From Matter to Life Quotes

“Information is widely used in physics, but appears to be very different from all the entities appearing in the physical descriptions of the world. It is not, for instance, an observable – such as the position or the velocity of a particle. Indeed, it has properties like no other variable or observable in fundamental physics: it behaves like an abstraction. For there are laws about information that refer directly to it, without ever mentioning the details of the physical substrates that instantiate it (this is the substrate-independence of information), and moreover it is interoperable – it can be copied from one medium to another without having its properties qua information changed. Yet information can exist only when physically instantiated; also, for example, the information-processing abilities of a computer depend on the underlying physical laws of motion, as we know from the quantum theory of computation. So, there are reasons to expect that the laws governing information, like those governing computation, are laws of physics. How can these apparently contradictory aspects of information be reconciled?”
― Sara Imari Walker, From Matter to Life: Information and Causality