Wednesday, January 29, 2014

Morning After Light Snow (and a rant)

Squirrel tracks.

How did I know they were squirrel tracks?

The night and earlier morning gently dusted us with a dry inch of snow--enough to show who's been by.  I walked through the back yard and all the way to the back of the tiny wood, but saw signs of only two visitors: a squirrel and probably a rabbit.  No coy wolf--though it's true the snow was only hours old, and an urban eastern coyote would typically roam a three-square-mile area.  I took the regular photos of my Wild Place.  

(or Might As Well Put This Here as Anywhere Else!)
Many Americans despise the metric system of measurements--the Systeme Internacional.  I do not, but neither do I follow it slavishly.  You may have noticed me mix the measurements even within the same post, as I did in "Domestic Science." 

I grew up with the English--or "customary"--units of measure: inches, feet and  miles, pints, quarts and gallons, ounces, pounds and tons, and so forth.  I well remember being taught that America was going metric, so we'd better learn it; this was in third grade in about 1967.  You'll have noticed by now we've been easing into it pretty slowly!   (As far as I am aware, the only time most of us use metric units is to buy soda!)   I am pretty comfortable with millimeters, meters and kilometers, though, as well as grams, kilograms and tonnes, and milliliters and liters.  They are universally used in the sciences which are my background.

Metric units have two great advantages over customary units.  First, they are more fundamentally derived: the meter comes (originally) from French measurements of the distance from the north pole to the equator through Paris.  A cube 1 centimeter on a side contained a volume of 1 milliliter, and this volume of water has a mass of one gram--all neat and tidy!  The second and a very practical advantage came when you had to do any kind of math: all the units related directly to each other, and all by powers of ten.  For example, a distance of 1000 meters was one kilometer, while a meter in turn contained 1000 millimeters.  A liter bottle of water has a mass of one kilogram.  Quick: since a mile is 5280 feet and a foot is 12 inches, figure out how many inches are in a mile!   Doing math in the metric system, by contrast, reduces to merely keeping track of the decimal point!

On the other hand, having physically-derived units doesn't make a system practical, and having units that relate by powers of ten limits, somewhat, their flexibility in size.  for example, I am 6'2" tall.  In the metric system, my height would usually be represented as 188cm --in my opinion, a rather unwieldy number of digits.  Feet and inches are better sized for many everyday purposes than centimeters and meters.  Furthermore, breaking down units fractionally has its own elegant simplicity: if you want a smaller unit, just halve the one you've got by doubling the denominator: 1/2 inch, then 1/4 inch, then 1/8 inch, and so on, limited only by the steadiness of your hands, the acuity of your eyesight, and your technology.  The problem  is it does force one to get down and diry with fractions, which still don't come easily to me.  Here's an example I wrestle with frequently. Put these drill bits in ascending order of size: 5/32, 1/8, 11/64. 

Finally, although the Celsius scale of temperature measurement is elegant in dividing the temperature difference between the melting point and boiling point of water into 100 equal parts, those parts--the Celsius degrees--are almost twice as big as Fahrenheit degrees, and they force you to use negative numbers in winter.

Therefore, I will continue to mix my systems in these posts: metric if much math is involved, English if it's much more convenient in size, and Fahrenheit pretty much always!

No comments:

Post a Comment