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The literature reviewed in this article shows that the evolution of vehicles is in line with the evolution of animal locomotion and that it is predictable from the constructal law of design and evolution in nature. The evolution of ships and airplanes illustrates the evolutionary design of the “human-and-machine species” as it moves and spreads on Earth: farther, faster, more efficiently, and with greater lasting power (sustainability). Every vehicle size has its design. The bigger vehicle is not a magnified facsimile of the smaller. The size fraction that the lifting organs occupy in the overall vehicle increases with the body size. Every vehicle size has its niche, the supporting territory, and population to which it belongs. All the designs of movement on the globe evolve. Vehicles do not evolve by themselves; they evolve hand in glove with the humans who design and use them. The result is hierarchy, and it is why hierarchy is natural and unavoidable. We see it in geophysical movement (river basins), animal movement (food chain), human social movement (global air and maritime traffic), and everywhere else. The appearance of a new hierarchical design of movement on earth does not eliminate the existing hierarchical designs of movement. The new hierarchy joins the old, and what works is kept. No evolving system deviates from the features dictated by the law of physics of evolution in nature.

This article shows that the sudden end of economic expansion (movement, wealth) emerges as a natural, physical feature of the spreading movement, which has access to power (money), freedom to morph, and power storage (savings) for future movement on even greater areas. The movement is driven by power generation, which is interspaced with power savings on the same area. The theory is constructed systematically from the physical basis of economics concepts (money, savings, time, and bubbles) to a physics model that accounts for the time-dependent spreading of movement on an area. Previous study has shown that physics accounts for the proportionality between the annual wealth (GDP) of a population and the annual consumption of fuel to generate power for that population. The present theory extends this view to the more realistic situation where every movement in society (wealth and fuel consumption) is time dependent.

Summary Why do individuals come to live (to move) together, to organize? Here, we propose that organization is a reflection of the physics reality (bio and nonbio) that it takes less power (useful energy, fuel, food, and exergy) to move 1 unit of mass in bulk than to move 1 unit individually. The objective of this work is to establish the connection between energy engineering and social organization and to bring social organization under the big tent of physics. We illustrate the predictability of organization and its evolution with 2 simple models of movement on an area, one inanimate (river basins, generated by several rules of construction) and the other animate (distribution of heated water for use in human settlements). The 2 models lead to the same conclusion: The movement becomes more hierarchical as the size and complexity of the architecture increase. The distribution can be made more uniform (more equal) by imposing identical channels distributed uniformly over the area. The flow architecture becomes a grid instead of a tree; yet, even in designs with imposed equality, the hierarchy persists. This theoretical framework also reveals the physical meaning of innovation: It is a local design change that liberates the flow over the entire territory inhabited by the organized movers.

Here we show how the size of a body affects its maximum average speed of movement through its environment. The theoretical challenge was to predict that ‘outliers’ must exist, such as the cheetah for terrestrial animals and the jet fighter for airplanes. We show that during a travel that starts from rest and continues at cruising speed, the body size for minimum travel time, or maximum average speed, is not the biggest. The results are compared with extensive data for military aircraft for chase, attack and reconnaissance, in addition to data for commercial aircraft. The paper also explains why in earlier studies of flying (animals, airplanes) the airplane data deviated upward (toward greater speeds) relative to the theoretical trend followed by flying animals, and why the fastest animal flyers are one thousand times smaller than the fastest swimmers. Unlike the biggest animals and airplanes (elephant, whale, commercial jet), which move constantly, the fastest animals and airplanes spend most of their lives at rest. When judged for speed averaged over lifetime, the fastest ‘sprinters’ are in fact the slowest movers (as in Aesop’s fable ‘The Tortoise and the Hare’).

Why are the rankings of universities not changing? Why is the demographic composition of top universities the same? In this review, these questions are addressed based on physics. Although size matters, higher ranks do not correlate with bigger sizes. The higher ranks belong to universities that have more authors who receive more citations. Citations are a record of how ideas spread from the source to the whole globe, in accordance with the physics of the logistics S-curve phenomenon. The spreading occurs in three periods – slow, fast, slow – and the population served by each idea during its lifetime depends on the size of the first big channel that carries the idea. An idea from a famous university has a larger spreading territory around it than an idea from a lesser-known university. Creativity is key: rankings come from visibility through citations, and, in turn, visibility for an author is aided by the higher visibility of the university. The demographic composition of the top universities is the same: for instance, the percentage of female authors and authors of East Asian origin among the 200 most cited authors does not vary significantly over the 20 highest ranked universities.

Increasing oil prices, the growing demand for energy, the adoption of new regulations for greenhouse gases and other harmful particulate emissions, as well as political instabilities and crises have necessitated the design of more efficient and environmentally-friendly plants. This paper presents a useful combination of mean cycle irreversibility (MCI) for thermodynamically optimizing the Rankine cycle using the MCI as the currently proposed criterion. The thermal irreversibilities and physical size of a system are evaluated together using the criterion that aims to minimize the ratio of the thermal irreversibilities or exergy destruction to a specified size that is characterized as the difference between the maximum and the minimum specific volumes of the cycle. The analyses consider the effects of different boiler-outlet or turbine-inlet pressures and temperatures, different condenser pressures, and different isentropic efficiencies on cycle performance. The results show that increasing the inlet temperature for a constant turbine-inlet pressure increases the MCI and increasing the turbine-inlet pressure at a constant inlet temperature decreases the MCI. With boiler pressure at 500 kPa, the boiler temperature increases from 500K to 600K, the MCI value increases nearly seven-fold, and thermal efficiency increases from 14% to nearly 16%. Also, the results show that the criterion gives more beneficial information to designers and engineers in terms of exergy destruction for designing more environmentally friendly and smaller thermal systems.

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