by Jay Johansen | May 17, 2014
When I was in high school and college and was studying physics and chemistry and math, the advantages of the metric system were obvious. When you are doing calculations involving multiple different units of measure -- distance, energy, mass, etc. -- metric is so much simpler and easier. You can change the scale by just moving the decimal point. Units of one quantity are routinely defined in terms of others quantities, for example 1 liter is defined as 1 cubic decimeter, so you can easily calculate volumes from lengths. I couldn't understand why we just didn't switch over.
But I majored in computer science, so by the end of college I wasn't spending much time on science any more -- most of the software I've worked on involves text processing and finance, not scientific calculations.
And I discovered something. The advantages of the metric system were not so obvious any more. I still care about measurements. I care about the distance to the next exit on the highway, the temperature outside, how much electrical power my appliances use, etc. But if you are just expressing, say, a distance, it doesn't much matter whether you give it in miles or kilometers. I rarely have to do calculations with measurements, and when I do, they tend to be fairly simple. Now and then I have to convert square inches to square feet and then I occasionally think how the arithmetic would be easier if I was converting square centimeters to square meters, but it's a minor inconvenience.
Sometimes the English system is more convenient. A foot is a handy unit because you can approximate it with the length of your own foot. A cup is a handy unit because it's a convenient amount to drink at one sitting. Etc. Some people try to make some more convenient size units in the metric system by defining, for example, a "metric cup" of 250 milliliters. But then you have 250 milliliters to the cup and 4 cups to the liter, and if you keep that up, before long you're right back where you started. But I digress.
For the average person going about his daily life, there's no particular advantage to the metric system. It's just a bunch of new units to learn, and it will take years before you are comfortable with them. It's a bunch of effort for no clear gain. Why bother?
© 2014 by Jay Johansen