Inches and Feet and Miles, Oh My!

Date: 04/14/2008 at 13:14:51
From: Elisha
Subject: English Measures: inconsistency

Why are English measures inconsistent in conversions?  The metric 
system works in the meter and power of tens, but English units are
kind of crazy (1 ft = 12 in, 3 ft = 1 yd, 1 mi = 1760 yd or 5280 ft, etc.)

I really don't understand where the measures come from.  After all, 
the metric system uses the universal meter for length, liter for 
volume, etc.

I've checked out the page "Millimeters, Inches, Feet, Miles" 
[http://www.mathforum.com/library/drmath/view/63332.html] and found 
it interesting, and it piqued my curiosity.

Thanks,
Elisha

Date: 04/14/2008 at 23:34:22
From: Doctor Peterson
Subject: Re: English Measures: inconsistency

Hi, Elisha.

The English system, like all other national systems before the metric
system, "just grew"--it wasn't planned, but formed gradually as
various units were borrowed from other countries, modified to fit
local needs and uses, and were eventually seen as a "system", though
it is more of a loose confederacy than an organized system.  Each set
of related units has its own reason, but they are all different
reasons.  It's a lot like English spelling, which grew in a similar
way and has little consistency.  It's also like an old city whose
roads wander in all different directions, because it was not planned
as a city.

If you want to see some of those reasons, and how these units
developed, try looking up some familiar units here:

  How Many? A Dictionary of Units
    http://www.unc.edu/~rowlett/units/ 

The metric system was deliberately put together as a consistent system
by people who were familiar with old systems, were willing to change
everything, and wanted to make it completely rational.  It's more like
an artificial language (say, a computer language), or a planned city
with regular rectangular blocks--uniform and consistent, but a little 
uninteresting!  I suspect one reason many people dislike metric is 
that it has no personality, and doesn't quite seem human.  But for its 
purpose, it is excellent.

If you have any further questions, feel free to write back.


- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/