Last year I devoted some words on correligion: the religious belief in the usefulness of correlations to solve real-life problems. I forgot to mention that correlations have one big advantage; they are dimensionless meaning that they are the same for everyone, including people from outside the US. Unfortunately this is not the case for most common units, and the struggle for standardization is the topic of this editorial.
Failure to standardize has caused a lot of problems in history. For example, in 1886, the railroad gauges were standardized in the whole of the U.S. Erie, Pennsylvania, functioned as a main junction point where three different widths of railroads met, and hundreds of citizens stood to lose their jobs created by the need to load and unload. Bloody riots followed, and a mob of women tore up all newly laid tracks only to be stopped by federal marshals.
In 1904, the need for nationwide standards became painfully obvious when Baltimore was on fire. Help from Washington (and later from as far as New York) became available in record time but did not work out because the fittings for the hoses were different. When the number of boiler explosions reached 1,400 a year in 1910, safety standards were finally established.
What happened to the Mars Lander when failing to convert from U.S. to SI units and Air Canada’s Boeing 767 when messing up units while refuelling are other horror stories.
It is interesting to read about the history of units. The cubit, widely used throughout the ancient world, was the length of a man’s forearm (in Egypt the hieroglyph for the cubit), or the distance from the tip of the elbow to the end of his middle finger. In these days the middle finger has quite a different meaning. Some call it progress. Two cubits made a yard. For precious metals, the Arabs used the weight of a small bean, called a ‘karob’, now still in use as the carat.
The Romans spread their standards throughout a large area. After the Romans left around 600, it took over 600 years before England’s King Edward I took a big step forward. He ordered a stick made of iron to serve as a master standard, its length pretty close to a yard. In 1793, the French adopted a new system called the metric system based on the meter and decimal ratios. Unfortunately, Napoleon was forced to renounce it in 1812 due to conservationist actions. However, in 1837 France went back to the meter, this time for good. In England, the Parliament legalized a new standard yard in 1824.
What happened in the US? Around 1830 copies of both the meter and the yard were brought to the US. Unfortunately, the English system was adopted, but, even more unfortunately, not completely, e.g., the U.S. gallon differed from the Imperial gallon.
Remarkably, much earlier, under a 1792 law, the U.S. chose the decimal system for its coins. Thomas Jefferson suggested switching to the metric system at large. In 1795, France tried to convince the U.S. to adopt their view, without success, not for the last time unfortunately. A small step forward occurred in 1866 when Congress passed a bill which permitted use of the metric system. In 1875 the U.S. was one of 17 nations to sign the Treaty of the Meter, establishing the International Bureau of Weights and Measures, the agency that administers the International System of Units (SI).
In 1893, the Mendenhall Order stated that the International meter and kilogram would be regarded as fundamental standards. In 1896 and again in 1901, bills were introduced recommending the adoption of the metric system, but no action was taken. Congress asked in 1968 for a three-year investigation of the metric question, and in 1971 the final report ‘A Metric America�.’ was released. In 1975, Congress passed the Metric Conversion Act to coordinate voluntary transition to the metric system. In 1991, U.S. law required the use of the metric system, but specified no date. Since 1996, surface temperatures in the National Weather Reports have been given in degrees C.
A couple of years ago, the author asked National Geographic to serve 95% of the world’s population by at least putting SI units next to their inches and degrees Fahrenheit. The answer was that they tried once, but were forced to renounce by their U.S. readers. Unfortunately, National Geographic didn’t reply on my argument that they have also an educational mission.
At this moment in time, the U.S. shares the dubious distinction with Myanmar and Liberia of not being converted to the metric system. But there may be a light at the end of the tunnel. If common sense will not work, maybe money will succeed. From 2009 onwards, all products in Europe are required to have only SI units. I would like to end with a positive point. In most engineering and science fields, the use of SI units is accepted. A hopeful note.
