In 2009, I was watching television in Cayman. The European Champions League final was being played in Rome between Barcelona and Manchester United. A free kick was awarded to Barcelona just outside the United penalty area. The Manchester players wouldn’t retreat as far from the ball as the Swiss referee thought they should and so he strode ten paces to show the defenders where they should be.
Why ten paces? Because the official rules of Association Football states that:
“For a direct or indirect free kick all opponents must be at least 9.15 metres from the ball until it is in play.”
So why did the ref stride 10 paces? Because 10 paces are 10 yards, and 10 yards is 9.15 metres.
The metre is an absurd unit of measurement but so are many of the metric units we are compelled to use in daily life. They are good for science but hopeless for everyday activity.
The yard, like all Imperial units, is based upon human experience. The basic Imperial measurement of length is the inch, and the inch is based on the width of a man’s thumb.
Anybody who is 6 feet tall, is tall – not very tall but tall. Do you think that a man of 1.83 metres is tall? Well, yes, he is. He’s six feet tall. The only useful or perhaps the only interesting metric measure of height is 2 metres. Someone who is two metres tall is 6’ 7” and that is very tall.
Metric units are based on our physical natural world and not upon our experience. The basic unit of metric length is the metre. When it was first adopted, it was intended to be 1/10,000,000 of the distance from the equator to the North Pole. Nowadays it is defined as the distance travelled by light through a vacuum in a tiny fraction of a second, so that is hardly based on everyday experience, is it?
“How much room have I got,” asks Caroline as she parks her car.
“About two feet,” I tell her.
I don’t say about 60 centimetres because a foot is a length that we come across all the time. There are lots of things that are about a foot long from a loaf of bread to.…... well, a foot.
The acre is the Imperial unit of area, and it is the area of land that could be ploughed by a yoke of oxen in one working day. What is a hectare? A lot bigger that’s all and of no natural or human significance whatsoever.
The Fahrenheit temperature scale is more subtle and sensitive than Celsius:
°F | Human Experience | °C |
30°F | Bitterly cold. Overcoat, scarf and gloves. | -1°C |
45°F | Cold. Warm clothing. | 7°C |
55°F | Not really cold but you need a jacket. | 13°C |
65°F | Mild. Jacket not needed. | 18°C |
75°F | Warm and pleasant. Shirtsleeves. | 23°C |
80°F | Hot | 27°C |
90°F | Very hot. Reluctant to leave the shade. | 32°C |
100°F | Unbearably hot. | 37°C |
110°F | Too hot for human activity. | 42°C |
For really noticeable change to take place a difference of 10°F has to occur but this change is only 5.6°C. Too much change takes place too quickly when measuring temperature in centigrade. It lacks the delicate variations of Fahrenheit.
As someone who has slept more than 1500 nights in the tropics, I can tell you that the difference between a night-time temperature of 75°F and one of 80°F is the difference between comfort and sweaty restlessness, whereas 24°C doesn’t seem that much different from 26.6°C yet they are the same temperatures as 75 and 80°F.
It is in the kitchen that the Imperial measures really come into their own. I am not a good cook, but I am effective. As with most things in life that I try, I can do it adequately but not wonderfully well. I have a tendency, when cooking, not to follow recipes but to bung in anything that takes my fancy and seems right. I also tend to work to ratios rather than absolute measures but when I do need a measure, give me a teaspoon of vinegar over 5 millilitres every time. It’s easier and much more convenient.
There is no internationally agreed standard definition of the cup and its volume ranges between 200 and 285 milliliters, but a cup of milk is so much easier to obtain, handle and estimate than 250 ml. When cooking, a teaspoon, a dessertspoon, and a cup are readily to hand and match up well with other Imperial measures. For example, a rounded tablespoon of flour is 1 ounce in weight and a cup of liquid is half a pint.
My car averages 45 miles per gallon of fuel (15.8 km/l). It also therefore does 9.9 miles per litre. If it would do 50 miles to the gallon it would make a big impact on my motoring costs and a similar improvement in fuel efficiency would give just less than 11 miles per litre (17.6 km/l). Although the improvement is the same, it hardly seems significant, does it? I assume that is why vehicle manufacturers still give figures in miles per gallon.
I suppose that problem would be solved if they used kilometres rather than miles but again the mile is a unit based on human experience. There was huge worldwide interest when the first four-minute mile was run but nobody got very excited when someone first ran 1609.34 metres in less than 4 minutes and even average ability club runners can run 1500 metres in under 4 minutes.
George Orwell anticipated the problem that we are having. In the novel 1984, when Winston Smith went into a pub, he witnessed an altercation between an old man and the barman. The old man had asked for a pint of beer:
“You telling me you ain't got a pint mug in the 'ole bleeding boozer?"
"And what in hell's name is a pint?" said the barman, leaning forward with the tips of his fingers on the counter.
"E could 'a drawed me off a pint," grumbled the old man as he settled down behind a glass. "A 'alf litre ain't enough. It don't satisfy. And a 'ole litre's too much. It starts my bladder running. Let alone the price."
“You must have seen great changes since you were a young man,” said Winston tentatively.
Spot on, George! Let’s stop this madness while we can.
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