Metric versus imperial: Reg readers weigh in

The snag with this debate is that most of the debaters (combatants?) are too young to know real units of measure, having been brainwashed at school. The old Imperial units are practical uniits for practical people. Most Metric units are too low or too high to be practical. Look at the metre. Far to large for a practical measure, so it has to be divided up, decimetre or millimetre, and even these are wrong. In Engineering, my Engineering at least the thou ruled A practical measure, you didn't need mant to make a difference. In Metric parlance it has to be the Micron, far too small. You need twenty five of the little bugger to make a thou. Likewise with the rest, it's either milli or mega to get a significant unit. I'm with the Yanks on this one, even if their pint is too small.

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It's difficult for most of us to change and unlearn what we have used since childhood. If we are comfortable with Imperial or USC measures we think in these measures even when we are using metric and conversion can cause errors. We only really appreciate metric measures when we use them, and I emphasize the word USE.

It's not true that metric measures are too small or too large. One has to USE them to know them. In the building industry only three linear measurements are used. The kilometer = 1000 meters, the meter = 1000 millimeters and the millimeter. We don't use decimeter or centimeter. In engineering the "thou" is  the supreme measurement in Imperial/USC,it's equivalent in metric is an unnamed unit that is smaller than a tenth of a millimeter but larger than a hundredth of a millimeter. There are 1270 per inch so it's a little smaller than the "thou". (a thou being 1000th of an inch)

To clarify ..As we shift to smaller units in metric it's often assumed that the next divisor must a tenth of the previous unit. This is not always correct. We know that a base 10 system can be divided by 2 and 5 as well as 10. As an example you will see that on an Engineers steel rule millimeters are divided into 1/2 millimeters. That is they are 5/10 of a millimeter. Not the assumed 1/10 of a millimeter. So we take an inch for example = 25.4 mm dived by 10 = 254 divided by 10 again = 2540 ..this is how many 100th of a millimeter are in an inch. This  more than double the "thou" and some machine tools can work to this level but if we want to bring it closer to the "thou" we dive it by 2 as the base 10 allows and we have 2540 divide by 2 = 1270 .. A bit smaller than the "thou". So just as we can use larger units we can also use smaller units also.

Can’t we all just get along?

Personally, on the matter of units, I agree with the motto of the 2012 Nobel Peace Prize laureate: In varietate concordia. Let each author and commentard use the units with which he is most comfortable. If a reader doesn’t know what a given unit represents in his preferred system, and is unwilling to do anything to increase his knowledge to aid his understanding, then that would reflect poorly only on the reader.

Lester, I disagree with you on the rightness and propriety of “flying at 35,000 feet”; five digits in the magnitude is at least two too many. This is a case where the furlong would be appropriate — e.g. “flying at 53 furlongs” (or thereabouts).

Don't convert

As an Australian I have to agree that the way the conversion was done here was the best approach. A gradual approach won't work, and suggesting you maintain two or more systems and expect people to convert between them is the worst idea of all. It's true that many imperial measures still remain; they still talk about acres in real estate and for some reason computer screens are in inches but TVs often (but not always) in cm, but really, you won't take long to get used to your weight in kg, your height in cm, road speeds in km/h and the temperature in celsius so long as that is all you hear.

Peter Melia

Not many of you out there remember, but in the old system you could go into any shop and order, say, 2 lbs potatoes, 4 carrots, 3 pints of milk, half a gill of cream, and hand over a quid, worth 20 bob. Without any hesitation she’d reply, “That’ll three and sixpence ha’penny love, and if you can give me a couple of half crowns that’ll save breaking into your pound note”.

Nowadays, you’ll order, say, 2 kg potatoes, 4 carrots, 2 litres of milk, 1 box of cream and stick a credit card in a slot. She’ll punch it all in and the machine will tell us the amount and the change.

A smaller shop will have the assistant struggling with a calculator.

The point is, the first shopkeeper was really, really mentally agile, and so were everyone, the workshop floor worker would work out his wages taking into account deductions, calculate extraordinary betting odds, all in his head.

When we did a mental calculation we had a good idea of the size of the end result. Now a child can have no idea of what is number crunching might end up with, and whether it’s wrong or right, or even near.

So the end result might well be more efficient calculations, but in fact we are all becoming numerically more illiterate.

Height in imperial...

... I can't believe there was any question - the "1.609km high club" just doesn't have the same ring to it...