Using quantum theory to improve measurement precision

Progress in science is inextricably linked with how well we can observe the world around us. It is by making increasingly better measurements that scientific theories are tested and refined. In this article we address the question of what the ultimate limit to measurement precision is and how it could be achieved in the laboratory. We focus on how, by making use of quantum theory, it is possible to make better measurements than anything that can be achieved with classical techniques. This opens the door to an array of new technologies and could help answer some of science's most engaging questions.