Exactly: How Precision Engineers Changed the World
Simon Winchester, William Collins, 2018, ISBN 978-0-00-824177-3
The Order of Time
Carlo Rovelli, Penguin, 2018, ISBN978-0-241-29252-5, 213pp
The late, great and much-lamented Tom Petty sang “you're flirting with time baby, flirting with time, but maybe time baby, is catching up with you” (on 2006’s magnificent Highway Companion). Tom Petty was right; time is indeed catching up with us. But Carolo Rovelli’s wonderful little treatise The Order of Time causes us to wonder exactly what time may be. We know from Einstein’s theory of relativity, as Rovelli points out, that “time passes faster in the mountains than it does at sea level.” This is a good reason for living on the coast, of course, but it also throws the question of what time is into the philosophical melting pot.
I find the reading several books at once is a useful way to pass the time. My mother would have said that I should do one thing and do it properly but whoever listened to their mother? So, when the Carlo Rovelli book arrived from BookDepository I was already reading the Simon Winchester book.
It was the redoubtable Janice in Moruya books who pressed Exactly: How Precision Engineers Changed the World into my not unwilling hands and said that I should enjoy it. And so it proved … though it is a book that is written in a style that may not be to everyone’s taste. To describe the language as flowery might be doing the word flowery a disservice but Winchester never uses one syllable when two will do and rarely uses a straightforward sentence construction when a complicated one will serve as well. I may be overstating this but, if so, then only slightly. So wonderfully 18th century did the language seem that I was moved to take out the first volume of Gibbon’s Decline and Fall of the Roman Empire to see how the two men’s styles, separated by nearly 250 years, compared.
Winchester tells the story of scientific progress (or at least the Graeco-Roman / Western civilisation version of it) through following how mankind has learned or discovered to measure things with an ever-increasing degree of accuracy. His chapter headings are subtitled with references to tolerance. They begin at Chapter 1 with 0.1 and proceed incrementally (or perhaps we should say, decrementally) to Chapter 9 with 0. 000 000 000 000 000 000 000 000 000 000 000 01 of an inch, which might be more conveniently written as 10–35 but, as I say, concision is not a feature of this book. By Chapter 10 he has given up on numbers and rightly so. Quantum theory has changed everything … or at least it will change everything if the physicists are to be believed.
Winchester discusses steam engines, locks and guns and the implications of accurate measurements on the reliable manufacture of these. He tells of Joseph Whitworth who is indirectly responsible for several spanners in my shed, inherited from my father and my wife’s grandfather, that are British Standard Whitworth. At the start of the 20th century the mass production of the motor car depended upon manufacturing tolerances of 10-10 while only a few years later Whittle’s development of the jet engine depended upon tolerances 1,000 times finer. We look at cameras, at the global positioning system (that’s GPS of course) and then the development of the computer. It takes light (and electricity) about a nanosecond (that’s one billionth of a second) to travel 30 centimetres so accuracy in the design of a printed circuit board is pretty important if you want to make sure that signals arrive in the right place at the right time.
Winchester does get carried away in his enthusiasm for his subjects. Two examples may suffice. At one point, he is discussing Moore’s Law; not the Moore that is your humble scribe but the one who started the chip maker Intel and who predicted that computers would halve in size and double in power every year. He refers to the “near exponential process of chips becoming ever tinier.” The mathematician in me is horrified by the term “near exponential.” Moore’s law is exponential, there is no “near” about it. I was equally horrified to read that bamboo is a “plant at once mathematically imperfect and yet quite perfectly useful.” I have no idea what “mathematically imperfect” means. On the other hand, Winchester did introduce me to some new words, such is his command of the English language (or at least its vocabulary). Sempiternal was one such word.
So, you may be wondering what Winchester’s book has to do with time. In the final chapter of the book, which he calls the Afterword, he traces the development of the International System of Units (more properly, as I am sure Winchester would wish me to point out, the Système International d’Unités) that defines the metre and the gram and so on. These are related to a single unit that is the key to all of them: the second. The length of a metre is now defined as the “length of the path travelled by light in a vacuum during a time interval of 1/299,792,458 of a second.” The kilogram is in the process of being redefined in terms of the speed of light and speed is distance divided by time.
As I read Winchester’s story, I made a connection with Rovelli’s book. Rovelli’s book will not take you long to read but it depends upon concepts that need some serious thought. Francis Bacon once said that “some books are to be tasted, others to be swallowed and some few to be chewed and digested.” Rovelli’s book is in the latter category: it needs to be digested. It probably needs to be read at least twice. He throws in the air any idea we have that time is a constant. Time is not a constant, neither is it necessarily unidirectional. Rovelli points out that there is nothing in Newton’s mechanical laws, nor Maxwell’s of electricity, nor Einstein’s relativity theory nor yet in quantum mechanics that distinguishes the past from the future. Indeed, the only thing that cannot go backwards is heat. Heat cannot move from a cold body to a warm one. This is the second law of thermodynamics. This is the law that tells us that entropy increases. It is the reason why, as I tell my wife, that the house gets untidy and there is nothing she can do about it. The fact is that the universe wants to be untidy. What underlies time is the idea of a sequence of events. When Winchester refers to length as being defined by the speed (which is a function of time) in a vacuum, that definition depends upon something that is ephemeral and that, as Einstein showed, is not a constant.
This all requires some serious consideration. In some ways the juxtaposition of the two books contrasts the Newtonian physics that has worked pretty well for hundreds of years (and still does work well) with the peculiarities and uncertainties of quantum mechanics on which, I suspect, much future technological development depends. If we cannot be certain about time, then can we be certain of anything. The more I think about this the more I am sure that Douglas Adams was right in A Hitchhiker’s Guide to the Galaxy. We are just part of an experiment by those hyper-intelligent pan-dimensional beings who, unbeknownst to the human race, are the most intelligent species on the planet Earth.
I speak, of course, as did Adams, of mice.
