How Pirates Of The Caribbean Hijacked America's Metric System (npr.org)

If the United States were more like the rest of the world, a McDonald's Quarter Pounder might be known as the McDonald's 113-Grammer, John Henry's 9-pound hammer would be 4.08 kilograms, and any 800-pound gorillas in the room would likely weigh 362 kilos. NPR explores: One reason this country never adopted the metric system might be pirates. Here's what happened: In 1793, the brand new United States of America needed a standard measuring system because the states were using a hodgepodge of systems. "For example, in New York, they were using Dutch systems, and in New England, they were using English systems," says Keith Martin, of the research library at the National Institute of Standards and Technology. This made interstate commerce difficult. The secretary of state at the time was Thomas Jefferson. Jefferson knew about a new French system and thought it was just what America needed. He wrote to his pals in France, and the French sent a scientist named Joseph Dombey off to Jefferson carrying a small copper cylinder with a little handle on top. It was about 3 inches tall and about the same wide. This object was intended to be a standard for weighing things, part of a weights and measure system being developed in France, now known as the metric system. The object's weight was 1 kilogram. Crossing the Atlantic, Dombey ran into a giant storm. "It blew his ship quite far south into the Caribbean Sea," says Martin. And you know who was lurking in Caribbean waters in the late 1700s? Pirates.

Comments

Like someone else illustrated

[Anonymous Coward]

very telling and accurate: the retarded rollercoaster

Re: Like someone else illustrated

[hey!]

There's a reason these are called "customary" units. They were contrived to be convenient for highly specialized and closely related tasks.

For example a rod was the typical length of a medieval ox-goad. If you laid out a line 40 rods long, you've got a furlong, which is about the length of furrow a man with a single ox could plow without giving his animal a rest. If you lay out a rectangle 1 furlong by four rods, you have an acre, which is about what he could plow in a day.

Customary units are far more convenient for the tasks they're optimized for. But it's the modern need to do more complex calculations relating things across problem domains that makes them awkward.

Re:Like someone else illustrated

[kenai_alpenglow]

I got tired of subtracting 273.whatever all the time. Just give me Kelvin instead.

Re: Like someone else illustrated

[Ungrounded Lightning]

Customary are far more convenient for the tasks they're optimized for.

The Farenhiet scale is another example, where the definitions make the scale a strong mnemonic for certain situations:

  * 100 was set as a best guess at the time for the human body's internal temperature. (They got within a fraction of a degree.) When temperatures approach or exceed 100 F, it isn't enough to just relax when you're getting overheated. You must stay hydrated or suffer heat stroke and risk death.

  * zero was set at the coldest temperature they could easily and repeatedly generate in a lab: The melting point of pure ice saturated with salt (at sea level pressure, etc.) This is important when driving in states that salt their roads in the winter. When the temperature in degrees F goes negative the salt stops working. Drive VERY carefully or you end up in the ditch, risking death.

Given that those situations are deadly AND rare, it'37.s nice that these easy to remember round numbers flag them. Meanwhile, the boiling and freezing points of water (212F and 32F) are used often enough that they get memorized. With C, 100 and zero are boil and freeze, but will you remember 37.777... and -17.7777 as important numbers for heat stroke and deadly road conditions?

No soft metrics!

[duckintheface]

If you really want to see the US move to the metric system, stop using soft metrics. People in the US think the metric system is complicated because they are always being told to convert from English to Metric measure, with the metric being non integral. No, a 9 lb hammer would not be 4.08 kilograms. it would be 4 kilograms. And a Quarter Pounder would be a 100 Grammer. If you want to think in metric, start with integer metric measures and don't worry about conversion.

I remember when Jimmy Carter was trying to move the US to metric in 1977, I saw a giant sign that said 1 inch equals 2.54 cm. Think Metric! At that moment I knew metric was dead in the US.

Re:No soft metrics!

[Pseudonym]

I live in a SI country. The customary units for everything use whatever scale prefix makes the most sense.

Cans, bottles, and glasses are measured in millilitres (pronunced "mil" for short), and reservoirs are measured in megalitres. Road signs are in kilometres. Weather reports give air pressure in hectopascals. The energy content of food is measured in kilojoules.

We cope.

Re:No soft metrics!

[bickerdyke]

And here's the beauty of the metric system: Even if mm instead of cm should be used as a kind of "style guide" you still can use any other decimal fraction/multiple prefix (if you have a reason to do so) and converting is as easy as adding a 0 or slashing a decimal.

Re: No soft metrics!

[Immerman]

Neither can most us customary units. What's 1/6 of an inch? 1/3? Ditto cups or pounds.

The only time you get nice multiples of 3 is when converting feet to inches - and even then you need a nice even number for it to work out. Whats one third of 1'2"?

Meanwhile, if you're using metric to measure something on the same scale, 1 foot = 300mm (near enough - there's nothing magical about a foot), which is indeed easily divisible by 2,3,4,5,6,10,12,25, etc.

Most importantly - any math you need to do in metric is simple integer arithmetic, while in US customary you have to constantly juggle mixed fractions in your head to accomplish anything. You can't even fall back to simpler improper fractions because there's not a ruler on the planet with a 317/8ths label.

What's 1/4 of 37-1/2 inches? Versus 1/4 of 950mm? Or scaling up - you want 7 shelves 13-3/4" apart - what's the total distance? Now try the same thing with 350mm per shelf. If 1/4 inch accuracy is enough, then all your metric measurements can be rounded to multiples of 5. At 1/8th inch, they can all be even. Keeps the math easy. About the only claim I've heard where customary actually has an advantage is that you can specify the precision along with the measurement - but realistically you rarely hear people give measurements of 2-32/64ths or 37-0/16ths

And frankly, weight and volume are an even uglier mess in customary. Not to mention the endless confusion and headaches caused by the fact that we measure things by weight rather than mass, rather than letting the scale do the conversion into a far more general unit for us.

No. It wont be.

[140Mandak262Jamuna]

If the United States were more like the rest of the world, a McDonald's Quarter Pounder might be known as the McDonald's 113-Grammer, John Henry's 9-pound hammer would be 4.08 kilograms, and any 800-pound gorillas in the room would likely weigh 362 kilos.

It would be a 100 gram patty, 5 kilo hammer, or half a ton gorilla. There is no need for precise conversion, and a good easy number is what marketing people and idiom pioneers would choose/use.

Re:Obligatory

[msauve]

Arrrgh, yes. Because "a McDonald's Quarter Pounder might be known as the McDonald's 113-Grammer, John Henry's 9-pound hammer would be 4.08 kilograms, and any 800-pound gorillas in the room would likely weigh 362 kilos", while (failing in) an attempt to show knowledge of the SI system, is severely lacking in basic math.

For colloquial measurements, no one would do conversions with 3 digits of precision. It might be a Hecto-Burger, or a 4 kilo hammer, or a 400 kilo gorilla. (does anyone say "kilogram" instead of "kilo" when the context makes it obvious that the reference is to weight [or mass, for the truly pedantic]?) Trying to play the 3 digit conversion game indicates an agenda designed to make it seem the SI system is more complicated than imperial units. Hint: it's not.