Review of Lightness by Adriaan Beukers and Ed van Hinte

Adriaan Beukers and Ed van Hinte, Lightness: the Inevitable Renaissance of Minimum Energy Structures, Uitgeverij 010 Publishers, July 1998

Adriaan Beukers is at the Laboratory for structures and materials of the faculty of aerospace engineering, Delft University, the Netherlands. Erik Wong is a graphic designer. Writer Ed van Hinte has worked closely with them both. Together, they have gathered together a profusion of insightful charts and delightful photographs to explore the lightness of planes, balloons, bridges, chairs, tents and much architecture besides. The maths also looks indisputable, even if the text has a few flaws.

All constructions, Lightness points out,are related to transport in one way or another. They are loaded for at least a part of their lives and in many cases they are vehicles themselves (p12). The book displays a great chart on the declining relative importance of metals compared with high-modulus and now high-temperature polymers and elastomers, composites (metal-matrix, and increasingly ceramics-based), and tough engineering ceramics such as Al203 or Si3N4 (pp14-15).

Lightness argues that the reason metals are gradually decreasing in significance ‘is not that metal resources are being exhausted, but that the most widely used ones, steel and aluminium, are no longer capable of meeting long term requirements of price and performance. Research and development to achieve small improvements are becoming relatively expensive’ (pp13-16)

So far, so good. But the U-shaped recovery of non-metallic materials coincides, the authors maintain, with a change in the importance of weight: ‘Whereas in prehistoric times man had to be able to carry things himself, heaviness became important later on as he got more help from animals, slaves and, later on, from engines. Now lightness, or performance per energy unit, is quickly gaining significance because… cheap energy is getting scarce’ (p16).

But in a deflationary world, it is quite a presumption to say that the price of energy will increase – or that ‘the price we pay for energy is unjustifiably low’. It is also quite a presumption to say that world population will have doubled by 2040, as does Dr G J Wijers, pro-lightness Minister of Economic Affairs in the Netherlands, who, in the preface to this book, makes a familiar call for a sustainable economy.

The authors look back to nomadic tribes for inspiration on lightness. This is fun, but of a piece with looking forward to government decrees on lightness (all cars to be less than 1000kg, for example (p163)). I love the book, but I can’t go along with that.