Metrication matters - Number 20 - 2005-01-10
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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
Several readers pointed out that the 'speed of lightning' cannot be faster than the 'speed of light'. This response was typical: 'There seems to be an error here. The speed of light is 3 x 108 metres per second. The real answer is that lightning travels at about half the speed of light at 1.5 x 108 metres per second'.
Sorry about the error – I can't even claim that ancient concept of 'greased lightning', as my mistaken calculation had the lightning travelling at about 60 times the speed of light – Oops!
I don't think that Albert Einstein would approve such a fast speed of lightning, especially in 2005, the international 'Year of Physics'.
While we are on the subject of feedback, could I ask you one question:
' What's the biggest metrication challenge you face in your business?'
Please send me your answer to this question before the end of January so I can incorporate your ideas into this year's Metrication matters. I would really appreciate you doing this, so if you answer this question for me, I'll send you a complimentary copy of my latest e-book 'Metrication – for and against' as a thank-you.
The public opinion expert, Elisabeth Noelle-Neumann, claims that our most common inclination is to conform to what we believe to be the viewpoint of the majority of people around us. She says that this conformity is what we use to protect ourselves from social estrangement and feelings of rejection. If she is right, this might help us to understand why so many people can see the sense of metrication, but cannot yet bring themselves to act on the direction that they know they will eventually take. Is it a fear of 'social estrangement and feelings of rejection' that is holding back metrication in many places?
Could I have a Jar of electricity, please', might have been the way we bought our electricity if the British Admiralty had its way. The Admiralty defined the practical unit of electrical capacitance – until the mid 1930s – as a standard Admiralty glass pint tankard covered with tin-foil as the outside electrode and filled with brine as the inside electrode. This container was said to have a capacitance of exactly one 'Jar'. These days electrical capacitance is measured by the farad – named after the English scientist, Michael Faraday. For the technically minded, 1 microfarad is approximately equal to 900 Jars; so 1 farad of electrical capacity would fill 900 million standard British Admiralty glass tankards – yo ho ho me hearties and splice the mainbrace.
If you write the expression, 10 mm, on your computer in 11 point Times New Roman with a non-breaking space between the number (10) and the unit (mm), it will measure very close to 10 mm when you print it out.
5 Signs of the times
In ten days, 2005 January 20, Ireland will change its distance road signs from miles to kilometres and its speed signs from miles per hour to kilometres per hour.
The Irish government has chosen to follow the practice (Australian – amongst others) of preparing carefully for several years, and then making the final metric transition, as near as possible, on a single day. This method worked extremely well, and absolutely safely, in Australia, so I can see no reason for it not to work just as well in Ireland.
The only issue that puzzles me is the kind of old mile that they are converting from; is it the old Irish mile (2048 metres), an old English mile (1609 metres) or some other kind of mile? Remember that there used to be miles and miles of different kinds of old miles.
The universe is change; our life is what our thoughts make it.
Marcus Aurelius Antoninus (121 CE – 180 CE)
Tom Keane wrote to the USMA mail list to state:
'Moreover, a decimal system isn't as easy as it sounds. One can easily divide a foot into thirds - 4 inches. But what's a third of a meter? 0.333 33 – an infinitely repeating decimal. Try measuring that when you're about to saw wood'.
Answer from Han Maenen in The Netherlands
I have never had any need to divide a meter by 3. This fraction stuff is medieval thinking. The same reason why your stock exchange (NYSE) only recently abandoned fractional division of dollars in favour of the decimal system. A US gallon or a US pound cannot be divided by 3 either. ... Yes, this is ONE area where decimal is whacko, using it in traditional units like US ones gives meaningless numbers, on the other hand all decimal subdivisions used in the metric system have meaning.
Answer from Pat Naughtin in Australia
I agree with Han. Since metrication in Australia I have only used millimetres, metres, and kilometres, so I have rarely had to use any fractions at all! Since the 1970s vulgar fractions and even decimal fractions occur very infrequently.
Another approach to this argument might be to answer Tom Keane's question with some more questions. Try these:
What's a third of a pound?
What's a third of an ounce?
Try measuring these when you're dividing a recipe by three when you are about to cook a smaller cake from a large recipe.
What's a third of an inch?
Try measuring that when you're about to saw wood.
What's a third of a mile?
What's a third of a gallon?
Try measuring these as you drive down the road.
8 Rule of thumb
In a healthy moist soil there might be 10 tonnes per hectare of earthworms. That amount of worms, digesting between 100 milligrams and 300 milligrams of soil each day, can produce about 100 tonnes per hectare of vermicast – one of nature's richest fertilisers – in a year.
The vermicast is particularly rich if there have been legumes grown in the soil; as Ted Floyd, a retired soil scientist and a member of Friends of the Earth in Sydney puts it: 'All we are saying is give peas a chance'.
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
One 13th century unit that fascinates me is the tun. A tun was a volume measure that consisted of a box that was quite close to one metre long, one metre wide, and one metre high. This early appearance of a length close to one metre was simply the length of two cubits (elbow to fingertip) at that time.
The tun was used to store dried grain for one family for a year. Each full moon you checked progress; if the level had fallen more than a man's fist width (100 mm), rationing was required or the tun would not last till the next season. Hopefully, after ten months of using stored material from the tun you again had access to fresh garden produce.
10 Hidden metric
Overall the USA is an importing nation – it imports more than it exports. Since the USA is primarily an importing country the need for metrication is not as pressing as it would be if they exported more. The reality is that the economy in the USA imports a substantial amount of goods produced using metric measures and deals with metric issues on a case-by-case basis. In almost all examples of imported metric measures they are simply hidden from the consumers – the citizens of the USA.
P.S. One of our new subscribers to 'Metrication matters' at http://www.metricationmatters.com/newsletter.html told me that a friend suggested that he subscibe and also sign up for the 'Metrication Basics' e-course at http://www.metricationmatters.com/MetricationBasics.html
Apparently his friend said, 'One of the best things I can do to encourage metrication in the USA and the rest of the world is to pass on a copy of "Metrication matters" to all of my friends with the suggestion that they subscribe.' What a compliment – Wheeee!
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