On board an aircraft carrier

Our article on how to take off and land on an aircraft carrier back in issue 5 was so popular we’ve gone a step further to bring you an insight to life on board the magnificent Nimitz Class carrier USS Abraham Lincoln. Discover what happens on this floating island – from the nuclear power at its heart to the aircraft stowed in the hangars and on the flightdeck.

Titan – the wonder of Saturn’s largest moon revealed

We take a look at the fascinating Titan and learn about the unusual activity that takes place on and below the surface of this, the most Earth-like of all the bodies in our solar system. A real eye-opener, this article explains the mystical methane rain that falls slowly through Titan’s dense atmosphere.

iPhone 4

Our cover feature comes complete with all you need to know about Apple’s latest smartphone. Read on to discover just what this anticipated update is capable of and follow our step-by-step guide to making your first FaceTime video call. We explain iOS4, the three-axis gyroscope and the A4 chip plus much more. And of course, all the gory insides are dissected for your viewing pleasure.

Cleaning up an oil spill

The headline-dominating disaster in the Gulf of Mexico has captured the attention of the world, and the grave situation has affected both the environment and the economy. Discover what is being done to seal the leak and clean up the mess in this feature that explores the techniques for ridding the world’s oceans of slicked oil.

Megastructures

Your jaw will drop when you consider the mammoth feats of engineering behind Earth’s biggest man-made structures. Learn how the longest bridge in the world was constructed, find out how the longest ever road tunnel beat the world record by seven kilometers, discover the pendulum swinging at the heart of the famous Taipai 101 skyscraper, plus loads more unbelievable megastructure facts.

King of the swingers

This bumper guide to our closest relatives reveals the lives and anatomy of the highly specialised and highly intelligent primates. See what happens when a group of chimps gives chase, learn about their amazing gripping hands and prehensile tails, and find out what is putting these incredible creatures at risk.

PLUS: today’s cutting-edge car technology, hangovers, baggage handling, adrenaline, in-flight refuelling, air bags, Facebook’s new privacy settings, blood vessels, the T-34 tank, mammoths, ion engines, dry cleaning, the Mars 500 mission, the Mavizen TTX02 electric superbike, air conditioning, IMAX cinemas, power drills, tree rings, starfish anatomy, the history of duelling, amphibian skin, beehives, Leyden jars, heatwaves, and much more besides.

Look out for How It Works issue 10 when it hits the shops 15 July – earlier if you’re a subscriber. And don’t forget, if you can’t get to the shops, you can also download the awesome PixelMag on your shiny new iPad, or your old iPhone or iPod touch. Just visit the Apple App Store and search for How It Works, then download any issue for just £1.79. Check it out today!

The human body requires a number of vitamins and minerals to function properly. Examples include vitamin A, which is required by the retina in the eye, vitamin D which is required for maintaining healthy bones, and vitamin E which helps form red blood cells.
A diet lacking enough essential vitamins is likely to result in vitamin deficiency syndromes. Scurvy, rickets and beriberi are examples of such syndromes.
Eating a healthy, balanced diet typically provides enough vitamins for the body’s needs. Some people, however, like to take multivitamins to ensure that they receive their required amounts. Multivitamins contain a range of different vitamins and minerals usually including magnesium, zinc, vitamin C and vitamin A in varying amounts. After ingestion the multivitamin’s casing is broken down by the gut, the vitamins are absorbed and pass to where they are needed.
Care must be taken not to take too many vitamins. In 2004, the Danish government was so worried about people overdosing on vitamins that it banned Kellogg’s breakfast cereals which had been enriched with extra vitamins! The effectiveness of multivitamins is often disputed by scientists. Most experts agree that the best and safest way to ensure that you receive all the vitamins you need is to have a healthy and balanced diet.

This is a widespread myth and has some variations, sometimes the spoon must be silver other times the material doesn’t matter. It’s unlikely that the spoon makes any difference. There is some suggestion that the metal will absorb more heat energy and keep the air in the bottle colder, which may aid the preservation of the sparkle in your wine.
The temperature is certainly important though. Colder liquids can hold more gas, in the case of sparkling wines, carbon dioxide (CO2). This is because the higher the temperature the more energy the atoms or molecules in the liquid and gas have, making it more likely that the gas molecules can escape the liquid. So the lower the temperature the lower the energy and less CO2 can escape. So putting the wine in the fridge is the most beneficial thing. The best thing to do, though, is finish the bottle!

Ants, like all insects, don’t have lungs, breathing through tiny holes in their sides – spiracles – one pair per segment. These lead into a network of tiny tubes – tracheae – permeating their entire body, getting narrower and narrower, supplying air (and hence oxygen), right to the tissues that use it, rather than using blood to transport it like us. Though they can open and close their spiracles, they have little ability to pump air in and out, which happens just through general movement. It’s this inability that stops insects getting as big as us, with our ultra-efficient lungs and blood.

Microwaves are a kind of electromagnetic wave and as such can create electric currents in metals. Many of the microwaves are actually reflected by the metal and can reflect back onto the magnetron – the part of the oven that produces the microwaves, which can overheat and become damaged. When microwaves hit metal surfaces, free electrons (negatively charged particles) in the metal start to move around and the movement of this charge is how an electric current arises. Some of these electrons will move too much and will actually jump from the metal to the air which becomes temporarily ionised (charged). This can result in a phenomenon called ‘arcing’ where an electric spark similar to a flash of lightning is produced. Thin metal such as rims of mugs, produce more resistance to an electric current than thick metal, and so can become very hot. If sufficiently thin the metal can become so hot that it actually melts!

Diet cola is actually not a modified form of the original cola recipe but is produced from an entirely different recipe. Original cola contains the sugar sucrose or high-fructose corn syrup depending on the country of origin, which both have a high calorific value. Diet cola, on the other hand, contains a blend of sweeteners – including aspartame and sucralose – which is 200 and 600 times sweeter that regular sugar respectively. This means that much smaller quantities of sweeteners can be used to achieve the same level of sugariness without adding lots of calories compared to just 1.3 calories found in a can of diet cola.

Don’t miss issue 9, which is packed full of articles to really feed your brain. Kicking off is an exhilarating four-pager on roller coasters and the science of thrills, and if you’re trying to decide between iPhone and Android, we’ve put them head to head in a useful buyer’s guide centred on how they work. Another close-to-home feature looks at superfast broadband and how new technology is capable of providing faster, more efficient internet services. An excellent feature on the nervous system reveals what keeps our bodies functioning and communicating properly, but if that doesn’t get your synapses firing we have another biology article that explains what heart bypass surgery entails. A mighty four-page article explaining the nature of explosives will keep you hooked while a hot and steamy spread on geysers will enlighten you on these spectacular geological features. Never get caught short during an avalanche as we explain what they are and how to survive them. If you want to learn how the most deadly chopper in the world works, check out our teardown of the Apache Longbow. Meanwhile, for information on the engineers attempting to break the land speed record take a look at our article on the race to 1,000mph. In space, we have a complete guide to Mercury, a look inside Jupiter’s moon Io, details about the Cassini-Huygens mission and how that’s working, plus a huge feature exploring our search for new Earth-like planets in the galaxy. Discover how the Greeks took to the seas and did battle in huge warships called Triremes, find out why the Tower of Pisa leans and how the west was won in our Wild West weapons article as well as a look at how the Battle of Britain was fought.

We also answer questions such as why can crocodiles snap their mouths so powerfully but not open them with the same force, how does bulletproof glass work, how do placebos work, what are allergies, how do hummingbirds beat their wings up to 80 times a second, how is it possible to rain frogs, how do volcanoes work, what is a Wankel engine, and what are solar flares?

So don’t miss out, get your copy of How It Works issue 9, available in all good newsagents and supermarkets. And if you want to enjoy the magazine on your iPad, iPhone, or iPod touch, simply visit the Apple App Store and search for How It Works, then download it for just £1.79. Check it out today!

Superfast broadband

So, we all rely on broadband for our insatiable internet habits, and as with many things in life, we’re also demanding a faster, more efficient service. In this month’s cover feature you’ll learn how broadband speeds are being maximised. You can also find out what superfast broadband can be used for, and with the help of some very snazzy infographics discover the cities currently enjoying the fastest services around the world.

Human nervous system

Another electrifying human science article this issue comes in the form of a complete guide to the human nervous system. The feature reveals the nature of our bodies’ built-in autopilot functions, as well as the anatomy of a nerve and the reason behind why our arm tingles if we knock our funny bone.

Volcanic eruptions

Thousands of air passengers around the world were left stranded or unable to travel due to the ash from an Icelandic volcano. Discover the amazing geography of these sleeping geological giants in our massive volcanoes feature.

The world’s deadliest chopper

Take a look inside the AH-64D Apache Longbow, the next generation of multi-mission attack helicopter that’s changing the face of modern warfare. We dissect the vehicle and explain its components in true How It Works style.

The race to 1,000mph

Three teams of world-class engineers from different corners of the globe – Great Britain, the United States and Australia – are all trying to smash the 1,000mph barrier and break the land speed record with their superfast rocket cars. We get under the hood of each vehicle and discover exactly how they will achieve their high-speed dreams.

Searching for new Earths

Focusing far beyond the solar system, this space special takes a look at how we’re searching for Earth-like planets capable of supporting human life. Discover the incredible techniques space agencies are employing to find extrasolar bodies, as well as info on where we’re focusing our search, not to mention the exciting results of recent missions.

There’s oodles more great stuff to discover this issue, including how the Battle of Britain was fought, why hummingbirds can beat their wings so quickly, the causes allergies, how a heart bypass could save your life, what a spark plug does exactly, an explanation of solar flares, why the Tower of Pisa leans, the difference between fog, mist and haze, what’s inside a worm, the reason crocodiles can snap their jaws shut with great power but can’t open them with the same force, causes of avalanches, a complete guide to the planet Mercury, inside a Greek warship and so much more great stuff that we simply can’t be bothered to list.

Look out for How It Works issue 9 when it hits the shops this Thursday, 17 June – earlier if you’re a subscriber. And don’t forget, if you can’t get to the shops, you can also download the awesome PixelMag on your shiny new iPad, or your old iPhone or iPod Touch. Just visit the Apple App Store and search for How It Works, then download any issue for just £1.79. Check it out today!

The eardrum is a thin membrane that helps to transmit sound. Air pressure is exerted on both sides of the eardrum; with the surrounding atmosphere pressure pushing it inwards while air being delivered via a tube between the back of your nose and the eardrum pushes it outwards. This narrow tube is called the Eustachian tube, when you swallow the tube opens and a small bubble of air is able to move causing a ‘pop’.
Rapid altitude changes in plnaes make the ‘pop’ much more noticeable due to bigger differences in pressure. Air pressure decreases as a plane ascends; hence air must exit the Eustachian tubes to equalise these pressures, again causing a ‘pop’. Conversely, as a plane descends, the air pressure starts to increase; therefore the Eustacahian tubes must open to allow through more air in order to equalise the pressure again, causing another ‘pop’. So there’s no need to worry, although popping ears are uncomfortable they’re part of a completely natural process.

The mass of an object is the amount of matter it contains; the weight of an object is the measure of the force exerted on that object by gravity.

Weight (newtons) = mass (kilograms) x gravity

For example, your mass on Earth and on the moon will be the same, but your weight will change as the force due to gravity on the Earth is greater that that on the moon.