Metrication matters - Number 64 - 2008-09-10
Dear Subscriber,
Metrication matters is an on-line metrication newsletter for those actively involved, and for those with an interest in metrication matters.
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Contents
1 Feedback - notes and comments from readers
2 Editorial
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 metric
1 Feedback
Edgar Warf from Colorado wrote to share some information about the Mars Climate Orbiter; he began:
Hello, Pat!
First, let me say that I greatly enjoy the newsletter. Many thanks to you and all contributors. It's a great service you provide - especially for those of us here in the USA who desire to see metrication take hold with a vengeance.
And then Edgar concluded:
We are not ignorant of metrication efforts or the ease and logic in using SI units, and we're converting to metric usage daily - admittedly, not quickly enough. I think the perception that the U.S. is greatly lagging in its metrication efforts is completely wrong. It may come from the idea that daily usage by the general public isn't common yet, but that will change dramatically once American consumers begin to see exclusive metric labelling. When that happens, there will be no going back to U.S. Customary units.
I can almost hear the cry now: Why on earth didn't we do this sooner!? We MUST get those units in front of the American public. It MUST be commonplace. That's the problem, but already, pre-1950 generations are well acquainted with volume measurements indicated in liters (L), and can easily identify beverage products on site as either 500 mL, 1 L, 2 L, or 3 L quantities. That alone is proof that a smooth transition to metric is possible.
Hey! Don't give up on us. We appreciate everyone's efforts to encourage our changeover.
Best regards, Edgar Warf
Harry Wyeth wrote to comment on my reference to Olympic running times, Harry wrote:
Hi Pat,
It takes a world-class sprinter to run those times! (such as 100 metres in 10 seconds)
I have, however, found that the rule of one minute for walking 100 m does work, but only with a brisk walk on a flat surface.
HARRY
Dear All,
Many thanks to the people who responded to this item in last month's newsletter. As I get more information on how and where you use the information in the Metrication matters newsletter, I am better able to focus future articles to your needs. All of your response will be used to improve the service provided to readers of the Metrication matters newsletter.
I hope that you are benefiting from the Metrication matters newsletter and that the metrication information is useful. If the newsletter is helpful to you could you please reply with a few words to let me know how you use the metrication information? I will look forward to receiving your comments as I continue to gather more metrication ideas from all around the world.
Pat Naughtin
2 Editorial
When the International System of Units (SI) was accepted as the universal measuring standard system in 1960, it became the first single universal system of measurement in the world — ever.
The International System of Units (SI) inherited all of the exploratory techniques that arose from John Wilkins' original concept for a 'universal measure' in 1668 that then became the French decimal metric system of the 1790s. Remember that the International System of Units (SI) was always intended to be a true 'universal measure' system in that, as the philosopher (and close personal friend of Thomas Jefferson) Condorcet put it, the metric system is:
For all time — for all people.
In 1901 an Italian, Giovanni Giorgi, showed that it was possible to combine the mechanical units of the metre-kilogram-second system with the practical electric units to form a single coherent measuring system. This led to the widespread use of a coherent metric system called the kilogram-second-Ampere system or by its initials, mksA.
Following the success of the mksA system in the first half of the twentieth century there were several attempts to reform the old pre-metric measures as if they, too, could be cobbled into some sort of a 'system'. Although these at best had only limited applications in small areas of engineering practice (where a definition of a foot could be agreed for example), they were often — inappropriately in my view — given the name 'system'.
Some of these so called 'systems' look fairly strange as they had to fit into a limited set of local or industry limitations. Here are some common examples of these partial 'systems':
◊ the foot-poundal-second (fps) 'system',
◊ the foot-pound-second (fps) 'system',
◊ the foot-slug-second (fss) 'system' and lastly, just for fun,
◊ the furlong-firkin-fortnight (fff) 'system'.
For more information than you will ever need about the furlong-firkin-fortnight (fff) 'system' go to http://www.uk-rec-sheds.org.uk/faq60.txt
3 Oddities
Recipe conversions
My wife, Wendy Pomroy, is a keen cook and she recently pointed out a web site for my amusement at http://www.recipezaar.com/175798. The recipe for Parmesan Oil required the following ingredients:
2 cups olive oil
3 1/2 ounces parmigiano-reggiano cheese, finely grated
3/4 ounce parmigiano-reggiano cheese, shaved (with vegetable peeler)
But if you use the change button to choose metric units you get:
- 18 ml olive oil
- 22 g parmigiano-reggiano cheese, finely grated
- 26 g parmigiano-reggiano cheese, shaved (with vegetable peeler)
Wendy said, 'It looks to me a lot like the original (probably Italian) recipe called for:
2 cups (500 mL) olive oil
100 grams parmigiano-reggiano cheese, finely grated, and
20 grams parmigiano-reggiano cheese, shaved (with vegetable peeler)'
And I replied (after a few days deep in thought):
Oh, how our lives we do pervert,
when first we practice to convert!
4 Tips
One thing you can do to promote the metric system at your work place is to pin pro-metric items on to notice boards around your work place. Here are some that you might like to download and print ready for 'National Metric Week' in the USA.
For a general purpose notice board think about:
/docs/degreesCelsiusPoster.pdf or
/docs/NationalMetricDay.pdf and
/docs/SIMetricUnitsVsUSAMeasures.pdf
Or if you work in a scientific or engineering environment you might like:
/docs/EnergyWords.pdf
Each year, the week containing 10 October (the tenth day of the tenth month) is called 'National Metric Week' by the United States Metric Association (See http://lamar.colostate.edu/~hillger/metric-week.html for details).
As a gift for your friends and to remind them of 'National Metric Week' you might like to pass along this one minute YouTube reference: http://www.youtube.com/watch?v=CeyGEwjLPGw or if you want to illustrate the cost of not going metric refer them to http://www.youtube.com/watch?v=Omh8Ito-05M/
5 Signs of the times
Apparently, it is a regular occurrence for a truck from Europe to get jammed under a bridge in England because the UK government cannot think how to put a sign on their bridges to tell its height in metres. See http://www.expressandstar.com/2008/06/18/metric-signs-call-after-crash/ for a recent example. My thanks to Markus Kuhn of Cambridge for passing on the Express and Star image and story.
6 Quotation
All the information in the world, however, doesn't change a thing until somebody takes action based upon it.
John Walker in The Hacker's Diet (http://www.fourmilab.ch/hackdiet/www/hackdiet.html )
7 Q&A
Question:
It annoys me to have to separate the number and the unit when I write metric units. When I write something like 12 m rather than 12m the number and the unit get separated onto different lines. To me the space looks odd, it seems unnecessary, and it wastes space. Why do I have to use a space between the number and the unit when we write SI?
Answer:
When you write something like 12 m you are actually writing the equivalent of two words using their internationally accepted symbols. In this case the words are 'twelve', and 'metres'. If we left out the spaces between the words this would become twelvemetres. In words it is obvious that spaces help us with readability. This is also true with numbers and units but it might not be so obvious.
At another level, you might like to check the decision of the Conférence Générale de Poids et Mesures (CGPM) on this issue. Go to http://www.bipm.org/en/si/si_brochure/chapter5/5-3-2.html where you will find this:
The numerical value always precedes the unit, and a space is always used to separate the unit from the number. Thus the value of the quantity is the product of the number and the unit, the space being regarded as a multiplication sign (just as a space between units implies multiplication).
You will notice that the CGPM includes the word, 'always' when it refers to the space between the number and the unit. This makes it clear that the space is not optional. My thanks to Jim Frysinger, from Tennessee, for this reference.
As a practical matter, I use a non-breaking space between the number and the unit so that the unit does not end up on the following line without taking its number along with it. As I use Microsoft Word on a Macintosh computer this is done by holding down the 'option' key while I touch the space bar. I believe that other software/computer combinations also produce a non-breaking space by using a similar method; try the Ctrl+space keystrokes for example. I have become so used to adding a non-breaking space between a number and a unit that it is now habitual for me; I even use a non-breaking space between the groups of three zeroes in a number like 6 000 000 so that the number doesn't get broken between lines.
8 Rule of thumb
The average daily food energy requirements for a man or a woman of average height and mass are as follows:
Activity | Men | Women |
Light | 12 MJ/day | 8 MJ/day |
Moderate | 14 MJ/day | 10 MJ/day |
Heavy | 16 MJ/day | 12 MJ/day |
Exceptional | 18 MJ/day | 14 MJ/day |
9 History
This is by way of being a history of a history. In Paris in 1901 the Ministère du Commerce et L'Industrie published a book called Le Systéme Metrique Decimal de Poids et Mesures by G Bigourdan (Paris 1901).
I was interested enough to request a translation of several sections of this book because the title translated into English as, 'The Decimal Metric System of Weights and Measures'. I assume that the book had been commissioned to commemorate the 100 years of the metric system in France from 1799 to 1899. Here is a translated segment from the introduction (Thanks to Marie McKenna and Barbara Hall for their help with the translation):
The creation of the metric system now dates back for a century, and the Weights and Measures of the metric system are now scattered throughout the world; very soon they will be the only measures used in all civilized countries.
After 100 years the time is right to recall the founding of this system which is honored as among the most useful creations of mankind, and whose merits are universally recognized. In fact no other achievement has brought such credit to the good name of France,
10 Hidden metric
From time to time academics play metric conversion games with their students to fill in some class time with truly pointless activities where metric conversion tasks might be written like these two:
Convert furlongs per fortnight into metres per second.
What is the speed of light in furlongs per fortnight?
You need to accept these conversion factors (without quibbling about how they varied in their historical definitions):
length — furlong — 1/8 of a mile — 201.168 m
mass — firkin — 9 gallons (Imp.) of water — 40.91481 kg
time — fortnight — 14 days — 1 209 600 s
So the answers are: 0.166 309 524 metres per second, and 1.802 617 x 10^12 furlongs per fortnight (say 1.8 terafurlongs per fortnight)
Astute readers will quickly notice that 0.166 309 524 metres per second is close enough — as a rule of thumb — to 10 millimetres per minute; and that 1.802 617 x 10^12 furlongs per fortnight might be more easily remembered as 1.8 megafurlongs per microfortnight.
And so, at the risk that I might bore you with repetition:
Oh, how our lives we do pervert,
when first we practice to convert!
See /metric_conversion.html for a commentary on the process of metric conversion.
Cheers,
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.
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