Shells - In chemistry there are shells that enclose the nucleus or node in this case and get larger and more complex as one moves from the inner circle... It seems fitting that the S orbital has two spots that one could assign to the parents who usually give the greatest influences on the person's later social development... from there it's not as simple as there are possible siblings, and other family members moving out but that could be one repeating shell. Friends of different intimacy and setting in another though transitivity could draw them all together. Shells, for work, education, entertainment, exercise, region, politics, etc with different strengths and capping out around Dunbar's 150 bonds for known people at least though weaker bonds exist (especially in information flows). But it should also be noted that the metaphor doesn't hold exactly as the bond for various institutions of their own as shell connections that can scale into larger super organism/structures like companies, movements, nations, etc with organizational structures as well. The last few chapters are calls to action: Failures in structures are almost always due to lazy designers or lazy manufacturing and these are critical moral failures of Biblical proportions. Parallel to this is failures in aesthetics: an engineer is mostly likely designing something that many people will use. Therefore, it is absolutely critical that what they're designing /is nice/. The Spartan ethic of functionalism is too narrow and close-minded. resiliance is the ability to store train energy and deflect elastically under a load without breaking/causing permanent damage

the failure of a structure may be controlled, not by the strength, but by the brittleness of the material work of fracture (aka toughness) is the quantity of energy requried to break a given cross-section of a material Gordon's old classic is very digestible with only the bare minimum for equations to cover all the concepts and is able to ingrate and contrast biological structures with man made materials for a source of biomimicry before it came to a larger conscious recognition and name (naming something usually give some power of it to dredge it from the subconscious hidden depths). So in that spirit of connecting similar patterns, I think this makes for a good abstract structure of social engineering: Before reading this book, I didn’t know anything about aeroplane engineering. I certainly didn’t think that very similar principles apply to it as to buildings or bridges. For example, aircraft wings act in bending as their static system can be simplified as a cantilever beam. However, what aeroplane engineers often were not aware of in the old days, is that the wings must also resist torsional/twisting forces. Quite some lives and planes were lost due to those kinds of structural failures (p.260-261). The book incorporated a fair bit of math, but it was simple to understand. If you intend to use the principles of this book in your own life, I suggest taking notes in a separate notebook.I detested the author's tone. To the author's credit, he wrote in what certainly seemed to be a sincere tone, so I suppose that I may just detest him. He writes in the manner of a charming, elderly British professor. this has effect in sailing, where chinese junk sails are rigged so that as wind pressure increasesthe radius of curvature diminishes and the tension force in the canvas remains roughly constant no matter how hard the winds may blow Can engineers learn from natural structures? What can doctors and biologists and artists and archaeologists learn from engineers?

Fatigue is another problem for materials such as metal. Fatigue occurs when a heavy load is applied to metal with varying intensity, causing fluctuations. Metal fatigue is so hard to spot that nowadays complex statistics are employed to calculate the probability of fatigue occurrence. These calculations were developed by doing a lot of experimentation. Between 1935 and 1955 around 100 types of airplanes were built to test their structural robustness.If however, by some miracle, the floor produced a larger thrust than my feet have called upon it to produce, say 201 pounds, then the result would be still more surprising because, of course, I should become airborne . Architects and engineers will appreciate the clear and cogent explanations of the concepts of stress, shear, torsion, fracture, and compression. If you're building a house, a sailboat, or a catapult, here is a handy tool for understanding the mechanics of joinery, floors, ceilings, hulls, masts--or flying buttresses. But also how worms came to be the shape they are and why a bat can y into a rose bush without tearing its wings.