User:Demi/Standard vs. metric measurement

In the occasional general flare-up of resentment against the U.S. and American things, one thing that comes up with great frequency is the supposed superiority of metric temperature and measurement scales to the real ones. I hope to disabuse the reader of this impression.

Yeah, that's what I said
Yes, I called the U.S. customary units "standard" and SI units "metric." I also used periods (yes, periods!) in "U.S." and called something from the U.S. "American." I'm punctuating everything in a way designed to piss off foreigners. And I don't mean "taking the piss," because I'm an American and I don't know what that means.

Calculation
Among the supposed advantages--okay, the only supposed advantages--of the SI units are their convenient "base-10" (sort of) relationship between scales of units, and the straightforward relationship of length, volume and mass.

First, I'll say that I'm not going to argue that SI units aren't more useful for science and engineering applications; I'm talking about average uses and average people.

The problem with the calculations being more convenient is that what they are really convenient for is for converting between scales (easily knowing that 1000 meters make up a kilometer, as opposed to 5280 feet to a mile) or between dimensional orders (knowing that a liter is a kilogram is a cubic... er... decimeter). But that isn't actually a very common thing to want to do. How many times do you say, "Hm. How big would I need to make a cube, such that it held a liter?" or "Hm. My member is 10 centimeters long. What is that in kilometers?"

On the other hand, in the case of some of the customary units, there is another much more common calculation that is more convenient: subdivision. Ever divide a meter into thirds? What do you get? A big pile of 3s, that's what. A foot, on the other hand, can be subdivided in halves, thirds, quarters, sixths (and twelfths, of course) and in whole units. Twelve, or powers of two, are more useful for this operation than decimals.

Convenience
Since metric measurements don't offer a real advantage for calculation, one must look at the units themselves, to see if they are of convenient measures for common tasks.

Where there is an appreciable difference, the customary units are invariably more convenient. This is best exemplified by the foot and inch, which are simply more convenient units (as shown by their very common use in building materials, such as 2x4s; and the vast number of things which can be measured in a "few feet."

Obviously any system of measurement can express these measurements, but we like round numbers--they're convenient. When metric calculations result in round measurements, after all, proponents consider that convenient, so it makes sense to favor round numbers.

The Fahrenheit temperature scale is also more convenient than the Celsius. Most of the time, the temperatures from "freezing" to "body temperature" are what's relevant (because basically you are interested in the temperature outside, or in), yet the Celsius scale provides only 37 degrees in this range, while the Fahrenheit scale provides 68. Of course, you can have decimal Celsius degrees, but we decided round numbers were better.

Elegance
Some deride the "quaint" nature of English measures, as if their historicity argued against them, and laud the "elegance" of the metric system. But the elegance doesn't bear scrutiny. For example, the basic (unprefixed) units of the metric system don't relate to each other. A straightforward organization would be to relate grams, meters and liters. Instead, it's kilograms, centimeters (what? not even a multiple of 10&sup3;) and liters. That's not elegant.

Even metric proponents cop out when the inconvenience of the metric system rears its ugly head. No one measures the velocity of cars (such as that given in speed limits) in meters per second. No, it's kilometers per hour. If the metric system is so convenient, why isn't that... megaseconds or something? No, it's 3600 seconds to an hour. Because miles per hour is a convenient measurement and the more similar the "metric" equivalent can be the more useful it is.

Conclusion
In short, you can do what turns you on, and I will keep drinking my twelve-ounce sodas from aluminum cans, thanks.

Footnote

 * 1) Well, not just any liter. A liter of water. Not just any water--water at 4&deg;C. And not just anywhere--at sea level. See how convenient?
 * 2) Assuming you have a need for cube to hold water at sea level at 4&deg;C, 0.1m.
 * 3) 0.0001 km.