How big is a raindrop? What is GPS? Where do volcanoes come from? Why does the sun's heat decrease in winter? When was the first computer invented? Why do vaccinations hurt? What is snot made of? These are all real questions that children ask. Experts from various fields spent weeks finding answers to such seemingly simple questions: after all, explanations must be clear and engaging so children can understand why the world works the way it does. In this book, you will find answers to the most frequently asked questions. Thanks to the comic diagrams, even the most complex information becomes crystal clear! The book won the French Book Prize for Science and Education in the 'Science for Children' category, 2015 (Gout des Sciences 2015). It was written by Marc Beynier and Bertrand Fichoud, editors of the popular children's science magazine Images Doc.