The physical microbe : an introduction to noise control and communication in the prokaryotic cell Physical biology is a fusion of biology and physics. This book narrows down the scope of physical biology by focusing on the microbial cell; exploring the physical phenomena of noise feedback and variability that arise in the cellular information processing circuits used by bacteria. It looks at the microbe from a physics perspective asking how the cell optimizes its function to live within the constraints of physics. It introduces a physical and information based (as opposed to microbiological) perspective on communication and signalling between microbes.