Why? The French system has exactly two benefits: it's popular, and it's easier to perform abstract conversions (i.e., conversions between units on paper). OTOH, it is worse at performing concrete manipulations (i.e., dividing one physical quantity into another): accurately cutting or dividing quantities into tenths without the aid of a guide of some sort (e.g. a ruler or measuring cup) is so difficult as to be basically impossible, while cutting or dividing into halves is so easy that a child can do it, and thirds are not much harder at all.
Yes, it happens that it's easier to 'do science' currently using French units, but that is because all of the standard constants happen to be based in those terms: there's no fundamental reason one couldn't use Rankine instead of Kelvin and so forth.
I won't claim that the standard system of units is perfect (the partial decimalisation the Brits attempted in the 19th century was misguided): indeed, it could get a lot better: nautical miles are probably better than statue miles; a reset in the length of the yard so that there are 1,728 yards in a mile would probably be a decent idea; a cup ought to be 16 cubic inches; and so forth.
But throwing away 12 (with its divisors of 6, 4, 2 & 3) for 10 (with half as many: 5 & 2) was a foolish, foolish decision by the French.
If they'd really wanted to be revolutionary, they'd have adopted base-12 numbering instead of trying to fit the world to base 10.
(I will grant the the French system of paper sizes is elegant, and I wouldn't mind us adopting a similar system based, of course, on the yard)
By your count, it seems that the metric system (do you call it the French system to devalue it? seems like it) has 3 points: elegant paper sizing, easier to do science, and popularity.
By your count, the "standard" system (how is it standard if it's used almost nowhere?) has 1 point: A foot being 12 inches means it has more divisors than 100 cm to a metre.
So, therefore the final score based on your appraisal is Metric 3, Freedom Units 1.
Historically, it seems baffling. Their real name, "imperial units", are a clue that they're all but rooted in freedom. They're inherited from the country that the US broke free from…
Plus, the Metric system stems from the French Revolution, making it a better contender for the term "freedom units".
Finally, wasn't there a whole PC phase in 2003 where expressions with "French" in it, like "French Fries", were renamed "Freedom Fries"? It all makes things rather confusing.
The times when the measurement can be divided by 2 are either so rare as to be irrelevant (the room isn't an even number of inches long anyway, and adding feet makes the calculation worse) or arrive by design (my dishwasher is 900mm wide, check the factors in that).
The paper sizes are German, and adopted by the ISO.
In physical trades like carpentry, brewing, farming & so forth, being able to easily halve, double or treble quantities is quite convenient. The customary units, being based on powers of 2 (with a few 3s thrown in …) tend to be really good at this, as anyone who's ever brewed or handled produce in standard units knows.
Dealing with French units is a pain.
(as an aside, the reason I call them 'French units' is because the name 'metric' privileges them: our standard units are no less a system of measures than are they; this too is my problem with 'SI,' since our system is (or was) likewise international)
The dishwasher was intended as an example for carpentry: standard kitchen cupboards etc are made in multiples of 300mm. It's the same for things like floor tiles, doors, etc.
No farmer or brewer deals in units that are easier to half in American rather than metric units. They use tonnes, hundreds or thousands of litres, and large areas. Outside America, they don't need to convert between units of the same type: no acre-feet, bushels, pounds, tons, or all that crap.
Calling them "French units" sounds like xenophobia. The American system was never international, and the British system didn't extend that much further than the French, at the time of the empire.
> They use tonnes, hundreds or thousands of litres, and large areas. Outside America, they don't need to convert between units of the same type: no acre-feet, bushels, pounds, tons, or all that crap.
In America, anyone who would deal solely in tonnes can deal solely in tons; anyone who would deal solely in hectolitres can deal solely in barrels (traditionally, 128 quarts); anyone who would deal solely in kilolitres can deal solely in tuns (traditionally, 1,024 quarts). No-one in America has to say '7 tuns, 2 hogsheads, 3 gallons, six quarts and a fluid oz' any more than he'd say '7.2850546 kilolitres.'
> Calling them "French units" sounds like xenophobia.
Oh, I'm not xenophobic! I just don't think they deserve a privileged position.
> The American system was never international, and the British system didn't extend that much further than the French, at the time of the empire.
The American system was used in Liberia; prior to the Russian Revolution the majority of the peoples of the world used systems of measurement substantially similar to the Anglo-American system, and could (should have, IMHO) rationalised and standardised that, rather than adopting the objectively inferior decimal principal.
> anyone who would deal solely in tonnes can deal solely in tons
Then your argument that these quantities are easily divided is irrelevant.
> 7.2850546 kilolitres
My house's water meter measures up to 99,999.999m³, or in litres up to 99,999,999 litres.
Europe other than Britain and Ireland didn't use the British system, and neither did their colonies, China, Japan, etc. All the British colonies except the USA chose the metric system after independence.
The SI system is the only one that's truly international, set up by international treaty between many countries.
And really they are SI units, the 'International System of Units', which may or may not 'privilege' them, but is certainly both correct and normal usage.
Yes, easy halving and quartering was important back when the population was not used to decimals. But surely, most people these day can tell that half of 100 cm is 50 cm, a quarter is 25 cm, and a third 33.33 cm.
So, the Gimli glider had a glide ratio of 12:1.
We're 10 km high, how far can we glide? Well, 120 km.
That's how we'd compute it in a metric world. In the real world, the Gimli glider was 32,000 feet high. How many nautical miles can it glide? Quick?
> In the real world, the Gimli glider was 32,000 feet high. How many nautical miles can it glide? Quick?
In the real world, the Gimli glider was 9,753.6 m high. How many km can it glide? Quick?
Of course, in real life one would cheat: a nautical mile is about 6,000 feet, so 32,000 feet works out to about 5 nautical miles, which means that it can glide about 60 nautical miles. One can always grab a calculator (or slide rule — they're actually quicker at this than calculators) to be certain (12:1 at 32,000 feet gives 63 nm/110 km).
> In the real world, the Gimli glider was 9,753.6 m high. How many km can it glide?
117,043.2 m. In about 5 seconds in my head. By doing value × 10 + value × 2. Because multiplying by 10 is so easy, because arabic numerals are in base 10.
And by cheating, which obviously we would do as a first approximation, it is also much more trivial in SI units: 9,753.6m is about 10km, × 12 → 120km. At most 1 second to find. Faster again.
But my fundamental point: we already have the mnemonics ready for base 10, and we won't switch away from arabic numerals any time soon, so we might as well benefit from it.
It isn't a competition. After all, the metric system is screwed up: having 60 seconds in a minute is a pain (but wow, so many divisors! — really though, just an inheritance of an ancient culture that did not use base 10 numerals; using higher bases isn't an indication of modernity) and the fundamental definition of the second doesn't map to any physical reality in an intuitive way anymore.
And you can count by twelves on the knuckles of your fingers, so anyone who still needs to count on his fingers can still do it (I'm not certain why this is such a selling point for decimals: surely we're all intelligent enough to use higher bases?).
Why? The French system has exactly two benefits: it's popular, and it's easier to perform abstract conversions (i.e., conversions between units on paper). OTOH, it is worse at performing concrete manipulations (i.e., dividing one physical quantity into another): accurately cutting or dividing quantities into tenths without the aid of a guide of some sort (e.g. a ruler or measuring cup) is so difficult as to be basically impossible, while cutting or dividing into halves is so easy that a child can do it, and thirds are not much harder at all.
Yes, it happens that it's easier to 'do science' currently using French units, but that is because all of the standard constants happen to be based in those terms: there's no fundamental reason one couldn't use Rankine instead of Kelvin and so forth.
I won't claim that the standard system of units is perfect (the partial decimalisation the Brits attempted in the 19th century was misguided): indeed, it could get a lot better: nautical miles are probably better than statue miles; a reset in the length of the yard so that there are 1,728 yards in a mile would probably be a decent idea; a cup ought to be 16 cubic inches; and so forth.
But throwing away 12 (with its divisors of 6, 4, 2 & 3) for 10 (with half as many: 5 & 2) was a foolish, foolish decision by the French.
If they'd really wanted to be revolutionary, they'd have adopted base-12 numbering instead of trying to fit the world to base 10.
(I will grant the the French system of paper sizes is elegant, and I wouldn't mind us adopting a similar system based, of course, on the yard)