By The Metric Maven

Bulldog Edition

When I was in college, I studied Electrical Engineering. I was told many times that one was no longer to use concatenations of metric prefixes, this was considered very bad practice. What this meant was that one should not use two metric prefixes concurrently to designate values. At that time there were capacitors which were marked micro-micro Farad (μμF). Micro is 10-6 so two of them together would 10-6 *10-6 or 10-12. There is a perfectly good metric prefix called pico to describe this small amount of capacitance. The slang term is puff. So these μμF capacitors should be described as picofarad pF capacitors. This made perfect sense to me. I was surprised that such an ad hoc nomenclature would make it into engineering or be tolerated. When I took my first job, we used a device called a directional coupler to calibrate the power level of measurements. The coupling factor for the directional coupler was shown on a graph which was on an attached metal plate. The coupling was different at different frequencies and the graph was used for correction. The frequency axis of the graph said KiloMegaCycles. I knew this designation was from a long time back as cycles per second had been called Hertz for decades. I found this antique item to be a source of humor for me. Who on earth would write a frequency in Gigahertz (GHz) [109] as (KMHz) [103 *106 = 109]. How on earth did that make sense? What I didn’t realize was that the US “do your own thing” anarchy of weights and measures allows, and seemingly promotes this type of designation.

Imperial and US Olde English unit usage have been retained in the metric system, and have never been purged as they should have been. I’ve spent considerable time expressing my views about the centimeter as a pseudo-inch, (and have condemned the entire prefix cluster around unity), but there is a much more sinister and in-your-face Imperial/US Olde English holdout in the metric system. It is the tonne. The fact that there is an extra n and e should make one think Ye Olde English metric. The designation tonne is actually an approved usage! The tonne is properly called the Megagram or 1,000,000 grams, but when used in a completely feral manner they are known as metric tons—no extra n or e, just pigfish. So what is a metric ton? Well it’s 1000 kilograms, or 1 kilokilogram (KKg). It turns out that 1 kilokilogram is close to a short ton (0.907 kilokilograms). A ton is probably derived from a tun which was the weight of a barrel of wine. So why was it so important to taint the metric system with an unnecessary non-metric-metric unit? Had someone been drinking? Worse yet the metric ton is just another way of writing kilokilogram and pretending it isn’t poor usage. If I wrote something has a mass of 97 kilokilograms I’ll bet most pro-metric people would wrinkle their nose and pitch a small fit, but If I said 97 tonnes or even 97 metric tons, well, only the tinkling of ice in glasses around the metric table would be audible. How about K2g for metric ton?—I’ll bet that wouldn’t go over well either. So why is tonne or metric ton acceptable in polite company?

This blog was originally to be about Naughtin’s Laws and the press. I was curious about how “professional” people talk about large quantities. Well, it turns out that there are many varied and mangled ways that this is done by journalistic denizens of the only country which embraces US Olde English Units. I was curious about the amount of metals produced world-wide, and found a slide presentation with this table:

When my mind encountered the word kilotonnes, it seized up for a moment and I experienced metric vertigo. Kilotonnes!!! So in other words the amount of metal is being described is in terms of kilokilokilograms or KKKg! That sounds rather ominous—perhaps K3g would be better? Let’s see what would that be in non-pig-Latin metric? Oh, it would be simply Gigagrams. This is not to be confused with Gt which is proper pig-Latin metric for Gigatonne or in improper pig-Latin metric is K5g . The source of this table will remain anonymous. There is no need to single out this person, he never chose to be in the spotlight. But news items which are written by “Journalists” for the public, well, I’m less inclined to invoke a Metric Maven Client privilege. Lest you think this usage is uncommon, the article Great Balls of Fire in New Scientist on 2013-06-29 (page 42) describes the explosive impact of meteors in megatonnes and kilotonnes. Here are some values in terms of metric tons I randomly found on the web using a google search:

Mining operations in Amapa, where Anglo American produced 6.1 million metric tons of iron ore in 2012

According to Philips estimates, using the LED replacement could also eliminate 11 million metric tons of carbon emissions annually, or the equivalent of removing over 2 million cars from the road.

This clean solar generation plant will displace the equivalent of approximately 54,000 metric tons of carbon dioxide (CO2) per year, which is equal to the amount that roughly 2.2 million trees would displace annually

“The ground fish fleet is a huge contributor to local port economies,” he said. “In my district alone, on any given year, you will have a dozen trawlers that contribute 10,000 metric tons of fish and that represents about $20 million worth of product,” he said.

The Wikipedia article referenced below indicates that the Earth has around 40,000 Gt of carbon in the hydrosphere, biosphere and atmosphere

More than 2,000 farmers in six communities in the Northern Region will benefit from a 500 metric ton certified warehouse for grain storage at Datoyili, in Tamale.

From July-February 2012-13 about 5,590,775 metric tons of cement worth US$ 376.85 million exported as compared to 5,589,372 metric tons valuing US$ 303.71 million of corresponding period of last year.

Do you really have any idea of the comparative magnitudes offered in these news stories? I would bet not. Let’s try to get a handle on these values using Naughtin’s Laws (mostly) and Metric Prefixes.

Material Article Value Metric Value Iron Ore 6.1 million metric tons 6.1 Teragrams (1012) Carbon 11.0 million metric tons 11.0 Teragrams (1012) Carbon 54,000 metric tons 54.0 Gigagrams (109) Fish 10,000 metric tons 10.0 Gigagrams (109) Total Carbon (Eco System) 40,000 Gigatonnes 40.0 Exagrams (1018) Grain Storage 500 Metric tons 500 Megagrams (106) Cement 5,589,372 Metric tons 5.6 Teragrams (1012)

There is no excuse for Americans not to have an idea of the relative magnitudes of Mega, Giga and Tera. Computer disk drives were in Megabytes, then as they became larger they came in Gigabytes, and now one can buy external hard drives of 1-2 Terabytes without a problem. Peta–well, that’s way big, but one can look it up online without a problem if needed.

The presentation of quantities using metric tons only obfuscates a person’s ability to immediately compare them. It also in many cases can serve to obscure the decimal nature of metric values and money. For instance here is the pricing of copper in one article:

Benchmark copper on the London Metal Exchange (LME) hit a session low of $7,439 a metric ton (1.1023 tons), its weakest since August 21, and closed at $7,465 a metric ton…

We note that the price is given in metric tons, and then they provide a conversion factor for US Olde English short tons. Let’s see, copper costs $7,439 per metric ton; how could we possibly compute the price of other quantities? I have an idea, perhaps actually using the metric system might help? How about $7,439 per/megagram, or $7.43 per kilogram, or 74 cents per gram. Look ma!—no calculator! The metric ton designation really screws up the simplicity of decimals, which is one of the reasons metric was adopted internationally in the first place. Seriously, the metric ton is just a tonne of problems, it should have never been accepted as a legitimate usage in the metric system. It only serves to obscure, and that means that for unscrupulous persons, it’s used for dishonest purposes. It’s not a metric ton, it’s a Megagram! Members of the press—learn to count!—by using the metric system!

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Correction 2013-12-20 Total carbon corrected to Exagrams.

Related essay:

The Olde English Prefix Modifiers