Explore the fascinating intersection of physics and biology in this lecture by William Bialek, part of the Alan Turing Lectures in Biology series. Delve into how evolution has shaped biological mechanisms to operate at the limits of physical laws, from atomic-scale vibrations in hearing to single-molecule detection in bacterial navigation. Examine intriguing examples of nature's precision, including embryonic development, human perception, and decision-making processes. Discover how life's complexity may ultimately reveal a simpler, more perfect system than previously imagined. Journey through topics such as photon counting in vision, fly embryo development, bat echolocation, and probabilistic reasoning in the brain, gaining insights into the remarkable efficiency of biological systems.