Category Archives: Metric Education

The International Unit of Mystery

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By The Metric Maven

I have had the pleasure of visiting a number of technology and manufacturing firms over the years. But whenever I question them about if and how they use the metric system, I often feel I’ve been thrust into an Austin Powers movie. Because Austin was frozen in the 1960s and thawed in the 1990s he had not kept up with the times. His use of groovy is clearly anachronistic.  Dr. Evil’s plan to hold the world hostage for ONE MILLION DOLLARS shows that he has not been out to purchase a Bob’s Big Boy Burger in a while. His cryogenic nap has left him  culturally temporally challenged. Here is a version of the Austin Powers conversation I have about metric:

MM: “So, do you use metric here at your company”

Proud Company Representative: “Yes we do, we use microns and millimicrons.”

My mind halts and is transported back to the time many moons ago, when I was employed at my first engineering position. This position is also where I produced my first drawings in metric, and was told in no uncertain terms that they would not be accepted. Not long after I had been told that metric was not acceptable in aerospace, I had a dimension described in microns. “Micron?, what the hell is a micron?” I thought. I’d never heard of it when I was in college or doing amateur projects. I opened up my copy of Reference Data for Radio Engineers, which was published in 1982. There was no entry for micron in the index. Another engineer who also had a copy said, “look on page 1-1” which is the very first page of the reference. When I did, the book did not exactly define the micron, but it did have this footnote: (Note that the term “micrometer” has superseded the term “micron.”). Micron was only mentioned as a term which should not be used in engineering work, which I was now told to use in my non-metric aerospace engineering environment. Now that’s groovy baby! Just as groovy, was the use of the term mil or 1/1000th of an inch. This was the aerospace default measurement “unit,” but the way micron and mil were used, one might never realize that one was Ye Old English, and the other a poor usage of the metric system. Microns were welcome, but no micrometers please, this is American aerospace, only proven “heritage” is welcome.

In fact I seldom heard micron used, so mil became the preferred default feral non-unit of choice. Then when discussing some coatings with a researcher one day, he said “yeah, these are really thin” and then quoted a value in millimicrons. Millimicrons? Ok, so we’ve proudly added a metric prefix to a non descriptive archaic metric moniker of French origin which has lost its prefix. In other words it’s a millimicrometer,  which is of course a nanometer for those of you out there who are numerate.

Wikipedia confirms my experience with a micron in industry:

The term micron representing the micrometre, was officially accepted between 1879 and 1967, but officially revoked by the International System of Units (SI) in 1967.[2]

Nevertheless, in practice, “micron” remains a widely used term in preference to “micrometre” in many English-speaking countries, both in academic science (including geology, biology, physics, and astronomy) and in applied science and industry (including machining, the semiconductor industry, and plastics manufacturing).[citation needed] Additionally, in American English the use of “micron” helps differentiate the unit from the micrometer, a measuring device, because the unit’s name in mainstream American spelling is a homograph of the device’s name.

In engineering it is common to use the micron as a replacement for the traditional thou or mil, each of which represent a thousandth of an inch. So a bin bag may be originally specified as 0.35 mil thick, but stated as 8.89 microns.

Part of this Wikipedia entry is laughable: “the use of “micron” helps differentiate the unit from the micrometer, a measuring device.” I used a micrometer when I worked as a printer, and experienced a bit of machining. Every US technical person I’ve met calls the measurement device a My-crom-et-er (accent on the first syllable). The measurement unit is pronounced mike-Crow-meter with an emphasis on the second syllable. The word micron is pronounced mike-ron, and the instrument for measurement, the micrometer, is proverbially called a “mike.” When I worked as an offset pressman, all other printers called a micrometer (the instrument) a mike. We generally shared one mike, and I never recall a single pressman requesting that he borrow the “micrometer.” This explanation appears to be yet another strange after-the-fact rationalization for strange versions of US metric non-usage. The micrometer-micron usage explanation also appears similar to folk etymology. There is no excuse other than the irrational urge for US engineers to continue Living in The Past.

Wikipedia also “weighs in” (I could not help myself) on the millimicron:

The nanometre was formerly known as the millimicrometre – or, more commonly, the millimicron for short – since it is 1/1000 of a micron (micrometre), and was often denoted by the symbol mµ or (more rarely) µµ.[1][2][3] In 1960, the U.S. National Bureau of Standards adopted the prefix “nano-” for “a billionth”.[4] The nanometre is often associated with the field of nanotechnology. Since the late 1980s, it has also been used to describe generations of the manufacturing technology in the semiconductor industry.

I’m not knowledgeable enough of the current workings of the semiconductor industry in the US to know if they use nanometers or not. I do know one of the largest  semiconductor corporations uses it as a company name. The irony of using micron is that it appears it was coined by the French in 1880 for one millionth of a meter, and became accepted in 1892. Apparently the tonality of a French term for a micrometer is so alluring that Americans just can’t give up sonorous franophonic sound of the word micron.

One would generally never get a clue that the micron is French, or a metric measurement when looking through a US technology catalog. Here is an advertisement for a micromachining product:

One of the most curious of articles I have come across, is in a trade magazine. The article has five authors, and is about a new glass material which allows one to create through glass vias (TGV). Vias are just methods of connecting electric circuits together. The entire article is nothing but a discussion of micron dimensions. The  caption for figure 2 is all microns:

The next figure has descriptions using microns, but also reminds the reader that it is a millimeter wave circuit.

The final figure in the paper is even more “descriptive,” it has millimeters, microns, and micrometers:

The mad desire for microns is not confined to engineers. Caleb Scharf in his 2012 book Gravity’s Engines on page 52 describes interstellar dust:

This is not the same kind of dust you find under your bed. This is far finer and very different in composition. A typical grain of interstellar dust is only about 0.001 millimeters (one micron) across….

It’s not Austin Powers fault that he had not kept up with the times, he never experienced them. We in the US have no excuse when it comes to metric usage, other than we refuse to experience change, and try to preserve the perfected world of 1789 forever.

Postscript

I thought the use of the micron was exclusively a US problem, but apparently it exists in Europe and the UK. A blog from the UKMA describes the problem: The Reports of the Death of The Micron are Greatly Exaggerated.

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.

Fossilized Units

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Cover

By The Metric Maven

Bulldog Edition

Recently I watched Elizabeth Kolbert give a lecture on Book TV about her book The Sixth Extinction. It was quite engaging. I put off purchasing the book as a lot of its contents were familiar. During a protracted period of free time I purchased a paperback copy. I sat down and began to work my way into the book. There were three pages of quotations which praised the writing and content. Then the title page, followed by the edition page. A page with quotations was next and then a table of contents. It was all very normal and snooze-worthy.

Then I hit a page entitled Author’s Note. I have reproduced it below:

Metric Disclaimer

The first clause of the first sentence just hit me like a slap. Here is a book, which is essentially about science, and asserts that “scientific discourse” uses the metric system, but we will not be using it in this book. The word discourse is about written and spoken communication, which 95% of the worlds population, scientific or not, uses the metric system to accomplish. There is 5% who do not, and they make their entrance after the comma.

The next assertion is that Americans “think in terms of miles, acres, and degrees Fahrenheit.” When I read this to Sven, he said exactly what was in my mind: “think?” Miles often act as a proxy for time, but seldom would anyone be able to walk along a stretch of the Bonneville Salt Flats and mark off a mile by estimation. I’ve asked farmers several times “how many football fields are there to an acre?” I’ve not met one that knew the answer. An American football field is about 6400 square yards. An acre is 4840 square yards and so an acre is smaller than a football field. Not even the average US farmer has any idea of the size of an acre.

I decided that as I read the book, I would keep track (as best as I can) of all the uses of measurements in the book. I was curious as to how many units would need to be changed for a readership which is outside of the US, that also speaks English, and uses metric.

I did my best to mark pages with units and tally them:

feet: 33    inches: 13     miles: 13    square miles: 9   acres: 6    pounds: 5

tons: 4 (?)  metric tons: 3   yards: 2    meters: 2   micron: 2   Fahrenheit: 2

pH:2   ounce: 1  quart: 1 megatons TNT: 1 hectare: 1    square foot: 1

parts per million: 1  square meter: 1

We see that Ms. Kolbert appears to have a preference for feet, followed by a tie between inches and miles.

Despite her best effort, the metric system sneaks its way into the prose. On page 85 and 154 they are embedded inside of quotations from scientists. There the author decided not to convert and put values in brackets.

Strangely the word micron appears twice in the book in prose generated by Ms. Kolbert:

Several groups of marine organisms came within a micron or two of annihilation. (88)

Riebsell has found that the groups that tend to fare best in acidified water are plankton that are so tiny—less than two microns across—that they form their own microscopic food web (119-120)

The first quotation is a metaphor, but it used a value from the metric system. In the second, a numerical estimate of magnitude is given, and so the unit is supposed to represent a range of metric values. The micron is an out-of-date term for the micrometer. What I’ve come to suspect is that Americans will use this unit, and incorrectly believe it’s part of our Ye Olde English arbitrary grouping of units.

Ms. Kolbert also uses “metric tons”:

Since the start of the industrial revolution, humans have burned though enough fossil fuels—coal, oil, and natural gas—to add some 365 billion metric tons of carbon to the atmosphere. Deforestation has contributed another 180 billion tons. Each year we throw up another nine billion tons or so, an amount that’s been increasing by as much as six percent annually.

It goes almost without saying, that using the term “metric ton,” instead of the proper term, Megagram, helps to start the confusion. The next two units cited are only called tons, not tonnes (which I also would do away with). Did she suddenly switch from metric to long or short tons in Ye Olde English?—or did she assume we would assume “metric tons.”

On page 200 a small bat is described:

They’re little—only about five inches long and two-tenths of an ounce in weight.

When we write the fraction symbolically, it’s 2/10, which my extensive Ye Olde English training tells me should be written as 1/5, so that Americans can “think in terms of ounces.” Is it possible she uses tenths because she can’t keep away from decimals—like those often found with the metric system?

Hectare is also found within a quotation on page 189, and square meters exists exactly once that I count, and was used by the author, but still refers to a number which was probably used by the researchers:

More recently, American researchers cracked open chunks of corals to look for crustaceans; in a square meter’s worth collected near Heron Island,…..

If Americans think in Ye Olde English, why didn’t she use 10.76391 square feet?—or 1.19599 square yards?—or perhaps 0.000 247 104 acres?

It seems almost juvenile to attempt to eschew metric. “Don’t use the m word around Americans little Johnny, it’s not polite—and they won’t understand it.” Instead we are served up a smorgasbord of fossilized units in place of a more succinct and expressive number of metric ones. Nothing demonstrates how provincial America is, when it comes to science, more than the idea that publishers need “special” books for our “special” country. Indeed with our need for medieval units, why should it be surprising that we have a medieval view of science? Other countries purposefully drove the extinction of non-metric units long ago. It’s one extinction I wish would occur in the U.S., so that we might better understand the Anthropocene extinction that’s underway, and better determine any course of action we might take. What we find instead are fossilized minds, using fossilized units, to describe fossilized creatures. Why would we expect anything other than a fossilized outcome?

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.