Archive for category Metric and measurement

Happy birthday Neptune?

Neptune

Happy birthday!

Just a quick post: according to The Observer, tomorrow (July 11) will be one Neptunian year since the discovery of the planet Neptune. Except…

One year on Neptune is 60,190 Earth days. Neptune was discovered on 23 September 1846, so Neptune’s first birthday will be 60,190 days after this date.

23 September 1846 + 60,190 days = July 10, 2011

Neptune’s birthday is today, not tomorrow! We’ll all be celebrating on the wrong day!

Never mind phone hacking, this is the real scandal.

Edit: The BBC is even more wrong, claiming Neptune’s birthday is July 12. The philistines!

Double edit: In fact, it looks like we’re all right! July 10 is one average Neptunian year after the date of discovery, July 11 is the day when Neptune will have made precisely one orbit around the solar system’s barycentre (i.e., its centre of mass when you take the Sun and all the planets into account), and July 12 is the day that Neptune will have made precisely one orbit around the Sun. (A figure of July 13 is floating around as well, most likely as a result of an Indian newspaper article which has taken timezones into account). Thanks to Up, Blogstronomy and the Wikipedia users on Talk:Neptune!

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Peter, don’t be a martyr

(H/T @RopesToInfinity)

Shylock didn’t ask for 454g of flesh…and no one wants to drink a litre of wine, says PETER HITCHENS

Because of course the traditional English pint of wine is much more convenient.

Anyway, most of the article is either scaremongering, rubbish, or doesn’t make sense, so here are the highlights.

Would it really be so difficult for those of us who still feel British to say: ‘No, thank you, please measure that in pounds and ounces,’ to the trader who offers us kilos, and to complain when the national broadcaster uses foreign expressions to replace perfectly good English ones.

It already is legal to offer to measure goods in pounds, as long as there as there is a kilogram measurement available too. The “metric martyrs” didn’t get in trouble for selling objects in Imperial, they got in trouble for not offering metric.

In truth, the only properly non-metric nation on the planet is America, the most technologically advanced, economically successful country in human history – and the most free.

Regardless of whether America is the most technologically advanced or the most free – how you’d measure either of these is beyond me – surely it would be difficult to say that metric Japan is not technologically advanced, or that metric Sweden is not free, and the metric EU is a larger economy than America. Whether or not a country is free or wealthy probably has very little to do with what they write on their rulers.

Besides, American scientists? They use metric. Every scientist does – metric forms the basis of the SI system; a rational, universal system of measurements based on the fundamental properties of the universe.*

I cannot imagine a kilogram, let alone a gram, or a metre or a litre or a hectare. I work out what they mean by converting them into the proper measures that have their roots and origins in the land, as I do – an acre is a day’s work at the plough, a fathom the width of a man’s outstretched arms.

For those of us who don’t plough fields with oxen, that might be a little less useful.

Why? Because our customary measures are a sign that we – almost uniquely among the nations – still run our own lives. These measures are rooted in daily life, are human, and honest, because they are polished in use, sound like what they are (can’t you hear a gallon sloshing in its bucket?) and because you can use them in poetry.

There are miles, inches and fathoms in the Bible and Shakespeare, and if you converted them it would sound ludicrous. Imagine Hamlet jeering as he holds Yorick’s skull: ‘Now get you to my lady’s chamber, and tell her, let her paint 2.5 centimetres thick, to this favour she must come; make her laugh at that.’

Why stop there? Bring back the lovely poetic bushel! The hogshead! The shaftment! The ell!

You see, this is the big problem with Hitchens’s argument. For all that he complains about “totalitarianism”, and measures “made up in an office”, the modern Imperial system is every bit as artificial as the metric system. Once upon a time, there were hundreds of different units, all created by people in different trades, in different parts of the country, and each one was pretty convenient for them.

Of course, that system was such a mess. Over the years – starting with the Magna Carta – the number of units was slowly whittled down (bye bye Scots measures) and the ones that were left were standardised (no longer was the Cheshire acre twice the size of the standard acre), culminating in the Weights and Measurements Act 1824. Measurements across the whole country were unified, and it became illegal to sell goods using the older units – more or less exactly what happened when metric was introduced.

Outside the oompah-band and leather-shorts regions of Germany, you will not see anyone drinking beer in litres either. This is because a litre is a measure made up in an office, whereas the old-English ‘bottle’ (equivalent to about 72 centilitres) and the old-French ’bouteille’ (the same) were enough for two people to share over a meal.

It has now been rationalised into 75 centilitres, three-quarters of a litre, but no further. And that is itself a significant departure from the metric system, which is based on counting our toes and doesn’t like quarters because ten can’t be divided by four (or three, for that matter).

Of course not, a litre of beer is rather massive. Anyway, metric doesn’t care what you divide things into. The whole point of metric is that it’s based on the decimal number system, so you can divide it however you like. If you want to split it into fours, that’s easy. If you want to split it in thirds, or fifths, or even sevenths, that’s no problem. On the other hand, if you want to split a mile into 7 pieces, how do you do that? It’s 0.143 miles, but how many feet is that? The answer is a bit more than 754 feet and 3 inches, but that’s an absolute bastard to work out in your head, unless you know your 5280-times tables off by heart.

The metric system officially doesn’t have such a thing as a foot. It scorns this useful measure, going straight from the metre down to the centimetre. But here’s a funny thing. School rulers in metric countries are not one metre long, but 30 centimetres, which is almost exactly a foot. Timber and building materials are often sold, in metric countries, in 30cm units. Just don’t call them feet.

So, err, why is measuring things in 30 cm units a defeat? Again, the metric system doesn’t care how you divide your measurements, so 30 cm is a perfectly valid length for a ruler… so is 50 cm, or 10 cm, or 87 cm, or any other length that takes your fancy.

It is almost invariably forced on people and nations by dictators, revolutions or invasion. It may have its uses in international commerce and science, though Man went to the Moon in feet and inches. But nobody ever wanted it in private dealings.

And NASA’s decision that it, and it alone, would continue to use U.S. customary units instead of metric resulted in the crash of the Mars Climate Orbiter. At any rate, every measurement system has been imposed by force by some people – why do you think India used Imperial until after it declared independence?**

Long story short, we use metric because it is more convenient than Imperial, not less – though, as Hitchens’s past record shows, given a choice between foreignness and inconvenience, he’ll take inconvenience every time.

* Except for the kilogram, which is admittedly still based on a chunk of platinum in a bank vault in Paris. Hopefully not for much longer though…

** Wikipedia also mentions occupied Japan using American units, but I can’t find an independent source for that so I’ll leave it in this footnote.

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