|THERMO Spoken Here! ~ J. Pohl © ~ 2019||www.ThermoSpokenHere.com (E1560-222)|
System is a mental construct, in each case it is an idea or biased vision. System is something in your head - not real. System incorporates the aspects of reality the user, the observer believes important. "What, precisely, is the system? What is relevant to the "system events," and how is it relevant?" There is rarely agreement. And when there is agreement; it is for trivial, called "classical" situations.
Mental means imaginary. A system is related to reality, provided the observer, the system creator has understanding of the reality to be modeled. Hence the system is imaginary with some imagination needed but grandiose imagination too much. The imagination forms a "construct," a "necessary view" of the physical reality observed. mentally by the observers mind selected for the purpose of mathematical and physical analysis. The system, an image of physical reality, is a tool. Humans select. Either of two basic perspectives is used (or a combination).
Material Perspective: Newton (and others) initiated the science of mechanics. The initial systems of their studies were of the model: BODY. Common cases of the model are projectiles on Earth, planets in their motion, and contained quantities of liquid or gas. Furthermore, these items which we know had size, shape and extent, were nonetheless assumed to have their masses localized at a point.
Spatial Perspective: This is the idea that a system might be defined to be a specified space. But space, in general, has no properties, no mass and no "conservation principles." Space is meaningless without matter, until matter gets involved.