The Brain Willis Circle and Ring Electric Power Systems: Analogies [Retrospectroscope].

The word analogy is a synonym of likeness, resemblance, similitude, or affinity and involves two concepts being placed side by side, as in a comparison [1]. The workings of nature and those of human societies are amenable to such analogous comparison-even though the evolution of the natural world obviously spans millions of years [2], while human societies are much younger, relatively puppies by comparison. This article considers two interesting examples from these two realms that show remarkable similarities (possibly a result of sheer chance), i.e., a circulatory brain anastomosis, the circle of Willis (CW), and modern power transmission-distribution systems in the ring arrangement. Remember that electric networks handle the flow of charges [say, in coulombs per second (C/s) or electric charge per unit time, which is current), whereas hydraulic systems deal with fluid flow [say, in liters per minutes (L/min) or volume/unit time or fluid mass/unit time]. Hence, these systems too are analogous, a well-known fact often mentioned by instructors of electrical engineering courses.