Table of contents for Issue 182 in How It Works

“This ingenious system begins before your birth and continues to make changes to your body throughout your entire life” We all know that there isn’t much we can do to influence the way we grow physically. Some people are just born to be bigger than others. Size is also the most recognisable form of a hormone imbalance, whether a person produces too much growth hormone and towers above even the tallest basketball players, or they don’t produce enough and are much smaller than average. But a lot of us don’t appreciate how much control hormones have over our energy levels, our moods and the way we think, our appetite and almost every facet of us as a person. This issue we’re exploring the endocrine system, the many hormone-producing glands that…

Up to half of the black holes that devour stars ‘burp up’ their stellar remains years later. Astronomers made the discovery after spending years watching black holes involved in tidal disruption events (TDEs). TDEs occur when stars venture too close to black holes. The immense gravity of these cosmic monsters exerts incredible tidal forces that stretch and squeeze the stars in a process called spaghettification. The unfortunate stars involved in TDEs are ripped apart or ‘unravelled’ in a matter of hours, signalled by a powerful flash of electromagnetic radiation in visible light. Some of the stellar material of the destroyed star is flung away from the black hole, while the rest forms a thin frisbee-like structure around it called an accretion disc, which gradually feeds that material to the black…

If you’ve ever wondered why you never seem to get any taller while your friends are regularly growing out of their clothes, why your skin always breaks out in spots when you want to look your best and why you’re always hungry no matter how much you eat, you need look no further than your hormones. But what exactly are hormones, and why do they seem intent on interfering in your life? In simple terms, hormones are chemical molecules that act like an internal postal service. These specialised proteins carry vital messages around the body via the bloodstream – thanks to the circulatory system and a strong, beating heart – to their target cells, where they give out clear instructions. Different types of hormones will give instructions to entirely different…

1 SHARP SIDE UP The sharp edge of the sword always needs to face upwards, whether it’s placed on a stand or being worn on the body. 2 DISPLAYING INTENTION If the handle, also called the ‘tsuka’, is on the left-hand side of the samurai, it portrays peace, while the right side indicates that the samurai is ready to attack. 3 BOWING OUT Retired samurai had their swords taken away and were required to bow to anyone with one for the rest of their lives. 4 DRAWING RULE If a samurai pulled their katana out of the sheath by at least nine centimetres, this was classed as officially drawing the blade. 5 DYING WITH HONOUR If samurai didn’t abide by the rules, they were ordered to commit seppuku, also called hara-kiri. This was thought…

Alfred Nobel was born on 21 October 1833 in Stockholm, Sweden, to engineer Immanuel Nobel and his wife Andriette. In 1842, Alfred and his mother moved to St Petersburg to join his father, who had moved to Russia to pursue a slew of successful engineering ventures, including providing materials for Russian military underwater mines. Once there, Alfred received a first-class education from private educators and showed an aptitude for the sciences, languages and literature. To discourage a growing interest in poetry and literature, Alfred’s father sent him to travel across Europe and the US in the early 1850s to further his studies in chemical engineering. While in France, Alfred spent time at the Paris laboratory of chemist Théophile-Jules Pelouze beside an Italian chemist named Ascanio Sorero, who had been working…

1 LANDMINES Landmines come in all different shapes and sizes, some made from metal and others made from plastic. 2 MAGNETIC FIELD The sweeper passes an electrical current through a coil to create an electromagnetic field, which penetrates the ground. 3 EDDY CURRENTS When a conducting metal object such as a landmine is exposed to an electromagnetic field, electrical currents called eddy currents form. 4 RETURNING MAGNETIC FIELDS The eddy current generated in the landmine creates its own weak electromagnetic field, which the sweeper can detect, revealing the presence of a metal object. 5 SENDING WAVES A transmitter in the sweeper emits radar pulses deep into the ground. 6 RETURNING WAVES The radar pulses bounce off objects within the ground and are detected by a receiver, which uses this to paint…

1 JACKFRUIT (ARTOCARPUS HETEROPHYLLUS) Found in tropical and subtropical parts of the world, the jackfruit has a rotten-onion scent, but with a pleasant hint of pineapple and banana. 2 CEMPEDAK (ARTOCARPUS INTEGER) As with many fruits, the smell they emit intensifies the riper they get. For cempedak fruit, an already-potent aroma turns to the smell of ammonia when overripe. 3 WOOD-APPLE (LIMONIA ACIDISSIMA) In the forests of Southern India you might find the interesting aroma of wood-apples, which has been described as a combination of fruity raisins and blue cheese. 4 MARANG (ARTOCARPUS ODORATISSIMUS) The presence of a marang fruit will quickly fill a room with an odour reminiscent of gasoline, despite having a fruity pear-and-pineapple taste. 5 PEDALAI (ARTOCARPUS SERICICARPUS) Found in Borneo and the Philippines, this melt-in-your-mouth fruit grows with an unusual…

1 VITAMIN A Vitamin A can be stored in the body for later use, so isn’t essential in daily tablets. 2 VITAMIN B1 This is also called thiamine. Too much sugar, caffeine and alcohol can cause a B1 deficiency. 3 VITAMIN B2 When taken as a tablet, B2 is best absorbed between meals. 4 VITAMIN B5. Some people with high cholesterol take B5 tablets. 5 VITAMIN B6 Maintains levels of certain proteins in the brain. B6 is prescribed to patients who suffer from seizures. 6 VITAMIN B9 Also called folic acid, B9 produces genetic material and impacts mental health. 7 VITAMIN C Taking vitamin C with iron tablets helps more iron to be absorbed. 8 VITAMIN D People often take vitamin D supplements to protect against the bone-weakening disease osteoporosis.…

Henna is a type of dye that’s derived from the leaves of the henna tree. When left on the skin, henna paste temporarily stains the skin a reddish-orange colour. It’s used around the world to decorate the skin with intricate patterns and body art, known as mehndi, for celebrations such as weddings and birthdays. you Unprocessed, the leaves of the henna tree won’t transfer a dye. To produce the dye, the dried leaves must first be pulverised into a powder and mixed with a combination of oils or an acidic solution such as lemon juice. The resulting paste, known as red henna, can then be applied to the skin or hair to alter its colour. The change in colour is due to dye molecules in the henna tree’s leaves called…

1 SIZABLE SPACE BEAM is 16 cubic metres, but is launched at one-tenth this size. 2 ACCOMMODATION The module can house up to six people at a time. They move around by holding onto these bars. 3 BULLETPROOF WINDOWS There are four windows to provide external views. These protect against space debris contact. 4 LABORATORY Plants can be grown for food or experimentation. 5 ENGINE The modules have engines at the rear that can be fired to keep the vessel in orbit. 6 CLOTH WALLS This soft, black wall can be put up in different sections of the module for privacy. The white box to its right is the toilet. 7 SOLAR PANELS The habitat’s electricity is generated by these solar panels. 8 AIR CIRCULATION The air supply from the…

Whether they’re used for recreation or for business, boats are often W limited to the perimeters of coastlines. However, thousands of inland waterways and hundreds of shipping canals are hidden away from the oceans. These human-made transport systems enable vessels to move between two large bodies of water, or create a network of routes within a city. The world’s waterways are direct courses for shipping vessels that navigate between continents, greatly reducing the mileage covered and reducing shipping times by up to ten days per journey. But not all of the benefits that stem from canals impact the boats that use them. Canals can be multipurpose and are a main source of hydroelectric power generation. This involves installing turbines along canals that are turned by the flow of the water…

In 2022, the Netherlands-based automotive company Lightyear premiered the first commercial solar-powered car, the Lightyear 0. Similar to the solar panels that are installed on rooftops, the Lightyear 0 uses Vehicle-Integrated Photovoltaics (VIPV) to transform the energy of sunlight into electrical power. The power is then fed into a 60-kilowatt-hour battery and transformed to turn the wheels’ electrical motors and power the car’s internal systems. This also means that while the car is out in the Sun, it continually recharges its battery. But the car isn’t completely powered by the Sun yet – traditional electric charging is required when the car has used more power than the VIPV can produce. One hour of solar charging produces enough power for a maximum range of around six miles. Lightyear is one among…

Could we terraform Mars? Many scientists believe that it’s possible to make Mars habitable, but there’s a lot of work to do. First, we need a new atmosphere. On Mars it’s about 95 per cent carbon dioxide, and very thin in comparison to Earth’s. We also need liquid water, since Mars is currently a desert planet. Since it’s further from the Sun, on average Mars has a temperature measuring about -60 degrees Celsius, so we’d definitely need more heat. Finally, Mars would need a magnetic field to hold in that atmosphere, heat and water, as well as protect us from solar radiation. We could help along some of these issues by creating a greenhouse effect on Mars – it’s how Earth is warmed, as sunlight is reflected off the planet’s…

BOATS! (AND OTHER THINGS THAT FLOAT) THIS BOOK MIGHT FLOAT YOUR BOAT AUTHOR BRYONY DAVIES ILLUSTRATOR MARIA BRZOZOWSKA PUBLISHER WELBACK PUBLISHING PRICE £12.99 /$14.95 RELEASE OUT NOW Humans have been using boats for thousands of years, in every culture that has had access to a coastline as far back as recorded history goes and for all manner of purposes – like the Vikings, who were famous for using their boats to plunder and conquer, or the Pacific Island nations who literally expanded their horizons and explored new islands. And even though in the last century or so we’ve found faster or more efficient ways of travelling above and below the water’s surface, there are more boats floating on waterways around the world today than there have ever been before. They…

BEES CAN RECOGNISE THE FACES OF THEIR BEEKEEPERS $2 MILLION A DAY GPS is free, but costs nearly $1 billion a year to run EIGHT HOURS The first photograph in 1826 took one-third of a day to expose 34 Some species of leech have more than 30 brains 1974 The first barcode was scanned 22 years after it was invented, in 1952 International Space Station astronauts change their underwear every four days 1,760 In 2010, the US Air Force built a supercomputer out of hundreds of Playstation 3 consoles 15 METRES Rats can fall from a five-storey building without injury IN 1760, A FRENCH COLLEGE CLASSIFIED THE BEAVER AS A FISH 225 TO 230 Mathematician 98 Terence Tao has the highest IQ in the world…

The pituitary gland is also known as the master gland since it oversees all other hormonal instructions. Hormones from the hypothalamus enter the hypophyseal portal, which connects the hypothalamus to the pituitary gland. A network of capillaries carry the hormones to the anterior lobe of the pituitary, where they start or stop the production of pituitary hormones. These hormones stimulate various endocrine glands that control a multitude of bodily functions. The thyroid-stimulating hormone, for example, instigates parts of the body’s metabolism such as temperature control, while the human growth hormone sends instructions to the skeleton, the liver and the muscles. Two hormones, oxytocin and vasopressin, are sent to the posterior pituitary lobe. Vasopressin, or antidiuretic hormone (ADH), controls water loss in the body, while oxytocin is vitally important during childbirth.…

DIABETES Diabetes occurs when the body is unable to produce the hormone insulin or use it effectively. This can lead to dangerously high blood sugar levels. Diabetes can occur in two forms: type 1 is an autoimmune condition that tends to develop in childhood or teen years. The body’s immune system attacks cells in the pancreas, stopping the production of insulin. With type 2 diabetes, the body becomes resistant to insulin, causing a spike in blood sugar levels. Unlike type 1 diabetes, type 2 tends to occur in adults and can sometimes be brought about by eating too many sugary foods. Both type 1 and type 2 can be caused by a combination of genetic and environmental factors. Symptoms can include feeling exceptionally thirsty, having blurry vision, needing to urinate…

Whether you’re boiling a kettle for your mid-morning brew, catching W up on your favourite television show or turning the radiators up a notch to escape colder weather, many of the utilities inside your home use precious energy. In this modern age, it’s near-impossible to live without consuming energy, but what we can control is where we source this from. Fossil fuels such as coal, gas and oil were some of the earliest sources of energy. Since ancient times, burning coal was used to heat homes as it burned for longer periods than wood. Since then, humans have continued to mine coal. It’s a primary source of fuel for electricity production, while other fossil fuels like gas are used to heat water in our homes. As the world’s population has…

The world is full of interesting and delicious fruits. From sour grapes to giant pumpkins, there are around 2,000 different types of fruits growing around the globe. In botanical terms, a fruit is a ripened ovary, a reproductive structure that bears the plant’s ovule, also known as the seeds. Once a plant is pollinated, fruits begin to emerge from the fertilised flower and develop, mature and ripen, by which time the encapsulated seeds are ready for dispersal. When it comes to identifying fruits, there are a whole host of subcategories they fall into. However, they largely sit within one of three categories: simple, aggregate and multiple. Simple fruits include the majority of fruits, such as stone fruits, pome and berries. Their anatomy is typically divided into three parts; the exocarp,…

Alzheimer’s disease is the most common form of dementia, a degenerative disease that leads to the loss of cognitive function, such as memory or critical thinking. It’s estimated that at least 55 million people around the world are living with Alzheimer’s disease or another form of dementia. Scientists have discovered that two proteins are involved in the development of Alzheimer’s, called amyloid and tau. In a healthy brain, amyloid proteins are broken down and removed by enzymes. However, for someone with Alzheimer’s, these proteins are allowed to build up and form clumps called plaques. Amyloid plaques can then lodge themselves between brain cells called neurons and inhibit or disrupt their function. Tau proteins, on the other hand, group together in what’s called a ‘neurofibrillary tangle’ within neurons. Within a healthy…

1 HENNA PASTE Henna is applied directly to the skin so the lawsone molecules can penetrate skin cells and bind to keratin molecules. 2 STRATUM CORNEUM This is the outermost layer of the skin’s epidermis, where keratin-carrying skin cells called keratinocytes rapidly reproduce. 3 DEEP SATURATION When applied to the thickest layers of skin, found on the back or on the hands, lawsone can penetrate up to 30 cell layers deep. 4 GRANULAR LAYER Henna doesn’t penetrate into the granular layer, which acts as the skin’s impermeable barrier against water. 5 BASAL LAYER The innermost layers of the skin, where new protective keratinocytes are produced.…

SPACE X Elon Musk Musk grew up in South Africa and later acquired Canadian citizenship, moving to America when he was 18 years old. He is best known as the founder of car manufacturer Tesla, electronic payment company PayPal and private aerospace company SpaceX. Due to his strong belief that humans need to start living on planets other than Earth to survive, Musk launched SpaceX in 2002. The goal was to make rockets that were more affordable than those before it. SpaceX’s Crew Dragon spacecraft took its first crewed flight to space in May 2022. Astronauts Doug Hurley and Robert Behnken were launched to the International Space Station, which orbits at an altitude of around 248 miles. The bell-shaped capsule can carry seven people at a time to and from Earth…

plus A FREE BOOK BUNDLE WORTH £42.96 How It Works is the action-packed science and technology magazine bursting with exciting information about the world around us. We stand for clarity, authority and intelligence, through expert explanations and breathtaking illustrations. It’s the ideal Christmas gift to feed those keen and hungry minds close to you. Great reasons to subscribe • Free book bundle worth £42.96 • Save 40% on the cover price • Pay just £43.99 every 12 months • Delivered direct to your door • The thoughtful gift that keeps on giving Treat yourself or gift a magazine subscription today How It Works: Space How It Works: Book of Amazing Technology How It Works: The Story of Humans How It Works: Science of Habits SUBSCRIBE NOW ONLINE magazinesdirect.com/HIW182 PHONE 0330…

ENDOCRINE OR EXOCRINE While both the endocrine and exocrine systems produce and secrete hormones, the difference between them lies in the way they distribute hormones around the body. Unlike the endocrine system, the exocrine system doesn’t rely on the bloodstream to transport hormones. It works outside of the bloodstream, planting the hormones directly onto an epithelial surface. This might be the outer layer of the skin – known as the epidermis – the lining of your intestines or the lining of your respiratory tract. The exocrine system achieves this by delivering hormones via a duct. These ducts can come in many different shapes and sizes, from simple to tubular, and can be individual or clumped together. 1 THE PITUITARY GLAND 2 PINEAL The pineal gland is located deep within the…

Samurai warriors ruled Japan from 1185 to 1868, replacing the S government and introducing immense discipline and loyalty to the military in the absence of a police force. To be a samurai, warriors needed to abide by the ethic code of ‘bushidō’, which translates to ‘the way of the warrior’. Included in this code were eight virtues that the samurai lived by: justice, courage, mercy, respect, honesty, honour, loyalty and self-control. While these sound like positive traits, samurai took bushidō to the extreme. Samurai couldn’t show any sign that they were afraid of death – a mistake on the battlefield might force a samurai to honour his name and end his own life. This was viewed as a much more desirable outcome than losing their samurai status. The most important…

1 MARU This is the most common blade, only made from one type of high-carbon steel. It is the simplest and easiest to manufacture. 2 KŌBUSE Shigane steel is used for the core and hagane steel for the exterior. Hagane is a strong and durable steel, while shigane adds flexibility. 3 HONSANMAI This is similar to a kōbuse blade, but has the addition of a third folded steel type at the sides, called kawagane. 4 SHIHŌZUME Shihōzume blades have hard steel positioned at both edges of the blade. This adds strength and prevents blade breakage. 5 MAKURI Makuri means ‘rolling’, and this type of blade consists of a durable steel rolled in hard steel. 6 WARIHA TETSU The hard tip of the blade is inserted into the softer steel, rather…

They’re usually found planted beneath the surfaces of fields, forests and pathways in countries in conflict or still affected by the remnants of war: landmines are some of the most sneaky and dangerous weapons around. From triggering ground-based blasts to igniting a fireball at head height, these explosives have been designed to take out their target in many different ways. Most landmines work using a metal or plastic casing that’s filled with an explosive charge. When a person’s foot or the caterpillar tracks of a tank hit a pressure plate at the top of the landmine, it triggers the explosion. As well as being a tool used in active warfare, landmines are often forgotten about by those who plant them. Due to their robust design, they can remain active for…

Tibbles was a tabby cat with blood on his claws. As the legend goes, he was the feline companion of a lonely lighthouse keeper posted at Stephens Island, a remote rock off the New Zealand coast. Not long after their arrival in 1894, Tibbles the cat started to bring his owner gifts: the remains of small birds not yet known to science. By the time naturalists could review the bodies and confirm that the Stephens Island wren was indeed a brand-new species, Tibbles had already wiped them all out. Like so many good yarns, Tibbles’ tale is likely to be apocryphal. But what is suspected is that the Stephens Island wren was once widespread throughout mainland New Zealand. It was a nocturnal flightless bird that had evolved in an ecosystem…

The science of photographic film developing works similarly to how our eyes see and process images. Our ability to see comes from the interaction of our eyes with tiny particles of light called photons. When light is emitted, photons bounce off the objects around us, head into our eyes and onto photoreceptor cells. These cells send signals to the brain, which then builds an image of what we’ve seen. The developing of photographic film begins the instant a photo is taken. When a camera’s shutter ‘eyelid’ opens, light is temporarily allowed to enter the camera through the lens and hit the photosensitive film. The light leaves an imprint on the film that can be interpreted and printed by a photographer in a darkroom. Photographic film has been in use since…

As we better understand the micro and macro nutrient requirements of our bodies, it can make us question whether we are getting everything we need through our meal choices alone. Many of us opt to take a daily vitamin tablet to help get the right balance. Specific vitamin supplements can be a vital addition to someone’s diet if they are suffering from a deficiency. Some of the most common deficiencies include a lack of vitamin D, due to a minimal selection of foods containing enough of it; iron deficiency, which can be caused by heavy menstrual periods, and vitamin B12, which keeps your nerve cells signalling efficiently. Just because you’re swallowing a measured dose of a vitamin doesn’t mean that it is all being absorbed. To make sure your vitamin…

SMALLSATS, BIG IMPACT Peter Beck When he was a child growing up in Invercargill, New Zealand, Beck already knew he wanted to build rockets. Despite most people gaining access to space through a university degree, Beck chose not to go to university when he saw no courses that would teach him what he wanted to know: how to build a rocket engine. He had envisioned his future career but aged 18 in 1995, New Zealand had no space industry. Instead, Beck worked in a local tool factory so that he had access to its machines. His passion for space gained Beck his first investor, internet entrepreneur Mark Rocket, in 2007. Together they launched Rocket Lab, a small satellite-launching company that now has the highest launch success rate of any rocket…

1 THE SUN IS AN AVERAGE STAR Our Sun is a middle-aged star that doesn’t seem remarkable in any way. It’s not particularly large or small – red giant stars are hundreds of times larger and red dwarfs are much smaller. The Sun seems to sit nicely in the middle of this range of sizes. Stars are not only classified by their size, though. The light they emit is also used, as this is easily measured. The Sun is a G-type star and has a surface temperature of around 6,000 Kelvin. This is where we start to see that this is not an average star, after all. In fact, 95 per cent of all the other stars that we see in the night sky are cooler than our Sun. Our star…

1 ATLANTIC OCEAN At one entrance to the Panama Canal is Cristóbal Port, which has 3,700 metres of berthing space. 2 GATUN LOCKS These locks take up 1.8 miles of the canal and consist of three large chambers, each big enough to house the Titanic. 3 GATUN LAKE This 89-square-mile body of water is an artificial lake made by damming the Chagres River. Its water is used to fill the locks during dry periods. 4 LAKE ALAJUELA At 76 metres above sea level, this lake serves as a backup reservoir for the canal. LOCK UP The physics behind uphill travelling on water 1 ENTERING THE CHAMBER At least one gate needs to be closed. The boat enters from the lower section of the canal through the lock’s open gate. 2…

WORTH £300 This month, every How It Works reader has a chance to win a NASA Apollo 15 American Moonphase watch by Xeric Watches. The lunar design celebrates NASA’s triumphant mission to the Moon in 1971. Along with a pair of lunar hands and a luminous glow-in-the dark coating, this watch tracks the Moon’s journey through its 29.5-day cycle For your chance to win, answer the following question: Which of these is not a gland in the human body? A: PITUITARY B: THYROID C: HUMERUS Enter online at howitworksdaily.com and one lucky entrant will win! Terms and Conditions: Competition closes at 00:00 BST on 26 October 2023. By taking part in this competition you agree to be bound by these terms and conditions and the Competition Rules: www.futuretcs.com. Entries must…

The Milky Way has a diameter of approximately 100,000 light years, meaning that it would take light that long to travel from one end to the next. Our Solar System – comprising the Sun, its orbiting planets, comets, asteroids and all kinds of other space bodies – doesn’t have a clear boundary. But if you use the orbit of its furthest known objects – the cloud of comets called the Oort Cloud, much farther from the Sun than Pluto – it’s about two light years. That gives you an idea of how small our Solar System is in comparison to the Milky Way as a whole. WHEN AND WHERE DID PIZZA ORIGINATE? The pizza, as a flat bread, can be linked to ancient times. The ancient Egyptians were expert bread-makers,…