|Left: a social piston and cylinder, on a rotating illuminated globe, often used by American electrochemical engineer Libb Thims, e.g. in lecture, to conceptualize thermodynamic modelling of social systems in terms of "boundaries" and social expansion and social contraction.|
The social piston and cylinder is "social system" model of the piston and cylinder boundary of the generic universal heat engine, which can be any volumetrically-defined working body in the universe, whatever the working substance may be, according to the logic that just as the fall of the water through gravitational height drives the water mill so to, in the original 1824 Sadi Carnot conception if the situation, does the fall of caloric (heat) from hot to cold drive the heat engine.
The "boundary" in the above steam engine model is the volumetric region of water contained in the delineated region of the piston and cylinder. Now, however, in the 1865 Rudolf Clausius definition of the situation, instead of the fall of caloric driving the operation of the heat engine, we have the increase in the transformation content (entropy) accrues per each cycle, and the free energy is now considered as the driving force of the heat engine.
Social heat engine
The following shows a conceptualized working body of a given socioeconomic system: 
The following shows the conceptual understanding of "boundary" of the given social volume under study in respect to the models of closed, open, and energetically boundary regulated semi-open:
Personal space | Vacuum power
The following shows the conceptual understanding of personal space and power associated with the vacuum in respect to aspects such as beauty (beautiful people are given more personal space), physical size, e.g. dihumanide molecule (two people attached) or height aspects (tall people are given more personal space):
● HCT | P4: Piston and cylinder view
1. Thims, Libb. (2013). “Econoengineering and Economic Behavior: Particle, Atom, Molecule, or Agent Models?” (video, 1:33-min) (Article pdf, 40-pgs) (PowerPoint ppt-pdf, 36-slides) (DB), Key speaker talk delivered at the University of Pitesti Econophysics and Sociophysics Workshop (UPESW) / Exploratory Domains of Econophysics News (EDEN V). University of Pitesti, Pitesti, Romania, Jun 29.