Metrication matters - Number 10 - 2004-03-10
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
A UK reader passed on some more reports on aircraft accidents that involved measurement errors. You can find the details at:
As we all know, from our own experience, learning is a developmental process; we learn in readily identifiable steps as we move from being a raw beginner to becoming an expert. Educational and psychological experts tend to suggest that there are about six stages necessary for each of us to make this transition. I began to wonder whether this idea of six steps was relevant to metrication transitions.
Based on my reading in educational and psychological texts and on my own experience, and also understanding that change evolves through a process that involves our emotions, our thoughts, and our behaviours, I identified six steps of metric change as:
Six steps to metric CHANGE
Change in measuring circumstances is occasionally considered briefly but no specific metric action is contemplated.
Have half a mind to do something about metric change, one day, but again, no specific action is planned.
Accumulation of metric articles (rulers, tapes, scales, and information) and a beginning in the adoption of positive attitudes towards metrication.
Now is the time for action. Planning and implementation of metric plans is carried out.
Generally stable and consolidating phase where the new metric information is incorporated into daily life.
Exit from the change process means that a part of the metrication process is now complete. There is no going back. Further metric development involves polishing of already highly developed skills.
Scientists have measured the shortest time interval ever. They used short pulses of laser light to watch an electron moving around inside an atom, and were able to distinguish events within 100 attoseconds. An attosecond is 0.000 000 000 000 000 001 of a second. The scientists noted, 'It takes an electron about 150 attoseconds to "orbit" around the proton at the center of a hydrogen atom. Opening up the attosecond timescale could therefore provide new insights into the incredibly fast processes of the atomic world'. The modern metric system (SI) is clearly readily able to handle this small interval of time. As breakthroughs in astronomy, chemistry, genetics, mathematics, or physics occur, there is already provision made for measuring them within the SI system of prefixes. No measurement is too big or too small for SI.
In most parts of the world, the most common grade of office paper is specified as 80 grams per square metre. An A0 piece of this paper, which measures 1189 mm X 841 mm, has an area of one square metre and a mass of 80 grams; A1 papers are half this size; A2 are half of A1; A3 are half of A2; and when we get to the most popular paper size, A4, it is half of A3. All of this halving means that an A4 piece of paper is a sixteenth of the size of the original A0, or 5 grams. So when you are estimating how many stamps you will need to post a letter: count the number of pages; multiply by 5 grams; and add another 5 grams for the envelope. You can now check the number of stamps you will need in your local postal charges book.
5 Signs of the times
I was listening to Radio Netherlands a few days ago and they reported their local temperature as 'Minus 2 degrees centigrade or 28 degrees Fahrenheit'. As the 'Conférence Générale des Poids et Mesures (CGPM), the world authority on weights and measures, officially deprecated the use of degrees centigrade, in favor of degrees Celsius, in 1948, and the National Institute of Standards and Technology in the USA does not recommend the use of degrees Fahrenheit, one wonders who Radio Netherlands is trying to communicate with when they say, 'Minus 2 degrees centigrade or 28 degrees Fahrenheit'.
The metric system did not really catch on in the States, unless you count the increasing popularity of the nine-millimeter bullet. Dave Barry, Journalist, USA
Q A reader from the USA asked, 'Do cooks in Australia use 'gills' when they cook as I have seen them do in England?
A Australian volume cooking measures are: 1 teaspoon (ts) = 5 millilitres 1 tablespoon (TS) = 20 millilitres 1 cup = 250 millilitres 1 litre = 1000 millilitres The old measure, the gill, suffered its demise when Australia 'went metric'. No provision was made for 'metric gills' when Australia changed to metric. My research has found many definitions of gills, all of which have slightly different volumes. My favorite was from a country woman who told me that, 'a gill is a tea cup, politely filled'. Although she didn't exactly specify the technical terms, 'tea cup' and 'politely', her definition is about as good as any of the others.
8 Rule of thumb
A compact disk (CD) is 120 millimetres in diameter and 1.2 millimetres thick. 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 like old 'Rules of thumb' that I might be able to convert. Please send any 'Rules of thumb' to
Most nations now prescribe SI in their legal system since it provides a logical framework for all measurements in science, industry, and commerce. Often there is debate about the value of older systems but the legal basis of most nations' international trade is SI. Contracts written using old units (lbs, ft etc) or even wrong units (micron, mils) may well be challenged in local or international courts since it is possible that they could render contracts null and void.
10 Hidden metric
Astute soft drink buyers in the USA have noticed that the 591 mL (= 20 oz.*) container looks exactly the same size as the 600 mL container used in Canada and Mexico. They suspect that the 591 mL container size is really the same as the 600 mL container, but that it is (filled and) labelled as 591 mL. This is an obvious way to hold down costs by using the same container design in all three markets. It also makes it easy to convert the 591 mL size to metric when they finally decide to make the inevitable transition to metric measures. In the meantime the 9 mL difference adds 1.5 % of sales to their net profit, which isn't too bad for a slip of the pen. (* these are U.S. fluid ounces; they are not the same as U.S. dry ounces or imperial ounces!)
Pat Naughtin is a writer, speaker, editor, and publisher. Pat has written several books and he has edited and published many others. For example, Pat was the lead writer of 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.
Copyright notice: © 2004 Pat Naughtin All rights reserved. You are free to quote material from 'Metrication matters' in whole or in part, provided you include this attribution to 'Metrication matters'. 'This was written by Pat Naughtin of "Metrication matters". Please contact for additional metrication articles and resources on commercial and industrial metrication'. Please notify me where the material will appear. Copying for any other purpose, whether in print, other media, or on websites, requires prior permission. Contact:
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