Introduction /6 Chapter 1 /8 Whipping Up a Batch of Planet Earth There's a whole amazing world below your feet (and all around you) Why is ocean water salty? /10 Why is some water turquoise and some water brown? /11 If metal sinks, how do boats float? /12 How does gravity keep us down? /13 Where does wind come from? /14 Why can't we feel the Earth moving? /15 What came first, the tree or the seed? /16 How do trees know about seasons? /17 Is there enough food in the world? /18 Why don't cars run on apple juice? /19 Chapter 2 /20 Creeping, Crawling, Living Things From the smallest to the tallest, animals are born to be WILD Why do worms come out when it rains? /22 Why don't jellyfish have brains? /23 Can rats burp? /24 Why do we have different faces but ants do not? /25 How do whales sleep? /26 Why can't you live with a wolf? /28 If a dog says "woof" will other dogs understand? /29 What's the smartest animal on Earth? /30 How many unfound species are there in the world? /31 Chapter 3 /32 Human Bodies from the Inside Out The skin you're in houses your brain, heart, and a whole lot more Why do my toots smell? /34 Why do you always have to go to the bathroom? /36 Why is poo brown? /37 Why are we tired when we run? /38 Why can't humans breathe underwater? /39 Why do humans have two eyes? /40 Why do teeth fall out? /41 Why is everybody different? /42 How do people think without language? /44 Why do people find things funny? Why is everyone so funny? /45 Why do people need to sleep? /46 Why do we die? /47 Chapter 4 /48 Stars, Moons, Planets, and Outer Space Gazing into the night sky just got way more interesting Are there other creatures on other planets? /50 How do the stars stay in the sky? /52 What happens inside a black hole? /53 Why are planets round? /54 Will another asteroid hit Earth? /55 If I were to sneeze in outer space, would my head blow up? /56 Can sound move in space? /57 What causes a solar eclipse? /58 Why do diamonds rain onto Saturn? /59 If the universe is expanding, then what's outside the universe? /60 Chapter 5 /62 Big Ideas About Past, Present, and Future Mind-blowing, keep-you-up-at-night scientific theories change our experience of EVERYTHING around us How did we discover the Big Bang? /64 Why are dinosaurs so BIG? /66 How do we really know a meteor killed the dinosaurs? /68 What would the world be like if dinosaurs were still alive? /70 Can we make dinosaurs from dino DNA? /71 How did the Ice Age start? /72 What is time? /74 Is time travel possible? /75 What hasn't been invented? /76 Conclusion /78 Acknowledgments /80 Sources and Further Reading /82 Index /86 About the Author and Illustrator /88.