Home/Science/How It Works/No. 81/In This Issue
How It Works|No. 81WELCOMEAre we alone? It’s one of the biggest questions humans have wrestled with through the ages. But while this was once a dream, now it is a scientific quest. The Breakthrough Initiative is a pioneering new search for intelligent life in the cosmos, backed by Professor Stephen Hawking.At the launch, he pondered what we might find: “A civilisation reading one of our messages could be billions of years ahead of us,” he said. “If so, they will be vastly more powerful and may not see us as any more valuable than we see bacteria.”It’s mind-blowing to think what’s possible in an infinite universe, particularly since we believe life began spontaneously here on Earth. In this exciting issue, we not only explain the where, how and why behind this project, we…1 min
How It Works|No. 81The future of personal submarinesSubmarines are no longer reserved for naval warfare and fictional spies, as DeepFlight’s new craft has made it easy for anyone to travel beneath the waves. The Dragon is a cross between a submarine and quadcopter, with six rotating thrusters that allow it to fly and hover underwater. The simple controls mean it operates just like a drone too, so anyone can pilot it without needing lengthy training.The onboard DeepFlight Dive Manager monitors depth control, battery consumption and oxygen flow, so all you need to do is set the dive limit and fly. The lithium-iron-phosphate battery allows you to cruise for up to six hours between charges and operates quietly so you can sneak up on any marine wildlife. You and your passenger will be protected by the carbon composite…1 min
How It Works|No. 81How penguins can prevent plane crashesDespite the freezing temperatures of their Antarctic home, penguins’ feathers never ice over, and new research has finally found out why. Near the base of their tail, penguins have a gland that secretes water-repellent oil over their bodies. This, combined with the tiny pores found on the surface of their feathers, means that water droplets roll straight off before they have time to freeze. Researchers hope these findings could be used to prevent ice forming on aircraft wings, a common cause of plane crashes in winter weather.©Thinkstock; Image courtesy of Asier Marzo, Bruce Drinkwater and Sriram Subramanian…1 min
How It Works|No. 81Piecing the puzzlePalaeoanthropologists are scientists who peer into our evolutionary past. As they try to piece together our family tree, their most important clues come from fossils – physical evidence of ancient hominins, like bones and teeth, which help to classify different species.In order to reconstruct how species evolved, it is crucial to know how old these fossils are. However, the commonly used method of radiocarbon dating can only be used on specimens younger than 40,000 years old.Instead, experts look at materials in close proximity to the fossils, such as the layers of rock they were discovered in. Careful study of local geology combined with chemical analysis allows fossils and artefacts within the layers to be dated.In the last decade, DNA sequencing has revolutionised this field. Because genetic mutations happen at predictable…1 min
How It Works|No. 81Tools and developmentFour major development trends separate humans from apes: terrestrialism, which is the move from tree-dwelling to ground living; bipedalism, the shift from moving on all fours to walking upright on two legs; encephalisation, which is an increase in brain-to-body mass ratio; and civilisation – a catch-all that includes social organisation, technological thought, communication and culture.Separating cause from effect in these areas is tricky and experts disagree over the order in which they unfolded. But climate science offers some of the most compelling evidence for where it all started.Beginning around ten million years ago, Africa’s climate altered profoundly from lush tropical forests to sparse, open grassland. As food sources became more thinly distributed, walking on two legs would have enabled early humans to forage over long distances and even carry provisions…4 min
How It Works|No. 81Surviving adversityAfter over six million years of human evolution, hom*o sapiens is the only species left standing. What is the secret to our success? Scientists believe it lies in our adaptability, our capacity for abstract thought and our ability to cooperate.Indeed, no other animal species has adapted to as wide a range of habitats and such divergent pursuits as modern humans. As successive waves flowed out of Africa and dispersed throughout the world, we learned in each new place how to find and eat local food and to survive different climate conditions.We could not have done this without technological ingenuity, nor without the cultural transmission of ideas – the ability to mimic one another, communicate concepts, and learn new skills. This allows the work of the most skilled or intelligent to…1 min
How It Works|No. 81Where are we headed?Of course, the story of humans is not over. Pressures of diet and disease, as well as our increasingly globalised lifestyles, continue to influence our genetic trajectory. In fact, some scientists think human evolution is accelerating. So what does our future hold?For the first time in history, genetic engineering may soon give us direct influence over our own or our children’s genes. But superhuman bodies will be useless if we continue to neglect the planet that sustains us. Despite our miserable environmental track record, we have the unique ability to comprehend the future consequences of our actions; the question remains whether we can learn to look beyond our immediate, individual interests.If the planet can’t meet the needs of the heaving population, we might eventually have to turn our gaze outwards.…1 min
How It Works|No. 81We’re over here!The Arecibo Message was a coded image sent out in the direction of 300,000 stars in the nearby M13 star cluster, over 40 years ago. It was constructed by shifting the frequency of the broadcast to spell out binary 0s and 1s. In less than three minutes, the message attempted to paint a picture of life on Earth for any intelligent life that might be watching.NumbersThe first ten digits are written here one to ten.Important elementsAtomic numbers of elements such as carbon and oxygen.DNA componentsFormulae of some of the chemical building blocks of the genetic code.DNA codeThis chain represents the number of DNA nucleotides (building blocks of DNA) in the human genome.Double helixThe distinctive structure of DNA is shown here.HumanA human figure is shown, with average height represented to the…1 min
How It Works|No. 81How to hunt for aliensThe first step in the search for life is to define what life actually is. This is still a topic of debate, but it is generally agreed that living things are complex and organised. They use resources from their environment to generate energy, and build molecules for replication and growth. They react to their surroundings, adapt and reproduce, all of which requires complex chemistry.The most abundant elements in the universe are hydrogen and helium, but helium does not form molecules with other elements, and hydrogen can’t make complex molecules on its own. Oxygen and carbon are the next most plentiful, and together with hydrogen are the most abundant elements in Earth’s organisms.It might seem a bit egocentric to assume that life elsewhere in the universe will be based on the…1 min
How It Works|No. 81Have there always been Earth-like planets?The universe is nearly 14 billion years old, but it hasn’t always been able to sustain life. In the early days, as everything began to cool after the Big Bang, there were only two elements available: hydrogen and helium. These simple elements are not sufficient alone to build any kind of life. These gases formed the first stars and galaxies, and these new nuclear reactors smashed the small atoms together to make heavier elements like carbon and nitrogen. When these stars exploded, the new elements went on to form new stars. Our Solar System formed around 4.6 billion years ago, and star-forged elements like silicon and iron make up the planet that we live on. Until recently, scientists thought that the oldest stars wouldn’t have Earth-like planets, but NASA’s Kepler…1 min
How It Works|No. 81Will we find alien life?MANY SCIENTISTS BELIEVE THERE COULD BE ALIENS….“What is the likelihood that only one ordinary star, the Sun, is accompanied by an inhabited planet? ... To me, it seems far more likely that the universe is brimming over with life.”– Carl Sagan, Cosmos“To my mathematical brain, the numbers alone make thinking about aliens perfectly rational”– Stephen Hawking“I think we’re going to have strong indications of life beyond Earth within a decade, and definitive evidence within 20 to 30 years,”– Ellen Stofan, NASA chief scientist“I think life is common in the universe. We may be the only civilisation in the Milky Way. There will be other civilisations in the universe”– Brian Cox…BUT PROVING IT COULD BE A CHALLENGE“We have a galaxy full of ten billion planets, in habitable zones, roughly Earth-size... no…1 min
How It Works|No. 81Star versus planetA star and a planet differ in the way that they form. Stars are born in large clouds of gas that collapse due to the inward force of gravity. From this, a rotating ball forms, attracting more gas from the surrounding cloud, which squashes the gas at the centre. Such an intense compression triggers nuclear reactions, igniting the star and causing it to release the energy we see as a star’s light.In order for a star to be made, it must have enough mass. If it doesn’t, then gravity is unable to compress the gas enough to trigger the nuclear reactions needed to make light. You may have heard of a ‘failed star’, which is another name for a brown dwarf, a gaseous object with less than about eight per…2 min
How It Works|No. 81Everyday elementsGas-discharge lampsThese lamps typically contain neon, argon, krypton, or xenon, which are noble gases. When an electric current is passed through the gases, they become excited, and when they drop back down to a normal energy level, they release photons of visible light.Smoke detectorsMany smoke detectors contain small amounts of americium. This radioactive element releases alpha particles, which ‘knock’ electrons away from gases in the air and towards a positively charged plate in the smoke detector, generating a current. When smoke gets in the way, the current stops and the alarm sounds.CoinsIn the UK, 1p and 2p coins are made from copper-plated steel (iron and carbon), 5p and 10p coins are nickel-plated steel, 20p and 50p coins are cupro-nickel (copper and nickel), and £1 and £2 coins are nickel-brass (copper,…1 min
How It Works|No. 81Inside a blood vesselInside your body there is a vast network of blood vessels that, if laid end to end, could easily wrap twice around the Earth. They are an important part of your circulatory system, carrying the equivalent of more than 14,000 litres of blood around your body every day to transport vital nutrients to where they are needed.There are five main types of blood vessel. In general, arteries carry oxygenated blood away from the heart and have special elastic fibres in their walls to help squeeze it along when the heart muscle relaxes. The arteries then branch off into arterioles, which pass the blood into the capillaries, tiny blood vessels that transport nutrients from the blood into the body’s tissues via their very thin walls.As well as nourishing the tissue cells,…2 min
How It Works|No. 81INSIDE THE LIVER AND PANCREASWeighing more than a bag of sugar, the liver is the largest of all the internal organs. It’s located mostly in the right side of your abdominal cavity and is capable of holding roughly ten per cent of your body’s total blood volume, with around a quarter of your blood supply passing through it every minute.The liver has many roles in the body, one of which is producing bile, the substance that breaks up fat molecules to aid digestion. Up to one litre of this greenish-yellow liquid is produced and released every day, containing a combination of salts, water, cholesterol and a pigment called bilirubin. Bile travels from the liver to the gallbladder, where it is stored. When a fat-containing food reaches the duodenum (part of the small intestine), the…4 min
How It Works|No. 8160 SECOND SCIENCE Archimedes’ principleBACKGROUNDAccording to the Roman author Vitruvius, King Hiero II of Syracuse commissioned a goldsmith to make him a crown, but upon receiving it, was not convinced it was pure gold. He asked Archimedes to determine whether he had been ripped off. Archimedes couldn’t melt the crown or damage it, and chemical analysis had not been invented. He had to find alternative means of determining its purity. The experiments that followed were the basis of our understanding of density and buoyancy.IN BRIEFThe ‘eureka’ moment reportedly came while Archimedes was taking a bath. When he climbed in, the water level rose and he realised that the volume of water he displaced must be equal to his body’s volume. If he was bigger, more water would spill onto the floor. He also noticed…3 min
How It Works|No. 81How champagne is madeA glass of bubbly is a lavish treat for most of us, or for the rich and famous it can be used to bathe in (Marilyn Monroe did it, apparently!). But what sets it apart from regular wine? It’s the lengthy double fermentation process that elevates champagne into the realms of luxury. True champagne only comes from grapes grown in the Champagne region in France; the rest are sparkling wines. It is usually made with Pinot Noir grapes, which must be picked and handled carefully to avoid the dark colour of their skins staining the pale champagne.The beginnings of a bottle start with a blend of still wine, or ‘cuvée’, to make the base of the champagne. The grapes are pressed and the juice is left to ferment in a…3 min
How It Works|No. 81LEARN FROM A ROBOT KNOW-IT-ALLPrice: £64.99 / $99.99Web: www.ique-robot.co.ukIf your friends and family are getting tired of answering your questions about anything and everything, then this little robot companion will give them a break. When paired with your internet-enabled smart device, i-Que can provide answers to even the most difficult questions, giving our Brain Dump experts a run for their money. Thanks to speech-to-text technology, he can understand almost anything you say and you can change the sound of his voice to control how he answers back. i-Que can also help you train your brain by challenging you with trivia questions, brain-teasers and memory games, so you can try to become as clever as him. As well as super smarts, i-Que also has some killer dance moves and a sense of humour, as it…1 min
How It Works|No. 81REMOTE-CONTROL CAR 2.0Price: £969.99 (approx $1,460) Web: www.hpiracing.comRemote-controlled cars don’t get much more powerful than the Baja 5B with D-Box 2. This large-scale buggy weighs a hefty ten kilograms and is roughly the size of a small dog, so it will certainly give your pets a fright. You can forget about chargers too, as the Baja 5B runs on petrol. The resulting fumes mean it’s strictly for outdoor use, but the large rubber tyres are designed to tackle all sorts of off-road terrain.Perfect for racing enthusiasts, this RC can reach top speeds of over 48 kilometres per hour and features quick acceleration, so you’ll be sure to leave your opponents in a cloud of dust. If things get really competitive, the heavy-duty chassis will help the car withstand more than a few…1 min
How It Works|No. 81How green roofs workBy combining layers of waterproofing, drainage and soil, a green roof supports plant life. Each of the six to eight layers has a specific function. First, there’s the foundation layer known as roof decking. This is generally made from plywood, concrete or metal, and it shields against the elements as well as providing structural support.On top of this sits a waterproof membrane and a drainage layer to get rid of excess rainwater. This is topped with a filter fabric that stops the drainage from becoming blocked. The final layer is comprised of plants and their growing medium. This layer absorbs rainwater, providing the plants with a steady supply.‘Living’ roofs reduce household bills by providing insulation, keeping the building warm in the winter and cool in the summer. They are also…1 min
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Research on Robot Control Technology of Tomato Plant Lowering in GreenhousesThe 100 Most Iconic Guitars of All Time: Complete List RevealedPriMera Scientific Engineering | International JournalAutomotive innovation the science and engineering behind cutting edge automotive technology - Engenharia MecânicaHow It Works|No. 81What is 4D printing?While 3D printing works by adding layer upon layer of a chosen material until a three-dimensional object is created, 4D printing produces objects that can transform over time. The process, which has been developed by scientists at Massachusetts Institute of Technology, involves feeding the printer a precise geometric code, defining exactly how the shape can bend and curl. This gives it the ability to change formation when it enters a different environment, such as water.The system uses two different 3D-printed materials: one that remains rigid and another that can expand to fill 150 per cent of its original volume. The expanding substance is placed strategically to form joints that stretch and fold under certain conditions, allowing the entire structure to transform.This technology could allow products to sense a change in…1 min
How It Works|No. 81Extreme oceans1 Most shark infestedJust like Jaws, only less cinematic trickery and more lose-a-leg scaryWhen it comes to shark attacks, there are three species that sit firmly at the top of the food chain: the great white shark, the tiger shark and the bull shark. This is one gnarly trio of hungry fish, who are all keen predators with heightened senses.The most extreme place on Earth for shark attacks recently is New South Wales coast in Australia and over the last year the country has seen two fatalities, 29 attacks and 18 injuries. It’s thought that changing ocean currents are bringing the sharks’ prey closer to shore, luring in the ocean beasts alongside the fish.However, before you march out with your torch and pitchfork to chase the sharks from the bays,…7 min
How It Works|No. 81How stinging nettles get under your skinA stealthy stingWhat happens when you touch a nettle?TrichomesStinging nettles are covered in tiny hollow hairs called trichomes, which are made of silica, just like glass.Razor sharpWhen you touch a hair, the tip snaps off, leaving a razor sharp edge that pierces your skin.Painful injectionThe pressure inside the nettle hair fires the toxic liquid into your skin.Toxic liquidAt the base of the hair is a sack of toxic liquid containing a co*cktail of painful chemicals.Stinging nettles can ruin a walk in the countryside, causing a searing pain if you brush your leg against them. The stinging sensation can last for hours, but it’s still not clear what causes it.What we do know is that nettles are covered with lots of tiny hairs that act like needles. When you come into…1 min
How It Works|No. 81What causes drought?For areas that rely on regular rainfall to nourish vegetation, animals and a large human population, drought can be devastating, but in other parts of the world, hot, dry weather is a normal everyday occurrence. These arid climate conditions are caused by circulatory patterns of air in the Earth’s atmosphere, known as Hadley cells.In this weather system, intense exposure to sunlight at the equator causes warm, moist air to rise. As the air rises, it cools again, forming a low-pressure system that results in regular thunderstorms across the region. Above these storms, the jet stream – a current that flows through Earth’s upper atmosphere – carries the air towards higher latitudes until it eventually descends over the tropics north and south of the equator. As it falls, it creates a…2 min
How It Works|No. 81‘Breathing’ batteriesInside a breathing batterySee how a lithium-air battery uses oxygen to generate an electrical chargeElectron flowThe lithium ions and electrons simultaneously flow from the anode to the cathode, creating an electric charge that can power an engine.Lithium ionsThe lithium anode reacts with oxygen to produce lithium ions.Oxygen supplyIn test models, pure oxygen is needed, but it is hoped that eventually oxygen can be supplied from the surrounding air.ElectrolyteThe new and improved lithium-air battery electrolyte is made of dimethoxyethane solvent and lithium iodide salt.Graphene electrodeThe lithium ions react at this carbon-based electrode, producing lithium hydroxide crystals that decompose when the battery is recharged.The efficiency of electric cars is unmatched by their fossil fuelled rivals, but they are held back by their limited range. Chemical engineers from the University of Cambridge believe…1 min
How It Works|No. 81Hybrid train technologyBy combining a conventional diesel engine with an electric drive system, engineers from Rolls-Royce believe they can make trains more efficient. The Hybrid PowerPack includes the standard diesel engine and cooling system, but is also fitted with an additional electric propulsion module and an energy storage system. The latter produces a type of regenerative braking, which was first used in Formula 1 cars. The kinetic energy created when the train is slowed down can be recovered by an electric motor, and then stored in batteries to be used later, rather than being wasted. This is particularly useful for trains that frequently stop and start during their journey. In the first trials carried out in early 2015, this hybrid technology reduced fuel consumption by 15 per cent compared to a standard…1 min
How It Works|No. 81Mercedes F1 W06 hybridIn 2014, the governing body of Formula One decided that it was time to introduce hybrid engines, and in doing so, changed F1 forever. The 2.4-litre V8 gas-guzzling monsters were replaced by the more economical, less noisy 1.6-litre V6 hybrid. The restrictions limited the amount of fuel the cars could consume, so it was a race to develop new technologies within F1.World Championship winners, Mercedes AMG, created the PU106A/B Hybrid Power Unit with a turbocharger that uses waste energy from the exhaust to power the car’s compressor – the part that draws in air at high pressure before it enters the engine. The internal combustion engine is powered by fuel, making it the traditional part of the hybrid engine. It consists of six cylinders arranged in a ‘V’ formation –…3 min
How It Works|No. 81The brazen bull1 Through the trap doorThe victim is placed inside the hollow brass bull through a trap door in its back or side.2 Light the fireThe door is closed and a fire is lit beneath the belly of the bull.3 Slow cookingThe heat from the fire turns the bull into an oven, slowly roasting the victim inside.4 Modify their screamsA series of pipes in the bull’s head amplify and distort the victim’s cries.5 Hear the bull roarThe victim’s screams leave through the nostrils of the bull, sounding like the bellowing roar of the beast.One of the most brutal methods of execution ever created took the form of a hollow bull statue. Invented in ancient Greece by Perillus, a bronze worker in Athens, it was given as a gift to a cruel…1 min
How It Works|No. 81Weapons of warChemical weaponsOn 22 April 1915, Germany shocked the world by launching the first large-scale gas attack in war. After waiting several weeks for the wind to blow in the right direction, German soldiers released clouds of chlorine gas near the enemy trenches in Ypres, suffocating the unprepared Allied troops. Although The Hague Convention of 1899 prohibited the use of poisonous weapons, Germany justified its actions by claiming that France had already broken the ban by deploying tear gas grenades in 1914. The chlorine gas attack kick-started a chemical arms race and by the end of World War I, around 50 different chemicals had been used on the battlefield. The most prevalent were chlorine, phosgene and mustard gas, which would result in slow and painful deaths if soldiers were exposed to…3 min
How It Works|No. 81Anatomy of an American GIJungle combatHow US Army soldiers were equipped to fight through the challenging conditionsM1 helmetStandard US Army issue since WWII, troops often customised their helmets with peace signs or playing cards.ArmourThe soldier’s zip-up flak vests provided protection and a means of storing ammunition and grenades.Utility beltFitted with a canteen and extra ammunition, these belts were heavy and cumbersome, but carried vital supplies.Smoke grenadesThe coloured smoke was used to provide cover, mark landing zones and identify the location of casualties.M16 rifleReplacing the heavy M14, this rifle was lightweight and produced a high rate of fire.Combat clothingMade of tightly woven fabric, the olive-green clothing provided camouflage and protection from all weathers.BootsA leather and canvas boots enabled the feet to breathe and water to escape through drainage eyelets.As the US involvement in the Vietnam…2 min
How It Works|No. 81FASCINATING FACTSIs there anywhere on Earth with no life at all?The only environments uncolonised by life are thought to be those with temperatures above around 150›C, such as inside deep sea vents, where proteins fall apart and chemical reactions cannot occur. ACSome of the least hospitable environments on Earth are found inside deep sea hydrothermal ventsHow much iron is there in your blood altogether?Adults have 12 to 17.5 grams of haemoglobin in every 100ml of blood, containing around 0.05 grams of iron. In the entire five to six litres of blood in your body, that adds up to around 2.5-3 grams. LMWhat was the first national anthem?There is some debate, but Japan is credited with having the first words to a national anthem, and the Netherlands lays claim to the first…1 min
How It Works|No. 81Build a spectroscope1 Make a viewing holePlace a CD on one side of a box just over a centimetre from the box’s edge, and draw around the circular gap in the centre of the CD. Centre your cardboard tube over this circle and draw around its edge, then move it slightly to the right and repeat the process. This will create an oval, which you can cut out using scissors. It needs to be wide enough for the tube to fit in at an angle.2 Position your light slitPlace the box flat on the table so that the oval you’ve just cut is on the side facing you. Take the CD and place it in the top left-hand corner of the side facing the ceiling, and draw around its central gap to…3 min
How It Works|No. 81WIN!We enjoy reading your letters every month, so keep us entertained by sending in your questions and views on what you like or don’t like about the mag. You may even bag an awesome prize for your efforts!AMAZING PRIZE FOR NEXT ISSUE’S LETTER OF THE MONTH!WIN A BINATONE U605 SAT NAV!Equipped with a large touchscreen, this superb GPS system comes pre-loaded with maps for the UK and the Republic of Ireland. Its speed camera alerts are a great feature, and you can even control it with your voice while driving!…1 min
How It Works|No. 81Meet the team…DuncanSenior Art EditorHistory’s most gruesome inventions… erm, yep, there were some horrific ones. I’m not going back to the dentist any time soon!KatyProduction EditorIf you overdid it on the mince pies and turkey this Christmas, head to page 40 to see how your insides coped and why you didn’t go bang!PhilStaff WriterThe jetpack is finally here and could be used by the emergency services in the near future. Watch out for flying firefighters…JackieResearch EditorTwo and a half years. I’ve been suggesting a humans feature for two and a half years. It’s finally happened! I can’t quite believe it.BrionyAssistant DesignerJust when you thought it was safe to go back in the water… our extreme oceans feature on page 54 will give you nine reasons not to.JoFeatures EditorAfter writing about stomach-churning inventions,…1 min
How It Works|No. 81Pluto goes psychedelicWhile it would be cool if Pluto really was all the colours of the rainbow, this image has been falsely coloured by NASA scientists. Using a technique called principal component analysis, they adapted an image taken by the New Horizons spacecraft’s Ralph/MVIC camera to highlight the subtle colour difference between Pluto’s distinct regions. It shows the incredibly varied terrain of the dwarf planet, including a heart-shaped icy plain, deep craters and enormous mountains, as well as what NASA now believes to be ice volcanoes that tower four kilometres above the surface.© NASA/JHUAPL/SwRI, Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute…1 min
How It Works|No. 8110 COOL THINGS WE LEARNED THIS MONTHThere’s a device to scan food ingredientsA new gadget called Nima can examine a food sample for allergenic ingredients in minutes. It’s composed of two parts: a disposable capsule that holds the sample, and a sensor that performs a chemical analysis of the food. Currently Nima only scans for gluten, but versions that detect peanuts, soy and dairy are being developed.Vampire bats donate bloodBlood-sucking vampire bats are much more friendly than they seem, at least if you’re a member of their social group. A recent study has observed females donating blood from their most recent meal to hungry members of their colony, ensuring that they don’t go without food if they’ve been unable to find a meal. It looks as if this sharp-toothed species has a more complex social life…3 min
How It Works|No. 81The hom*o genushom*o species identifierDiscover the characteristic features of some of the most prominent members of the genushom*o HABILISHeight: 1.1-1.2m Weight: 30-36kg Average brain size: 610cmEvolving brainThe brain was small, but larger than in the Australopithecus species, allowing it to create the first stone tools.Mixed featuresThe species had a smaller face and teeth than earlier hominins, but retained a protruding, ape-like jaw.Adaptable bodyA modern-type foot arch, which allowed upright walking, with long, ape-like arms for tree climbing.hom*o NALEDIHeight: Approx 1.5m Weight: Approx 45kg Average brain size: 560 cmPetite skullThe skull was advanced in shape, but with a tiny brain case; it contained a puzzling mix of modern and primitive teeth.Apeish upper bodyThe species has primitive shoulders and curved, elongated fingers, useful for climbing and hanging in trees.Human-like lower bodyLong, slender leg bones…4 min
How It Works|No. 81Tools of the ageModern humans and our ancestors have been using tools for at least three million years. As intelligence increased, the tools that humans made became more sophisticated and specialised. Equipment for hunting, stripping animal carcasses and breaking open bones heralded an expansion in the ancient hominin diet, making more energy available for larger bodies and bigger brains.Simple toolsAround 2.6 million years ago, early humans learnt to strike one stone with another to remove sharp-edged flakes. These simple tools represent a major evolutionary advance – the first technological thought. Toolmakers had to plan, learn from their mistakes, and select appropriate materials.Refining the designBy 300,000 years ago, toolmakers understood how to prepare a stone ‘core’ so that flakes knocked from its surface with a single blow would have long, clean cutting edges. These…1 min
How It Works|No. 81Why did the Neanderthals die out?Between 35,000 and 45,000 years ago, modern humans spread throughout Europe, while the Neanderthals, present since over 250,000 years earlier, mysteriously disappeared. Many scientists suspect the two events are closely linked, and argue that hom*o sapiens out-competed their close cousins for resources and perhaps even actively attacked them.Others wonder whether the narrow Neanderthal gene pool might have been to blame. Some studies suggest that the Neanderthal population never grew bigger than a few thousand individuals. The lack of genetic diversity and small population size would have made them vulnerable to infections, radical shifts in the environment and natural disasters.…1 min
How It Works|No. 81THE SEARCH FOR ALIEN LIFEParkes TelescopeThis 64-metre movable radio telescope is located in New South Wales, Australia.Hours of dataThe telescopes will spend thousands of hours scouring the universe for signals, compared to tens of hours in previous projects.Green Bank TelescopeLocated in West Virginia, this is the largest movable radio telescope in the world, with a 100-metre dish.Search timeThe Green Bank telescope will spend 20 per cent of its time hunting for alien civilisations, while the Parkes Telescope will dedicate 25 per cent.Automated Planet Finder TelescopeThe Lick Observatory in California will hunt for optical laser messages in case they are being used instead of radio signals.Optical lasersIf civilisations are using lasers to send signals instead of radio waves, the Lick Observatory will pick them up.Radio signalsThe two radio telescopes will scan five times more of…3 min
How It Works|No. 81Extreme Earth lifeTardigradesTardigrades can survive without water, in extreme cold, under high levels of pressure or radiation, and even in the vacuum of space.Electric bacteriaShewanella bacteria can use metal ions and other compounds to release energy, instead of oxygen. This is not seen in any other organisms on Earth.Animals that live without oxygenIn 2010, scientists reported three complex species living at the bottom of the sea, in an area known as a ‘dead zone’, where there is no oxygen.ExtremophilesMany other species thrive in extremes. For instance, thermophiles survive at high temperatures, and acidophiles withstand acidic conditions.…1 min
How It Works|No. 81Life in our Solar SystemMarsNASA’s rovers have shown that Mars was once home to vast pools and rivers, and in 2015, NASA confirmed that liquid water still flows on the Red Planet today.EuropaJupiter’s icy moon may have a salty ocean beneath its surface. NASA believes that it touches the moon’s rocky core, providing chemical elements that could sustain life.EnceladusSaturn’s moon Enceladus releases jets from its icy surface. Scientists believe that they could be carrying materials from a hidden liquid water ocean underneath.TitanSaturn’s largest moon has an atmosphere of nitrogen and methane that intrigues scientists. Some suggest that methane-based life forms could inhabit Titan’s seas.…1 min
How It Works|No. 81ARE WE ALONE IN THE UNIVERSE?There are billions of stars in the universe, and some astronomers think it’s likely that each one in the Milky Way galaxy has at least one planet. The director of the Space Telescope Institute in Baltimore, Matt Mountain, told NASA: “What we didn’t know five years ago is that perhaps ten to 20 per cent of stars around us have Earth-size planets in the habitable zone.” Being in the right zone is one thing, but being home to life is another. And being home to intelligent life with the technology to send signals out into space is something quite different again.On Earth, moving from single-celled organisms like bacteria, to complex, multicellular organisms, like worms, fish, and humans took around 2.5 billion years, and it only happened once. As Professor Stephen…2 min
How It Works|No. 81What makes a planet habitable?For life to exist on a planet, there’s a bit of a Goldilockssituation. The conditions can’t be too hot or too cold, with somewhere in the region of -15 and 115 degrees Celsius being about right. Within this range, liquid water can exist, and therefore, in theory, so can life.In order to be at this optimum temperature, a planet must be the right distance from its host star. This is known as a habitable zone, and lies closer to smaller, cooler stars than large, hot ones. If the habitable zone is too close to a star, stellar flares can destroy the planet’s atmosphere, which is needed to keep it warm and protect it from radiation and meteorites. To maintain an atmosphere, a planet must be the right mass to have…1 min
How It Works|No. 81Could brown dwarfs just be ejected planets?The idea that brown dwarfs could just be worlds ejected from their home system rather than being failed stars is something that astronomers have considered. It is reasoned that, since planets are made from within a disc, they shouldn’t possess one of their own. However, studying brown dwarf candidates using both ground and space-based telescopes, it has been found – in most cases – that signals detected from these brown dwarfs are similar to those from young stars. This means that brown dwarfs can have discs and therefore formed like stars rather than planets.…1 min
How It Works|No. 81Phone ingredientsThe shiny metal, glass and plastic exteriors of smartphones can contain lots of different elements, including aluminium, magnesium, carbon, and oxygen, but this is just the tip of the iceberg; the circuitry, battery, cameras and speakers contain dozens more. Silicon chips coated with antimony and arsenic sit beside batteries containing lithium and cobalt, and the features that we take for granted, like colour screens, are made possible by rare Earth metals like terbium and europium. Finding uses for all of these elements is a real achievement, but as demand for electronics soars, our limited resources could start to run out.Indium tin oxide filmThree elements – indium, tin and oxygen – make up the conductive film inside touch screens.Aluminosilicate glassThis tough glass is made from a mixture of aluminium, silicon, oxygen…1 min
How It Works|No. 81What is hyperventilation?Also known as over-breathing, hyperventilation is a common side effect of a panic attack or strong feelings of anxiety. When you feel breathless, you breathe more rapidly in an attempt to get more oxygen into your system. However, rather than increasing the levels of oxygen in your blood, this instead causes the carbon dioxide levels to decrease. As a result, the pH of your blood becomes more alkaline, causing the red blood cells to cling on to their oxygen instead of passing it on to the tissue cells as they would normally. This simply exacerbates the problem, causing you to try to breathe in more oxygen and lowering your carbon dioxide levels further.One way to stop the vicious cycle is to breathe into a paper bag, forcing you to re-breathe…1 min
How It Works|No. 81What is a mirage?Stumbling through the scorching desert, you spot something up ahead. A shimmering pool of water appears in the middle of the vast emptiness, but as you scramble towards it for a much-needed drink, it suddenly vanishes into thin air. In actual fact, the pool was an optical illusion created by a cruel trick of the light.Mirages such as this occur when the ground warms up the layer of air above it. They are common above roads and deserts, because tarmac and sand absorb a lot of heat, some of which is transferred into the surrounding air. As the layer of warmer air is less dense than the cold air above it, the change in density causes light to refract, or bend, as it travels through it.However, your brain isn’t aware…1 min
How It Works|No. 81What happens when you eat too much?When you’ve just polished off a plate piled high with food, it can sometimes feel like you’re going to explode. Although it is possible for your stomach to rupture after overeating, your gag reflex is likely to kick in long before you reach that point. The average human stomach can handle between one and one-and-a-half litres of food before getting the urge to throw it back up, but can stretch to accommodate four times that much before a rupture occurs.When you eat a meal that’s high in fat, sugar and carbohydrates, your parasympathetic nervous system tells your body to slow down and focus on digesting the food, causing you to feel lethargic. As the food is digested, cells in your pancreas produce the hormone insulin, which in turn leads to…2 min
How It Works|No. 81ADOPT A STAR WARS DROIDPrice: £129.99 / $149.99 Web: www.sphero.comOf the many toys inspired by the new Star Wars movie, Sphero’s mini replica of the BB-8 droid is certainly the most adorable. This cute cousin of R2-D2 connects to an accompanying app via Bluetooth, so you can control it with your smart device. You can design a route for BB-8 to patrol autonomously or give it voice commands to follow. For example, saying “it’s a trap” will cause BB-8 to panic and roll away. The more you play, the more BB-8’s actions and attitudes will evolve. Eventually it will recognise your voice, respond to your commands in different ways and become your loyal companion. What’s more, you can use BB-8 to send and view holographic messages for a truly futuristic experience.Behind the scenes of…1 min
How It Works|No. 81FOAM FIREPOWERPrice: £89.99 / $99.99 Web: www.nerf.hasbro.comGetting your hands on a Nerf gun is the best way to launch a full-scale attack on your friends or family without causing any casualties. While the foam bullets are enough to send your enemy running for cover, you can rest safe in the knowledge that they won’t leave any scars – at least not physical ones.Nerf guns used to require exhausting pump-action, but modern versions are simpler to operate and can hold multiple bullets so you don’t have to keep reloading. The Nerf N-Strike Elite Rhino Fire Blaster features two separate barrels, each capable of holding 25 foam darts. Its immense firepower means you can hit targets from up to 27 metres away and motorised firing lets you control the rate of fire. The…1 min
How It Works|No. 81ADD SOME AI TO YOUR RACINGPrice: £149.99 / $149.99Web: www.anki.comTrack-based racing games are making a comeback thanks to the latest technological advancements, and Anki Overdrive is one of the new players on the starting grid. The kit includes a series of track pieces that can be snapped together with magnets to create eight different layouts. The cars wirelessly connect to your smart device and a free app lets you control the acceleration, but they can navigate the track by themselves. Each vehicle has an onboard computer and a camera that scans the track 500 times per second to identify its position and anticipate corners or opponents. Up to four players can race at once, or you can battle Anki’s artificially intelligent Commanders instead. You can even fire virtual weapons to slow down your opponent, like…1 min
How It Works|No. 81How to tunnel through anythingExcavating a tunnel is a complicated and potentially dangerous procedure, depending on the methods used and the type of ground being dug through. Tunnel-boring machines (TBMs) help to make the entire process safer and more efficient, and they are able to tackle tough terrain such as rock, which would be all but impossible to dig through by hand.These enormous contraptions are fitted with cutting wheels, which are pressed against the rock and rip it apart as they spin. When the head turns, it slices through the rock and reduces it to rubble. This waste is dumped onto a conveyor belt, which transports it to the machine’s rear where it can be loaded onto a truck and removed. To make sure the machine doesn’t stray off course, two drills protrude from…3 min
How It Works|No. 81Mapping the ocean floorMultibeam sonar (sound navigation and ranging) uses sound waves to calculate the depth of water. A transmitter on the bottom of the vessel fires numerous pulses of sound, called ‘pings’, towards the seafloor, and once the sound waves hit something solid they’re reflected back up to the receiver. The faster the pulses travel back to the boat, the smaller the distance they’ve travelled and therefore the shallower the depth of the water below.Working in conjunction with this is a system called side scan sonar. Rather than firing pulses straight down, this transmitter emits sound waves in all directions below the surface. The reflected sound waves help to build a more comprehensive picture of the ocean floor, covering a distance of 100 metres.Specialist computer software compiles the readings from both systems,…1 min
How It Works|No. 81Hurricane formation1 Cloud formationOver warm, tropical waters, seawater begins to evaporate. As it rises, it cools to rapidly form clouds. Cooler air from the surrounding area rushes in to replace the warm air, which then warms up and rises again, causing updrafts.2 Rotation beginsThe warm air continues to rise, cool and suck in more air from the surroundings below, gaining energy. As the Earth rotates, the clouds start to spin too. A hurricane is formed once wind speeds reach 120km/h.3 Mature stormWarm, moist air continues to rise from the ocean and forms clouds in bands around the eye of the storm. Cool, dry air sinks through the eye and also flows out between the cloud bands at the edges of the storm.…1 min
How It Works|No. 81Butterfly wings under the microscopeIn the rainforests of South America, the blue morpho butterfly can often be seen glimmering in the sunlight with its wings changing from brilliant turquoise to electric blue as they flutter. This clever trick is used by many species of butterfly and moth, and is a result of the insect’s incredible wing structure.A butterfly’s wings are covered in several layers of tiny scales, which give them their colourful patterns in two different ways. Some scales contain a chemical pigment that reflects just one wavelength of light, creating one unchanging colour. However, some butterflies also have transparent scales that cause iridescence. As light hits the top layer of these scales, some wavelengths are reflected straight away while others pass through and are reflected by the next layers. If the two wavelengths…1 min
How It Works|No. 81Fuel of the futureReports indicate that roughly 1.2 billion vehicles occupy our roads, and this number is constantly on the rise. By the year 2035, this figure is expected to reach two billion. As traditional sources of fuel start to dwindle and prices keep on rising, it’s imperative that we find alternative fuels.Although there is no shortage of options, we are still searching for one breakthrough energy source that can bear the brunt of our requirements. Solar power, biofuels, wind and ethanol have all been suggested, but among the most viable replacements for petrol and diesel is hydrogen. It’s the most abundant element in the universe and is environmentally friendly, as burning it produces water and heat, both of which can be recycled. The problem is that getting it into a form where…2 min
How It Works|No. 81Boeing’s eco technologyThe ecoDemonstrator 757With active flow control, Boeing’s smaller vertical tail provides excellent stability and directional controlActuatorsA series of tiny actuators are located along most of the length of the tail, releasing air through exit nozzles at high speed.Exit nozzlesWhen the air is expelled, it creates the same side force during take-off and landing as a larger vertical tail does.RudderHeat exchangerLocated under the plane, this sucks in air and sends it to the actuators.Testing the systemTo test the system’s efficiency, Boeing fitted the tail with numerous instruments to measure the flow of air.StabiliserA passenger plane such as the Boeing 747 burns around four litres of fuel a second, which equates to 150,000 litres over a ten-hour flight. With roughly 100,000 commercial flights departing each day, airlines are keen to boost fuel…1 min
How It Works|No. 81The Super Yacht SubExploring the oceansSee the features that help the submarine to function underwaterSafetyThe safety buoy is automatically released when the sub dives, marking its position to anyone at the surface.Single lifting pointThe sub can be lifted from the top using only one cable, making it easy to retrieve from the water and return to the yacht’s garage.Underwater visibilityThe sub’s viewing window is made from acrylic, which withstands 3,600 tons of pressure when the vehicle dives to 300 metres.ThrustersFour thrusters allow the sub to move in all directions while underwater.PowerThe lithium-ion battery provides 21.6 kilowatt-hours of power, allowing the sub to dive for up to six hours on a single charge.ControlsOperated mainly by the handheld controller, all other controls are kept away from the front to leave the underwater view unobstructed.The Super…2 min
How It Works|No. 81THE MARTIN JETPACKJetpack anatomySee the clever design that keeps the gadget airborne and safeBuilt-in safetyThe parachute system automatically deploys if the engine fails, allowing the aircraft to slowly return to the ground.In-flight controlsTwo joysticks and a touchscreen control the aircraft; if the pilot releases these it will automatically hover at its current altitude.Taking offThe aircraft takes off and lands vertically, much like a helicopter.Pilot protectionThe roll bar and arm restraints help to keep the pilot safe; the aircraft’s structure adds additional protection from the rear and sides.Carbon structureThe jetpack’s central beam is made from carbon fibre with a foam core, while the fuel tank is encased in Kevlar and a fuel-resistant resin.Fan propulsionTwo carbon fibre fan ducts provide thrust, drawing air in through the top, where it’s accelerated by the rotors and…2 min
How It Works|No. 81Inside a torture chamberTorture has been used as a method of punishment and interrogation for centuries, with the ancient Greeks and Romans regularly torturing criminals as part of their justice system. However, by the Middle Ages torture had become particularly prevalent, especially in response to crimes of treason. If you had been disloyal to the sovereign and your country, a whole plethora of horrifying torture devices awaited you.Torture was usually conducted in secret, with most medieval castles featuring an underground dungeon in which these diabolical deeds took place. A great deal of ingenuity and artistic skill went into developing instruments that would inflict the maximum amount of pain. Often simply threatening to use one on a person was enough to get them to confess, while others would quickly give in after seeing it…4 min
How It Works|No. 81How were Anderson shelters built?Even before the outbreak of war in 1939 and the Blitz that followed, the British government realised the nation was vulnerable to air raid attacks. Free to those who earned less than £250 ($378) a year, the Anderson shelter was designed to protect up to six people from bombings, and was made of curved, corrugated steel sheets.First, a shallow pit was dug in the ground, then the six steel sides were put in place and bolted together. Once complete, the shelter’s roof was covered in a thick layer of earth. By the end of World War II, more than 3.5 million of these structures had been erected throughout the UK.Due to their corrugation, these shelters stood up to nearby bomb blasts surprisingly well. The explosive force of a bomb would…2 min
How It Works|No. 81MEET THE EXPERTSLuis VillazonLuis has a degree in zoology from Oxford and another in real-time computing. He builds steampunk gizmos and electronic gadgets, and his articles about science, tech and nature have been published around the world.Laura MearsLaura studied biomedical science at King’s College London and has a master’s from Cambridge. She escaped the lab to pursue a career in science communication and also develops educational video games.Alexandra CheungHaving earned degrees from the University of Nottingham and Imperial College London, Alex has worked at many prestigious institutions, including CERN, London’s Science Museum and the Institute of Physics.Ella CarterFascinated by the underwater realm, Ella studied marine biology and oceanography at university before embarking upon a career in publishing. She adores the natural world and loves researching and writing about the wonders within.Shanna FreemanShanna…1 min
How It Works|No. 81BOOK REVIEWSBreaking The Chains Of Gravity: The Story of Spaceflight before NASAExplore the thrilling history that led to Neil Armstrong’s small stepAuthor: Amy Shira TeitelPublisher: Bloomsbury SigmaPrice: £16.99 / $27Release date: Out nowThe US national space agency has a long and famous history peppered with world-changing breakthroughs, but the story of what came before it is not so familiar. By the time NASA was established by President Eisenhower in 1958, non-Soviet scientists had already made great progress in building rockets to travel beyond Earth’s atmosphere.In her debut book, Amy Shira Teitel tells the story of the characters, rivalries and scientific breakthroughs that led to the agency’s creation, and does so in a wonderfully engaging way. In the prologue, Teitel writes: “Spaceflight is part of our shared human history and shouldn’t be…6 min
How It Works|No. 81Make a foldable egg1 Remove the raw eggThe first step is to remove the raw egg without causing too much damage to the internal membrane. Hold the egg over a bowl, and use something sharp like a skewer to make a hole in either end. The hole at the bottom should be larger. Then break up the egg’s yolk and use a drinking straw to blow through the small hole; the air pressure should expel the liquid egg. Run a little water through the empty egg to make sure it’s clean.2 Dissolve the shellTo remove the eggshell, you’ll need to dissolve it in vinegar. Pour roughly 400 millilitres of vinegar into a glass jug and add the egg. Using your fingers, gently push the egg under the liquid until all of the air…2 min
How It Works|No. 81How did our oceans form?Dear HIW,I have a question for you to answer. How did Earth’s huge oceans form millions of years ago? Thanks, Noor Al-ossmi (aged 9)Today, water covers roughly 71 per cent of the Earth’s surface. It’s thought that Earth’s oceans have been present for roughly four billion years, driving the climate and controlling the evolution of life itself. When our planet was born around 4.5 billion years ago it was a molten rock, far too hot for liquid water to exist on its surface. When the first volcanoes began to erupt they released steam, which formed enormous clouds as the planet began to cool. These clouds are thought to have given the planet its first rainy season; precipitation poured from the sky, possibly for thousands of years, delivering some of Earth’s…3 min
How It Works|No. 81Meet the experts…Laura MearsScience expert Laura gives you a lesson in the fundamental building blocks of the universe – the elements. Did you know that we’re all made of star dust? Find out more amazing facts like this on page 30.Gemma LavenderThis month, All About Space magazine’s Gemma tells us how gravity wells keep the planets in orbit, and how we distinguish between stars and planets.Ella CarterIn between taking her border collie Dexter to agility classes, Ella found time to explain how there have come to be so many breeds of dog (page 62), and give us a round up of the most extreme oceans on Earth.Alexandra CheungAre snakes immune to their own venom? Why do women live longer than men? Alex answers some of your burning questions in this issue’s Brain…1 min
How It Works|No. 81The real-life tractor beamThey have long been used in science fiction to pluck humans from the Earth, but now tractor beams have finally become a reality. Scientists at the University of Bristol have invented a device that can pick up and move objects using sound. Using an array of 64 miniature loudspeakers, the device produces high-pitch and high-intensity sound waves that create a force field around an object to keep it in place. By carefully controlling the output of the loudspeakers, the shape of the acoustic force field can then be manipulated to either move or rotate the object.…1 min
How It Works|No. 81THE STORY OF HUMANSHominin family treeGet acquainted with your long lost cousinsAustralopithecus groupSpecies in this group were equally at home walking on two legs or climbing in trees.hom*o groupThis group – which includes modern humans – had large brains, used tools, and was the first to expand beyond Africa.Paranthropus groupCharacterised by their large teeth and powerful jaws, this group fed on tough plant matter during difficult times.Ardipithecus groupOur closest link to other primates, these earliest humans evolved in Africa and took the first tentative steps to walking upright.Palaeoanthropologists reconstruct the evolution of human species by studying their fossilised remainsIn the iconic March of Progressillustration, human evolution is depicted as a single flowing process that begins with apes and ends with our modern selves. But in truth, our evolutionary past is a messier affair,…1 min
How It Works|No. 81HUMAN HISTORY TIMELINE6-8 MILLION YEARS AGODivergence of human and chimpanzee lineages from the last common ancestor.6-7 MILLION YEARS AGOSahelanthropus tchadensis develops small canines, distinguishing it from apes.6 MILLION YEARS AGOSahelanthropus walks upright, becoming the first bipedal hominin.2-6 MILLION YEARS AGOBrain size undergoes a slow, steady increase as bipedalism and tool use proliferate.4 MILLION YEARS AGOHuman ancestors are mostly bipedal, but are also still comfortable in trees.3-3.5 MILLION YEARS AGOMany species of Australopithecus thrive within Africa.3.3 MILLION YEARS AGOInfant growth rate slows and starts to resemble that of modern humans.2.8 MILLION YEARS AGOThe earliest known member of the hom*o genus – hom*o habilis – emerges in Africa.2.6 MILLION YEARS AGOThe dawn of technology: hammerstones and cores are used to produce sharp flakes.2.6 MILLION YEARS AGOStone tools give access to new foods, including meat…2 min
How It Works|No. 81How we conquered the planetIn our brief 200,000 years on Earth, hom*o sapiens – unlike any of the human species before us – has managed to colonise the entire globe. But we were not the first to venture beyond Africa. Some of our ancestors took those initial steps at least 1.8 million years ago.The first waves of adventurous hominins travelled east towards Asia, before eventually moving west and north into Europe. hom*o erectus spread throughout Asia, reaching as far south as Java, and hom*o heidelbergensis dispersed through both Asia and Europe.As for our own species, all evidence suggests that we lived in Africa for the first 100,000 years of our 200,000-year existence. After a shaky first migratory attempt, it was another 30,000 years before we struck out again. This time marked the start of…4 min
How It Works|No. 81A thriving speciesThe moment when modern humans transitioned from merely surviving to convincingly thriving happened somewhere around 12,000 years ago, coinciding with the advent of agriculture.For millions of years leading up to this time, early and modern humans alike were preoccupied with foraging, hunting and scavenging food. But once we discovered that we could control the growth and breeding of certain plants and animals, we quickly became farmers and herders.As these practices gained momentum, settlements began to form around them. These grew from villages to towns to cities as food became more plentiful. Within them, the human population began to explode, eventually reaching levels where we were unlikely to be wiped out by anything less than a global catastrophe.Cities became the focus of social interaction, idea exchange and technological innovation. The ballooning…1 min
How It Works|No. 81The search for intelligent lifeWe have begun searching for signs of life in our own Solar System, but the search for intelligent life is different. We can reach our neighbouring planets and moons with probes and rovers, allowing us to sample the atmosphere and the soil directly to find even the tiniest traces of biological materials. But to find out whether there is life beyond the reaches of our spacecraft, scientists must take a different approach. We cannot yet tell whether primitive life exists on distant planets, but if advanced, intelligent civilisations have developed the technology to send messages out into space, we might be able to detect their signals.…1 min
How It Works|No. 81SIGNS OF LIFEThe search for intelligent life focuses less on what aliens might be made of, and more on how they might communicate. Distant planets in other star systems are too far away to see clearly, but we can pick up signals released into space. But how do we know what to listen for? We live in the same universe, so we share the same fundamental physics and chemistry. Communications have to reach over vast distances, travelling through the dust and gas of the universe without being lost or degraded, and scientists think that it is most likely that they would be sent using radio waves or powerful optical lasers.Listening out for every single signal across the entire electromagnetic spectrum would be impossible, so to detect these communications, we need to try…2 min
How It Works|No. 81Hunting for planetsTo identify Earth-like planets elsewhere in the galaxy, scientists watch out for their shadows as they pass across their parent stars, but the closest stars are so bright that their planets are a real challenge to detect. The private aerospace and defence company Northrop Grumman are developing a screen known as the ‘Starshade’, which will fly in between orbiting telescopes and the stars they are trying to image. The petal shape should block out most of the star’s light, letting only the reflected light from the planets pass through.1 StarNearby Sun-like stars are so bright that their planets become invisible.2 ExoplanetPlanets in the ‘habitable zone’ are particularly hard to see.3 StarshadeThe centre of the Starshade blocks the bright light of the star.4 Space telescopeThe Starshade will orbit alongside a space…1 min
How It Works|No. 81Are we being buzzed?Fast radio bursts (FRBs) are brief, high-energy pulses of electromagnetic waves that have been appearing in scientific data gathered at the Parkes Telescope since the early 2000s. The bursts contain high and low frequency wavelengths, which travel at different speeds through space, and the delay between the arrival of the highest and lowest frequency waves can be used to calculate the distance to the source. Strangely, the ten FRBs all had delay times nearly divisible by 187.5. There is no natural object known to be able to do this, leading scientists to speculate about a possible alien source. However, other signals, called perytons, have since been found to have much more local origins – scientists discovered that they could produce the same interference patterns by opening the door of the…1 min
How It Works|No. 81What is a gravitational well?While we are all familiar with gravity being the force that causes a dropped phone to clatter to the ground, Albert Einstein was the first to describe gravity as what happens when space is warped around a mass, creating a dip called a gravitational well. To better understand this, think of a large rubber sheet, held taut. The sheet acts as an analogy for space-time. Then take a bowling ball – which will act as a planet in our example – and place it on the rubber sheet. The sheet will dip and bend with the mass of the ball, forming a concave shape – the gravity well.Now put a marble on the sheet, which represents a smaller object in space such as a comet or an asteroid. It creates…2 min
How It Works|No. 81YOUR GUIDE TO THE ELEMENTSAll of the 118 elements in the periodic table are made from the same three key ingredients – protons, neutrons and electrons. The protons and neutrons make up the nucleus at the centre of each atom, while the electrons whizz around the outside and make chemical bonds with other atoms. The identity of each atom is determined by the number of protons in its nucleus, known as the atomic number. Hydrogen has one, helium has two, lithium three, and so on. The periodic table lists the elements in this order.Protons are positively charged, while electrons are negatively charged; an atom will have an equal number of each. The electrons are arranged in ‘shells’ around the nucleus. Each row of the periodic table represents a new layer of electron shells, and…3 min
How It Works|No. 81YOU ARE MADE OF STARDUSTHydrogen is the smallest element, and formed in vast quantities after the Big Bang, along with a less plentiful supply of helium, and even smaller amounts of lithium and beryllium. But making the heavier elements required more energy. Hydrogen and helium gas clumped together to form clouds, and these clouds collapsed to form stars with enough heat and pressure to trigger nuclear fusion; inside the stars, the nuclei of hydrogen atoms slammed together, fusing to form helium.As the stars aged, the helium atoms started to create even heavier elements, including carbon, nitrogen and oxygen. Depending on the mass of the star, this process sometimes continued, producing the nuclei of most of the elements up to number 26, iron. After this critical point, fusion reactions stop releasing energy. When stars run…3 min
How It Works|No. 81How does moisturiser work?The job of moisturisers is to trap and replenish the moisture that evaporates from the upper epidermis layer of your skin. They fall into three main categories, but most products are made of a combination of ingredients from some or all of these. The most basic are occlusives such as Vaseline, which contain molecules that repel water to create a barrier over the skin that stops evaporation.The second kind, known as emollients, are absorbed into the skin instead of sitting on top of it. They fill the gaps left in the epidermis when fatty proteins that join together dead skin cells are broken down by a lack of moisture in the air. By plugging these gaps they stop any moisture from evaporating and smooth the skin to make it soft…1 min
How It Works|No. 81Why do balloons go bang?When you stick a pin in an inflated balloon, all of the tension of the stretched rubber is transferred to the edges of the pierced hole. As this force is too much for the hole to take, it quickly expands until the entire balloon has been ripped apart.This happens faster than the speed of sound, so as the high pressure air inside the balloon is released, it expands to create a pressure wave that breaks the sound barrier. Our ears pick up this wave as sound, and so the noise you hear is actually a sonic boom, similar to that created by a supersonic aircraft flying across the sky.If you want to avoid making everyone in the vicinity jump out of their skin, then simply place a piece of sticky…1 min
How It Works|No. 81STEP ON A HOVERBOARDPrice: £499.99 (approx $755)Web: www.futurewheels.comOkay, so it’s not technically a hoverboard, but the self-balancing SmartGlider is the closest you’re going to get to Marty McFly’s transport of choice for now. Although the two wheels are kept firmly on the ground, you’ll feel like you’re gliding through the air – once you get the hang of it that is. Placing your feet on the board activates a touch-sensitive motor that drives you forward. Gyroscopes then help keep you balanced and as you shift your weight, they move the board in the corresponding direction. After a bit of practice – the manufacturer recommends an hour’s worth – you’ll be able to get from A to B with minimal effort. The electronic board takes around one to two hours to fully charge and…1 min
How It Works|No. 81UPGRADE YOUR PAPER PLANEPrice: £39.99 / $49.99 Web: www.poweruptoys.comThat’s right, even the humble paper aeroplane has gone high-tech! Power Up 3.0 lets you fit an electric motor and rudder to your folded creation, so you can steer it using a free mobile app. The kit also comes with several templates to help you get folding, but here’s our favourite configuration…How to fold your PowerUp 3.01 Fold in one cornerTake an A4 piece of paper or card and create a crease down the middle. Then fold one corner into the middle so that it lines up with the crease.2 Fold the other cornerRepeat step 1 with the other corner so that they meet along the middle crease, forming the tip of your plane. Press down the folded edges so they stay in place.3 Reinforce…1 min
How It Works|No. 81What makes smart bulbs so clever?Smart lighting is growing in popularity, offering a quick and inexpensive way of customising a home. Most smart lighting systems are fitted with light emitting diode (LED) bulbs. When you connect an LED to a source of electricity, the current flows through the diode and excites the electrons within it, forcing them to release photons of light.Philips Hue smart bulbs contain a special semiconductor material that only partially conducts current, and are designed so that the flow of current running through the LEDs can be varied. A range of colours can shine out of the bulb, depending on the strength of the current.Smart lighting is more than just an aesthetic gadget; it offers a number of practical benefits too. It’s highly efficient, as it allows you to control exactly when…1 min
How It Works|No. 81Bone-conducting headphonesOne major flaw with regular headphones is that you can’t hear anything but the music being blasted into your ears. While this might be a blessing when sitting on a crowded train or bus, it also means that you won’t hear a car come speeding towards you if you step into the road. Bone conduction offers a clever solution, sending the music straight to your inner ear so your outer ear remains free to pick up sounds from your surroundings.The futuristic looking Batband is a device that uses this bone conducting technology. Its spring steel frame grips around the back of your head and can be paired with your smartphone or music player via Bluetooth. When you play music, three transducers – two on the sides of your head and…2 min
How It Works|No. 81Arc welding versus ultrasonic weldingWelding has advanced dramatically since the days of pounding two pieces of heated metal together. There are now many different methods used in electronics and medical devices, as well as in the metal structures this process was originally designed for.Arc welding uses an electric arc to melt two metals together. First, a grounding wire must be clamped to the welding material, which is connected to an AC/DC power supply. Another wire, called the electrode lead, is then placed on the metal’s surface, and when this is lifted off, an electrical arc is created. It looks like small sparks, but is actually a continuous discharge of plasma produced when gas is broken down by electricity.When the arc is generated, it produces extremely high temperatures that melt the two pieces of metal,…2 min
How It Works|No. 81Hydrothermal ventsOften forming at mid-ocean ridges where tectonic activity is high, hydrothermal vents are cracks and fissures in the Earth’s crust where super-heated water escapes into the ocean. The temperature of this water can reach 400 degrees Celsius, but doesn’t boil due to the extreme pressure.Hydrothermal vents can support vast communities of life. The organisms that live around them use chemosynthesis – as opposed to photosynthesis – to survive. The primary producers of a chemosynthetic food chain are microbes that use the chemicals expelled by the vents as the basis to create energy, akin to how plants on land use sunlight.…1 min
How It Works|No. 81The diversity of dogsWolves and wild dogsOur four-legged friends evolved from wolves as a result of domestication and selective breeding. Although domestic dogs still show traits of their ancestry, such as marking territory and burying belongings, they are now a different species to their wild relatives.TerriersThese dogs are often (but not always) small, wire-haired and feisty, and were originally bred as vermin-catchers in the 19th century. The word terrier comes from the Latin word ‘terre’, meaning ‘earth’, and refers to their tendency to dive into burrows, barking furiously to flush out rodents, foxes, badgers and more.NorthernNorthern dog breeds hail from bitterly cold countries. The likes of Siberian huskies, Alaskan malamutes and Norwegian elkhounds are muscular breeds with thick fur. They were bred for hunting, herding and snow-sled pulling as well as for companionship…3 min
How It Works|No. 81Evaporation powerThe moisture millTake a look inside the ingenious evaporation engine1 EvaporationWhen the water in the chamber walls evaporates, it creates a humid environment.2 Bacterial sporesThe tiny tape-mounted spores within the chamber absorb the moisture and expand, lengthening the tape and therefore changing its centre of mass.3 Creating torqueThe lengthened tape creates an imbalance, shifting the centre of mass away from the axis to create torque – a force that causes rotation.4 Spinning wheelAs the wheel turns it moves the rubber band, which rotates the vehicle’s front wheels and propels the car forward.5 Water releasedOnce the bacterial spores reach the dry air they release their water and shrink, and the centre of mass reverts to its original position.Evaporation is a fundamental part of the water cycle, where liquid turns into a…2 min
How It Works|No. 81Hall thruster enginesRegular rocket engines work by the principle of Newton’s third law of motion: every action has an equal and opposite reaction. By firing exhaust gases out from the rocket engine’s nozzle, a reactive force is produced that pushes the rocket in the opposite direction. This method has been used since the earliest space flights, but is inefficient and not a feasible method of powering long-distance trips.That’s why NASA are working on a propulsion system that could overcome these problems. Engineers from the Glenn Research Center have developed a Hall thruster, a type of ion engine that will use ten times less fuel than a chemical rocket equivalent. It works by electrically charging the propellant (usually xenon gas), which then gets accelerated in an electric field so it is fired out…1 min
How It Works|No. 81Writing in the skyBy adding a paraffin-based oil into a plane’s exhaust, thick, visible, white smoke is produced that can be used to graffiti the sky. This technique is mainly used for advertising, acting as an enormous, temporary billboard.When the pilot is ready to start writing, they flip a switch in the co*ckpit, opening the reservoir containing the paraffin oil and releasing it into the plane’s exhaust. The incredibly hot temperatures instantly vaporise the fluid, producing white smoke that pours from outlets at both ends of the plane. Once released, the smoke expands to a width of over 20 metres, making each letter visible from up to 50 kilometres away.Pilots have to execute precise manoeuvres in small, powerful planes to write the letters accurately, while pressed into their seat by strong G-forces. The…1 min
How It Works|No. 81History's most gruesome’s inventionsFrom the wheel to the World Wide Web, we have invented some truly ground-breaking things during our time on Earth. Yet throughout history, inventors have also been known to put their skills to use in horrifying ways, creating contraptions that have caused unimaginable suffering.In the past, if you committed a terrible crime, a punishment much worse than a long prison sentence awaited you. From boiling people alive to sawing them in half, execution methods were often developed to be as cruel as possible. These gruesome events were usually carried out in public to deter others from following in the footsteps of the accused.Even if you weren’t sentenced to death, there were plenty of ghastly implements that could be used to torture you instead. Typically used to extract a confession or…3 min
How It Works|No. 81Miserable medicineTerrifying treatmentsHorrifying medical instruments and procedures from the pastTrepanningUsed to treat:Headaches, seizures, mental disordersTrepanning is one of the oldest surgical practices in history, with evidence dating back to prehistoric times. It involves drilling a hole in the skull to relieve pressure.Dental keyUsed to treat:ToothacheTo remove a damaged tooth, the claw end of the dental key was clamped around it and then the entire device was turned like a key in a lock to lift it out of the gum.Artificial leechUsed to treat:Various infections and diseasesUsed for bloodletting a popular treatment for a wide range of medical conditions, this device mimicked the action of reel leeches, with rotating blades that cut into the skin whilst a vacuum in the cylinder sucked out the blood.LithotomeUsed to treat:Bladder stonesWith the patient still awake,…2 min
How It Works|No. 81Who invented the toilet?Contrary to popular belief, the first man to invent the flushing toilet was not Thomas Crapper. It was actually a member of Queen Elizabeth I’s court, Sir John Harrington.First described in 1596, Harrington’s device was composed of a deep oval bowl, which was made waterproof with a mixture of pitch, resin and wax. This was flushed with water released from a cistern above the toilet, on the next floor or in the roof.In spite of this breakthrough, it took more than 200 years for the flushing toilet to catch on. Advances in technology that accompanied the Industrial Revolution helped to spur on the toilet’s development, as did the invention of the ‘S-trap’ in 1775. Still present in modern toilets, this S-shaped pipe allows standing water to seal off the bowl,…1 min
How It Works|No. 81BRAIN DUMPWould headlights work when driving at light speed?Alfred CrossIt’s impossible for a car to travel at light speed. Einstein’s special theory of relativity states that an object with mass cannot move at the speed of light. Your car would have to accelerate with an infinite amount of force in order to reach close to light speed, which of course couldn’t ever happen. If we assume that a car could travel at almost the speed of light, though, the driver would not notice a difference because they would not be moving relative to the headlights. An analogy to help understand this is that fire engine drivers don’t notice the pitch of their sirens changing as they are travelling, because relative to the source of the sound, they aren’t moving. SFWhy do…13 min
