• The author of the book, Henry Petroski, died shortly after this review was written.

From its title, you might expect a book called Force to simply explain how forces work. Instead of a purely educational, fact-driven narrative, however, author Henry Petroski – an engineer and popular-science writer – uses a mix of personal essays, musings and biography to convey how scientific concepts govern and influence everyday life. This is not to say that you won’t learn a fair amount of engineering from Force, or that you won’t come away with a better understanding of how, on a fundamental level, “things work”. But you will also be given the tools to recognize how these things are connected, literally and metaphorically.

Humans have always had the ability to recognize patterns, breaking down complex structures into simpler, recognizable components and using this knowledge to satisfy their curiosity

Force begins by showing how humans have always had the ability to recognize patterns, breaking down complex structures into simpler, recognizable components and using this knowledge to satisfy their curiosity and understand the mechanics of things. Rather than just providing a material understanding of forces, the book delves into how people perceive the world around them, and how these feelings frequently affect our world as much as any physical “pushing or pulling” force does.

In the prologue to Force, Petroski observes that “research and development takes place in a grander context than one of hard physical force; it is also subject to the softer forces imposed by ethics, morals and judgement – none of which is easily and unambiguously defined by laws and limits”. He illustrates this by discussing the medical innovations that brought us from the prehistoric era, when humans had only their five senses to help them avoid harm, to the present day, when technologies such as stethoscopes allow doctors to monitor hearts, lungs and stomachs much more thoroughly than simple listening would permit.

He also mentions how the COVID-19 pandemic spurred innovation, despite the distresses we were under. It led, for example, to the mobilization of vaccines in record time, as well as improvements to mask technology. Although not even close to perfect, today’s masks have undergone major upgrades compared to those worn by, say, plague doctors in medieval Europe.

Petroski complements this sentiment by comparing literal examples of pandemic-driven innovation with more subtle advances made simultaneously in society. During a time when mundane affectionate interactions like embracing, shaking hands and even standing next to someone were heavily discouraged to prevent the spread of the virus, people adapted as best they could, replacing higher-risk gestures with fist and elbow bumps, hip checks and toe taps.

For physicists, one of the most enjoyable parts of Force may be Petroski’s discussion of the work of Michael Faraday, who many (including myself) will know primarily for his discoveries in electromagnetism. Faraday was, however, also well practised and gifted in explaining complex concepts to the public in an easy-to-understand way. As such, people came from far and wide to listen to him speak and to marvel at the practical props he regularly used to assist him – including the rubber balloon, which Faraday invented for his experiments on hydrogen gas.

Much of the book continues in this manner: a case study of a known engineer or piece of engineering, an explanation of how something works on an accessible scientific level, and a discussion that illuminates the social and societal changes that accompanied or indeed motivated it. Each chapter is named after either a fundamental force, a more general derivative force or a feeling you’ll recognize.

The author winds up detailing the inverse square law that governs both gravity and the electromagnetic force, all while weaving in stories of his and his children’s childhoods

In the electromagnetism chapter, for example, Petroski explores how telephones produce and relay sounds. After using older, simpler types of phones to describe the fundamentals of how they work, he moves into the more complex technology of the modern age. Eventually, he winds up detailing the inverse square law that governs both gravity and the electromagnetic force that permeates our planet and the wider universe, all while weaving in stories of his and his children’s childhoods.

Other chapters continue in the same vein, happily building up our idea of what forces can be. As well as the more accessible fundamental forces of electromagnetism and gravity (which gets its own chapter), Force covers everyday sensations such as squeezing a football, feeling inertia on mass transit, and even global effects like winds, hurricanes and earthquakes. It is also chock-full of Petroski’s personal experiences, which gives a biographic feel to the work and makes the explanations very clear.

My favourite example of this blend of the personal and the scientific is Petroski’s account of getting roof tiles replaced on his house. From this mundane and perhaps even annoying task, he creates both a compelling explanation of how gravity works and an opportunity to reveal some of the quirks of his personality. Whereas most of us would try to be anywhere else to avoid the noise, Petroski remained in his attic office, recognizing and enjoying the individual rhythms of the roofers as they hammered in the nails.

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In the book’s epilogue, Petroski returns to his earlier medical theme and reflects on the epidemic of bubonic plague that struck London in 1665. During this time, Isaac Newton, like many others who could afford it, sheltered from the disease in the countryside. It was there that he made great strides in physics and (at least in the Western view of science history) discovered gravity after being inspired by the fall of an apple. Though the more recent coronavirus pandemic has been horrendous, Petroski reflects that it also offered unexpected opportunities for some lucky people to change their lives, make progress on their work or become more prepared for the future.

Overall, Force is a great book that roots you in reality and gives solid explanations of some of the world’s most complex phenomena. The accompanying biographical feel is another positive too, as Petroski’s personal experiences from his life and from stories he’s read act as a base for the learning within the book. This gives his narrative a uniqueness and flair when it might otherwise have slipped into a very dry style. Experts and non-experts alike can gain something from it, whether it’s finally understanding how it is that speakers can replicate almost any sound, or simply remembering the countless ways forces impact our day-to-day lives.

• 2022 Yale University Press $30.00hb 328pp