Notes on the Essential System to Acquire Information

This paper introduces a short survey on recent information theories and reviews some critical notes expressed on quantum information. The severe difficulties emerging from the literature lead us to argue about the way to follow, and in a preliminary stage, we consider how to proceed in order to provide a reasonable contribution to the conceptualization of information in classical and quantum physics. We conclude that we should go toward the essential elements of the system that acquire information and should define the common components of the measurement processes. In this way we should be able to establish fundamental properties and to circumvent tricky difficulties arisen by the concept of the observer and the variety of interferences that disturb the acquisition of information. Universal experience shows how sharpness is the indispensable feature of detected signals and we calculate the discernability of observables using various mathematical formalisms. The present logical frame brings evidence on how information is not an absolute quantity, and we close with a few notes on the information relativism which modern literature tackles from the operational stance and the philosophical stance.