Measure the world, record the data and display it graphically. Ever wanted to know more about the real world by measuring it? This book is aimed at getting you started measuring and recording information and presenting it graphically on a web page. Is this book for you? It's not written for experts. It's put together as a guide to get you started if you're unsure about how to make the first move. It reads more like a story as it leads the reader through the basics of using a Raspberry Pi, connecting sensors, recording information into a MySQL database and presenting that data on a web page using d3.js.