It's National Metric Week - always celebrated in the week that contains Oct. 10, because that's the 10th day of the 10th month. Metric folks love the number 10.
The International System of Units — that's the official name of the metric system — is a decimal system of weights and measures based on the meter and the kilogram. Abbreviated SI, for Système international d'unités, the metric system was first suggested as early as the 16th century.
It's now used almost universally throughout the world, though a few places still use some non-metric measurements (known as English or Imperial standards). You can still order a pint in a British or Irish pub, for example.
Although its use has been sanctioned in America since 1866, the U.S. has stuck to ye old English system of feet and ounces. Only three countries — Burma (also known as Myanmar), Liberia and the United States — have not adopted it.
As the CIA World Factbook says, "The U.S. is the only industrialized nation that does not mainly use the metric system in its commercial and standards activities, but there is increasing acceptance in science, medicine, government, and many sectors of industry."
In 1999, an incident demonstrated the serious repercussions of America's reluctance to adopt the metric system. The Mars Climate Orbiter mission was a $125 million NASA project to investigate the atmosphere and surface of the red planet. But the mission was a complete dud — communications were lost and the orbiter burned up due to a navigation error caused by the failure to translate English units to metric.
There have been several attempts by Congress to encourage — but not require — use of the metric system in America; efforts to introduce the system go all the way back to Thomas Jefferson and John Quincy Adams. The U.S. Metric Association has been around since 1916, promoting the system. The problem, it says, is that the U.S. teaches the metric system badly.
"Conversions between unit systems are a poor way to learn the metric system, and conversion factors ... can make the metric system look complicated," the USMA says. That's certainly the way I remember it from elementary school.
Some contend that the U.S. hasn't fully adopted the metric system because American women don't want to wear size 39 shoes or have a 63.5 centimeter waist (although telling someone you weigh 56 kilograms instead of 125 pounds doesn't sound so bad). But since Congress has never mandated compliance, most people have been unwilling to learn a "new" system when they consider the established one to be perfectly adequate.
P.S. To answer our headline: A cubic dekameter is a metric unit of volume equaling 1,000 cubic meters. A gill is a unit of volume used in America, which equals 4 fluid ounces. Thus, there are 8,453,505.675 gills in a dekameter.