Title: Physical description of nature from a system-internal viewpoint,
Abstract: Objectivity is often considered as an ideal for scientific description of
nature. When we describe physical phenomena, thus, we have exclusively taken an
objective viewpoint by excluding a subject. Here we consider how nature can be
described from a subjective viewpoint and how it is related to the objective
description. To this end, we introduce a viewpoint-shift operation that sets
perspective within a system, and subject the system to the laws of
thermodynamics. We consider a situation in which the activation of an active
part of the system starts to influence an objective part at t = 0, bringing the
system into non-equilibrium. We find that the perspective alters physical state
functions of the system, or leaves a viewpoint-dependent physical trace that is
detectable. In the system-internal viewpoint, a system in the heat bath
self-organizes to maximize the free energy, creating order. The active part
keeps increasing a gap from an initial equilibrium state as long as the energy
is available, forming a memory in the form of organized matter. This outcome of
a system-internal viewpoint in physics matches our intuition coming from our
daily-life experience that our subjective action leads to a change of our
environment. This suggests that this system-internal viewpoint may provide a
clue to understand a long-standing problem on the physical meaning to be
subjective.