A Brief History
On October 21, 1983, the standard metric unit of length, the meter, was redefined as “the distance light travels in a vacuum in 1/299,792,458 of a second.” The meter had been defined originally in 1791 by the French National Assembly as one 10 millionth the distance from the Equator to the North Pole.
Digging Deeper
This calculation means the circumference of the Earth via the polar route was exactly 40,000 kilometers. Other units of length were based on a decimal system of the meter, such as “millimeter” or 1/1000 of a meter or a “kilometer,” or 1000 meters.
Metric units of volume are based on the meter as well, using the liter, or 1000 cubic centimeters, as the base unit. The metric weights were based originally on one cubic centimeter of water being called a “gram,”
The “metric” system has been modernized today as the International System of Units with highly scientific standards defining each measurement.
Question for students (and subscribers) to ponder: Why did the US not totally go metric?
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Historical Evidence
For more information, please see…
Brownridge, Dennis. Metric in Minutes: The Comprehensive Resource for Learning and Teaching the Metric System. Professional Pubns Inc, 1994.
Shoemaker, Robert. Metric for Me!: A Layperson’s Guide to the Metric System for Everyday Use With Exercises, Problems, and Estimations. Cousin Communications Llc, 1998.
