How did a piece of gold foil completely change our understanding of atoms? What part did a hot air balloon play in the discovery of cosmic rays? How do we know all that we know about the world today? It's not simply because we have the maths – it's because we have done the experiments. Accelerator physicist Suzie Sheehy introduces us to the creative and curious people who, through a combination of genius, tenacity and luck, staged the groundbreaking experiments of the twentieth century. From the serendipitous discovery of X-rays in a German laboratory, to the scientists trying to prove Einstein wrong (and inadvertently proving him right), The Matter of Everything takes us on a journey through the history of experiments that transformed our world.