The lovely and talented Mark Spahnwait, hold on. We have never seen him. He could be horrifying in appearance. Perhaps. So the monstrous and talented Mark Spahn of West Seneca, New York, sends some thoughts our way on the metric system and its many trials and tribulations.
Your essay needs a few tweaks.
You write, “If you worry about the wattage on your electric bill, or think about how many gigabytes a downloaded movie is, or think about a roller coaster in terms of Gs, and so on, you are using the metric system.”
Well, not quite.
Electric bills are expressed not in watts but in kilowatt-hours (kWh), where the “kilo-” is a numerical prefix meaning 10^3, the “W” stands for watt, which is defined as a joule per second, and the “h” stands for “hour” which is 60*60 seconds. (Note that the time unit “second” is common to both the metric and the non-metric systems.) Thus a kilowatt-hour is a unit of energy expressed in joules, which is defined as joule = kg m/s^2 (kilogram meter per second squared), and the kilogram and meter are indeed metric units.
But what about “gigabytes” of a downloaded movie? Is this metric? A byte is not a metric unit; it’s just an item you count with integers, as you would count marbles or kumquats. It is metric imperialism to say that a quantity becomes metric just because it is preceded by one of the “Systeme Internationale” numerical prefixes.
It is convenient to measure commuting distances in California in megainches (10^6 inches = 15.8 miles). Is a megainch a metric unit just because of the prefix “mega-“?
Well, the Czar is not familiar with anyone using megainches; but day-to-day, we do encounter bytes, kilobytes, megabytes, gigabytes, terabytes, and their weird kin the bits. Indeed, since 1988, the International Electrotechnical Commissionwhich is recognized in the technology sectors of the United Statesconsiders the order of bits and bytes fully metric.
Inches, in your question, are not metric because units of distance are measured using meters. There is no alternative in technology for data sizes or information throughput except to use the IEC method.
And your roller-coaster example is not metric at all. First, G, spelled uppercase, is Newton’s gravitational constant, a quantity whose dimension is [length]3 [mass]-1 [time]-2. Its value, expressed metrically, is 6.67×10-11 N m2/kg2 (“newton square meters per kilogram squared”), or, as Sir Isaac would prefer to say, 3.44×10-8 ft3(slug s2) (“feet cubed per slug per second squared”).
When discussing the accelerations experienced on a roller-coaster ride, we speak of lowercase g’s, where g is the netherward acceleration one experiences at the Earth’s surface; its value expressed metrically is 9.8 meters per second per second, or expressed “imperialistically”, 32 feet per second per second. This g is a certain acceleration value, which we need not express in any other quantities; that’s the beauty of speaking of g’s.
The Czar recognizes you are objecting to his use of Gs in the colloquial sense, rather than the strict physical sense. Yes, the Czar might have used gs rather than Gs.
Moving on to temperature, defining the temperatures at which water freezes and boils as 0 and 100, respectively, may be convenient for parboiling, but for describing weather, the Fahrenheit scale is much superior. The Fahrenheit scale ranges extensibly from 0 to 100 degree, and for most people in the Temperate Zone, its midpoint, 50 degrees, feels pretty neutral, neither cold nor hot, while at the extremes, 0 is just as chillingly cold as 100 is oppressively hot. Fahrenheit is the perfect weather-temperature scale. This is all the more ironic when you learn that, historically, the Fahrenheit scale was never defined with weather description in mind.
Correct across the board. The Czar of course deals with folks who use the centrigrade method since childhood who have never used the Fahrenheit system. Curiously, one of their complaints about °F is its ridiculously small degrees. You cannot physically feel the difference between 42°F and 43°F, making all those degrees inelegant. Seriously: we have heard this argument more than once. Of course, when one points out that one cannot determine a temperature change between 22°C and 23° either, because the human body is not that sensititve whereas most digital thermometers can detect hundredths of a degree change in either scale, the whole argument collapses into which you prefer. Actually, the Czar does not care much for centigrade, although he is sympathetic to Kelvin put 0 at absolute 0.
You write, “the gram was basically equal to the weight of water in a cubic meter.” Uh, no. A gram was defined as the mass of a cubic *centimeter* of water.
The heck did we write? Alas, Mark is quite correct: the Czar has no idea what happened to that original sentence, but rest assured: Mark is completely correct on the cubic centimeter. A cubic meter of water would be a hell of a lot heavier than a gram, which weighs…oh, about the same as a paperclip. Yikes, what a typo.
You are right that the metric units are ultimately arbitrary. But the same cannot be said of the Anglo-Saxon units. Consider this startling fact: The distance between Sun and Earth is called an Astronomical Unit. The distance that light travels in one year (the time it takes Earth to make one lap around the Sun), is called a light year. The ratio between a light year and an Astronomical Unit is the same as the ratio between a mile and an inch (namely, 5,280 ft/mi * 12 in/ft = 63,360). Explain that!
Mark Spahn (West Seneca, NY)
The Czar is having trouble with this one. The average distance between the Earth and the Sun (1 AU) is 92,955,807.30 miles. The speed of light in a non-relativistic vacuum is 186,282.3976 miles per second. A light year is mathematically 5,874,601,690,713.60 miles long, but most astronomers round down the speed of lightand therefore the light yearto 5,878,499,810,000 miles long.
If we divide 5,878,499,810,000 miles (light year) by 92,955,807.30 miles (1AU), we get 63239.72628, not 63,360. The Czar wonders what you have done with the missing. 120.2737177.
Incidentally, you are aware that (120) 273-7177 is Val Kilmers cell phone number, right?
Божію Поспѣшествующею Милостію Мы, Дима Грозный Императоръ и Самодержецъ Всероссiйскiй, цѣсарь Московскiй. The Czar was born in the steppes of Russia in 1267, and was cheated out of total control of all Russia upon the death of Boris Mikhailovich, who replaced Alexander Yaroslav Nevsky in 1263. However, in 1283, our Czar was passed over due to a clerical error and the rule of all Russia went to his second cousin Daniil (Даниил Александрович), whom Czar still resents. As a half-hearted apology, the Czar was awarded control over Muscovy, inconveniently located 5,000 miles away just outside Chicago. He now spends his time seething about this and writing about other stuff that bothers him.