In ancient times, measurements were made using local standards which varied from one country to another depending on the person whose biometrics defined what the standard would be. In Egypt, a cubit was about the distance from the elbow to the fingertips. In some areas the width of a thumb was considered to be an inch. In the 14th century, King Edward II of England decided the official inch should equal the length of 3 grains of barley placed end to end. A foot closely approximated the 12 inches we now call a foot. A yard was determined by the distance from the tip of a different king’s nose to his thumb on his out-stretched hand. The height of horses was measured by the number of hand-widths from the hoof to the withers.
As commerce increased and
expanded beyond a country’s borders, it became advisable to develop a system of
weights and measures which would be the same regardless of the origin and
destination. A pound or a foot or a gallon should be the same in country B as
they are in country A. In the 1790’s, France recognized the value of uniformity
and began developing what became the International System of Weights and
Measures abbreviated “SI” units. (SI for the French Systeme Internationale.) They began with the meter for length and
the kilogram for mass (weight). Ultimately the SI system established five
additional standards: the second for time, the ampere for electric current, the
kelvin for temperature, the mole for amount of a substance, and the candela for
intensity of light.
Before the 1790's the framers of our Constitution recognized the value of regulating weight sand measures:
Before the 1790's the framers of our Constitution recognized the value of regulating weight sand measures:
“The regulation of weights and measures
is necessary for science, industry, and commerce. The importance of
establishing uniform national standards was demonstrated by the drafters of the
U.S. Constitution, who
gave Congress in Article 1, Section 8, the power to "fix the Standard of Weights and Measures."
-- legal-dictionary.thefreedictionary.com
-- legal-dictionary.thefreedictionary.com
Until 2013, the United
States of America shared the distinction with two other world powers, Liberia
and Myanmar (formerly Burma), of resisting the adoption of the Metric System.
We are one of the last holdouts. (In 2013, Myanmar began the transition.) Why
have we resisted the change? Because we don’t like change. In 1866, Congress
authorized the use of the metric system but our resistance for the past 150
years has resulted in only small steps in the metric direction.
With an early interest in
the Sciences, the Metric System seemed almost natural after a very short time.
For those unfamiliar, the internet offers many conversion tools but for easy
daily use some units become so familiar that an official converter is not
necessary. Weights: A Kilogram is equal to 2.2 pounds. A Pound is equal to 454
grams. An Ounce is 28 Grams. A Gallon is 3.8 liters. A Liter is 0.26 Gallons
(that’s very close to a quart). These equivalents are quite satisfactory for
everyday use. On the other hand, in a laboratory, measurements to several
decimal places are absolutely crucial – micrograms, milliliters and so on. If
you work in a lab, you already know that.
Two units of daily
concern to most are miles per hour/kilometers per hour. Most vehicles now come
with double numbering on the speedometer. Mph on top of the display, Kph
underneath the display. Digital speedometers have a push button switch allowing
the driver to switch to the applicable units. If a vehicle doesn’t have this
luxury, two equivalencies are easy to remember: 100 kilometers per hour is the
same as 62 miles per hour. The ratio is very close to the decimal equivalent
for five-eighths which is 0.625. Kilometers per hour times 5/8 yields miles per
hour. (Converting in the other direction is the inverse operation –
eight-fifths or 1.6).
The only other regularly occurring concern
might be temperature readings. The United States and most of its territories
remain the only ones to continue using the Fahrenheit scale (Named for Daniel
Gabriel Fahrenheit, a German physicist) which marks the melting point of ice at
32 degrees and the boiling point of water at 212 degrees. The rest of the world
since the end of the 20th century is using the Celsius scale
(previously known as the centigrade scale until named for the Swedish
astronomer Anders Celsius) which marks 0 degrees as the freezing point of water
and 100 degrees as the boiling point of water.
In daily life, how
crucial is it to know the temperature to a precise number? Can you feel the
difference between 72 F and 74 F? Or 33 F and 35 F? It’s funny that a 2 degree
difference between Fahrenheit temperatures is about equal to a one degree
difference in the Celsius temperature. The major difference is the starting
point. Remembering a few equivalencies might make the transition easier.
Celsius degrees Fahrenheit degrees How they feel
Minus 10 Minus 14 Frigid
0 32 Freezing
10 50 Chilly
20 68 Comfy
30 86 Hot
40 104 Too
hot
50 122 Danger
If you really have to exactly
translate Celsius to Fahrenheit, an easy method is to multiply
the Celsius
temperature by two. Reduce that result by ten percent. Add 32 and you will have
the Fahrenheit temperature. For example, 25 Celsius times two is 50, minus 5 is 45,
plus 32, equals 77 Fahrenheit degrees.
77 degrees.
Now all you need is a bit of shade, a comfortable chair and a well made Margarita.
Enjoy.
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