Whatever Happened To the Metric System?

Guest Book Review By Sven

Is the metrication of a nation a technical exercise, or a social problem? Of course it is both, but in practice, one or the other view predominates. This should be recognized as framing all underlying debate. The classic example of a nation that came late to metric, but approached the transition as a technical hiccup, is now among the most successfully metricated: Australia. The nation that briefly flirted with metrication at about the same time, the 1970s, but dropped it on the dubious grounds that it would have required too much penicillin, is The United States of America. The Metric Maven has always sided with Oz, sometimes to the point of testing the patience of long-time readers. Keep this in mind, because it’s crucial to what follows.

A new book, Whatever Happened to the Metric System? How America Kept Its Feet, by John Bemelmans Marciano, ostensibly on the failure of metrication in the US, has us here at TheMetricMaven.com in a quandary. If the subject matter matches the title, then we might be expected to have an opinion. Silence might even be misinterpreted. On the other hand, if the book is something else, we could find ourselves in the position of electrical engineers trying to make sense of a seriously bizarre piece of dilettante sociology.

The book certainly starts off at the right point: the early 1980s, when Ronald Reagan gave the coup de grâce to any hope for imminent US metrication, by abolishing the US Metric Board. The Board had been in existence for only seven years, and still represents the sole official attempt to bring US measurement into alignment with the rest of the world. (I can personally attest that it was a time when kids were told by teachers that, ten years out of high school, we would never have to worry about confusing an ounce weight with a fluid ounce again.) But the Board foundered early, for reasons that will not be easily explained to citizens of European democracies. (Long story short: some members of the Board apparently saw their function as more than purely nominal.)

Before exploring this failure, however, Marciano indulges in an extended historical digression: at least twelve of his sixteen chapters. Our first major stop is actually the French Revolution. And I do mean stop: we will be stuck in France from well before the Reign of Terror, and will be hanging around for at least two Napoleons after (numbers I and III, I’m pretty sure — I’ve forgotten if II gets a mention, and frankly it’s not worth checking). The French chapters run from at least three through six and beyond, with chapter two, on the francophile Thomas Jefferson, as a kind of preamble. This makes the French section well over one fourth of the book. Although the book’s title suggests a specific focus on the failure of the US, alone among the nations, to metricate, the bulk of the book takes place elsewhere, and has only tenuous relevance to the US failure. The book seems to be intended more as a capsule history of the metric system. And if this is indeed the intention, then there is a grave problem. To paraphrase Sherlock Holmes, there is a dog that didn’t bark in the night: the complete absence of John Wilkins (1614-1672).

Ten years ago, a book on the history of the metric system might have been excused for not mentioning John Wilkins, and parroting the conventional wisdom that the metric system sprang fully formed, like Athena from the head of Zeus, out of revolutionary France. But it is now known, largely from the research of Pat Naughtin, that the idea of systematized measures, divorced from any artifact, had been around long before: at least one hundred twenty years before the Revolution. In 1668 Wilkins published An Essay Towards a Real Character, and a Philosophical Language, which included a proposal for an integrated system of linear, volume, and weight measures. It was not an isolated effort. William Brouncker, and the far better known Christian Huygens, collaborated. But the man who came up with the technological device that made the system possible, the “seconds pendulum,” may have been Christopher Wren, not primarily a scientist (or “natural philosopher”), but the architect of London’s St Paul’s Cathedral. Wilkins’ book was widely read well into the 1800s, and the units for length, volume, and weight it advocated were remarkably close to those later arrived at by the French by more dubious means.

Marciano is aware of such devices as the seconds pendulum, and of Jefferson’s disgust at the French rejection of them, which makes his silence on John Wilkins even more puzzling. The same silence, incidentally, is found in Marcus du Sautoy’s recent BBC documentary, Precision: The Measure of All Things. Du Sautoy also makes the astonishing claim that the French insistence on basing the meter on the Paris meridian was somehow an act of cooperative internationalism. Marciano doesn’t go this far, and seems to understand that their seven-year exercise in trigonometry was ultimately pointless, but persists in calling this nationalistic reboot or retread of some very old ideas an act of invention. He also discusses problems with the seconds pendulum that were apparent at the time, but which could have been compensated fairly readily. (A seven-year study of the behavior of pendulums in various parts of the world would also have provided a lot of information on the precise shape of the earth.)

The author’s Tilt-A-Whirl approach to history is engaging, his chapters on the French Revolution more fun than a free ride in a tumbrel, but perhaps not by much. It’s actually hard to find much in the book that has anything to do with SI, today’s metric system, or even measurement per se, except by implication — possibly invidious. There are long sections devoted to such things as English spelling reform: Noah Webster’s partially successful efforts to redefine American English; and the completely unsuccessful attempts of such disparate characters as the rather pathetic Melvil Dewey (of Dewey Decimal fame), and Teddy Roosevelt. The efforts of advocates of artificially constructed languages, Esperanto, and its less-known predecessor Volapük, are detailed. One entire chapter is devoted to the development of standard time; and another is on attempts to rationalize the calendar, which continued through the 1920s. Cranky figures take the front row, including extended discussions of perhaps the greatest of nineteenth-century crackpots, Charles Piazzi Smyth, and his obsession with the Great Pyramid. Yet another chapter is given over to a man who, although no crank, is no more than a footnote in metric history: John Quincy Adams and his pointless and unreadable Report on Weights and Measures.

A great deal of the book concerns something that most people today wouldn’t think of as measured at all: money. This is justified on the grounds that “In the late eighteenth century, coinage was not only a part of weights and measures, it was the most vital part, and had been for thousands of years.” This is arguable (although some of us might point out there was an awful lot of measurement-based engineering going on in the ancient world, and when buildings and aqueducts fail, people die). But even granting this, money today is counted rather than measured: a very different thing. Neither SI, nor any of its several predecessors has a monetary unit. This doesn’t mean, however, that we aren’t going to be spending some time in Bretton Woods.

Eccentrics and guru-like figures continue to dominate in the “contemporary” section, from about 1970 onward (essentially just the last three chapters). Two of these are introduced in chapter one: Stewart Brand, described as a “libertarian prototechie,” and Tom Wolfe, a “literary icon in a white suit.” Brand, editor of The Whole Earth Catalog in its myriad forms (all of them aging ungracefully, or thankfully forgotten) specialized in demagoguery by using metric system and nuclear power in the same sentence on all occasions. Wolfe then apparently dealt metric a crushing blow when he judged a “Most Beautiful Foot” contest at a party called a “Foot Ball.” Yet another oddity: the editor of the American Journal of Physics (actually a teaching journal) is cited, apparently with approval, for using such units as the “jelly doughnut” (106 joules) in an attempt to make science more understandable. (Last time I looked, the joule was an SI unit, and 106 was the prefix mega-. I like reporting food energy in megajoules, and I’m completely on board with making science understandable. I’m just not sure rebranding the megajoule as a jelly doughnut is the best way to do this.) The book also degenerates into reporting anti-metric t-shirt slogans and schoolyard taunts of the era.

Does the book address any technical issues at all? Very few, but one comes up at least twice, attributed to Tom Wolfe: “NASA had gone to the moon on inches and pounds and had never considered any other system.” Not true, of course. The computers aboard the Apollo spacecraft performed all calculations in metric. Only the displays were in archaic units. Considering the low speed of those early computers, that unit conversion must have been a significant extra computational load. But it is true that NASA was and is hostile to metric.

The author is under the curious impression that NASA learned a lesson from the Mars Climate Orbiter: “America has gone metric where it has been useful to do so. Thankfully, this now includes space travel.” Sorry, but again no. Official policy to the contrary, NASA and its supporting industries are as intransigent as ever. For as long as the Space Shuttle was in service, NASA baulked at any attempt at metrication, on the grounds that the conversion of drawings would have been too expensive. Now the Shuttle is retired, and the US has no manned spacecraft. American astronauts thumb rides on Russian spacecraft. NASA has as near a clean slate as it will ever have. But the contract for Orion, the manned spacecraft intended to replace the Shuttle, was awarded to Lockheed Martin, at least in part because Lockmart specified in its proposal that archaic units would be used whenever possible.

And our poster child for rational, democratic metrication? Australia gets one mention, and only to say that it had found metrication a “relatively straightforward project.” Come to think of it, there is another dog that didn’t bark lurking here. The Australian experience was that metrication costs were so low they were instantly swallowed up in the benefits. Considering how money-oriented this author is, it’s strange he never considers such terms as one-time costs, or ongoing benefits.

The book ends on a weirdly inverted triumphalist note. In fact, the entire book is a kind of celebration of technical and economic eclipse as social triumph. When I picked it up, I had in mind a map of a metric world with one obvious, US-shaped black hole in it, and the question “What happened?” Now that I’ve put the book down, I still have the same question.



Expanding The Metric Vocabulary

By The Metric Maven

My Grandfather in Montana read an amazing number of books in his lifetime. Many of them were science and science fiction. He was one of the last of the US blue collar autodidacts.  A spare bedroom contained the books he had finished reading. There was little room to move, and the books were stacked almost from floor to ceiling in open half-high cardboard boxes. This arrangement placed the spines upward, which made the titles easy to read. He often gave books he read to charities, and always was generous with them. I could take any of the books I wanted. There was one exception.   My Grandfather had a very small shelf where he kept his favorites, with which he refused to part, come hell or high water. One I recall was Isaac Asimov’s Only a Trillion. I inherited another, which I believe made it to his 500 mm long literary shrine, it is Mathematics in Everyday Things by William C. Vergara (1923-1994). Vergara was an Electrical Engineer.

I ran across my Grandfather’s fragile paperback copy recently, and began to page through it. The book has short questions and answers. One which attracted my attention is: “Why is the color of incandescent light different than sunlight?” This caught my fancy because electromagnetism (EM) is my specialty, and also because it made me think of James Clerk Maxwell (1831-1879). It was Maxwell who first explained light mathematically, and suggested it be used to scientifically redefine the meter, which it was in 1960. Light is a wave which travels at approximately 300,000 kilometers per second. These waves are often explained with a simple wave diagram—even though they are more complex than this. Below is Figure 43 in Vergara’s book:

Vergara shows the number of wavelengths which pass by a stationary observer in one second. The diagram shows a wavelength of one foot—sigh. The frequency of this wave is 984.25 MHz. Had he chosen 300 mm for a wavelength, this would have produced a value nicely rounded to 1000 MHz for its frequency. The higher the frequency of a wave, the shorter its wavelength. Light waves are usually expressed in wavelengths and not frequency. Vergara then gives a table which details the wavelengths of different frequencies of EM waves:

I suspect some of you are cringing at the way the table describes lengths of different frequencies of light. I’ll get the complete horror over quickly, I will show you the next table, which gives the perceived colors of the rainbow and their wavelengths:

I’m sure by now you are expecting me to chastise Vergara for his sloppy use of the metric system. Clearly you probably expect me to first rewrite the first table using metric prefixes kilometers, millimeters, micrometers, nanometers, picometers and femtometers thus:

Radio, television, communications…….1000 km to 10 mm
Infrared……………………………………………300 µm to 760 nm
Visible Light……………………………………..760 nm to 400 nm
Ultraviolet………………………………………..400 nm to 13 nm
X-Rays……………………………………………10 nm to 10 pm
Gamma rays……………………………………100 pm to 500 fm

And you would be partially right.

One might have tried to spell them all out, as some readers might not be familiar with the prefix symbols.

Radio, television, communications…….1000 kilometers to 10 millimeters
Infrared……………………………………………300 micrometers to 760 nanometers
Visible Light……………………………………..760 nanometers to 400 nanometers
Ultraviolet………………………………………..400 nanometers to 13 nanometers
X-Rays……………………………………………10 nanometers to 10 picometers
Gamma rays……………………………………100 picometers to 500 femtometers

This looks rather clear for a popular audience. Another option is to not use metric prefixes and instead express all the values in meters, multiplied with appropriate engineering notation power of ten exponents. Honestly, I think spelling out the prefixes probably works best for a popular audience—or even an engineering or scientific one. One tends to look at the mantissa (significand) and the exponent is then later noted. This tends to obscure the interpretation of the magnitude of the values presented:

Radio, television, communications…….1000 x 103 to 10 x 10-3   meters
Infrared……………………………………………300 x 10-9 to 760 x 10-9  meters
Visible Light……………………………………..760 x 10-9 to 400 x 10-9  meters
Ultraviolet………………………………………..400 x 10-9 to 13 x 10-9    meters
X-Rays……………………………………………10 x 10-9  to 10 x 10-12    meters
Gamma rays……………………………………100 x 10-12 to 500 x 10-15   meters

The second table with perceived colors and their range of wavelengths, might be better shown in a modern way as:

Color                              Wavelength in nanometers (nm)

Violet…………………………….. 400-420
Blue………………………………. 420-490

Certainly the tables as originally written are not very clear, or cognitively easy to access, but it’s probably not Vergara’s fault. So why is it that I’m not blaming Vergara for the incredibly poor use of metric prefixes, crazy decimal expressions, and millionths of a centimeter?—and longtime readers know how much I dislike the centimeter. Because Vergara was restricted in his vocabulary of accepted prefixes. The copy of the book I have has a 1959 copyright. In 1959, the prefixes micro, nano, pico, and femto were not officially accepted as SI prefixes. The first three would be adopted in 1960 and femto added in 1964. Americans, fixated on the pseudo-inch British version of the metric system, known as the cgs system, latched onto the centimeter as a replacement inch, whether it was a good idea or not, and shoehorned it in. This remains far too prevalent in the US and is counterproductive.

Even though the prefixes had not been officially accepted, clearly there was some usage of micro by Vergara, but not the best use. On page 270 of his book Vergara has:

We think of one sound being so many times as loud as another, whereas, we would be hard put to say that the former is 43 micromicrowatts per square centimeter more intense than the latter.

Yes, he used micromicro (µµ) as a prefix which is the same as picowatts. Pico had not been accepted just yet either. Electrical engineers of this time period even had a slang term for micromicro, it was mickey mouse. Vergara’s first table of approximate wavelengths even had another option, which I’m glad he did not exercise: the angstrom. An angstrom Å is 10-10 meters, or one ten-billionth of a meter. This completely does not fit with the 1000 or 103 separation of modern metric prefixes, and destroys any logical consistency. Throwing angstroms into the mix has the potential to make the table even worse. Its usage is now discouraged, and I discourage it also.

The refinement of the metric system and its usage is an ongoing project. There were at least three different versions of the metric system at one time, and thankfully they were finally distilled to SI. The metric vocabulary was again increased in 1975, and 1991 when it was needed, but unfortunately the prefix cluster around unity has not been eliminated. The metric system becomes sleeker and sleeker, whereas the medieval Ye Olde English Arbitrary Grouping of Weights and Measurement units used in the US, linger, remain stagnant, and become more and more irrelevant to describe the modern world. There is no microbarleycorn. The use of Olde English units retards the maximum understanding of science by the general US population, which was the very group for whom Mathematics in Everyday Things was targeted. The refusal to adopt the metric system as the sole measurement system in the US, makes the modern world recede into incomprehensibility, and move toward explanations more congruent with magic than with engineering and science.