Description ┃Earth Science Edition┃ 1. How Much Do You Know About Earth? How old is Earth? The Birth of Earth 12 What does Earth look like? The Appearance of Earth 14 Let's look inside Earth: Earth's Internal Structure 16 Why is seawater salty? Seawater and Salt 18 What does the seafloor look like? The World Beneath the Sea 20 Which is colder, the North Pole or the South Pole? The Polar Regions 22 Rivers, the Starting Point of Life's Cycle: The Water Cycle 24 The Shield That Protects Earth with Its Whole Body: The Atmosphere 26 2. Look at the Land and Rocks, and You'll See Earth Water and air meet to create rocks? Weathering 30 How does water change the shape of land? Erosion 32 The Power of Rivers That Creates Fertile Land: Transportation and Deposition 34 Rocks Formed by Deposition: Sedimentary Rock 36 We Can Learn Earth's History: Rock Strata 38 A Living History Book of Earth: Fossils 40 Why do volcanoes form? Volcanoes 42 Rock Formed from Hardened Magma: Igneous Rock 44 Another Transformation of Rock: Metamorphic Rock 46 Why do earthquakes happen? Earthquakes 48 3. Let's Travel Through Space Let's look inside the sun: The Sun's Appearance 52 Oh no, the sun disappeared! The Sun and Earth 54 Not Just Anyone Can Join the Solar System Family: The Solar System 56 The Moon's Transformations Are Innocent!: The Moon's Orbit and Rotation 58 Why do day and night differ from country to country? Earth's Rotation 60 The Moon Swallowed the Sun: Solar Eclipse 62 Various Celestial Bodies Shining in the Night Sky: Stars, Planets, Moons, and Comets 64 Do constellations have maps too? Constellations 66 Do different constellations appear each season? Seasons and Constellations 68 The River of Stars in the Universe, the Milky Way: Galaxies 70 4. Curious About Weather and Seasons Weather Changes with Air Pressure: High Pressure and Low Pressure 74 The Continent Discovered Because of Wind, New Zealand: Monsoon Winds 76 A Wind That Helped Sailors Circle the Globe? Trade Winds 78 How do typhoons form? Typhoons 80 The Principle Behind Cloud Formation: How Clouds Form 82 What's the relationship between clouds and weather? Clouds and Weather 84 Why do deserts cool down quickly at night? Temperature Differences Between Land and Sea 86 Why do seasons change? Seasonal Change 88 How can we predict the weather in advance? The Secret of Weather Forecasting 90 An Instrument That Precisely Measures Weather and Humidity: The Stevenson Screen 92 Let's look at a weather map: Weather Maps 94 ┃Physics Edition┃ 5. The Amazing World Created by Light and Heat Why are shadows created? Light and Shadows 98 Mirrors were used to defeat enemies? Reflection of Light 100 How do we see objects? Eyes, Light, and Objects 102 Oh, a coin is floating in the water? Refraction of Light 104 Light Can Be Gathered or Scattered: Convex Lenses and Concave Lenses 106 Let's make a rainbow! How Rainbows Work 108 Why does the sky change color? Scattering of Light 110 Which conducts heat better, metal or wood? Heat Conduction 112 The water temperature in a bathtub is different? Heat Convection 114 Why is asphalt especially hot in summer? Heat Radiation 116 How do hot air balloons float in the sky? How Hot Air Balloons Work 118 What scientific principle is hidden inside a thermos? How Thermoses Work 120 Let's keep the house warm! Insulation 122 6. Amazing Magnets and Wonderful Electric Circuits Why do magnets attract iron? Properties of Magnets 126 Can we see the power of magnets? Magnetic Force and Field Lines 128 How does a compass show direction? How Compasses Work 130 Electricity was discovered while rubbing amber? Electricity 132 Does electricity have its own special path? Electric Circuits 134 All Home Appliances Are Connected in Parallel: Series and Parallel Connections 136 Does electricity prefer certain materials? Conductors and Insulators 138 Are electricity and magnetism friends? Electric Current and Magnetic Fields 140 How do maglev trains run? Electromagnets 142 How does a light bulb produce light? How Light Bulbs Work 144 Electricity is convenient, but how do we use it safely? Electrical Safety 146 7. Here We Go! Everything About Force and Energy Earth Is Pulling Me: Gravity 150 Why does your weight decrease on a mountain? Weight 152 What secret is hidden in a spring? Springs and Elastic Force 154 A moving object tends to keep moving? The Law of Inertia 156 What force makes things float on water? Buoyancy 158 You can lift the Earth with a lever...