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Introductory Physical Science


Metric Prefixes

tera T 1,000,000,000,000 1012
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1,000 103
hecto h 100 102
deca da 10 101
  1 100
deci d 0.1 10¯1
centi c 0.01 10¯2
milli m 0.001 10¯3
micro µ 0.000001 10¯6
nano n 0.000000001 10¯9
pico p 0.000000000001 10¯12




Timeline of Important Dates In The History Of The Metric System


 Gabriel Mouton proposed his decimal system of measurement based on a fraction of the Earth’s circumference.


 Jean Picard proposed the swinging pendulum as a measure of length.


 The National Assembly of France asked the French Academy of Sciences to create a standard system of weights and measures.


 France adopted the metric system.


 French government required all Frenchmen to convert to the metric system.


 Congress legalized the use of the metric system in the United States. However, its use was not required.


 The Treaty of the Meter was signed at the close of the International Bureau of Weights and Measures conference.


 The U.S. Army and Marine Corps adopted the metric system. Used as the basis for their weapons and equipment.


 Great Britain began adopting the metric system.

1970 Practically all the world has adopted the Metric System - the US, Liberia and Burma remain the only countries still using the English Imperial units
1975 Metric Conversion Act (Public Law 94-168) passed by Congress
1988 Congress passed the Omnibus Trade and Competitiveness Act. This act called for all federal government agencies to use the metric system for business by the end of 1992. ”

   Mars Orbiter Loss

The use of two different unit systems was the cause of the loss of the Mars Climate Orbiter. NASA specified metric units in the contract. NASA and other organizations applied metric units in their work, but one subcontractor, Lockheed Martin, provided thruster performance data to the team in pound-force-seconds instead of newton-seconds. The spacecraft was intended to orbit Mars at about 150 kilometers (93 mi) altitude, but incorrect data probably caused it to descend instead to about 57 kilometers (35 mi), burning up in the Martian atmosphere.

21st Century

On December 31, 2012, a petition was created on the White House's petitioning system, petitioning the White House to "Make the Metric system the standard in the United States, instead of the Imperial system." On January 10, 2013, this petition garnered over 25,000 signatures, exceeding the threshold needed to require the Obama Administration to officially respond to the petition. Patrick D. Gallagher, director of the National Institute of Standards and Technology, provided the official response stating that customary units were defined in the metric system, thus making the nation "bilingual" in terms of measurement systems. Gallagher also said that using the metric system was a choice to be made by individuals.

Early in 2013, state Representative Karl Rhoads introduced bill HB36 into the Hawaii House of Representatives that sought to make the metric system mandatory within his state. Called "Relating to the Metric System", the bill stipulated that the law would come into effect on January 1, 2018. By June 2014, bill HB36 had not gained enough support and was considered dead. If the bill had become law, Hawaii would have been the first state to introduce the metric system on a broad scale.

In January 2015, Oregon State Senator Brian Boquist, at the request of metric enthusiast David Pearl, proposed Oregon Senate Bill 166, which is similar to the Hawaiian bill. It would establish the International System of Units as the official units of measurement within the state of Oregon.



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