Metrication matters - Number 91 - 2010-12-10
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Contents
1 Editorial 2 Feedback - notes and comments from readers 3 Oddities - measurements from around the world 4 Tips - pointers and methods to make your measurements easier. 5 Signs of the times 6 Quotations 7 Q&A - readers' questions and answers 8 Rule of thumb 9 History 10 Hidden metric1 Editorial
Recently, my doctor suggested that I speak to a dietitian. Among her early remarks was:
"You should eat less kilojoules".My response was to ask:
"How could I do that? I’ve never eaten a kilojoule in my life?"I was tempted, but didn't, add:
"I don't even know how to cook kilojoules? What do they taste like?"Later, when I reflected on this unsatisfactory conversation, I realised that the dietitian was still using the old idea of using the word, calories, to refer to the energy content of food. She had simply taken Dr Lulu Hunt-Peters (1919) advice that said:
"You should eat less calories."And translated this to the post-1889 metric system energy unit, joule, and then chose kilojoule as appropriate for food energy when she said:
"You should eat less kilojoules."Clearly she was unaware of the basis of all measurement, which is that all measurements have four components. This is probably best understood by a fully written out example that applies to the air in the world's atmosphere.
The average pressure is 100 kilopascals.
In SI symbols:
p = 100 kPaThe four components are:
1 A statement of the quantity being measured — in this case pressure.
2 A mathematical sign to indicate equality, or in some cases inequality.
3 A number to indicate the amount of pressure.
4 A unit from the International System of Units (SI) with a suitable prefix (and with a space before it to show that the number and the unit are separate things).Going back to the dietitian, in her case the four essential components of a measurement have become:
1 A statement of the quantity being measured — in this case kilojoules are used in place of food energy.
2 A mathematical sign to indicate how many kilojoules — in this case "less than or <".
3 A number to indicate the amount of food energy — in this case the number is missing.
4 A unit from the International System of Units (SI) with a suitable prefix and a space before it to show that the number and the unit are separate things — in this case kilojoules is an appropriate unit.So the dietitian's measurement reads:
kilojoules less than kilojoules Her advice did not help me a lot. It would have been better for her to say:
In SI symbols
kJ < kJYou should reduce your intake of food energy each day, let's say you should eat a bit less than average. Your energy intake should be less than 6000 kilojoules.And you should increase your output of energy in the form of exercise; the energy balance rule is "Energy output should be more than energy intake", so your energy output should be more than 6000 kilojoules.
2 Feedback - notes and comments from readers
The words "metric conversion" owe the world a lot. As an approach to metrication, "metric conversion" has never worked anywhere on the world, and more importantly it delays real "direct metrication" upgrades dramatically.
Randy Bancroft wrote to tell me about a company from the USA who believed in "metric conversion" as they approached a challenge in Hungary. As you read the article at http://www.marshallindependent.com/page/content.detail/id/524515/Fagen-s-far-reaching-expansion.html?nav=5015 you might like to reflect on how much the company is paying for their "metric conversion" approach to metrication.
Their best choice was to take a few days to plan and adopt a "direct metrication" approach and then get on with their lives without "metric conversion"; without training Hungarian workers to use old pre-metric measuring words from the USA; without numerous errors due to "metric conversion"; and without corrective engineering to repair the "metric conversion" errors. See /docs/ApproachesToMetrication.pdf
3 Oddities - measurements from around the world
One of the characteristics of measurement before the metric system was the random invention of new measuring words by individuals. These were not and are not parts of any systems. Many people have not yet grasped the idea that the International System of Units (SI) is — a system! So they pluck parts of the SI and use these with old pre-metric measures. These are sometimes called hybrid units, mongrel units, or quite often, in Australia, using a name (b------ units) that refers to their doubtful parentage.
SI-imperial hybrids
These hybrid measuring words are what they are: randomly generated measuring words with very doubtful, even variable, definitions. Here are some recent examples:
- In the medical community, you can find references to grams per fluid ounce and grams per pound of bodyweight.
- In the athletic community, micrograms per fluid ounce, grams per pint and milligrams per quart are relatively commonly used for sports nutrition.
- Miners sometimes use something called an assay ton (abbreviated to AT). An AT is as many milligrams as there are Troy ounces in an avoirdupois short ton (1 short ton = 29166.6667 troy ounces). To find how many ounces of gold there are in a ton of rock, you measure the number of milligrams of gold in an (milli) assay ton of rock 29 1/6 Troy oz.
Borrowed prefixes
Sometimes the borrowed parts of the metric system are the prefixes:
- Gunners in the navies of the UK and the USA have used kiloyards.
- Engineers use the kilopound for 1000 pounds with kip as an abbreviation.
- The kilofoot is used in telecommunications when cable distances are measured in thousands of feet.
- Some optical distance measuring instruments have an option to display results in kilofeet
- Metal machinists often use the mil to mean 1/1000 of an inch; this is also known as a thou (both of these are close to 25.4 µm depending on the size of the inch)
- Some sawn timber suppliers in the UK also refer to a metric foot when they cut timber in multiples of 300 mm to supply customers who have asked for a foot or for 30 cm. In the 1960s during the metric changeover in the UK timber was sold by the metric foot; at that time wood could not be bought in either imperial feet nor in international standard metres.
- The similarly derived metric foot, of 300 mm, was at one time used in the United Kingdom for some expensive materials such as silver wire for jewellery, increasing the merchant's profits by about 1.6 % of their turnover.
- Scientists, still struggling to retain the jargon of old pre-metric measures, and for other reasons best known to themselves, sometimes talk about a rule of thumb for the speed of light as a foot per nanosecond.
- Computer scientists also use the foot per nanosecond but call it a light-nanosecond following the lead of the lead of Grace Hopper, an early American computer scientist and United States Navy officer, who popularised the light-nanosecond as the distance a photon could travel in a nanosecond.
- Astronomers cling to their old pre-metric measures such as astronomical units, parsecs, and light-years, as if these were accurate or even precise — when they know that they are not. A parsec is quite close to the accurate and precise value of 30.8568025 × 1012 kilometres but it often taken to be exactly 30.
- Computer programming managers, especially at IBM, use the expression KLOC (pronounced kay-lock) to mean a thousand lines of code using the metric prefix kilo and the in-house abbreviation LOC for 'Lines of Code'. Written 'Kilo-Lines of Code' and abbreviated KLOC, managers estimate that a programmer can produce 20 lines of bug-free working code per day so they estimate that 1 KLOC will take 50 days or about 10 weeks.
4 Tips - pointers and methods to make your measurements easier
Some metrication authorities identified the very few metric system "words" that people would need as their metric system vocabulary. For example, here is the complete set of eight metric system "words" that anyone needs to build or renovate any building in the world: cubic, gram, kilo, litre, metre, milli, square, and tonne.
And here is how they fit together:
1000 grams = 1 kilogram
1000 kilograms = 1 tonne1000 millilitres = 1 litre
1000 litres = 1 cubic metre 1000 millimetres = 1 metre
1000 metres = 1 kilometre1 metre x 1 metre = 1 square metre
1 metre x 1 metre x 1 metre = 1 cubic metreFor most people these eight "words" and their relationships can be learned in less than a minute. To prove this point here is a test:
How many grams are there in a kilogram?
How many millilitres are there in a litre?
How many millimetres are there in a metre?
How many kilograms are there in a tonne?
How many litres are there in a cubic metre?
How many metres are there in a kilometre?
The only other thing needed for an individual to be able to upgrade fully and quickly to the metric system are some personal measurements. These are the ones that I use almost every day:
- My little fingernail is 10 millimetres wide.
- My longest finger is 20 millimetres wide.
- My palm is 100 millimetres wide.
- My handspan is 240 millimetres.
- My normal pace is 750 mm, and I can walk with a stretched pace of 1000 mm ( =1 metre).
- A litre of water has a mass of 1 kilogram.
- If I place the tips of my two long fingers together and spread out my arms, my elbows are 1 metre apart.
The Metrication Board in New Zealand put it like this:
Public education was directed at teaching people the few little words which would make up their metric vocabulary and at encouraging them to develop new mental images of some five or ten familiar objects in metric numbers which would serve as benchmarks for metric sizes.5 Signs of the times
In the UK a simple policy change based on a metric system unit has had a significant effect on carbon dioxide emissions into the world atmosphere. See http://www.elopak.com/language=en/1956/key-principles where they say:
In 2007 the cap was set at 160 grams of CO2 emissions per litre of fuel for each car and employees had to select company cars which fell within this scope. In 2009, this was reduced to 140 grams per litre and is expected to reduce the annual CO2 emissions further.6 Quotations
Here is another thought from John P. Kotter (to consider as you reflect on your metrication planning):
What if good ideas are crushed 1) twenty times per day in one single big company (which, if it has 10,000 employees is a small number of ideas) and 2) once a day for every 1000 people in a country (which also sounds very small)? Do the math, and you find that's over 5,000 good ideas per year shot down in a big company and over 3 million per year in North America. 3 million good ideas a year, the best 1% of which—30,000!—might have a very large effect on a few, or maybe most, of us.
And never underestimate the negative effect of just one major change effort being derailed at your employer. Job losses go up, stock price goes down, quality of products or services slip, ... and what if it's not your employer but an organization that supplies your firm with critical software or has the mission of protecting your family against a terrorist attack.
The numbers add up. The consequences add up. And that, obviously, is not good, nor necessary.
So let's stop it.Did you, too, think of the "good idea" of beginning or completing your upgrade to the metric system as you read this? I sometimes go to http://www.kotterinternational.com/ then scroll to the bottom of the page to watch and be inspired by John P. Kotter's videos.
7 Q&A - readers' questions and answers
I received this request from a student in the USA, and as I prepared a reply, it occurred to me that others might also find this material useful. I have removed the student's name and address.
Mr Naughtin,I'm currently a student at (Named University) and I'm working on a term paper about the cost of metrication in the USA. I was wondering if you have any suggestions of where I could find information on how much this conversion might cost and different conversion methods (the actual steps the US would have to go through to make a full conversion).
Thank you for your time,Dear Student,
I am delighted if I am able to help you a little. Here are a few web pages that will answer some of your general questions:
/why_metrication.html
/articles
/newsletter scroll to the bottom for back issues.On the question of costs, you might like to consider these questions that I found on the USMA maillist:
- How many businesses in the USA have lost orders or contracts because they could not do the job in metric?
- How many businesses in the USA have made costly mistakes in converting a metric job to old pre-metric measures? See http://lamar.colostate.edu/~hillger/unit-mixups.html
- How many have had to pay a premium for metric parts because they only bought enough for a specific job?
- How many people have had their jobs terminated because they refused to work in metric? How much does it cost to find and employ their replacements?
- How much does it has cost the USA for not being metric?
- How much has not going metric really cost us? Have any estimates ever been made?
In answer to the final two questions, for an estimate of the cost of non-metrication in the USA, see /docs/CostOfNonMetrication.pdf
8 Rule of thumb
I think of normal air pressure as 100 kilopascals. And I think of the range of air pressure as going from about 110 kPa as the highest possible with 90 kPa as the lowest air pressure.
This rule of thumb is based on these observations.
1 Standard sea-level air pressure is regarded as 101.325 kPa
2 The highest air pressure ever recorded on a clear, very cold day in northern Siberia (with temperatures around -50 °C) was 109.4 kPa.
3 The lowest pressure ever measured was 87 kPa inside Typhoon Tip in the Pacific Ocean.By the way the number, 101.325 kPa, has no magic associated with it. It is simply an approximate conversion to SI units of the metric, but not SI, 760 millimetres of Mercury, which in turn is a rough approximation of 30 inches of Mercury. It seems that no one ever bothered to do any rational or even reasonable rounding when the "metric conversion" to SI was done.
9 History
The International System of Units (SI) that we usually call by the simple name, "the metric system", is the first complete, all embracing, system of measurement that was specifically designed for general measurement, trade and commerce, science and technology, and educational use. Such a world movement towards a single system of measurement had never happened before.
Before the invention of the metric system by Bishop John Wilkins, in 1668, no one had ever devised a "system" for measuring. There were only loose collections of old pre-metric measuring words that often had many different definitions. For example, the inch started out as a group of barleycorns but, many variations later, most people now use the metric inch of exactly 25.4 millimetres.
After the legalisation of the metric system in France in the 1790s other nations tried to retrofit metric system benefits to their old measuring words. One such attempt, in 1879, was the so-called British absolute system of units. They adopted a poundal as the unit of force to replace the gravitational pound weight but the system only applied to a few measuring words used by physicists and mechanical engineers. It was not widely used because it had already been superseded by the more comprehensive and coherent metric cgs (centimetre-gram-second) system of units that the British Association for the Advancement of Science had previously adopted in 1873 – the BAAS later un-adopted cgs in favour of mks (metre-kilogram-second) units in 1889.
10 Hidden metric
Martin Morrison wrote to clarify my position on something I had written in Metrication matters 89. I was delighted to reply as I have long admired Martin's work in "Metric Today", the newsletter of the U.S. Metric Association (USMA). Martin writes the column called "Metric Training & Education" and he has been writing similar columns for about 25 years! You can find out about membership of the USMA (and how to get your subscription to "Metric Today") from http://lamar.colostate.edu/~hillger/member.html
Martin wrote:
Here in the U.S. we seem to use "hard" and "soft" conversion for what you term "direct" and "hidden."I replied:
Dear Martin,
To me these are quite separate and distinct. For "hard conversions" and "soft conversions", I am referring to definitions like this (that I got from Kevin Wilks):
"hard" conversions
Where a product is not free-standing, and its dimensions or measurements must interlock or co-ordinate with those of other products which have been changed for the purposes of metrication, for example, door sets or window sets, changes in the dimensions of the product in question and the plant used in its manufacture are unavoidable. Because of the greater difficulty and effort involved in doing so, this operation is described as a "hard" conversion."soft" conversions
Where a product is free-standing and its measurements do not need to match, or coordinate dimensionally with, the measurements of any other product (for example, a table), that product and the plant used to make it do not need to be changed, except for the documentation used to describe it. In such cases, all that is required is to give the product a metric name in sensible metric numbers, in which its measurement name appears to be neither more nor less accurate than its original, for example, a 5 x 3 (ft) table becomes a 1500 mm x 900 mm table, though it actually remains 1524 mm x 914 mm. This is called a "soft" conversion.However, when I use the words, "direct" and "hidden", I am referring to the process you choose to use for your metrication upgrade. The definitions might be like this:
"direct" upgrade to the metric system
To do this you decide on the metric system units you will use in your daily activities. I choose these according to whether I am able to work in whole numbers with prefixes that are multiples of 1000:millimetres metres kilometres If I ever need to use less common units, (say joules for food energy) I select units from the International System of Units (SI) using the same principles of choosing whole numbers with prefixes that are multiples of 1000 (in this case I choose kilojoules).
grams kilograms tonnes
millilitres litres kilolitres
joules kilojoules megajoules
watts kilowatts megawatts
square metres cubic metresThen you decide on a date to "Go metric" – today is always good.
From the day you choose, you no longer use any of the old pre-metric measuring words, you do not use any of the old pre-metric words and you do not use any of the older metric units from the old cgs or mks collections. And you do not do "metric conversions" or support other people who want to take the, at least, 200 year-long "metric conversion" approach. I call this "direct metrication" because it is open, it is honest, and it goes in a "direct" manner from all of the old measuring words directly to metric system units.
"hidden" upgrade to the metric system
To do this you choose the metric system units that you will use and then you use them for designing and building your products and developing your internal processes. Then you choose to hide from the public the fact that you are using the metric system.
Examples of "hidden metric" abound in the USA; here are some:
Example 1: The computer you are now working on is completely metric. It was designed using nanometres for its computer chips, micrometres to layout its circuits, millimetres for its logic board, its case, and its screen. Finally, the screen was called something like 13" to mean thirteen inches. This is a deliberate delusion on the part of the computer company that is designed to fool you (and most other citizens of the USA) into believing that the USA is not metric. Your all-metric computer is "hidden" from you.
Example 2: You probably drive an all-metric car where all 100 000 measurements of the car’s 10 000 parts are all designed and built in millimetres. You were then deliberately deceived with the mph and ml on the dashboard and the ” and psi on the tyres. The car companies clearly do not want you to know that the motor industry in the USA successfully upgraded to the metric system in the 1970s. Your all-metric car, truck, tractor, or motorbike is "hidden" from you.
Example 3: In Utah, at the Kennecott copper mine, all the machinery is designed and built in millimetres. The ore is crushed and graded in millimetres. The chemical processes are done in grams, kilograms, and moles using volts, amperes, and ohms. And then, 280 pound ingots of copper are delivered to the public in tons (not tonnes). See http://www.kennecott.com/our-products/copper for the products and see http://www.kennecott.com/visitors-center/amazing-facts to see the information they make available (presumably) for school projects. The all-metric mining and refining processes are "hidden" from the company's customers and from school children.
Pat Naughtin
Geelong Australia
Pat Naughtin is a writer, speaker, editor, and publisher. Pat has written several books and has edited and published many others. For example, Pat has written a chapter of a chemical engineering Encyclopedia, and recently he edited the measurement section for the Australian Government 'Style manual: for writers, editors and printers'. Pat has been recognised by the United States Metric Association as a Lifetime Certified Advanced Metrication Specialist.
Pat is the author of the e-book, Metrication Leaders Guide, that you can obtain from /MetricationLeadersGuideInfo.html
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