Table of contents for Issue 205 in How It Works

“It’s the microwave afterglow of the Big Bang as it was 380,000 years after the universe was born” The image above is the cosmic microwave background (CMB), taken by the now-decommissioned Planck space telescope over a decade ago. It’s the microwave afterglow of the Big Bang as it was 380,000 years after the universe was born. And if it looks like the noisy grain of a detuned analogue television set, that’s because between channels, those old TVs pick up the CMB signal, along with signals like human radio transmissions and other astronomical phenomena. The CMB itself represents the edge of the observable universe – though not everything that’s in space. In this issue, we’ve tackled a series of compelling space questions, arriving at answers that we think will surprise and…

HESTIA FROM €199 (APPROX. £170 / $234) VAONIS.COM With the help of Hestia, you can turn your smartphone into a smart telescope in minutes. Once your smartphone camera is aligned with Hestia’s ocular eyepiece, you can use Vaonis’ Gravity app to capture different celestial bodies with an additional 25x magnification to your smartphone’s camera. Hestia doesn’t come with the automated movement of a Go-To mount, so manual positioning and focus are required. There are several imaging modes to explore in the Gravity app, including lunar, planetary and solar modes. These modes are set to capture impressive detail, including features such as sunspots. PHOTOPILLS £10.99 / $10.99 (APP STORE) £9.49 / $10.99 (GOOGLE PLAY) PHOTOPILLS.COM For the astrophotographers out there, PhotoPills is the stargazing app that assists you in finding the…

Your eyes are the windows to the world. They mark your point of view, shape your memories and experiences and enhance your understanding of your environment, so keeping them functioning properly is essential to optimising how you sense and interact with everything around you. They can reveal details of the objects you focus on and alert you to danger and events in your peripheral vision. However, not all pairs of eyes are the same. Humans are born with a range of sight abilities, and the best way to assess what treatment is needed for your eyes – if anything – is to check in with an optician. Eyesight professionals analyse the journey of light as it interacts with your eyes. Eyes can’t function without light, which is allowed in so…

When Albert Einstein died, his brain became a scientific curiosity. In the months following the famous physicist’s death in 1955, pathologist Thomas Harvey dissected it into 240 blocks. Over the years, he distributed tissue samples and photos to a select group of scientists and, gradually, little clues to Einstein’s genius emerged. Humanity is utterly fascinated by intellect, and with good reason – a higher IQ is linked to better jobs, income and health, as well as a lower risk of accidents and premature death. In 1904, English psychologist Charles Spearman noticed that high-school grades in different subjects tended to cluster around the same children – those who were good at maths were usually good at English too. He proposed that there was some common factor, or ‘g’, for general intelligence,…

Magma in the snow In February 2025, one of Italy’s best known volcanoes once again began to spew its molten guts. Mount Etna sits on the eastern coast of Sicily, and from time to time ejects molten lava from its caldera, which erupts from a fissure in Earth’s crust around 3,000 metres below sea level. This snowy scene was captured from the nearby town of Adrano, around 50 miles from the mountain. Stealthy seahorses These tiny seahorses clumsily swim around the waters of the Philippines while blending in with their surroundings. Bargibant’s pygmy seahorses have evolved to be perfectly camouflaged against the pink corals and sponges that surround them, keeping them concealed from fishy predators. At less than two centimetres in length, these creatures dine on tiny crustaceans using their…

DID YOU KNOW? Supernovae can be so bright they outshine all the stars in their galaxy for months 1 WHAT’S AT THE EDGE OF THE UNIVERSE? It’s a question that sort of undoes itself when asked. To imply that the universe has an edge would mean that there’s something beyond it. But if we consider the universe to include everything that exists, then it isn’t possible for it to have an ‘edge’. What we know about the universe is that it’s continually expanding from an event known as the Big Bang. Without any boundary or edge, the universe could be one of two things – it’s either infinitely expanding or the universe is finite, but its geometry is causing it to fold back in on itself. Did you know? The…

What started as a cautionary letter from Albert Einstein ended in the detonation of the first nuclear bomb. In the early 1900s, the world of physics was buzzing with a new wave of ‘nuclear’ science following the discovery that atoms could be ‘split’ into smaller elements when they were bombarded by high-energy subatomic particles called neutrons. In 1938, the work of four researchers – Otto Hahn, Fritz Strassmann, Otto Robert Frisch and Lise Meitner – showcased for the first time that bombarding an element called uranium not only split the atom into a lighter element called barium, but also released a significant amount of energy. This reaction came to be known as ‘nuclear fission’. While news of this feat of physics was initially celebrated, two scientists foresaw its overwhelmingly destructive…

Gluten is a combination of two proteins that form in the grains wheat, barley and rye. Because of the widespread use of these grains in food products, such as breads, pasta, pastries, cakes and cereals, gluten makes up a significant part of many people’s diets. Gluten’s structure is stretchy and springy, so it’s often extracted and added to processed food products to give them these textures or hold the other ingredients together. Gluten is a vital ingredient in baking bread. It holds the bread together and traps air in it while it cooks, making it light, chewy and textured. This transformation can be seen almost instantly when making bread dough. As wheat flour contains the essential proteins that make up gluten, when water is added to flour, gluten is produced.…

Sudoku Complete the grid so that each row, column and 3x3 box contains the numbers 1 to 9 EASY MEDIUM HARD Word search Find the following words SPACE NUCLEAR MOON VIDEO DUST SURVIVE GLUTEN BUBBLES EYE GAME TELESCOPE SMART What is it? Hint: All that glitters A Spot the difference See if you can find all six changes between the images below Answers Find the solutions to last issue’s puzzle pages Q1 LITTLE MOUSE Q2 BOA CONSTRICTOR Q3 EMPEROR PENGUIN Q4 ROYAL AIR FORCE Q5 100 Q6 NINTENDO WII What is it? ALLIGATOR Spot the difference QUICKFIRE QUESTIONS Q1 Which animal ‘laughs’ when threatened? ○ Tiger ○ Orangutan ○ Black rat ○ Hyena Q2 When was the periodic table of elements discovered? ○ 1677 ○ 1753 ○ 1821 ○ 1869…

Queen ants chew their own wings off after mating Bats aren’t blind, they just prefer to use echolocation at night 400 GRAMS A newborn human’s brain is around one-quarter the size of an adult’s 40,000 A single queen honey bee can run a hive of thousands 300 METRES Hawaiian volcano Kīlauea’s eruptions can shoot lava three times higher than Big Ben 350 MILLION In just 14 seconds, your body makes more new cells than there are people in the US $2,500 In 1959, the IBM 1401 computer could be rented for ‘just’ a few thousand dollars a month 30,000 CELSIUS Lightning is five times hotter than the Sun’s surface 6.6 MILLION SQUARE MILES Russia makes up 11 per cent of Earth’s total landmass ALL THE OTHER PLANETS IN THE SOLAR…

HEALTH We may finally know how paracetamol works WORDS CLARISSA BRINCAT Acetaminophen is widely used to relieve pain, but exactly how it works has long been a mystery. Now, a new study suggests that a key byproduct of acetaminophen may block pain signals at the nerves before they can reach the brain. Acetaminophen, also called paracetamol, is broken down by the liver into a compound called 4-aminophenol, which travels through the bloodstream to different organs. There, an enzyme links it with a fatty acid to produce AM404. Previous research found that AM404 can act in the central nervous system, the brain and spinal cord. But the new study reveals that AM404 also affects the peripheral nervous system, which is where pain signals originate. “Even though we’ve been using paracetamol for…

Telling the time used to be a lot more complicated than it is now. Today we have 24 one-hour time zones set across the world, and if we move west or east, crossing from one zone to another, we know to set our watches and phones back or forward an hour. But 200 years ago in Britain, before digital timepieces existed, when wristwatches were the preserve of the wealthy and most people told the time by the gong of a church bell or even a sundial, we had local time. The time differences between cities and major settlements were a matter of minutes. For example, Plymouth is around 180 miles west of Greenwich in London, so clocks on the Devon border city were 16 minutes and 30 seconds behind those…

With a bubble wand in hand and lungs full of air, your breath can create a perfectly spherical soap bubble. But why are bubbles this shape, rather than a cube or prism? A bubble is essentially a ball of trapped air from your lungs that has been encased in a thin film. This film is created when soap molecules, also known as surfactant molecules, sandwich water molecules with a type of force applied to liquids called surface tension. This force is responsible for keeping the water molecules strongly attracted to one another. Surface tension also reduces the surface area of a liquid by pulling the molecules together. When this soapy film is filled with your breath, surface tension makes quick work of pulling all the water molecules together, shrinking into…

EXTRACT GLUTEN Discover which flour types contain the most gluten and what it feels like in your hands 1 MEASURE THE FLOUR Measure out one cup of each of the flour types and place them in separate bowls. 2 LABEL THE BOWLS Using sticky notes, label the bowls to show which type is in each one. This is a good idea as the flours will look very similar. 3 ADD WATER Take one bowl and add 1.5 cups of water into the flour. Stir the flour and water with a fork until it eventually forms a rough ball shape. Repeat for each bowl. 4 SPRINKLE A SURFACE Take some more of the flour you are using and sprinkle it over your workspace evenly. This will stop the dough from sticking…