Metric and Standard Rulers

Date: 04/20/2001 at 16:21:39
From: Janae
Subject: Metric and standard rulers

In the United States we only use a customary (standard) ruler, and in 
other parts of the world they use the metric side. Why is it that the 
United States just uses the standard side of a ruler?

Date: 04/20/2001 at 22:42:57
From: Doctor Peterson
Subject: Re: Metric and standard rulers

Hi, Janae.

I wouldn't quite say that we use _only_ the customary units; but the 
movement toward the metric system has been very slow here. That's just 
the nature of human systems: we have a lot of inertia.

It's important to understand that at one time every country had its 
own system of units - and often several different systems. What we see 
in America, with two competing systems side-by-side as your ruler 
shows, is just a small remnant of what used to be the state of 
measurement worldwide. America isn't so different, just late in 
changing. In the rest of the world, it's the metric system that is 
"standard"; but they still have traditional units everywhere that are 
hard to forget.

I've speculated that America's slowness to change in this area is due 
to several factors. We're a large country, geographically isolated 
from much of the world, so we can do things the way we want to without 
worrying too much about how the rest of the world wants them done. We 
have a large investment in technology based on the old units, so it 
would cost a lot to change over. We tend to think of ourselves as 
apart from the rest of the world, and do not want to follow anyone's 
authority but our own. But as the world grows more interrelated, and 
markets become worldwide, there will be more motivation to make more 
and more of our measurements metric.

Here are a few sites that talk about this change:

   The Metric System in the United States, in How Many? -Russ Rowlett
   http://www.unc.edu/~rowlett/units/usmetric.html   
   http://www.unc.edu/~rowlett/units/metric.html   

   THE UNITED STATES AND THE METRIC SYSTEM, from NIST
   http://ts.nist.gov/WeightsAndMeasures/Metric/lc1136a.cfm   

   Metric Land or: What I think of the metric system by Joan Pontius
   http://www.tysknews.com/Depts/Metrication/metric_land.htm

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