Metrication matters - Number 47 - 2007-04-10
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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
Michael Worstall wrote from the UK:
Pat ... absolutely with you on the editorial and your two page article referenced there.
(See: http://www.metricationmatters.com/docs/AWordAboutGlobalWarming.pdf )
Regrettably the energy industry in UK quotes domestic supplies in kilowatt-hours which is all very well but again needlessly complex because it is merely power x time when what they are selling is really energy i.e. joules. Currently I am in a painful struggle to get a howler corrected in the official literature of British Gas where (three times) on all their UK bills they have printed kilowatts instead of kilowatt-hours thus making complete nonsense of their explanation of their financial charging policy. The first difficulty is to find anyone who answers the phone to realise that there is a difference between power and energy (as you mention). The combination of ignorance and apathy is deeply shocking to behold in a private company.
Good luck with your joule campaign.
Joules for ever.
Chartered Electrical Engineer, UK
Michael Worstall has a footer at the bottom of his emails that reads:... the greatest invention of human ingenuity since that of printing ...
John Quincy Adams, praising the metric system, 1812
Medical errors have, once again, become an item of news in the USA. On Tuesday, 2007 March 6 the Washington Post carried this article:
Risk of Errors In Medication Said to Rise With Surgery
Patients going under the knife face a significant risk of becoming the victim of a medical error involving medication, according to a report being released today.
The report, the largest examination of medication errors before, during and after surgery, found that operations are among the riskiest times for mistakes involving drugs.
The report was prepared by U.S. Pharmacopeia, a private group that sets standards for the drug industry. It has been gathering reports from hospitals nationwide about medication mistakes.
Its latest report is based on data voluntarily supplied by more than 400 hospitals about medication errors from 1998 to 2005 that occurred during outpatient surgery, in preparation for surgery, in the operating room and in recovery.
A total of 11,239 errors were reported, including giving the wrong drug or the wrong dose, or giving it at the wrong time.
Many of these errors arise when medical people are trying to convert between metric units and old pre-metric measures for no apparent reason.
In Beverley Sutherland Smiths Australian cookbook The seasonal kitchen she writes:
1 level teaspoon = 5 fluid ounces
1 level tablespoon = 15 fluid ounce
This is an interesting error in that anyone would find it exceedingly difficult to fit over half a cup of something like sugar or flour into a teaspoon (at one sitting!)
I think that she meant to write:
1 level teaspoon = 5 millilitres
1 level tablespoon = 15 millilitres
But even then she would be wrong as, since the mid 70s, volume measures for Australian cooking are:
1 teaspoon = 5 millilitres (mL)
1 tablespoon = 20 millilitres (mL)
1 cup = 250 millilitres (mL)
Standards Australia AS 1408 1997: sizing scheme for cooking utensils.
By the way, I suspect that the 15 millilitres for a tablespoon chosen by Canada, the UK, and the USA, is simply a soft conversion from the old pre-metric 'half an ounce' (without specifying whether this approximation is an avoirdupois, a fluid, or even a Troy ounce).
Clearly, conversions can lead you to all sorts of problems.
The Australian government has decided to phase out all incandescent light bulbs within the next three years in favor of the fluorescent lights as a means of saving thousands of tonnes on greenhouse gas pollution.
In the light of this global warming news, you may be trying to decide whether to use the old incandescent lamps or the newer fluorescent ones. This information might help.
We use the watt (named after the English engineer James Watt) as the unit of power in the International System of Units (SI). Some people believe that the watt is used to describe the brightness of a light bulb, but that's not correct.
Bill Hooper, from Florida says:
The number of watts labelled on a light bulb is not a measure of its brightness; it is a measure of how fast the bulb uses energy. The brightness is measured in lumens.
For example, a fluorescent bulb I recently bought produces 850 lumens of light while burning 15 watts of power (15 joules of energy per second). That compares to a 60 W incandescent bulb that requires 60 joules of energy per second and typically produces between 850 and 870 lumens of light (depending on the design of the bulb).
5 Signs of the times
You have possibly heard that after much prolonged debate, Pluto has been downgraded from a planet to an asteroid.
This poses a problem; as you will need to truncate your planetary mnemonics. Sentences such as:
- Mary's Violet Eyes Made John Stay Up Nights Proposing,
- Men Very Easily Make Jugs Serve Useful Nocturnal Purposes,
- My Very Early Model Jeep Sits Unused Needing Petrol,
- My Very Earnest Man Just Save Us Nature's Plan, and
- My Very Educated Mother Just Showed Us Nine Planets,
can only survive if you mentally delete the last word.
While all this is true, it has nothing to do with Metrication matters except that no-one has yet devised a mnemonic for the list of preferred prefixes. Here's a reminder from Metrication matters 4 to challenge you:
Prefixes less than 1 (sub-multiples):
millie, mike's nana, pickled fish at zepto's yacht(o)
Note: I considered fems instead of fish, but I couldn't bear its sound or its political incorrectness.
Prefixes more than 1 (multiples)
killer Meg, Giggling, Terrified Peter's Extra Zits. Yuk!
Note: I considered 'kindly Meg' but then I grew to like 'killer Meg' much better.
I make no apology for the silliness of the words that I chose for these mnemonics. Mnemonics seem to work best if they contain off-the-wall ideas or reasonably strong rhymes or rhythms; I've been wondering for years why: 'Every Good Boy Deserves Fruit'; but this music mnemonic still works, and works well.
Every truth passes through three stages before it is recognized.
In the first it is ridiculed, in the second it is opposed, in the third it is regarded as self-evident.
Arthur Schopenhauer (1788/1860) German philosopher
Recently we learned about times on a 24 hour scale at my school in Canada? Our teacher said that it is called military time and that it is used in military operations but I have also heard it used on the BBC radio. Do people around the world actually use the 24:00 times in their day-by-day activities?
You are right. You did hear it on the radio as you were listening to the BBC outside the United Kingdom. The BBC has an interesting practice of using the 24:00 hour format for broadcasting outside the UK; but they change this to the am/pm format for their internal domestic radio and television output! Here are some other examples:
- Military operations all around the world use the 24:00 format. This includes the military in Canada and the USA.
- In most countries, including Canada, 24:00 hour times are used for air and train travel for both timetables and for the status displays at airports and train stations.
- When I last visited Canada I noticed that the 24:00 hour time used more in Quebec than in the other provinces. Perhaps this is in keeping with their French heritage; in France, it is usual for (say) a wedding invitation to be for 16:00, with the reception at 18:00.
- The 24:00 hour format is also common throughout continental Europe. In Poland, for example, 24:00 hour times are used for most day to day activities. You might invite guests for dinner at 18:00, or tell your friends that you put your young kids to bed at 21:00.
- When a friend of mine was in Germany, he noticed that signs in shop windows stated that the store opens at 9:00 and closes at 18:00. A German friend even asked him, 'What do a.m. and p.m. mean?'
- In the USA, other than for military purposes, the 24:00 hour time format is regularly used for work environments such as hospitals, public utilities, and manufacturing plants that operate around-the-clock.
To find out more about this (for a school project for instance) put "ISO 8601" into a search engine such as Google.
8 Rule of thumb
Your skin is your largest organ as it is between 12 % and 15 % of your body mass. Usually you skin is between 2 millimetres and 3 millimetres thick and you can estimate the surface area of your skin by noting your height in metres (say 1.7 metres) and simply calling this square metres (1.7 square metres).
If you are 1.65 metres tall then your skin has an area of about 1.65 square metres; if you are 2 metres tall then your skin has an area of about 2 square metres; and so on.
As a comparison, the surface area of:
- your lungs is about 50 times larger than your skin at about 100 square metres, and
- your intestines is about 150 times larger than your skin at about 300 square metres.
A decisive choice about money was made by the German leader, Bismarck, in 1875. The German recoinage of 1875 ended the inconsistent muddle of the coins of the German states; the new 20 mark coin was fixed at 7.168 5 grams of pure gold, as against the 7.258 1 grams or the French 25 franc coin.
This was an historic decision since the 89.6 milligram difference (1 1/4 %) between these two coins meant that Europe could not share a single currency in 1875. It also made it impossible to make any further progress towards a common European currency for another 100 years. Although Bismarck's motive was based on internal German politics, the great English economist William Stanley Jevons commented:
It cannot be too much regretted by all friends of progress that, in deciding upon the weight of the new mark piece, the German Government should have studiously avoided assimilation to the France system.
10 Hidden metric
When you measure an iPod nano, you find that it is exactly: 90 millimetres high, 40 millimetres wide, and 6.5 millimetres thick, with a screen diagonal of 38 millimetres. However, the iPod nano is listed at http://www.apple.com/ipodnano/specs.html as: Height: 3.5 inches, Width: 1.6 inches, Depth: 0.26 inch, with a screen of 1.5 inches.
You have to wonder if any purpose is served by all of this dumbing down!
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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