The first area I recall comprehending was “a block,” whose boundaries I was instructed not to cross. Growing up in a small town, I quickly learned who lived in each of the houses on my block. I knew the name of each family and the first names of each occupant. I was told that 12 city blocks equal one mile. I immediately assumed, without thought, that this length would be that of a single edge of each block in a line. After all, wooden building blocks have equal sides, and I had considerable experience with them. I did not confuse area and linear extent, it seemed obvious. What seems natural to most people is to name areas as an independent dimension. It is so natural that a vast number of defined areas were accepted around the world prior to the metric system. When the metric system was originally developed, this penchant for an area that is arbitrarily defined was adopted. The unit of area in the metric system was given as the are. An are is equal to 100 square meters, because?—I have no idea.
People don’t think about the fact that when expressing total area, we divide the area of interest up using an arbitrary shape of enclosed area. We could use circular meters, or equilateral triangle meters, but we have chosen to use squares with one meter sides. * The are has sides with lengths that are the square root of 100 meters, or 10 meters. Why choose ten?—no idea—other than area had always been arbitrarily chosen in the past and ten can become a thoughtless fetish for the are. My favorite reference has this set of equivalent named pre-metric areas in terms of an are:
There are about 130 named areas listed in terms of an are, including a line and a loan. Despite what George Orwell might think, this large number of names for non-equivalent named areas only leads to a lack of comprehension, not a clearer description. It does not make them “more human” unless it is meant they produce more opportunity for human fraud.
Metric prefixes were then applied to the are, to create other areas. The most common one used is hectare, which is 10 000 square meters. Why? I can only guess that it’s like
a myriameter of area? Whenever one of the prefix cluster around unity is implemented in the metric system, it produces a kludge. We could have decaares or daa (yes deca or deka has a two letter prefix da). How about deciares or da, or centiares?—-longtime readers know what I think of this already. Thankfully, the modern official SI is square meters, but once a bad usage has been adopted, it takes an act of Congress (which never happens with the metric system) to change anything. Hectares are still with us, and in the US they are a sure sign of Americans Using The Metric System. Recently on Vice News (2017-01-24) I saw a graph, presented on-screen that showed the increase in poppy cultivation in Mexico had gone from 10 K to 30 Kha indicating the base unit is hectares. It’s easy to understand why this chart has such poor metric usage, it was generated by the White House:
So the White House took hectares and then produced Kilohectares (Kha) by concatenating metric prefixes. So they did not use square meters or square Kilometers, they instead used ares with the metric prefix hecto, then concatenated Kilo to create Kilohecto. It reminds me of when I lived in a Spanish speaking country and if a person there did not speak English, the answer was to say a phrase louder, modifying an English word so that it sounded like Spanish to that person. I recall a person loudly asking a waiter for “El knife-o.”
So how large is 10 Kha to 30 Kha in metric? A hectare is 10 000 square meters, with a Kilo at the front becomes 10 000 000 square meters or about 10 square Kilometers. The production has gone from around 10 square Kilometers to almost 30 square Kilometers.
The chart has two axes on it, the other is the amount of potential production in MT, which I can assume is not Montana, but is instead Metric Tonnes. At least they didn’t need to use another prefix with MT. Would Mg for Megagrams really have caused that much confusion, when MT is not even defined on the graph.
So in 2011 about 11 square Kilometers could produce about 30 Megagrams of poppies or about 2.7 Mg/Km2, by 2015 it is about 70 Mg over an area of 28 Km2 or about 2.5 Mg/Km2. The yield per square Kilometer is about the same.
This chart was only on screen for a few seconds, has two axes, uses ill-defined units, and is therefore typical of what I often see in the media. Telling the story is generally more important than conveying information. The measurement free-for-all that is the US, conspires to reduce our numeracy the same way that 130 named areas dilutes the meaning of 100 square meters.
* A more in-depth discussion of this choice for area shape is found in The Dimensions of The Cosmos (pp 29-31).
The Metric Maven has published a book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.