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