Realm of Measure

Realm_of_MeasureBy The Metric Maven

Bulldog Edition

It can be interesting to read books from a bygone era about measurement. The current attometer per Zettasecond pace of metric change in the US requires one to look back historically to notice any change at all. I recently read the 1960 book Realm of Measure by Isaac Asimov. It is an interesting time capsule with which to compare the world of 1960 to current times. Early in the book (pg 4) Asimov asserts:

Even in modern times we are still refining our measurements. And although the world’s nations quarrel so desperately that it would seem they could never agree on anything, all have been honestly co-operating in the establishment of international systems of measurement.

Asimov’s statement indicates that more than one international system of measurement exists in 1960. This makes sense because it was in 1959 when a number of English speaking countries (including the US) finally decided to agree what the length of an inch is—well actually a yard—in terms of the metric system.

After Asimov presents pages of complicated units such as chains and the Russian verst he states (in 1960s vernacular):

Well, surely, you might think, the ingenuity of man can work out a better system. If you think so, you are right. The ingenuity of man has indeed worked out a better system, and this was done a hundred and fifty years ago. Unfortunately, we, in the English-speaking countries, have chosen not to benefit from it.

This better system is of course the Metric System.

Asimov spends time on centimeters and Kilometers in Chapter 3. Twenty-Three years later, when he writes his book The Measure of The Universe, Asimov realizes the non-utility of centimeters, centigrams, centiliters, and so on and makes this clear to his audience. But in 1960 he still introduces a table to convert from hectometers to dekameters, to decimeters, to centimeters. I have argued in the past, that from a twenty first century perspective this usage appears unnecessarily complicated, but when viewed in comparison with the plethora of US Anarchy Units of the era, even this bloated version of the metric system looks like a significant simplification (page 44-47).

The good doctor goes on to introduce the micron (pg 47):

For instance, people who work with cells, bacteria, viruses, and other microscopic objects find it useful to deal with the micrometer, which is one thousandth of a millimeter. (The prefix “micro-” comes from a Greek word meaning “small.”) This unit is very commonly abbreviated to micron, but I think this is sloppy because it hides the relationship to the meter.

Indeed, the micron is still a blemish on the metric system.

The notion of concatenated prefixes is still embraced at this time, which also balloons the metric system with unnecessary complication:

A thousandth of a micrometer is naturally called a millimicrometer, a unit which is invariably abbreviated to millimicron. The millimicrometer is a billionth of a meter and in 1960, the National Bureau of Standards has adopted the prefix “nano-” for a billionth. The millimicrometer may therefore be called the nanometer.

There is also a fatalism and acceptance of eponymous units:

..This unit [nanometer] is small enough to be used conveniently in measuring the lengths of light waves. The Swedish astronomer Anders Jonas Ångstrom suggested, in the 1860s that a tenth of a millimicrometer be used for this purpose. That length could be called a “decimillimicrometer,” I suppose, but no one ever uses that term. It is called simply an Ångstrom unit, in honor of the astronomer. Again, no one can tell from the name what the relationship is to the meter, but the thing is done, and cannot be changed.

The concatenated prefix fun of 1960 does not end there, we can even embrace the bicron if we want (page 48):


The accepted unacceptable ideas of 1960 continue when Asimov explains a contemporary desire to introduce a new unit called the X-unit! A division of this unit would be in honor of Enrico Fermi! Yet another eponymous unit. Here is a table from the text:


Asimov mentions the barleycorn and the mil, which is a feral unit that should have been vanquished from usage decades ago in the US, but is still used ubiquitously in the US Aerospace industry.

The gentle doctor argues for an idea that history and experience will squarely weigh-in against, metric gradualism. If the metric system is slowly introduced in schools he argues, the later adults would not find it so foreign:

Then, little by little, metric measurements should be introduced into common use, without necessarily replacing the common measurements. For instance, distances between cities might be given in both kilometers and miles on road maps. (pg 34)

Dual units only encourage the use of old units. This is clearly the situation in the US. Metric gradualism may eventually work, if one waits 1000 years or so.

The metric system of 1960 often accepts a pre-metric style of usage:


The Megagram is then dissed by Dr Asimov:


Asimov does not indicate that the term Megagram should be commonly used, and just accepts the current farrago of homonyms, where a metric unit is interpreted using a pre-metric Ye Olde English term for context, but I must remember, this is the world of 1960. Unfortunately, it is also the world of 2016. No one seems to notice that metric ton has nine letters and Megagram has eight. So why is the term metric ton so much more acceptable? Too many syllables?

The book lurches back and forth between cgs and mks expression which produces an intellectual vertigo. This dichotomy has always appeared to me as a proxy war between a Ye Olde English usage of the metric system (cgs), with the centimeter as a pseudo-inch, and mks, which would become SI. This struggle continues in the US, but is invisible to its participants. I see cubic centimeters and centipoise used regularly in the US.

One can be thankful that the use of millimicrons, quintals, myriagrams and such have apparently receded into history, even if the micron has not. The idea of X-units, fermis and bicrons have also exited from view. Unfortunately in the US, it is only omission of these bad practices that produce any noticeable change, as metric usage in the the US is of little consequence in the life the average person. It is easy not to use X-units, fermis and myriameters when the entire metric system is invisible in the US, but this omission is not exactly progress.


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.


3 thoughts on “Realm of Measure

  1. The 1960 timing of his book is slightly unfortunately as the International System of Units was only defined in 1960 by the CPGM. Prior to that prefixes nano and pico did not exist and double prefixes were common. Additional expansions to the prefix list were made in1964, 1975, and 1991.

    With no Internet back then, it took a while for word to get out. I’m not sure when the 1960 decisions began to be used extensively. The micron as a unit was a prior decision of the CPGM and was not abrogated until the 13th CPGM, 1967/8.

  2. An epiphany for the SI burst upon me in the fall of 1970 as I began my first college biology laboratory course. One graduate fellow quoted his infrared spectrophotometer readings to us in millimicrons, which seemed to me to be an awkward measurement unit. What is this, a millimicrometer? What kind of an expression is that? Well, in walked grad student number two, and he said the magic word. He gave us the readings in nanometers! I had not yet been exposed to the official table of SI prefixes, but nevertheless, it hif me—betcha that’s a better, logical way of breaking down that power of 10. Now, how sweet is that? This was four years before I signed on to the fight for U.S. metrication.

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