Professor Blue

Serious about science since….first grade

Metric vs Yardstick

soda pop can

What would you call this?

In some places, like Chicago or St Louis, peo­ple call this pop.  In other places like Philadel­phia, peo­ple would call it a soda.  We’ve even heard peo­ple in Mass­a­chu­setts call this tonic.

There’s no risk hav­ing dif­fer­ent ways of nam­ing some­thing like soda pop.  It’s no big deal when you buy some­thing to drink to go with your sand­wich while you’re vis­it­ing the museum of sci­ence.  “Pop? You mean soda?” the lady at the cash reg­is­ter asks.  “OK, that’ll be $1.25.”

See?  Easy.

But talk­ing about using mea­sure­ments can be tricky.

Your mom goes to the gas sta­tion and fills up the car with 10 gal­lons of gas.  Your father puts a 12 ounce sir­loin steak on the grill.  Gal­lons and ounces are a cou­ple of exam­ples of how we mea­sure stuff in the US.  We use a sys­tem that was based on the Impe­r­ial sys­tem from Eng­land but changed slightly.

Here’s how Amer­i­cans used mea­sure­ments in the time of Thomas Jefferson:

Two mouth­fuls are a jig­ger; two jig­gers are a jack; two jacks are a jill; two jills are a cup; two cups are a pint; two pints are a quart; two quarts are a pot­tle; two pot­tles are gal­lon; two gal­lons are a pail; two pails are a peck; two pecks are a bushel; two bushels are a strike; two strikes are a coomb; two coombs are a cask; two casks are a bar­rel; two bar­rels are a hogshead; two hog­head are a pipe; two pipes are a tun-and there my story is done!

from http://library.thinkquest.org/J002831/missionmetric.htm

We need to be able to have a stan­dard of mea­sure so that if a gro­cery store buys a bushel of corn from Iowa, and it gets deliv­ered to Wash­ing­ton State, that every­one will know exactly how much corn they’ll be get­ting, as long as it’s in the US.

The same is true at a hos­pi­tal.  The doc­tor tells the nurse to give you 10 ccs of some med­i­cine.  CC means cubic cen­time­ter, which is part of the met­ric sys­tem, or SI, the Inter­na­tional Sys­tem of Units.  It’s a com­pletely dif­fer­ent way of mea­sur­ing than the Amer­i­can stan­dard.  So the doc­tor has two ways of mea­sur­ing inside his or her head.  At the gas pump?  Amer­i­can.  At the hos­pi­tal?  Metric.

If you’re a sci­en­tist, you, too, work in the met­ric sys­tem.  It does not mat­ter if you’re a sci­en­tist in Brazil, Bangladesh, Spain, Canada, or the US.  Sci­en­tists use the same sys­tem.  But Amer­i­cans who have other jobs like car­pen­ter, recep­tion­ist, police offi­cer, all use the Amer­i­can sys­tem of mea­sure­ment.  Right now there are only three coun­tries in the world that do not use the met­ric sys­tem for everything.

World Map Metric

which coun­tries do not use the met­ric system?

The coun­tries on this map (cour­tesy of Kate Sedg­wick at Mata­dor Nights) in pink are the United States, Liberia, and Burma.  Every­body else uses the met­ric sys­tem for every­thing, steaks and gaso­line, included.

Will this ever change?

posted by professor blue in General and have Comment (1)
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