Science Squad An Introduction to STEAM

Science Squad An Introduction to STEAM

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  Written by LisaBurke Consultant Professor Robert Winston Science squad Science squad
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  Contents 4 Introduction 6 Meetthe Science Squad 8 The Universe 10 The Solar System 12 Our super Sun 14 The Earth 16 The Earth’s atmosphere 18 The Moon 20 The water cycle 22 Solids, liquids, and gases 24 The weather 26 Dangerous planet 28 Animals 30 Plants Senior editor Sam Priddy Senior art editor Fiona Macdonald Designer and illustrator Bettina Myklebust Stovne Additional editing Jolyon Goddard,Katy Lennon, MeganWeal,AminaYoussef Managing editor Laura Gilbert Managing art editor Diane Peyton Jones DTP designer Rajesh Singh Jacket designer ElleWard Producer,Pre-Production Rebecca Fallowfield Producer Isabell Schart Creative director Helen Senior Publishing director Sarah Larter Educational consultants Jacqueline Harris, Trent Kirkpatrick First published in Great Britain in 2018 by Dorling Kindersley Limited 80 Strand,London,WC2R 0RL Copyright © 2018 Dorling Kindersley Limited A Penguin Random House Company 10 9 8 7 6 5 4 3 2 1 001–305910–May/2018 All rights reserved. No part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted,in any form,or by any means (electronic,mechanical,photocopying,recording, or otherwise),without the prior written permission of the copyright owner. A CIP catalogue record for this book is available from the British Library. ISBN: 978-0-2413-0185-2 Printed and bound in China AWORLD OF IDEAS: SEE ALLTHERE ISTO KNOW www.dk.com
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  32 Evolution 34 TheArctic food web 36 Ecosystems 38 Inside a rainforest 40 Climate change 42 Microlife 44 The human body 46 Think about it 48 The senses 50 Technology 52 Simple machines 54 Time 56 Measuring 58 Using numbers 60 Materials 62 Building bridges 64 Take to the skies 66 Floating and sinking 68 Friction 70 Electricity 72 The Internet 74 Robots 76 Glossary 78 Index 80 Acknowledgements
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  Introduction This book isabout science and how it’s used. Science is about trying to understand our surroundings – the world and Universe around us and all the things and creatures in it, from atoms to huge mountains, from tiny bacteria to large whales. As we learn more, we find so much that is puzzling. What lies outside the Universe we can see with a telescope, and how does the brain think and feel love?
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  It is importantto know as much about science as we can so that we use our inventions, our technology, wisely. They can be used for the good of everybody, but science used in the wrong way can be harmful. You are fortunate because we now know so much more than when I was a child, and books like this did not exist. Properly used, the knowledge that science brings helps us to be healthier and to live better lives. Professor Robert Winston
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  6 Meet the Science Squad TheScience Squad is made up of different subjects that work together to show you how the world works. Science is all about asking questions and discovering the answers to explain how things work. Technology uses science to create new machines and more effective ways of doing things. Engineering is all about finding and designing solutions to problems – using science, technology, and maths.
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  7 Maths is about numbers, patterns,and problem-solving. Art is all about using your imagination and style to create brilliant new things. We’ll be here to help you with handy tips!
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  8 The Universe The Universe iseverything around us. Some of this we can see, but most we cannot. It is a huge expanse of mainly empty space, with billions of galaxies, each containing millions of stars. The Big Bang Astronomers believe the Universe exploded out of a tiny point about 14 billion years ago. This is known as the Big Bang. Before this, the Universe did not exist. It is still continuing to expand today. There are more stars in the Universe than grains of sand on all of the beaches on Earth. Light travels really fast, but space is so enormous that it takes time to reach us. This means that when we look into the Universe, we are only ever viewing the past! Light travels nearly 10 trillion km (6 million miles) a year. Scientists call this a light year, and use it to measure the huge distances in space.
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  9 Our Solar Systemwas formed billions of years after the Big Bang. The Hubble Telescope travels 600 km (370 miles) above the Earth. It took this photo of the Universe! It can get really cold in space because the stars and galaxies are so spread out. Astronomers are scientists who study space.
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  The Solar System The SolarSystem is made up of our nearest star, the Sun, and everything that orbits, or travels around, it. This include planets, moons, comets, asteroids, smaller rocks, and dust. Our star The Sun is a medium- sized star. The Sun’s powerful force of gravity pulls on the planets, keeping them in orbit around it. Venus has thousands of volcanoes on its surface. Mercury is the smallest planet in the Solar System. It’s a little bigger than our Moon. Earth is the only planet that we know for sure has life on it. Many spacecraft have visited Mars to study its weather, surface, and rocks. The Sun is a kind of star that scientists call a yellow dwarf. Scientists think the asteroid belt contains the leftover rocks from when the planets were formed. Venus Mars A s t e r o i d b e l t Mercury E a r t h Mars is known as the “Red Planet” as its dusty surface contains rust. People have invented ways to study and travel around our Solar System. 10 Su n
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  Milky Way Our SolarSystem is part of a galaxy called the Milky Way. It is spiral in shape and has more than 100 billion stars. Scientists think there is a huge black hole, sucking in dust, gas, and light, at its centre. You are here! Jupiter is by far the largest planet in our Solar System. It is made mostly of gas and has more than 60 moons orbiting it. Neptune is the furthest planet from the Sun, which makes it freezing cold! Saturn has more than 50 moons. It is most famous for its rings, which are made of lumps of ice and rock. The Kuiper belt is a very distant part of the Solar System. It is the home of icy dwarf planets and comets. J u p i t e r Pluto Kuiper belt Satur n Neptune U r a n u s Launched in 1977, the space probe Voyager 2 reached Neptune in 1989. Unlike the other planets, Uranus spins on its side. This might have been caused by a collision with an Earth-sized object. Pluto is the largest dwarf planet in the Kuiper belt. If it was possible, it would take a jumbo jet about 400 years to fly from Earth to Neptune. Jupiter is so huge that all the other planets in the Solar System could fit inside it. 11
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  12 The surface ofthe Sun is a sizzling hot 6,000°C (11,000°F). That’s 30 times hotter than an oven! Our super Sun The Sun is our nearest star and it sits at the centre of our Solar System. It is a massive ball of burning gases, mostly hydrogen and helium, which produces an enormous amount of energy. At the Sun’s core, temperatures soar to around 15 million °C (27 million °F)! Solar flares Gigantic explosions on the Sun’s surface blast energy outwards. These are called solar flares. Sunspots Dark, cooler patches that develop on the Sun’s surface are known as sunspots. They often appear in pairs and last a few weeks.
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  13 Life on Earth Animalsand plants depend on energy from the Sun to survive. Technology, such as solar panels, has been developed to absorb the Sun’s energy and turn it into electricity. Lightning speed Light travels really fast, but it still takes time to get to us on Earth. A light year is the distance a beam of light would travel in one year. Solar prominences Huge eruptions from the Sun’s surface are called solar prominences. They form loops due to the Sun’s invisible magnetic field. It takes eight minutes for the Sun’s light to reach Earth. Solar panels Some sunshine is good for us. We need it to make vitamin D, which helps our bones stay healthy. 8 m inutes Total solar eclipse A total solar eclipse occurs when the Moon passes in front of the Sun and covers its face perfectly. This blocks out most of the light, making it appear as if it is night-time.
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  14 T h e E a r t h p l a n t s a n d a n i m a l s to survive. r i g h t d i s t a n c e f r o m t h e Sun for k n o w n t o c o n t a i n l i f e . It isjust the E a r t h i s o u r h o m e a n d t he only planet Seasons We have different seasons on Earth because the planet is slightly tilted. This means that at different times of the year different parts of the planet are closer to the Sun. Sun rays The middle of the planet, the equator, gets a fairly constant amount of direct sunshine. Earth’s axis is tilted at an angle of 23.5˚. Countries near the equator have a wet and a dry season, rather than spring, summer, autumn, and winter. Summer happens in the northern half of the world when that part is tilted towards the Sun.
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  15 Stardust Everything on Earthis made from materials that were created when dying stars exploded. Even you are made of stardust! Crust Lower Mantle Upper Mantle Outer Core I n ner Co r e Inside the Earth The Earth is made many different layers, a bit like an onion. The rocky outer layer is the crust. The upper and lower mantles consist of hot rock, while the outer and inner cores are hot metal. Oceans make up most of the Earth’s surface, so our planet looks blue from space. The Earth spins around an imaginary line through its middle, called an axis, once a day. This is why we have day and night. It is colder in the winter because the sunlight is weaker. Land takes up about one-third of the Earth’s surface.
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  16 Auroras happen when tinyparticles from the Sun hit particles in our atmosphere. The Earth’s atmosphere The atmosphere is a blanket of gases that surrounds and protects the Earth. It keeps us warm, blocks some of the Sun’s harmful rays, and helps stop space rocks from hitting us. Auroras These dazzling coloured lights dance in the night sky in places close to the North and South Poles. They are also called the northern and southern lights. Meteorites Space rocks that make it through our atmosphere and hit the ground without burning up are called meteorites. Aeroplanes Planes usually cruise at about 9–12 km (6–8 miles) high. There are often strong winds at these heights, which can make flights turbulent, or bumpy. Weather balloon Launched every day, weather balloons help forecasters predict the weather. The balloons carry small tools to measure things, such as air temperature and wind speed. Planes fly high up, where the air is thinner. This means they can travel easier and faster, and burn less fuel.
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  17 Astronauts have flownout several times to service the Hubble Space Telescope. Exosphere Scientists divide our atmosphere into five main layers. The exosphere is the outermost layer before outer space begins. Mesosphere Most space rocks that enter the atmosphere burn up in the mesosphere. The top of this layer is the coldest part of the Earth’s atmosphere. Stratosphere The stratosphere contains the ozone layer. Ozone is a form of oxygen. It stops harmful ultraviolet rays from the Sun reaching the Earth. Troposphere All of our weather happens in the troposphere. It contains most of the air we breathe and a lot of water, including clouds. Thermosphere This layer protects us by absorbing a lot of the dangerous energy from the Sun, such as X-rays. Hubble Space Telescope Launched in 1990, this space telescope travels around the Earth, taking amazing photographs of distant stars and galaxies. International Space Station This space station has a crew of up to six astronauts. Each stays about six months, looking after the station and doing experiments. It orbits the Earth once every 90 minutes. Venus’s atmosphere Venus’s atmosphere contains thick layers of deadly sulphur-containing clouds. Heat from the Sun becomes trapped below these clouds. This makes Venus the hottest planet in the Solar System. Venus’s clouds trap heat below them. The gas carbon dioxide makes up 96.5% of Venus’s atmosphere.
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  18 Apollo 12 Apollo 14 Apollo 11 Apollo 16 First Moon landing Last manned Moonlanding Do you like my space buggy? The proper name for it is a lunar roving vehicle and it runs on batteries. Apollo 17 Apollo 15 T h e M oon Earth. Let’s take a closer look. is orbiting, or travelling around, the The Moon is a small, rocky world that Moon landings Humans first set foot on the Moon in 1969. The flags show where each Moon mission touched down on the surface. Moon c r a t e r 2 1 A p r il 19 7 2 5 F e b r u a r y 1 9 7 1 3 0 J u ly 19 7 1 1 9 N o v e m b e r 1 9 6 9 1 1 D e c e m b e r 1 9 7 2 2 0 J u l y 1 9 6 9
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  19 Orbiting the Earth TheMoon travels around the Earth about once every 27 days. The Moon appears to change shape in the sky depending on which parts of it are lit by the Sun. The Moon The Earth Rocket power To get to the Moon, humans had to first develop a rocket powerful enough to launch the Apollo spacecrafts into space. The heat produced by a rocket could heat 85,000 homes for a day! Rockets travel at about 35,400 kph (22,000 mph). That’s pretty fast! There is no air on the Moon, so astronauts have to wear spacesuits so they can breathe. Ladies and gentlemen, I present the Saturn V rocket! The Saturn V rocket is the largest and most powerful rocket ever built. Apollo spacecraft
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  The water cycle All thewater on Earth moves around in a cycle. It rises into the air as moisture and clouds. Rain and snow bring it back to the Earth. It then flows along rivers into the oceans, and the cycle goes on. Evaporation Oceans, rivers, and lakes are warmed by the Sun. As they heat up, liquid water at the surface turns into water vapour, which is a gas. This process is called evaporation. Clouds As water vapour rises, it cools into tiny liquid droplets, which gather to form clouds. This process is called condensation. Water has been used to transport people and goods for thousands of years. Water droplets freeze into ice crystals in very high clouds. The Sun plays a key part in the water cycle. It heats the Earth, causing liquid water to become gas. 20 Seawater contains minerals, which is why it tastes very salty.
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  Rain and snow Whena cloud holds enough water droplets or ice crystals, it makes rain or snow. This water falls back to Earth. Back to the sea Rainwater flows over and under the Earth, slowly making its way back to the oceans. The water picks up minerals on its journey. Dams are built to break the flow of rivers. We do this to create lakes, generate electricity, or prevent floods. Winter sports such as skiing rely on a good amount of snowfall! Rainwater is almost pure water, except where it has been polluted by fumes from vehicles and factories. Groundwater is water in the soil or rocks in the ground. It may flow in underground rivers. 21
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  22 Liquids If you canpour something, then it’s probably a liquid. Liquids take on the shape of the container they’re in. However, they’re hard to squash down. Solids, liquids, and gases The molecules in a liquid are close but aren’t held together as strongly as in a solid. This lets them move past each other, or flow. Everything around us is a solid, liquid, or gas. They are all made of something we call “matter”. This, in turn, is made up of tiny particles called atoms and molecules.
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  Solids Solids feel firmand are hard to squash. This book is solid, and so are things that you can hold, wear, or sit on. Gases Gases are all around us – the air is made up of gases. A gas will fill any container and can be squashed. Most gases are invisible. Evaporation When they are heated, molecules jump out of liquids and become gas. This is called evaporation. Melting When a solid heats up, its particles vibrate. When it reaches a temperature called the melting point, its particles break free and become liquid. Freezing A liquid freezes to a solid at a temperature called the freezing point. The particles in a solid are packed together so tightly that they make a fixed shape. Gas molecules are spread out and move about very quickly. Condensation When a gas cools, it turns into a liquid. This is condensation. If you breathe out water vapour onto a cold surface, such as a window, it condenses into water droplets. 23
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  The weather The weather affectswhat people do everyday. One of the reasons it happens is because the Sun heats up the air, causing it to move around. This creates lots of different types of weather. Snow When cloud temperatures are 0°C (32°F) or below, water droplets in the clouds freeze. They form delicate ice crystals and fall as snow! Rain Clouds are made up of millions of water droplets that fall as rain when they get too heavy. Rainbows form when it is raining and sunny at the same time! Thunder and lightning Thunderstorms are electrical storms that normally happen in hot, humid weather. Lightning is like a giant electrical spark. Thunder is the sound caused by lightning. Snow chains are put on winter tyres to give vehicles more grip. 24 Snowploughs clear heavy snowfall to make travel easier. Can you paint all the colours of the rainbow?
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  Fog Tiny water dropletshanging in the air create cloud at ground level. This is called fog and it is a form of water vapour. Thick fog can make it hard to see into the distance. Wind Wind is caused by warm air rising and cold air rushing in to take its place. Sun Some parts of the Earth get more sunshine than others. That’s why it’s cold at the North Pole and hot in the Caribbean. Weather satellites Weather satellites help forecasters to see what the weather is doing. This makes it easier to predict how it might move or change in the near future. These satellites watch storms as they move across the Earth. Special instruments help pilots to land planes safely in fog. 25 Large solar panels and batteries power satellites.
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  26 Dangerous planet The top, rockylayer of the Earth is made up of gigantic plates that float on a layer of hot rock. Where these plates meet, earthquakes and volcanoes are common. Earthquakes When plates collide or scrape against each other, pressure builds up. After this pressure is released, shock waves travel through the ground. This is known as an earthquake and it can be very dangerous. Tsunamis Earthquakes happen underwater, too. When they occur, it can cause water levels to rise and create gigantic waves called tsunamis. They travel at great speeds and can cause a lot of destruction. The point on the ground directly above the red dot is the epicentre. This is where the most damage occurs. Earthquake strength is measured using the Richter scale. Over eight on the scale is a very strong earthquake! In places where earthquakes are common, buildings are designed to wobble but not collapse. Seismographs record the movement of the Earth. The red dot is called the hypocentre. This is where an earthquake begins.
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  27 Volcanoes Volcanoes are openingsin the ground where hot, melted rock, called magma, escapes from deep underground. It’s best not to be near a volcano when it’s erupting! A magma chamber is a pool of hot, melted rock. Lava can ooze from cracks in the sides of a volcano. The main vent is the biggest opening for magma to escape. When magma flows out of a volcano it is called lava. A thermometer measures lava temperature, which gets as hot as 700-1,300°C (1,300-2,400°F)! Scientists take measurements of changes in the volcano’s shape, vibrations, and gases to try to predict when the next eruption might be.
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  28 Animals There are millionsof different types of animal in the world. Scientists divide them into two groups – vertebrates and invertebrates. However, all animals have things in common, such as breathing air, moving around to find food, and sensing the world. Vertebrates These animals have a backbone and a skull. A strong skeleton inside their bodies lets them grow larger than invertebrates. Mammals Mammals have hair and are warm-blooded. They give birth to live babies, which they feed with milk. You are a mammal! Birds Birds have feathers, wings, and a hollow skeleton. Most can fly, but some, such as penguins, cannot. Birds lay eggs and are warm-blooded. Reptiles Reptiles have scaly skin and are cold-blooded. Most lay eggs. Apart from snakes, almost all other types of reptile have four legs. Amphibians Amphibians, such as frogs and newts, live in water and on land. They are cold-blooded and have moist skin. Fish Fish live in water, breathe in oxygen using gills, and are cold-blooded. They have fins to help them swim. Cold-blooded animals sunbathe to warm up their bodies. Pandas spend 16 hours each day eating bamboo. Less than 5% of all the different types of animal are vertebrates. There are many, many more types of invertebrate.
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  29 Invertebrates These animals don’thave a backbone, or spine. Some, such as slugs, are soft and squishy. Others, such as insects, have an exoskeleton, which is a kind of shell. Insects Insects have six legs, two antennae, or feelers, on their head, an exoskeleton, and many can fly. There are more than one million known types of insect. Molluscs Molluscs have soft bodies. Many, including snails and clams, have hard shells. Most live in water – for example octopuses – but those living on land must keep damp. Crustaceans Most crustaceans, such as crabs, lobsters, and shrimps, live in or around water. They have hard shells. Arachnids Spiders, ticks, mites, scorpions, and daddy longlegs are all types of arachnid. They all have eight legs. Echinoderms These spiny-skinned animals do not have brains! They include starfish and sea urchins, and live on the ocean floor. If a starfish loses one of its arms, it can grow a new one to replace it! Small and tall Animals come in all shapes and sizes. Some are so small you need a microscope to see them. Bumblebee bats are the smallest mammals, while giraffes are the tallest animals in the world! Octopuses are the cleverest invertebrates. It’s been found that they can solve problems to get food. Paper clip 3.2 cm (1.2 in) Bumblebee bat 4 cm (1.57 in) Giraffe 6 m (20 ft) Adult man 1.7 m (5.8 ft)
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  Plants From daisies topalm trees, there are thousands of different types of plant in the world. They provide us with oxygen to breathe, many kinds of food, and wood to make homes and furniture. Plant parts Many plants are made up of similar parts. They have roots in the soil, strong stems, leaves growing from the stems, and sometimes flowers. Farming Farmers grow crops, such as corn, wheat, fruit, vegetables, and cotton. They give their crops fertilizers, which are extra nutrients, to make them grow bigger and faster. Stem The stem supports the plant, and both water and food travel along it. We get wood from tree stems. Leaves A plant’s leaves absorb sunlight, which is used to make food for the plant. The leaves also release oxygen into the air. Roots The roots anchor the plant and absorb water and nutrients from the soil. Stamens These parts of the flower make a fine powder called pollen. Plants get their energy from sunlight. Engineers and scientists change crops to improve them – for example, so they don’t get diseases. Stigma This part of the flower has a skicky end. It collects pollen to make seeds. 30 Some plants have flowers, some lose their leaves in the winter, and some even eat insects!
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  Insects Insects spread pollenbetween flowers so that they can make seeds. Many flowers attract insects with a sweet liquid called nectar. When they come to drink it, the pollen sticks to them. Fruit Fruit have seeds inside them. When animals eat fruit, the seeds come out in their poo. This way, the seeds are carried to new areas, where they grow into new plants. Butterflies can carry pollen long distances. Bees are the most important pollen carriers. Fungi Mushrooms and toadstools are not plants. They belong to a kingdom of living things called fungi. They feed on living or dead plants and animals and soak up their nutrients. Mushroom 31 Machinery lets farmers plough, sow, or harvest huge fields of crops quickly. Apples, nuts, tomatoes, grapes, cucumbers, and pumpkins are all types of fruit.
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  32 Evolution Over time, animalsand plants change, or adapt, so they can survive in their environment for longer and have more babies. This is called evolution. Evolution isn’t a quick process – it takes millions of years! Pakicetus Pakicetus lived on land, possibly near water. It had four hoofed feet and sharp teeth for chewing flesh or plants. Darwin Charles Darwin was a scientist who studied how animals and plants changed over time. He came up with the theory of evolution to explain what he saw. Short legs and padded feet were perfect for paddling in water. Natural selection means that some living things are better at surviving than others. Whale evolution Incredibly, the ancestors of whales lived on land! Over time, they grew bigger and bigger and moved to different places, including the ocean. Ambulocetus Ambulocetus evolved from pakicetus. It lived in water and hunted like a crocodile. The powerful long tail helped to steer in water. Wide tail 55 million years ago 50 million years ago
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  33 Long, pointed snout Wolf Chihuahua Breeding It’shard to imagine that a chihuahua evolved from a wolf, but it did! Humans breed dogs for herding, security, companionship, and even for their appearance. Palaeontologists are scientists who study fossils – the remains of ancient animals and plants. Bowhead whale By the time the bowhead whale evolved, it had grown enormously in size, with an appetite to match. They feed on a massive 100,000 kg (220,000 lb) of plankton a year! Dorudon Twelve million years later, the front feet had evolved into flippers and had become webbed. Much smaller legs than ambulocetus Bowhead whales can survive for more than 100 years! Giant flippers 38 million years ago Today
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  The Arctic food web Animalsneed food to give them the energy they need to move and think. A food web shows what different animals in a particular place, or habitat, eat – and how they all link together. Polar bear Polar bears are apex predators, which means they eat other animals, such as ringed seals, but no animals eat them. Arctic tern These seabirds catch fish by diving into the water at great speeds. Adults are safe from predators, but their eggs and chicks are not. Killer whale Killer whales hunt in the ocean and also grab unsuspecting seals near the water’s edge. They are apex predators, too. Polar bears have white fur so that they blend into their surroundings. The killer whale is also known as an orca. 34
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  Draw your own Todraw your own food web, start by choosing a habitat, such as a forest or a desert. Now think about what the animals in that habitat eat and show how they link together. Arctic cod These fish are a food source for many marine animals. Arctic cod eat plankton, shrimp, marine worms, and sometimes even each other! Ringed seal This meat-eating animal eats fish, shrimp, and plankton, but is hunted and eaten by polar bears and killer whales. Plankton Tiny drifting animals and plants called plankton are eaten by Arctic cod and coldwater shrimp. Coldwater shrimp Coldwater shrimp live near the ocean floor and mostly eat plankton. They make a tasty snack for seals. Some plankton are so small they can’t be seen with the naked eye. 35 Plant plankton rely on the Sun for energy.
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  36 Ecosystems Plants and animalslive and interact with each other and their surroundings in communities called ecosystems. Ecosystems can be as small as a tree trunk or as large as a rainforest. American desert The deserts of southwest USA are extremely hot but lots of animals and plants live there. Animals avoid the heat of the day by hunting at night, and plants can survive a long time without any rain. The biggest coral reef is the Great Barrier Reef off the coast of eastern Australia. Coyotes survive in many different places because they will eat whatever is available! The organ pipe cactus opens its flowers at night. The great horned owl makes its nests on saguaro cactuses, where its eggs will be safe from predators. The saguaro cactus is the largest cactus in the USA. This rattlesnake will shake the rattle on the end of its tail if it feels threatened. The sharp spines will put off any egg thieves!
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  37 Under the sea Coralreefs are amazing underwater structures formed by living creatures. They grow in warm, shallow waters in tropical regions and are home to a dazzling variety of life. ...while clownfish scare off fish who want to eat the anemone! Reefs are home to all sorts of fish. Golden eagles have incredible eyesight for spotting prey from great distances. The banded sea krait is a type of sea snake. This type of coral is called table coral. Mountains The Himalayan mountain range in Asia is a tough place to live. Animals and plants have to cope with extreme cold, storms, and living at great heights. Mount Everest in the Himalayas is the world’s highest mountain. Wild goats, like this markhor, munch plants and spread seeds in their dung. Pikas are hunted by golden eagles. Snow leopards are incredibly rare. They eat wild sheep and goats. A stinging anemone provides a safe haven for clownfish...
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  38 Inside a rainforest Tropical rainforestsare made up of four different layers. Each one provides a home for different types of animals and plants. Canopy The canopy is a thick layer of treetops that is home to animals, birds, and lots of climbing plants. Understorey Short trees and shrubs provide cover for small animals as well as predators such as jaguars. Forest floor This is the darkest part of the rainforest. It’s muddy and covered in leaves that have fallen from the trees above. Emergent layer The tallest trees can reach heights of up to 55 m (180 ft). That’s a long way up! Tree frogs rarely leave the canopy. Sloths move very slowly. O k a p i P i t c h e r p l a n t
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  39 Sunlight in layers Eachlayer of the rainforest gets different amounts of sunlight. Emergent layer Full sunlight Understorey Sunlight and shade Canopy Lots of sunlight Forest floor Mostly shade Gibbons are a type of ape from Asia. Toucans use their beaks to grab fruit and nuts. Blue morpho butterflies are found in the emergent layer. Chameleons can make their skin change colour! Snakes slither between the layers. This gigantic flower stinks of rotting flesh to attract flies that will spread its pollen. A n teater J a g u a r S c a r l e t macaw The toucan’s beak is so colourful. Why not try to paint a picture of it? Leafcutter ants
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  Polluted planet Fossil fuels,such as oil and coal, are the buried remains of ancient plants and other living things. Burning them releases harmful gases, especially carbon dioxide (CO2 ), into the air. These gases heat up and pollute our planet. 40 Climate change Climate is the general weather conditions over a large area. It changes naturally over long periods of time. However, recently Earth’s climate has been getting warmer faster than usual. Factories Over the last few hundred years, many coal-burning factories were built. They pumped more CO2 into the atmosphere. Chopping down forests Trees soak up CO2 like a big sponge. By chopping down forests for timber or to make farmland, we take away one of the best ways to remove CO2 from the air. Motor vehicles Cars and lorries use diesel and petrol as fuel. These fuels are made from oil. Burning them releases CO2 into the air. Carbon dioxide is called a “greenhouse gas” as it traps the Sun’s energy in our atmosphere, heating the planet.
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  A greener future Scientistsand engineers now look for ways to make energy that do not burn fossil fuels. They are especially interested in energy sources that won’t ever run out, such as wind and sunlight. Flooding Melting Arctic sea ice 41 Wind farms Wind turbines make electricity from wind power rather than by burning fossil fuels. Groups of turbines are called wind farms. Trees Planting trees helps to fight climate change because plants absorb CO2 from the air. They use the carbon to make their own food and grow. Solar panels Solar panels absorb sunlight to make electricity and heat. Electric cars These cars run on rechargeable batteries, rather than petrol. Because of this, they don’t pollute the air with CO2 and other harmful gases. Experts predict that by 2040, one-third of all cars bought will be electric cars. Every tree makes a difference. This little one could live for 200 years! Effects of climate change A warmer climate can lead to extreme weather. Big storms are becoming more common, often causing flooding. Climate change is also melting the sea ice covering the Arctic Ocean.
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  42 Microlife There are billionsof very tiny living things around us, on us, and even inside us! Our eyes can just about see some of this microlife. However, we need to use a microscope to see how amazing they really are. Hair lice These tiny insects live in hair, usually children’s. They bite the scalp to feed on blood. However, apart from causing itching, they are not harmful. Dust mites These blobby creatures eat bits of dead skin found in house dust and mould. They’re very hard to see because they’re tiny and almost see-through. Tardigrades Also called water bears, these little animals live in wet places, such as mud. They are super tough, can survive in space, and can go without food and water for more than 30 years! Hair lice glue their eggs, called nits, to shafts of hair. Dust mites have many little hairs, called setae. Hair lice have two antennae, or feelers, on their heads. Tardigrades have four pairs of chunky legs with tiny claws. Their name means “slow stepper”.
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  43 Viruses Viruses are tinythings that can make people, animals, and plants ill. They enter cells and then make copies of themselves. Flu, colds, and measles are all caused by viruses. Bacteria Bacteria are microscopic living things, made of just one cell each. They are much smaller than the cells that make up our bodies. In fact, our bodies contain billions of bacteria! Some of these bacteria are useful, supplying us with important nutrients. However, others can cause nasty diseases. This bacterium has started to split into two new cells. Plankton Plankton are living things that drift about in oceans, rivers, and lakes. Some are microscopic, or really tiny, but others, such as jellyfish, are much bigger. Many sea and freshwater animals eat plankton.
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  44 The human body An adult human body contains 206 bones, 650 muscles, and trillions of tiny building blocks called cells. Each part of the body has a different job to do, but they all work together to keep the body running smoothly. Organs Our body is made up of lots of different organs. The organs that help us digest food include the stomach, the liver, the intestines, and the kidneys. Even our skin is an organ! X-rays are not just used to look at bones, they also scan luggage at airports. The liver has more than 500 jobs. We wouldn’t be able to survive for more than two days without it! The human body is made up of systems. The nervous system controls how we think, feel, and move, the immune system fights sickness, and the digestive system turns food into energy. Lungs transport oxygen from the air into our bloodstream. Liver Heart Brain Lungs Our supercomputer, the brain, controls our thoughts and actions. The heart pumps blood around our body. K i d n e y s i n t e s t i n e S m a l l S t o m a c h Large intestine
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  45 Bones Newborn babies have more than 300 bones. By the time we reach adulthood, some bones have joined together to make 206 in total. They fit together to form the skeleton, protecting our inner organs and keeping us upright. Muscles Muscles are the stretchy cords connected to our bones that allow us to move. Some muscles work without us having to think about them, while others are controlled by our brain. Skin Skin is the waterproof outer layer that stops us from injuring or infecting our insides. It is the biggest organ in the human body, making up 15% of our weight! Blood The heart pumps blood around our body through tubes called blood vessels. Blood transports oxygen to parts of the body and fights germs. X-rays allow us to see what our bones look like. Veins and arteries are blood vessels that carry blood to and from the heart.
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  46 Two sides The brainhas two sides. The left side controls the right side of our body, while the right side is in charge of the left side of the body! Think about it Your brain may look like a big wobbly ball of jelly, but it works like an amazing supercomputer. It sits in your head and allows you to see, hear, talk, move, feel, think, imagine, and remember. Thinking and personality Speech Memory Hearing Right Left Planning movements Movement You figure out what different sounds are in this part of the brain. This part of your brain is where you keep all of your memories, like the first time you rode a bike or your last birthday party. This part of the brain is in charge of how we move our bodies. It can tell us to walk, run, or dance! The front part of the brain is all about your personality – how you behave, and what you like and don’t like. This part of our brain allows us to speak to each other. The more wrinkly your brain, the smarter you are! ?
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  47 Awareness of space Making images Seeing Emotional understanding Touch Coordination This bitof the brain helps us to move smoothly. It’s useful for things such as walking and writing. The spinal cord carries messages to and from the brain. Every time you touch something a message goes to this part of the brain. Being able to understand our surroundings helps us to make good decisions about how to move around. Understanding emotions, like happiness or sadness, helps us to respond well to other people. Our brain receives information from our eyes and makes sense of what we’re seeing. Artificial intelligence Computers can be taught to think and make decisions like humans. This is called artificial intelligence (AI). Mobile phones use AI to help answer any questions you might have or tell you what’s in your diary. Nervous system We have a huge network of nerves inside us, which link the brain and the spinal cord to the other parts of the body. What’s the weather like today? It’s raining. Take an umbrella!
• 50.
  The senses Our senseslet us understand the world around us. They tell us what’s safe and what’s dangerous, and let us see and hear each other. Special receptors in our bodies help us to sense our world. Sight A lens inside each of our eyes focuses light onto the back of the eye. There, receptors sense brightness and colours. Touch The skin contains many receptors that react when we touch things. Taste Taste buds on the top of the tongue sense five different flavours. These are salty, sweet, sour, bitter, and a savoury flavour called umami. Smell Tiny receptors inside the nose pick up many different odours. Smell is closely linked to the sense of taste. The main senses Sight, smell, touch, taste, and hearing are our five main senses. However, we also have other senses that help us survive. 48
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  Hearing Sounds travel intothe ears and are sensed by receptors in the inner ears, inside our head. The inner ears also give us our sense of balance. Other senses There are many other kinds of receptor in our bodies, checking what’s happening outside and inside us. Heat Receptors in the skin let us feel heat. Needing the toilet Receptors deeper inside our bodies let us know when it’s time to go to the toilet. Pain We have receptors in our bodies that let us feel pain. 49 Echolocation Bats have a special sense called echolocation, which they use to catch flying insects at night. They make calls and listen for echoes as the calls bounce off the insects. This tells the bats exactly where the insects are. In a similar way, submarines use technology called SONAR to find other objects under the sea. Bat Submarine A human eye contains more than 125 million receptors.
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  50 Technology Technology uses scienceto create inventions. Often the aim of these inventions is to make our lives easier. Engineers use a series of steps to come up with new and exciting products. A problem The first thing to do is to find the problem that needs solving. Ask questions to find out as much as you can so that you can properly understand the whole problem. 1 2 Tubes make great linking devices. 50 This tube looks like it will be large enough to pick up tiny bits of dirt and big pieces of paper. Hmm, this cat makes so much mess! I wish I had a way of easily cleaning up...
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  51 3 4 5 Ideas Think ofas many different ideas as you can at the start. Write or draw them all down so you can see everything in front of you. It’s great to work in a team to come up with as many ideas as possible. Research Once you’ve decided on your best idea, it’s time to research. Find out what materials you will need to build your design. Building The first thing that you build is called a prototype. You’ll be able to see your idea coming to life and be able to spot anything you can tweak to make it better. Improving the design After you’ve made your invention, test it over and over again. You might come up with new ideas for how to make an improved version! Next time we could try to design a vacuum cleaner without a cord. Someone could trip over a cord or wire. Engineers use lots of different tools. Building your invention in stages makes it easier. Wheels will make it easier to move a heavy object. 51
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  52 Simple machines Machines help usto transport, fix, and power things. We have designed lots of different types of machine to carry out jobs, and many are surprisingly simple. Screw Pointy metal screws hold things together. They are placed inside both parts that you want to join. You use a screwdriver to twist and push them in. The screw turns into place. By pulling down, I lift the weight up! Clever, eh? The grooves grip the ground. Wheel These round parts help machines to get about. Different wheels are used for different surfaces. Grooved wheels suit slippery ground.
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  53 Pulley If an objectis very heavy, you can use a pulley to lift it. A rope is passed over the top of a wheel and attached to the weight. You pull on the rope to lift the weight. Wedge A triangular wedge is used to split things in two. The wedge is swung downwards into the object. Ramp To raise or lower an object that is too heavy to lift, we can push it along smooth ramps that slope upwards or downwards. Lever You use a lever to lift things. An example of a lever is a plank balanced on a single point called a fulcrum. You wouldn’t be able to lift these weights by hand. The weight is hooked onto the pulley. This wheel is too heavy to move by hand. The fulcrum is near the middle. A wheeled cart carries the object. If I push down here, the weights lift up! An axe is a type of wedge. Gears Gears are connected wheels with sticky-out bits called spokes. A smaller, lighter wheel is turned by hand. The spokes catch the heavier wheel to push it round.
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  Time We use timeto work out when things happen – from dates in history to what time you have to get up in the morning. We measure time in seconds, minutes, hours, days, and years. 54 12:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 Travelling by plane across different time zones can confuse our bodies and cause tiredness, headaches, and problems sleeping. This is called jet lag. The Greenwich Meridian Line is the centre of all time zones. It is where east meets west. Greenwich Meridian Line Body clock We, and other animals, have a built-in, natural body clock. This tells us when we should be awake and when we should sleep. Our body clock is linked to light and darkness. Time zones The world is divided into 24 different time zones, one hour apart. When you’re having your breakfast, someone else in the world is having their dinner. Russia is so big it has 11 time zones! What’s the time? Well, that depends on where you are on Earth. It can be midnight in one place and midday in another!
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  55 13:00 14:00 15:0016:00 17:00 18:00 September 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 19:00 20:00 21:00 22:00 23:00 24:00 Telling time People have been telling the time for thousands of years. But it wasn’t until quite recently – 1884 to be exact – that time zones were established. How shall I tell the time? Sundials use shadows, analogue clocks have faces and hands that tick, and digital clocks display the time on a screen. If I walk from one time zone to another, am I time travelling? The International Date Line Calendars help us to keep track of days and months. Months and years One year on Earth is 365 days long. This is the time it takes the Earth to travel around the Sun. One month is roughly how long it takes for the Moon to travel around the Earth. Sundial The International Date Line is an imaginary line in the middle of the Pacific Ocean. It separates one day from the next. Analogue clock Digital clock Day Night
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  Measuring Temperature We measure temperature withthermometers. They tell you exactly how hot something is. Time In the past, people told the time using the Sun and the Moon. Today, we use clocks as our main timekeeping device. Height How tall are you? Get someone to measure you with a tape measure. Now measure a friend. Who is the tallest? Water boils at 100°C (212°F). We divide time into seconds, minutes, and hours. 56 Tape measures, rulers, and even digital lasers measure height and distance. Chefs must use precise measurements of temperature and time when cooking. To find out how hot, how big, or how heavy something is we have to measure it. Special tools help us to get accurate measurements. This is especially important when building a house or baking a cake!
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  Volume Volume is theamount of space something takes up. Volume measures size, not weight. Two objects might have the same volume but very different weights. Keep a record Scientists note down measurements regularly, so they can see how things change over time. They use graphs and charts to compare measurements. Weight Weight tells us how heavy something is. If you have some scales at home you can weigh yourself! Kitchen scales help us weigh ingredients for cooking. Litres and millilitres are used to measure liquid. Graphs make it easy to see how things are changing. 57 In the USA, people often use cups to measure volume.
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  Using numbers We use numbersto count, measure, and compare amounts. Scientists and engineers have to be good at maths – or their experiments and inventions won’t work! Counting Counting different things allows us to compare them. For example, you could compare the number of spots on different ladybirds to see which type is the most common. This could take a while... Ladybirds’ spots can vary in number. Tally charts have been used since the Stone Age! 1st A A B C B C 2nd 3rd 58
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  Addition Addition is usuallythe first type of maths we learn. When adding numbers, it doesn’t matter what order they are in, the answer will be the same. Subtraction To subtract means to take away or make smaller. You have to take the second number away from the first number to get the answer. Positions Ordinal numbers tell you about the position, order, or sequence of something. 1st , 2nd , and 3rd are examples of ordinal numbers. 2nd place is the silver medal position. This is called the minus sign. The equals sign means that the sum and the answer are the same. This is the answer. This is the answer. This plus sign means add the two numbers together. Sports events reward 3rd place, too. The winner of the race comes in 1st place. 59 − + 2 5 4 3 6 2 = = The equals sign was first used about 500 years ago. 3rd 2nd 1st
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  Materials Everything around usis made of materials. Different materials have different qualities. Some, such as metals, are hard and strong. Others, such as plastics, can be easily moulded, or shaped. Engineers, scientists, and designers create and use materials in lots of different ways. Ceramics Ceramics are hard but break easily. They can cope with really high temperatures – space shuttles have ceramic tiles to protect them from extreme heat. Glass Glass is made from sand. It’s useful in windows because it can keep the weather out but still allow us to see through it. Metal Metals are usually strong and easy to shape when heated. They are conductors, which means electricity and heat can travel through them. Some metals are magnetic. Plastic Plastic is a human-made material that has many different qualities. It is light, waterproof, and can be hard or soft. People have been making ceramic pots and vases for thousands of years. At very high temperatures, metals become soft and can be reshaped. 60
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  Wood Wood is anatural material that comes from trees. It is used to make homes and furniture. Different types of wood have different colours and grains, or patterns. Fabric Fabrics can be made from natural things, such as sheep’s wool, or be created in a factory. Scientists have created protective fabrics that are waterproof or that block the Sun’s rays. Composites Combinations of two or more materials are called composites. They have the best qualities of the materials used to make them. Plastic is easy to mould into lots of different shapes. Wood is used to make paper and toilet roll, too! Carbon fibre is a very strong composite used to make surfboards. Fabrics can be dyed or patterned to make beautiful clothes. 61 Uh-oh! I’ll be in pain if I break this pane!
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  62 Cantilever A cantilever isa structure that is only supported at one end. To create a cantilever bridge, lots of these structures are joined together. Cable-stayed A cable-stayed bridge has one or two towers. Cables fan directly down from these towers to the bridge base, holding it up. Log bridge A log bridge is the most ancient form of bridge. It is made from trees that have fallen or are cut down on purpose. Suspension In a suspension bridge, steel wires connect two tall towers that are sunk deep into the ground. The crossing hangs from these towers. The cables can make interesting patterns. Suspension bridges can span great distances. Building bridges Bridges are designed by engineers to get us from one place to another as quickly as possible. They can cross canyons, rivers, roads, and train tracks.
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  63 Beam A beam bridgeis the simplest sort of bridge, combining a strong plank with supports at either end. Arch Arch bridges became popular during the Roman Empire. The arch transfers the weight of the bridge to the supports at either end. Bascule A bascule bridge has one or two parts that can move upwards to allow boats and ships through. These bridges take a long time to build. A bascule bridge is sometimes called a drawbridge. These piers support the bridge and go deep into the water. More than 50 designs were suggested for London’s Tower Bridge. Arch bridges get stronger over time!
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  64 Take to the skies Inorder to fly, you have to overcome the force of gravity pulling you towards the ground. Helicopters and aeroplanes use rotors, wings, and engines to soar through the air. Drag Drag, or air resistance, is the force that pulls the helicopter backwards. Drag increases as the helicopter moves faster. Without a tail rotor the helicopter would turn in circles! In a hovering helicopter, all the forces balance exactly. Dreams of flying The Italian artist and inventor Leonardo da Vinci was fascinated with flying. He studied birds and drew many imaginary flying devices, such as a wing-flapping machine for humans. Da Vinci’s wing design Helicopters can fly b a c k w ards! Forces of flight There are four main forces working on a helicopter as it flies. Drag tries to slow it down, gravity tries to bring it back to Earth, lift raises it upwards, and thrust propels it forwards. Tail rotor
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  65 Lift Lift holds thehelicopter in the air and is created by its rotors. It is the force that is the opposite of gravity. Thrust Thrust is the force that pushes the helicopter forwards. It is created by the helicopter’s engine. Gravity Gravity pulls the helicopter in a downward direction, towards the centre of the Earth. Cockpit The cockpit contains all of the instruments and controls that allow the pilot to fly the helicopter. Sycamore seeds are also called “helicopter seeds” because of the way they spin. Search and rescue helicopters have night-vision cameras. Planes use their wings to create lift. Main rotor
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  66 Floating A huge metalship can float because it’s full of air. The amount of space the ship takes up weighs less than the equivalent, or same, amount of water. Sinking Objects sink if their weight is greater than the force of the water pushing them upwards. Dense materials, such as metal and stone, usually sink, unless they have air inside them. Water pushes against the weight of the ship. The upward force of the water is greater than the ship’s weight, so the ship floats. The weight of the metal ship, plus the air inside it, is less than the upward force of the water. The upward force of the water is less than the weight of the anchor. The heavy, dense, metal anchor is specially designed to sink in water. Scuba divers use inflatable jackets and weights to move up or down, or stay at the same depth underwater. Why does the anchor sink while the ship floats?
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  67 Floating and sinking Why isa massive ship able to float when a small pebble quickly sinks? It depends on which is greater – the weight of the object in the water or the upward force of the water pushing against it. Changing weight Submarines can change their weight. They have tanks that can be filled with water to make the submarine heavier, or filled with air to make it lighter. This way, they can sink or rise. Archimedes Archimedes was a scientist in ancient Greece. He noticed that sinking objects push aside water. He worked out that an object will sink if it weighs more than the water it pushes aside. If it weighs less, it will float. Going down When the submarine takes water into its tanks, the extra weight makes the submarine heavier compared to the water around it. The submarine then sinks. At the surface The submarine’s tanks are filled with air when it’s floating at the surface. Tanks fill with air to make the submarine rise. Tanks fill with water to make the submarine sink. Submarines can stay underwater, with people living on them, for many months! The largest submarines are 175 m (575 ft) long and have 160 crew members. Eureka! Archimedes figured out why things float or sink while having a bath!
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  68 Friction When two surfacesrub against each other it creates a force called friction. Let’s take a look at a bicycle to see friction in action. How friction works No surfaces are completely smooth – up-close they are covered in tiny bumps. When these catch on each other they slow down the moving object, in this case a tyre, helping it to grip the road. Rubber or metal pedals create friction to stop your feet from sliding. Bike chains are greased with oil. The wheel moves across the ground. Friction with the ground slows the wheel. Friction between the brake pads and the wheels slows the bike down. There’s friction between your clothes and the seat. This stops you from falling off! Oil reduces friction so the chain moves smoothly. Rubbing your hands together creates friction, which produces heat.
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  69 Overcoming friction Skis are flat,smooth, and lightweight. This allows them to slide over icy surfaces easily, because less friction occurs when surfaces are smooth. As a parachute falls, the air pushes back up against it. This is a type of friction called air resistance. Tyres are now often made from Kevlar® to stop punctures. Kevlar® is a very strong and light human-made material. Handlebars are often textured to create friction. This makes them easy to grip. Mountain bikes have thick, grooved tyres to grip uneven trails. Racing bikes have thin, smoother tyres to move fast on roads. The lighter the bike, the quicker it moves!
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  Electricity Electricity is atype of energy that is used to power many everyday objects, from light bulbs to TVs. Take a look around your home and see how many electrical devices you can spot. Batteries Batteries are small objects that can create their own electricity. They’re often used for remote controls, radios, and torches. Without electricity, vacuum cleaners wouldn’t be able to suck up dirt. 70 Electrical gadgets make my life easier at home! Although I wish someone else would do the hoovering… Power lines carry electricity over long distances – from power stations into our homes.
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  Wires Metal is aconductor. This means that it lets electricity pass through it. Wires have metal inside them and plastic on the outside. The plastic is an insulator that stops electricity from escaping. Light bulb Can you imagine life before the light bulb? It wasn’t so long ago that people used candles and oil lamps to work once it got dark. Now we have light with the flick of a switch! Switch Switches control most electrical things around the home. Turn them on to start the flow of electricity, or turn them off to stop it. Lights should be turned off when not needed! Tablets, computers, and mobile phones give off light, too. Plastic Metal 71 The battery in my toothbrush can be recharged and used many times, so my teeth are always sparkling clean! During storms, water particles in clouds bump into each other. This can create electricity in the form of lightning. Solar panels absorb sunlight to make electricity. This is a renewable, or replaceable, source of energy.
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  72 The Internet The Internet isa worldwide network of computers that are connected together. Using the Internet you can chat with friends in faraway places, order a new pair of shoes, watch the latest blockbuster, and much more! Social networking Social networking is a way of using your computer to talk to other people all over the world. It’s important to stay safe online, so only connect with people you know and never give out personal details, such as your address or phone number. Maps Smartphones have clever systems that can tell exactly where you are on Earth. From this, they can tell you the best way to get from one place to another using maps. We can use the Internet to make video calls – even to people in space! Most smartphones can tell you how long it will take you to get somewhere! A smartwatch links to your smartphone using the Internet and lets you make calls, pay for things, and play music. Webcams can be used to video chat with people, or can be set up to study areas, like nature reserves, for a long time. Smartphones are computers that we carry in our pockets.
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  73 Shopping Lots of peopleuse the Internet to buy food, clothes, books, and more without having to leave the house. It can all be ordered, paid for, and delivered straight to your front door! Speedy parcels Viruses When a computer virus spreads it can slow a computer down or stop it working altogether. One of the main ways a virus spreads is when we download things from the Internet. Research The Internet lets us find out more information on our favourite subjects and learn more about the things that interest us. Streaming We can use the Internet to watch TV shows, films, and funny cat videos, or listen to music by our favourite singers or bands. Vans drive all over the world with Internet deliveries. You can buy presents and get them delivered straight to your friends and family. You can even get same-day delivery! Pick a topic and see how much you can find out about it online. Since its invention, the Internet has completely changed the way we live! parcels Speedy
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  Robots Robots are machinesthat can do jobs for us. They can be programmed by a computer to work alone, or they can be controlled by humans. Robotics is one of the most exciting areas of technology, with new robots being invented all the time. Humanoid robots Some robots are designed to copy the way humans look, move, and feel. These humanoid robots can do basic tasks and keep people company. Entertainment Robots can entertain us. Some robots sing, dance, or play musical instruments. Pet robots are very popular, and some theme parks have huge robot dinosaurs. Robotic dogs act like real dogs. They wag their tail and bark. 74 Image courtesy of Softbank Robotics Body parts Robotic body parts are attached to people with missing arms or legs. This lets them carry out everyday activities that they might not have been able to do before.
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  Domestic robots Robots cancarry out the boring chores we don’t always enjoy doing. They can wash floors, clean windows, iron shirts, and even clean a cat’s litter box! Security robots Security robots are fitted with cameras and sensors. They can patrol large areas, such as shopping centres, on their own at any time of day or night. Mobile robots Robots are perfect for working in extreme conditions. They can go down cracks in glaciers, travel to the bottom of the sea, and even work in space! A robotic vacuum cleaner moves around by itself. A drone is a flying robot that can take photographs and videos. If this roving security robot detects an intruder, it will alert its owner. 75
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  76 Glossary absorb To soak upor take in asteroid Small, rocky object that travels around, or orbits, the Sun astronaut Someone who is trained to travel and work in a spacecraft atoms Tiny particles that make up everything around us axis Imaginary line that passes through the centre of a planet or star, around which the planet or star turns black hole Object in space with such a strong force of gravity that nothing can escape it, not even light calendar Chart showing the days, weeks, and months of a year comet Object made of dust and ice that orbits the Sun, developing a tail as it gets near to the Sun dwarf planet Small type of planet, such as Pluto electrical storm Storm with thunder and lightning galaxy Huge group of stars, gas, and dust gills Organs of fish and some amphibians that lets them breathe underwater glacier Large mass of ice that moves slowly down a slope laser Narrow beam of strong light magnetic Word used to describe the force created by magnets, which can pull certain metals towards them magnetic field Force field surrounding a planet, star, or galaxy marine Word used to describe animals or plants that live in or near the sea
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  77 molecule Group of atomsstuck together moon Object made of rock, or rock and ice, that travels around a planet mould Type of fungus that grows in damp places online Connected to the Internet organ Part of the body that does a particular job, such as the heart or the stomach planet Huge round object that orbits a star pollution Waste that has been dumped in water, in the air, or on land. Pollution usually harms the environment predator Animal that lives by hunting and eating other animals prey Animal that is hunted for food receptor Part of the body that picks up information satellite Any object that moves around the Earth, often a human-made machine that collects scientific information scuba Equipment worn by divers that lets them breathe underwater sensor Part of a machine or robot that picks up information from the surroundings space Place beyond Earth’s atmosphere space probe Unmanned spacecraft designed to study objects in space and send information back to the Earth star Huge glowing ball of gas submarine Boat that can sail on top of the sea or dive deep underwater telescope Instrument used to look at distant objects turbine Wheel or rotor that is turned to make power, used in places such as wind farms webcam A camera that sends photographs or images over the Internet
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  78 Index Aa addition 59 aeroplanes 16,64, 65 air resistance 69 amphibians 28 animals 28–39 Apollo spacecraft 18–19 arachnids 29 arch bridges 63 Archimedes 67 Arctic 34–35, 41 art 7 artificial intelligence 47 asteroid belt 10 astronauts 18–19 astronomers 8–9 atmosphere 16–17 atoms 22 auroras 16 axis 14, 15 Bb bacteria 43 bascule bridges 63 bats 49 batteries 70, 71 beam bridges 63 bicycles 68–69 Big Bang 8 birds 28 blood 45 body 44–49 body clock 54 bones 45 brain 46–47 breeding 33 bridges 62–63 building 51 Cc cable-stayed bridges 62 calendars 55 cantilever bridges 62 carbon dioxide 40, 41 cells 43, 44 ceramics 60 climate 14–15 climate change 40–41 clouds 20, 21, 24 composites 61 computers 47 , 72–73 condensation 20, 23 conductors 60, 71 coral reefs 36–37 counting 58 crustaceans 29 Dd dams 21 Darwin, Charles 32 deserts 36 domestic robots 75 drag 64 drones 75 dust mites 42 Ee Earth 10, 13, 14–17 , 20–21, 24–27 , 55 earthquakes 26 echinoderms 29 echolocation 49 eclipses, solar 13 ecosystems 36–37 electric cars 41 electricity 70–71 energy 13, 70–71 engineering 6, 50 entertainment 74 equator 14 evaporation 20, 23 evolution 32–33 exosphere 17 Ff fabric 61 farming 30 fish 28 flight 64–65 floating 66–67 floods 41 fog 25 food webs 34–35 forces 64–69 fossil fuels 40, 41 freezing 23 friction 68–69 fruit 31 fungi 31 Gg galaxies 8, 11 gases 22–23 gears 53 glass 60 graphs 57 gravity 64, 65 Hh habitats 34–39 hair lice 42 hearing 49 height 56 helicopters 64–65 Hubble Space Telescope 9, 17 human body 44–49 humanoid robots 74 Ii ideas 51 insects 29, 31 International Space Station 17 Internet 72–73 invertebrates 28, 29 Jj Jupiter 11 Kk Kuiper belt 11 Ll land 15 lava 27 Leonardo da Vinci 64 levers 53 life 13, 14, 28–39, 42–49 lift 64, 65
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  79 light 8, 13 lightbulbs 71 lightning 24, 71 liquids 22–23 log bridges 62 Mm machines 52–53 magma 27 magnetism 13, 60 mammals 28, 29 maps 72 Mars 10 materials 60–61 maths 7 , 58–59 matter 22–23 measurements 56–57 melting 23 memory 46 Mercury 10 mesosphere 17 metal 60, 71 meteorites 16 microlife 42–43 Milky Way 11 molecules 22, 23 molluscs 29 months 55 the Moon 13, 18–19, 55 mountains 37 muscles 45 Nn Neptune 11 nervous system 47 numbers 58–59 Oo oceans 15, 20, 21, 37 orbits 10, 17 , 19 organs 44 Pp palaeontologists 33 parachutes 69 planes 16, 64, 65 planets 10–11 plankton 35, 43 plants 30–31, 32, 36, 37 , 38, 41 plastic 60 plate tectonics 26 Pluto 11 pollution 40 predators 34, 36, 38 problems 50 prototypes 51 pulleys 53 Rr rain 20, 21, 24 rainforests 38–39 ramps 53 receptors 48, 49 renewable energy 41, 71 reptiles 28 research 51, 73 robots 74–75 rockets 19 Ss satellites 25 Saturn 11 science 6 screws 52 sea ice 41 seasons 14 security robots 75 senses 48–49 shopping, Internet 73 sight 48 sinking 66–67 skiing 69 skin 45 smartphones 72 smell 48 snow 20, 21, 24 social networking 72 solar flares 12 solar panels 13, 41, 71 solar prominences 13 Solar System 9, 10–11, 12 solids 22–23 SONAR 49 space 8–9, 75 stardust 15 stars 8 stratosphere 17 streaming 73 submarines 49, 67 subtraction 59 the Sun 10, 12–13, 20, 24, 55 sundials 55 sunlight 39 sunshine 14, 15, 25 sunspots 12 surfaces 68–69 suspension bridges 62 switches 71 Tt tardigrades 42 taste 48 technology 6, 50–51 temperature 56 thermosphere 17 thrust 64, 65 thunder 24 time 54–55, 56 time zones 54, 75 touch 48 trees 40, 41 troposphere 17 tsunamis 26 tyres 69 Uu Universe 8–9 Uranus 11 Vv Venus 10, 17 vertebrates 28 viruses 43 viruses (computer) 73 volcanoes 26, 27 volume 57 Ww water 66–67 water cycle 20–21 weather 24–25, 40 weather balloons 16 weather satellites 25 wedges 53 weight 57 , 66–67 whales 32–33, 34 wheels 52, 68 wind 25 wind farms 41 wires 71 wood 61 Xx X-rays 44
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  80 Acknowledgements DK would liketo thank the following: Dave Ball and Katie Knutton for design assistance; Yamini Panwar for hi-res co-ordination; Caroline Hunt for proofreading; and Helen Peters for the index. The publisher would like to thank the following for their kind permission to reproduce their photographs: (Key: a-above; b-below/bottom; c-centre; f-far; l-left; r-right; t-top) 1 123RF.com: Andrzej Tokarski / ajt (clb); Mariusz Blach (crb); Imagehit Limited | Exclusive Contributor (cb). Alamy Stock Photo: Samyak Kaninde (br). Dorling Kindersley: Wildlife Heritage Foundation, Kent, UK (crb/Leopard). Dreamstime.com: Diosmirnov (c); Shakila Malavige; Santos06 (bl); Okea (crb/Coffee); Dragoneye (bc). Fotolia: Auris (cla). 2-3 Dreamstime.com: Shakila Malavige. 4-5 Dreamstime.com: Shakila Malavige. 4 Dreamstime.com: Tuulijumala (br). 5 Dreamstime.com: Jaroslaw Grudzinski / jarek78 (bc, br). 6-7 Dreamstime.com: Shakila Malavige. 8 Alamy Stock Photo: Granger Historical Picture Archive (clb). 8-9 NASA: ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team. 9 NASA: (ca). 10-11 Dreamstime.com: Shakila Malavige. 11 NASA: JPL-Caltech (ca). PunchStock: Westend61 / Rainer Dittrich (cla). 12-13 Dreamstime.com: Shakila Malavige. 13 NASA: Carla Thomas (tr). 14-15 Dreamstime.com: Shakila Malavige. 15 Dreamstime.com: Jacglad (clb). NASA: MPIA / Calar Alto Observatory (br). 16 Dreamstime.com: Clearviewstock (crb); Lars Christensen / C-foto (bc). 16-17 Dreamstime.com: Shakila Malavige. 17 Dorling Kindersley: Andy Crawford (tr). 18 123RF.com: Boris Stromar / astrobobo. Dreamstime.com: Loren File / Lffile (Flag). 18-19 Dreamstime.com: Shakila Malavige. 19 NASA: (c). 20 123RF.com: luisrsphoto (bl). Dreamstime.com: Melonstone (crb). 20-21 Dreamstime.com: Shakila Malavige. 21 123RF.com: Andrzej Tokarski / ajt (cla); klotz (crb); Vitalii Artiushenko (ca). Dreamstime.com: Terracestudio (ca/Hat). 22 123RF.com: Imagehit Limited | Exclusive Contributor (cb); Pongsak Polbubpha (cl); Mariusz Blach (cb/Coffee cup). Dreamstime.com: Okea (br); Shakila Malavige (t). 23 123RF.com: Mariusz Blach (clb). Dreamstime.com: Bigphoto (cb); Grafner (cr). 24-25 Dreamstime.com: Shakila Malavige. 24 123RF.com: Gino Santa Maria / ginosphotos (cr); lurin (cb). Dreamstime.com: Mangojuicy (bl). 25 123RF.com: Andrew Barker (cb); Stanislav Pepeliaev (bl); mreco99 (crb). Getty Images: Erik Simonsen (t). 26 Alamy Stock Photo: Hideo Kurihara (cra). U.S. Geological Survey: (b). 26-27 Dreamstime.com: Shakila Malavige. 27 Dorling Kindersley: Stephen Oliver (cr). US Geological Survey. 28 123RF.com: / Ermolaev Alexandr Alexandrovich / photodeti (ca). Alamy Stock Photo: Benny Marty (cl). Dorling Kindersley: Jerry Young (ftl, tc). 29 Dorling Kindersley: Gyuri Csoka Cyorgy (fcr). Dreamstime.com: Cosmin Manci / Cosmin (cr); Johnfoto (tl). 30-31 Dreamstime.com: Shakila Malavige. 30 Dreamstime.com: Alisali (c). 31 123RF.com: ccat82 (crb). Dreamstime.com: Alle (clb, c). iStockphoto.com: thawats (cl). 32 Dreamstime.com: Christophe Testi (c); Travelling-light (c/ Pad). 32-33 Dreamstime.com: Shakila Malavige. 33 Dreamstime.com: Guido Nardacci (cr). 34 Dreamstime.com: Iakov Filimonov / Jackf (cl). Getty Images: Rhinie van Meurs / NIS / Minden Pictures (cr). 34-35 Dreamstime.com: Shakila Malavige. 35 Dreamstime. com: Jlcst (br); Travelling-light (cb). 36 123RF.com: Steve Byland (clb). Alamy Stock Photo: B Christopher (cb). 37 123RF.com: Ten Theeralerttham / rawangtak (cl, fcra). Alamy Stock Photo: blickwinkel (c); imageBROKER (cra); Roberto Nistri (fcl, cr); Samyak Kaninde (br). Dorling Kindersley: Wildlife Heritage Foundation, Kent, UK (cb). Dreamstime.com: Dragoneye (bl); Kevin Panizza / Kpanizza (ca); Fenkie Sumolang / Fenkieandreas (tr). Getty Images: Paul Kay (c/Green sponge). 38-39 Dreamstime.com: Shakila Malavige. 38 Dorling Kindersley: Thomas Marent (cr). Fotolia: Eric Isselee (c). 39 Alamy Stock Photo: Amazon-Images (bc); Life on White (br). Dorling Kindersley: Jerry Young (crb, bl); Natural History Museum, London (cla/Butterfly); Andrew Beckett (Illustration Ltd) (cl). Dreamstime.com: Travelling-light (c). Getty Images: Gravity Images (cla). 40 123RF.com: Ekasit Wangprasert (cl); rawpixel (crb). Dreamstime.com: ArchitectureVIZ (clb); Whilerests (cb); Haiyin (fcl); Maksim Toome / Mtoome (c). 40-41 Dreamstime.com: Shakila Malavige. 41 123RF.com: Andrey Kryuchkov / varunalight (c); jezper (cb). Dreamstime.com: Radha Karuppannan / Radhuvenki (cla); Jan Martin Will (br). Getty Images: Jeff J Mitchell / Staff (crb); Miles Willis / Stringer (cra). 42-43 Dreamstime.com: Shakila Malavige. Science Photo Library: Steve Gscmeissner (c/Dust mite). 42 Dreamstime.com: Sebastian Kaulitzki / Eraxion (cb). Science Photo Library: Steve Gscmeissner (c). 43 Getty Images: Kateryna Kon / Science Photo Library (clb); Science Photo Library (b). 44-45 123RF.com: Natallia Yeumenenka (cb). 45 Depositphotos Inc: chaoss (ca). Dreamstime.com: Alexey Romanenko / Romanenkoalexey (bc). 46-47 Dreamstime.com: Shakila Malavige. 47 Dreamstime. com: Tuulijumala (cra). 48-49 Dreamstime.com: Shakila Malavige. 48 123RF.com: Peter Lewis (c). Dreamstime.com: Bjørn Hovdal (cra). 49 123RF.com: Evgeny Atamanenko (ca); Peter Lewis (cl). Dreamstime.com: Cebas1 (cra). 50-51 Dreamstime.com: Shakila Malavige. 50 123RF.com: Aleksandr Belugin (cra); Andriy Popov (clb). Dreamstime.com: Petr Jilek (clb/Mud). 51 Dreamstime.com: Daniel Ryan Burch (ca); Petr Jilek (bc). 52-53 Dreamstime.com: Shakila Malavige. 52 123RF.com: Dejan Lazarevic (r). Dorling Kindersley: A. Hardesty (cl). 53 Dreamstime.com: Daniela Pelazza (clb); Jannoon028 (clb/wood); Santos06 (cb). Getty Images: Andrew Harrer / Bloomberg (cb/Object). 54-55 Dreamstime.com: Shakila Malavige. 54 Dreamstime.com: Lars Christensen / C-foto (cra). 55 123RF.com: belchonock (clb/Clock); yarruta (cla); Tim Markley (bc). Depositphotos Inc: tangjans (clb). Dreamstime.com: Georgii Dolgykh (ca); Marilyn Gould (cl); Vladvitek (cr). 56-57 Dreamstime.com: Shakila Malavige. 56 123RF.com: tobi (cl). Dreamstime.com: Diosmirnov (ca); Winai Tepsuttinun (r). 57 Dreamstime.com: Diosmirnov (c); Travelling-light (cla). 58 Dorling Kindersley: Jerry Young (c, crb/Snail). Dreamstime. com: Brad Calkins (crb); Travelling-light (bc); Elena Schweitzer / Egal (cra); Olga Popova / Popovaphoto (cra/Marker); Jannekespr (br). 58-59 Dreamstime.com: Shakila Malavige. 59 123RF.com: Andrzej Tokarski / ajt (cb). Dorling Kindersley: Booth Museum of Natural History, Brighton (ca, ftr). Dreamstime.com: Andrey Burmakin / Andreyuu (c/Shield bug); Svetlana Larina / Blair_witch (ca/Butterfly, ftr/Butterfly); Cosmin Manci / Cosmin (ca/ Beetle, c/Beetle); Isselee (ca/Firebug, c/Firebug); Sutisa Kangvansap / Mathisa (cl, cr). Fotolia: Auris (ca/Flask). 60 123RF.com: Natthapon Ngamnithiporn (cb). 60-61 Dreamstime.com: Shakila Malavige. 61 123RF.com: Steve Collender (cr); Antonio Balaguer Soler (fcr). Dreamstime.com: Minaret2010 (bc). 62 Alamy Stock Photo: Maurice Savage (c); Mihai Andritoiu - Creative (cb); oroch (br). 62-63 Alamy Stock Photo: Arch White (t). Dreamstime.com: Shakila Malavige. 63 Alamy Stock Photo: Clair Dunn (ca); Xinxin Cheng (c); Mark Davidson (crb). 64-65 Dreamstime.com: Shakila Malavige; Zhanghaobeibei (c). 64 Alamy Stock Photo: Granger Historical Picture Archive (crb). 65 123RF.com: spaxia (c). Dorling Kindersley: Stephen Oliver (cl). Dreamstime.com: Gv1961 (tr); Luis Louro (bc); Nadezhda1906 (br). 66 Alamy Stock Photo: Dariusz Kuzminski (tl); studiomode (cra). 66-67 Dreamstime.com: Shakila Malavige. 67 Dorling Kindersley: Fleet Air Arm Museum (c, br). Dreamstime.com: Chris Brignell (fcra, cra). 68-69 Dreamstime.com: Shakila Malavige. 69 Dreamstime.com: Maksym Gorpenyuk / Tass (cra); Yudesign (tl). 70-71 Dreamstime.com: Shakila Malavige. 70 123RF.com: Pablo Scapinachis Armstrong (bc). Dreamstime.com: Kitchner Bain (bc/TV). 71 123RF.com: Kanoksak Tameeraksa (cla). Dreamstime.com: Dary423 (cr); Juan Moyano (cra); Milkos (crb). 72 Dreamstime.com: Ali Mustafa Pi kin (cra); Tuulijumala (cl); Axstokes (clb, crb); Erol Berberovic (cb). iStockphoto. com: Luca di Filippo (cr). 72-73 Dreamstime.com: Shakila Malavige. 73 Dorling Kindersley: Peter Minister (cra/T.Rex). Dreamstime.com: Ali Mustafa Pi kin (tl); Robwilson39 (tc); Angelo Gilardelli (cra); Profyart (cr); Badboo (crb); Axstokes (fcrb). Fotolia: Maxim Kazmin (tl/Computer). 74-75 Dreamstime.com: Shakila Malavige. 74 123RF.com: Kanoksak Tameeraksa (c). Dorling Kindersley: John Rigg, The Robot Hut (clb). Getty Images: John B. Carnett / Bonnier Corporation (br). Humanoid robot created by Softbank Robotics: (cra). 75 123RF.com: chris brignell (cb); goodluz (cra); Thomas Hecker (clb, cb/Frame); Vadym Andrushchenko (fcrb). Dreamstime.com: Alex Scott / Alexjpscott (clb/Garden); Nikolai Sorokin (crb). iStockphoto.com: ernie decker (tc). Knightscope, Inc.: (bl). 76 Alamy Stock Photo: Roberto Nistri (bc). Dreamstime.com: Kevin Panizza / Kpanizza (br). 76-77 Dreamstime.com: Shakila Malavige. 77 NASA: JPL-Caltech (tc). 78-79 Dreamstime.com: Shakila Malavige. 80 Dreamstime.com: Shakila Malavige Endpaper images: Front: Dreamstime.com: Shakila Malavige; Back: Dreamstime.com: Shakila Malavige. Cover images: Front and Back: Dreamstime.com: Diosmirnov (chef hats); Front: 123RF. com: alisali cl/ (flowers), Andrzej Tokarski / ajt crb/ (snail), Mariusz Blach br/ (cup), tobi tr/ (pot); Alamy Stock Photo: Samyak Kaninde bl/ (pika); Dorling Kindersley: Booth Museum of Natural History, Brighton cra/ (beetle), Wildlife Heritage Foundation, Kent, UK bl/ (leopard); Dreamstime.com: Alle fcl/ (bees), Andrey Burmakin / Andreyuu cra/ (bug), Cosmin Manci / Cosmin cr/ (beetle), Torian Dixon / Mrincredible tl/ (planets), Dragoneye bl/ (goat), Isselee cra/ (firebug), Okea br/ (coffee splash), Santos06 bc/ (cart), Shakila Malavige br/ (background), Sutisa Kangvansap / Mathisa cr/ (butterfly), Svetlana Larina / Blair_witch fclb/ (butterfly), Travelling-light tr/ (note pad); NASA: cla/ (Voyager); Back: 123RF.com: tobi cra/ (pot); Dreamstime.com: Jannoon028 crb/ (plank), Tommy Schultz / Tommyschultz clb/ (coral); iStockphoto.com: thawats fclb/ (butterfly); Spine: 123RF.com: goodluz b/ (remote control). All other images © Dorling Kindersley For further information see: www.dkimages.com