Is 'information' a thing? As a physicist myself, this is a very important question, given the amount of emphasis the field places on ‘information’ right now. It seems to be treated as a real, tangible thing by most scientists, yet strangely its fundamental nature never seems to be questioned. If one examines multiple physical systems that contain ‘information’, I feel as though the definition seems to get pretty arbitrary quickly.
One could perhaps with reasonable certainty say that the fundamental unit or ‘quanta’, of information are bytes. Bytes can be expressed in countless systems in countless different ways. One can assign the notion of ‘bytes’ to transistors, saying that there is a 1 when it is switched on and zero when off. Equally one could create a system in which we have a crowd of people interacting in a way such that when someones hand is raised, this represents a 1 and lowered represents a zero- computation can be achieved just as effectively, data can be stored; as far as things go, such a system would have the exact same properties of any computer with its information processing etc. The point here is that any physical object or system can have these ‘bytes’ and the bytes themselves can manifest themselves in innumerable physical ways. So if bytes/information are a real, physical thing, how can they express themselves in the same ways in completely different physical systems?
Maybe information is this invisible, transcendental thing that can be seen to express itself in all manners of completely different systems in arbitrary ways or perhaps, information is simply an abstract concept we assign to things- surely it is one of the two. There is little reason to believe the former- to do so would be faith (there is no proof for information being some real, physical thing after all). It is more reasonable to assume that information is an abstract concept we assign to systems- there is no ‘physical’ aspect to it (as there is really no reason to believe it is). A physical thing would have limits to what it can be seen in and influence, whereas information does not. The physical reality is that the transistor has current flowing towards it or doesn’t, the individual has raised his\her hand or not- we then take the leap to label each of these binary states 1 or 0 and say that they transmit or store ‘information’. In reality these systems are completely different, there is no physical thing that is being stored/transmitted by both as there is really no common ground between them besides our labelling of certain aspects of them.
So in the conventional sense at least id say that information is not ‘real’.
How do we define this abstract concept? Well, if system A has a lot of ‘information’ on system B, then from system A’s state (from its fundamental quantities maybe, its position, momenta, temperature, order etc) we can deduce a lot about system B and the quantities associated with it. Again, the key is we can ‘deduce’. In reality these two systems are simply similar to one another or connected- we take the step to take certain qualities of A that are similar to B and label these ‘information’, disregarding the innumerable other qualities of the system that we can deduce less about B from. There is nothing physically special about these qualities apart from the fact that we can use them to find out more about the nature of B.