Metrication matters - Number 18 - 2004-11-10
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1 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
7 Q&A - readers' questions and answers
8 Rule of thumb
10 Hidden metric
Jim Frysinger wrote to say that he found a metric oddity on an investigations into Mars. He 'found an interesting page' at: http://www.gwydir.demon.co.uk/jo/units/sea.htm where they said:
Jim Frysinger then went on to say,
'If you want an irrelevant fact, one minute of arc on Mars is close to a kilometre (.987 km to be more accurate). Perhaps the French who defined the kilometre were really Martians!'
Jim is a Lifetime Certified Advanced Metrication Specialist with the USMA and a Senior Member of the IEEE. You might like to check his web page at: http://www.cofc.edu/~frysingj
'The nekkid decimal point is not my fault! I would have written 0.987 km'.
Bruce Raup, from the National Snow and Ice Data Center, in Boulder, Colorado, wondered whether the cubic metre of air that I said had a mass of 1.2 kilograms would still have that mass if we moved it to Boulder. In Boulder, at a height of 1700 metres the air pressure is only about 83 kilopascals; in Geelong, at sea level, the air pressure is about 101 kilopascals. Maybe a reader of 'Metrication matters' could do a calculation for us.
The initial students of the 'Metrication Basics' e-course have now almost completed their ten week course, and I have been getting positive feedback with suggestions to improve the course. If you would like to join them, go to:
A student, Robert Tye, wrote to me and included this thought: '. . . there are very deep impulses in human nature towards universal common standards - and also very deep impulses to deny them.'
My take on this is that there have always been two opposing forces that apply to questions of measurement. One force is toward 'honesty in measurement' and the other is toward 'deception in measurement'.
The 'honesty in measurement' forces try for:
- fixed and well known standards of measurement
- honest well defined unit names that do not change according to personal or national whimsy
- methods such as the metric prefixes to avoid fractions (both vulgar and decimal) wherever possible
- readily available access to standards by everyone
- simple systems that are readily understood by all
- traceable pathways to national and international standards
- unit names that are protected by 'standards definitions'
- whole number rounded measures
The 'deception in measurement' forces try for:
- change size of 'standard' sizes and shapes of containers according to commercial needs and requirements
- complex unit names and methods that require 'expert' translation and interpretation
- downsizing and up-pricing as regular marketing techniques
- encourage jargon in measurement language e.g. micron, parsec, caret
- seek to claim false measures as 'industry standards' e.g. barns, barrels, carets, sheds
- use unit and concept names that can be and are corrupted at will, e.g. metrics, micron, kilo, mil
- use unit names that have many different meanings, e.g. tons of mass, tons of weight, tons of shipping capacity, tons of air conditioning, and tons, and tons, and tons, of other kinds of tons.
- use of fractional measures with complicated numbers
- use of fractions wherever possible - the more complex the better
- use of racial and ethnic slurs as arguments for keeping old measures e.g. describe the International System of Units (SI) as foreign French muck
I believe that the history of these issues is worth researching. We have little understanding of how measurement - which affects us all profoundly - is used by others for their own nefarious purposes.
The other day, in an Australian pub, I was served a 'pint' of Guinness. As I had a tape measure in my pocket (as you do!) I measured the beer as follows: internal diameter of 'pint' glass was 80 millimetres; froth on top of beer (say) 14 millimetres; volume of froth (approximately) 70 millilitres.
Assuming that the capacity of the Guinness 'pint' glass - it wasn't marked - was somewhere near 568 millilitres, then I received 568 - 70 = 498 millilitres of beer, which is close enough to 500 millilitres to call it 'half a litre'. In any case, its near enough for me to order 'half a litre of beer, please' next time I visit any pub that serves 'pints'.
You might like to run a special 'Metric Day' at your work, school, or college. Here is a story to inspire you.
Sally Mitchell, a chemistry teacher in the USA, says that her personal goal is 'to have the USA metric by 10/10/10!' She aims to achieve this by 'doing it one school at a time'. As she is a chemist she is a big supporter of Mole Day, which is named after the SI base unit, the mole.
Mole Day was celebrated on October 23 this year and, among many other activities, Sally baked a metric cake 1000 mm x 1000 mm x 100 mm.
5 Signs of the times
What a muddle we create when we try to use dual methods of measuring units. Jim Elwell bought a bottle of Duraflame 'fresh light' lighter fluid for lighting charcoal. On the front it had a typical label: '32 FL OZ (1QT) 946 mL', but on the back it read: 'Apply 70 ml (2 firm squeezes) per two pounds of charcoal'. Jim commented, 'Far more Americans would be comfortable with a 1 liter bottle than have a clue how much 70 ml is. Of course, no one is going to measure it (just give it two squeezes), but I still was surprised to see it labeled this way'.
A friend, in the USA, found a message board that discussed the weather, especially its technical aspects. He posted a message requesting that weather information be given in metric units (such as rainfall in millimetres and temperatures in degrees Celsius). The responses he got included:
'move to Europe'
'What are you, boy, one of them foreign national subversives?
This is the U.S., we don't need no stinkin' metrics.'
Men have the 'macho' thing, which requires them using feet, gallons, and cubic inches, etc, rather than this quiche-eating 'metric' stuff.
'Metric is for third world countries'.
Whenever I need to confirm my beliefs about the complexity of old measures I point my web browser to Russ Rowlett's list of units at: http://www.unc.edu/~rowlett/units/ and while I was there recently, I found this question and answer on Russ Rowlett's home page. It was listed as one of the most frequently asked questions.
What countries besides the U.S. have not adopted the metric system?
Many U.S. teachers think the answer is 'Liberia and Burma' (make that Myanmar). Let's give Liberia and Myanmar a break! All countries have adopted the metric system, including the U.S., and most countries (but not the U.S.) have taken steps to eliminate most uses of traditional measurements. However, in nearly all countries people still use traditional units sometimes, at least in colloquial expressions. Becoming metric is not a one-time event that has either happened or not. It is a process that happens over time. Every country is somewhere in this process of going metric, some much further along than others.
8 Rule of thumb
As you descend below the surface of the sea the pressure increases. The increase varies a bit with salinity and temperature, but in general, you can guess that the water pressure will increase by about 10 kilopascals of pressure for each metre you go below the surface.
By the way, I am always on the lookout for 'Rules of thumb' to add to my collection. I prefer metric ones but I also convert 'Rules of thumb' from old units to SI units. Please send your 'Rules of thumb' to
So there I was, sitting at the kitchen table measuring my shaftment - it is 165 millimetres long - and that's only on my right hand.
Before measuring tapes and rulers became freely available, most (men) folk simply used the measures that they had 'to hand'.
Approximate common measures were: the digit (the width of a finger, 20 mm), the nail (length of the last two joints of the middle finger, 60 mm), the palm (across the face of your hand at the base of the fingers, 90 mm), hand (width of your closed fist across the knuckles, 100 mm), the shaftment (width of the hand and outstretched thumb, 160 mm), the span (width of the outstretched hand, from the tip of the thumb to the tip of the little finger, 225 mm), and the cubit (length of the forearm from elbow to length of longest finger, 450 mm).
Note that these are the historical values for men; regular readers of 'Metrication matters' know that my wife, Wendy, has measured, and memorised, her own set of 'handy' measures and she uses them regularly. Check your own measurements and memorise your millimetre values. Note that using millimetres means that you don't have to fiddle with fractions or diddle with decimals.
10 Hidden metric
Each year, a horse race called the 'Melbourne Cup' is held on the first Tuesday in November. Aficionados of horse racing will know that horses from all over the world gather in Melbourne to compete for the four million dollar prize money. The race has been run over a distance of 3200 metres since 1974, but many traditional race horse fanciers still refer to the Melbourne Cup as a 'two-miler'. Melbourne is 70 kilometres from Geelong.
Please contact for additional metrication articles and resources on commercial and industrial metrication'.
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