QR2.1.2 Information Isn’t Physical

Quantum realism proposes that the quantum network can be understood in terms of information theory but not in terms of how we implement information theory physically.

Modern information theory began with Shannon and Weaver, who defined information as the power to the base two of the number of choice options (Shannon & Weaver, 1949). By this definition, a choice between two physical options is one bit of information because two is two to the power of one, and a choice between four options is two bits because four is two to the power of two. By this logic, two to the power of eight, or 256 is 8 bits or one byte. Equally a choice of one option, which is no choice at all, is zero bits. Processing was then defined as changing information, i.e. the event of making a new choice.

Hence while the choice between two states is one bit, according to information theory a physical state in itself has no information at all because it is just one way. A book “contains” information but has zero information in itself because, being physical, it is fixed in one way. This may seem wrong but it isn’t, as hieroglyphics no-one can decipher do indeed contain no information. A book only gives information when a reader decodes it and that depends entirely on the decoding context, so reading every 10th letter of a book, as in a secret code, gives a different message with different information.

The amount of information “in” a physical state depends on the assumed number of physical states it was chosen from. One electronic pulse sent down a wire can represent one bit, or it can be one byte as ASCII “1”, or as the first word in a dictionary, say Aardvark, can represent many bytes. It is because the information in a physical message depends on the decoding context that data compression can store the same data in a smaller signal, using more efficient encoding. If information was a physical thing, data compression couldn’t pack the same data into a physically smaller signal!In general, the information in a physical signal is undefined until a reader decodes it. Only when sender and receiver agree on the encoding-decoding context can they exchange information.

It follows that information only emerges from a physical state when an observer is added. The same applies to information in a book or database – the states in themselves contain no information at all until read. If one writes a book in English say, that language is the encoding context that allows communication. The receiver can only extract the information the sender put in if they know the encoding context.

If processing is defined as creating information, writing a book is processing, as one can write it in many ways, and reading a book is also processing, as one can read in many ways, but the physical book itself, being just one way and no other, is empty of information. Information stored as physical states doesn’t exist without a reader to decode it by a series of dynamic events. By Shannon and Weaver’s definition, processing is the dynamic means by which static information is encoded and decoded so the information in a physical book literally doesn’t exist until an observer decodes it.