Why isn't the metric system popular in the United States ? The author seems to know little or nothing about the construction trades. It is very efficient and fast to measure lumber and other items using inches and fractions, or feet and yards, and it is time consuming to use metric, requiring at least some serious math skill. There also is a sense of time that people have internalized from youth. We all know how far a mile is by how it "feels" on the road when driving. Why bother to learn another system ? Similarly with quarts and gallons, once learned there is no felt need to learn another system which does the same thing but which clearly is no improvement. Besides, why junk an entire infrastructure of bottles, drums, barrels, etc, when there is no good payoff ? Still, where metric has room to expand is in new areas, like film ( 35 mm, etc ), microbiology, forensics, etc, areas where pinpoint accuracy and precise measurements are at a premium. In construction you can be "off" by a 64th of an inch, at least this is so in most residential building, or even a 32nd, and no harm done. There is a plus or minus factor that is part of how things are done. But you can't do this in precision manufacturing or scientific measurements. Still, baking a cake is not the same as making a valve to be used in a power plant, and door framing, which does require high order accuracy, regardless can be done quite well with 1/64th " tolerances. Ever watch "This Old House" ? Anyway , Americans have an advantage over others who use metric exclusively. We use whichever system is most appropriate for the task and this gives us savings in time and efficiency. Billy ================================== Real Clear Science Why the Metric System Doesn't Measure Up Posted by Katherine Dickinson at Sat, 10 Mar 2012 01:00:00 Over one hundred and fifty years ago, the U.S. signed the Treaty of the Meter in order to _recognize_ (http://lamar.colostate.edu/~hillger/origin.html) unified control over the metric system. In the eighties, Congress passed two bills in an effort to convert U.S. trade and commerce to the metric system. One amendment even set a deadline: 1992.
Needless to say, a U.S. transition to the metric system has been a little slow. We've made some headway. The scientific community generally recognizes that the metric system (or the International System of Units) is way more logical and intuitive, and more businesses are converting to metric all the time. Yet many Americans are still very reluctant to use the system in their everyday lives. Could they have some good reasons? Metric system is flawed The meter was initially _defined_ (http://physics.nist.gov/cuu/Units/meter.html) as one ten-millionth of the distance from the pole to the equator. Now length of a meter is tied to the speed of light in a vacuum, which is something that can always be found in nature and will never change. Almost all of the metric system's units have now been linked to some sort of universal constant, except one--the kilogram. Originally, a _kilogram_ (http://physics.nist.gov/cuu/Units/kilogram.html) was defined as the mass of a cubic decimeter of water. Later, the experts forged a cylinder of mostly platinum and declared it to be exactly one kilogram. This hunk of metal has been used to calibrate the world's scales ever since. However, earlier this year, the International Committee on Weights and Measures finally met to discuss the kilogram and its lack of a constant. The committee _recommended_ (http://www.guardian.co.uk/science/2011/jan/24/scientists-weigh-up-shrinking-kilogram) the use of Planck's constant, but the new standard has yet to be made official. I should also point out that most of the imperial units are solely defined according to the metric system. Yes, an inch is literally 2.54 centimeters--no natural constants attached. Metric system isn't practical While the metric units' association with physical constants makes them accurate, it makes them less _practical_ (http://www.bwmaonline.com/Death%20of%20Measurement.htm) for common use. The units of cups and tablespoons developed naturally because these objects were right there in the kitchen. The gram, on the other hand, was not developed with cooking and baking in mind, so it is much smaller than it needs to be. For the same reason, the foot and the ounce are also much more user-friendly than their metric counterparts. Also, because they have a base of ten, metric units cannot be divided into as many even fractions as imperial units. A meter can only be evenly divided into 2 or 5, while a foot can be divided into 2, 3, 4, or 6. So if you ever have to measure a third of a meter, good luck. There may be better options Before we consider going to all the trouble of adopting a new measurement system, shouldn't we be sure that the metric system is the best option? One physicist, Johannes Koelman, has _proposed_ (http://www.science20.com/hammock_physicist/metric_vs_imperial_end_epic_battle) another alternative to the imperial system that he has dubbed the "post-imperial" system. The post-imperial system takes advantage of some coincidental properties of the pound and the inch. It uses these properties to fix a couple things that the metric system lacks. Both of these repairs involve time. Unlike the metric system, Koelman's model measures time using the same units as distance. This feature relieves us from having to do calculations involving miles per hour or meters per second. It also incorporates the fact that time is simply a fourth dimension of our 3D world. Even though Koelman's idea would be hard to implement, it has some very useful features and opens the door to other possible alternatives. Imperial system is more quirky As you may have noticed, the witches and wizards at Hogwarts [ what the hell is this., and who cares what is featured in fantasy fiction anyway ? BR comment ] don't use the metric system. Harry's wand, for instance, is described as eleven inches long (also niiiice and supple). This is not simply an adaptation for the U.S. edition. In fact, despite her editor's protests, J.K. Rowling insisted that even the British editions keep the imperial system. After recalling the wizards' system of _currency_ (http://harrypotter.wikia.com/wiki/Wizarding_currency) (29 knuts to a sickle, 17 sickles in a galleon), it's not difficult to understand Rowling's decision. She says that the imperial system is much more quirky and therefore is better suited to the wizarding world. Rowling even accepted an invitation to become a member of the British Weights and Measures Association. She admits, however, that she accepted the invite as a joke, and that she really does prefer the metric system.* Imperial system is traditional I think the main reason why Americans are reluctant to make the metric plunge is simply because they are afraid to change their ways. Maybe it's a valid reason. Mathematics _professor_ (http://www.unc.edu/~rowlett/units/metric.html) at Chapel Hill, Russ Rowlett, says "In fact, the metric system has met popular opposition in every country at the time of its adoption. People don't want to change their customary units, which are part of how they see and control the world. It is naturally disturbing to do so." -- Centroids: The Center of the Radical Centrist Community <[email protected]> Google Group: http://groups.google.com/group/RadicalCentrism Radical Centrism website and blog: http://RadicalCentrism.org
