We’ve been exploring how well these apps and online programmes work. APPS AND ONLINE WORKOUTS CAN BE HELPFUL… …but they’re even better if they’re supplemented with a personalised smart watch that guides you through the exercises and gives you feedback on how well you’re doing them. We have found that people with these watches exercised more and were less likely to give up than the people without them. THINK ABOUT EXERCISE INTENSITY Our research made us realise that it’s vital to teach people how to exercise. Exercise intensity is important. Too intense and it will…