The New Science of Strong Materials: Or Why You Don't Fall through the Floor

Citation

Gordon, J. E. (2018). The New Science of Strong Materials: Or Why You Don't Fall through the Floor. Princeton University Press. (Princeton Science Library edition, with an introduction by Philip Ball; first published 1968.)

Chapter Summary

The book has eleven chapters, an opening chapter followed by ten chapters in three parts, then two appendices, a note on the conversion of units and suggestions for further study. Princeton's edition adds an introduction by the science writer Philip Ball, dated 2005, which describes Gordon's career and how materials science has changed since the book was written at the end of the 1960s. Every chapter carries a two-part title: a plain statement of the subject followed by a joke or a question.

Chapter 1: The new science of strong materials – or how to ask awkward questions

The opening chapter sets out the book's questions. According to Ball's introduction, Gordon states at the outset that his themes are questions such as why things break, why steel is tough and glass brittle, and why wood splits; the book begins by quoting Michael Faraday on the mystery of cohesion; and Gordon tells the reader that he has cut out almost all the mathematics, keeping only very elementary algebra.

Chapters 2–4: Stresses and strains – or why you don't fall through the floor; Cohesion – or how strong ought materials to be?; Cracks and dislocations – or why things are weak

Part One, "Elasticity and the theory of strength", builds the basic ideas. Chapter 2 introduces stress and strain, the source of the book's subtitle. Chapter 3 asks how strong solids should be, given the forces holding their atoms together. Chapter 4 explains why real materials are far weaker than that: cracks and dislocations. Ball notes that the book does not shy away from tables of Young's moduli, stress–strain curves and a few equations.

Chapters 5–8: Crack-stopping – or how to be tough; Timber and cellulose – or wooden ships and iron men; Glue and plywood – or mice in the gliders; Composite materials – or how to make bricks with straw

Part Two, "The non-metallic tradition", is about toughness and the materials that achieve it without metals. Ball summarises its central argument: strength is of little use without toughness, and the key problem is stopping cracks from forming or spreading. He describes how Gordon explains the fast running of cracks through brittle solids, how laminates and other composites defeat them, and why glass fibres are unexpectedly strong. The chapters on timber, glue and plywood draw on Gordon's wartime work on laminated-wood aircraft, and the composites chapter reflects his later work on fibre-reinforced materials.

Chapters 9–10: Ductility in metals – or the intimate life of the dislocation; Iron and steel – Hephaistos among the Satanic Mills

Part Three, "The metallic tradition", explains why metals bend and stretch instead of cracking, through the behaviour of dislocations, and then turns to iron and steel.

Chapter 11: The materials of the future – or how to have second thoughts

Gordon writes that he added this chapter "rather against my judgement". Ball points out that it identifies the trend that later shaped the field: designing materials to suit particular needs, and seeking a balanced combination of properties rather than strength alone.

Appendices

Appendix 1, "On the various kinds of solids – and what about treacle?", and Appendix 2, "Simple beam formulae – or do your own stressing", give technical background, followed by a note on units and suggestions for further study.

Key Concepts

Chapters 1–4: Introduction and Part One, Elasticity and the theory of strength

• Stress and strain: force per unit area and the resulting fractional deformation, the basic quantities of the subject.
• Cohesion and theoretical strength: the strength a solid should have if its interatomic bonds failed all at once.
• Cracks and dislocations: the defects that make real materials far weaker than their theoretical strength.

Part Two: The non-metallic tradition (Chapters 5–8)

• Toughness and crack-stopping: a material's resistance to the spread of cracks, distinct from its strength.
• Laminates and weak interfaces: layered structures, such as plywood, that deflect or blunt cracks.
• Composite materials: strong fibres held in a weaker matrix, combining strength with toughness.

Part Three: The metallic tradition (Chapters 9–11)

• Ductility: the capacity of metals to deform plastically through the movement of dislocations rather than cracking.
• Balanced combination of properties: Gordon's view, in the final chapter, that new materials must meet several, sometimes conflicting, requirements at once.

Critical Analysis

Strengths

• Physical understanding first. The book explains why materials behave as they do rather than how to calculate with them: why cracks matter, why theoretical and real strength differ, why metals bend and stretch while glass shatters.
• Real engineering, told from experience. Ball's introduction describes Gordon's career as a naval architect, then at the Royal Aircraft Establishment working on wood, plastics and fibre composites, and later on whisker-reinforced materials. The chapters on timber, plywood and composites are therefore written from first-hand experience.
• Readable and enjoyable. Ball compares Gordon's combination of clarity and delight in how things work to Richard Feynman's, and notes that his books were translated into more than twenty languages and set as study texts in British schools.
• Light but honest mathematics. Gordon limits himself to elementary algebra but keeps numbers, tables and curves, so readers learn the orders of magnitude of real material properties rather than just a qualitative story.

Limitations

• Written in the late 1960s. Ball says plainly that a popular-science book from that period is in some sense old-fashioned. The final chapter is speculative by Gordon's own account, and the materials developed since then are not covered.
• Strength, not function. By Ball's account, the field has since moved from structure to function: semiconductors such as silicon, which Ball calls the most significant material missing from the book, and responsive or "smart" materials lie outside its scope.
• Not a course text. It is a popular account, and its contents list shows no problem sets; apart from the appendix of simple beam formulae, stress analysis is not developed as a calculation method. It supports a mechanics-of-materials course but cannot replace one.

Where It Fits in the Course

This is the non-technical companion to the mechanics-of-materials textbooks in the course. Hibbeler's and Beer, Johnston, DeWolf and Mazurek's Mechanics of Materials teach the calculation of stress, strain, torsion, bending and buckling through worked and homework problems; Gordon explains what those quantities mean physically and why materials fail as they do, especially through cracks. Read it before or alongside the first weeks of either textbook.

David Blockley's Structural Engineering: A Very Short Introduction is the other non-technical book in the course; it looks at structures as a whole, whereas Gordon looks inside the material. Ugural and Fenster's Advanced Mechanics of Materials and Applied Elasticity and Sadd's Elasticity are much later steps into elasticity theory. Gordon's chapters on theoretical strength and cracks give useful motivation for their more formal treatments. Gordon's own sequel, Structures: Or Why Things Don't Fall Down, which Ball names as the follow-up to this book, appears in the structural engineering course.

How to Use This Book

The book suits first-year engineering, materials and physics students, and any general reader who is curious about why things break. No technical background is needed; Gordon's mathematics stays at very elementary algebra.

A practical plan:

• Read Part One straight through (Chapters 1–4). These chapters carry the ideas the rest of the book depends on: stress, strain, theoretical strength, cracks and dislocations.
• Core for engineers: Chapter 5 on crack-stopping and Chapters 9–10 on metals connect most directly to a mechanics-of-materials course and to later study of fracture.
• Read for perspective: Chapters 6–8 on timber, plywood and composites, which draw on Gordon's own work with wood and composites and are especially useful for students interested in composites or lightweight design.
• Read critically: Chapter 11, together with Ball's introduction, which updates Gordon's view of the future.

Alongside a textbook course, keep a short list of the quantities Gordon introduces, such as Young's modulus and the difference between strength and toughness, and match each to its definition and units in the textbook. Appendix 2 on simple beam formulae is a good bridge to the beam chapters of a standard course.