Physical thinking in system thinking ​

In systems thinking, a theory often used is akin to "Aristotelian physics": when a finger presses on a table, but the table does not press back on the finger, as the finger is living and active, while the table is passive! In systems thinking, a system as a role object "plays its role": behavior, it functions, performs its function — but it is considered active and changing the world around it without undergoing significant changes in its states (at least without destruction during operation, stable/steady), while systems in the environment are mainly seen as passive, undergoing changes and significantly altering their states, sometimes up to destruction.

Changes in the system's states while fulfilling its function are considered separately afterwards. This approach is also used in modern physics. In constructor theory, the concept of a constructor is proposed to be someone who changes their environment an unlimited number of times without their own degradation (as an example, a catalyst molecule is presented, producing catalysis in some reaction, but remains unchanged after each catalysis, and on the other hand, a self-replicating robot that remains unchanged after each act of replication).

The stability of some systems in a chaotic environment that interacts with them is the subject of physicists' keen study. Atoms are very stable, molecules are also stable, as are living forms. Boundaries of systems are typically drawn along the line of stable existence, non-destruction during usage. In physics, this is known as a non-equilibrium steady state (NESS), which is actively studied in the 21st century: in contrast to equilibrium, which does not require any energy or work to maintain, a non-equilibrium state needs energy and work to be maintained, which overall keeps this state.

Imagine a tightrope walker on a wire keeping balance against gusts of wind — this represents it. On one side, there are many small changes in the state of the target system, while on the other side, there are no catastrophes or sharp changes in the state or system destruction. Stability to external influences lies in constant changes and adjustments, paradoxical as it may sound. Although NESS started to be studied in complex systems in physics, the thesis was picked up by chemists and later by biologists, but it describes a general description of systems that "balance" around a certain state, remaining "almost the same" despite significant changes in the environment.

The concept of a constructor/creator is that they are a universal transformer of matter/things in a similar way to how a computer/computing machine is a universal computer. These transformations according to some algorithm/theory for a universal constructor are limited not only to computations but also to changes in the physical world. Universality lies in the potential to make any transformations allowed by the laws of physics.

In conclusion, using the notion of "interaction" between parts of systems in systems thinking, but in reality each time considering not "mutual" but simply "action": a pair of an active system-creator and a more or less passive environment. The backward action (the target system during its creation on its creators), is neglected, but if it is really important, another consideration is conducted explicitly to account for this action.