Soon yall will have to learn what an ounce is.
http://www.wisinfo.com/thereporter/news/archive/opinion_10640925.shtml

In 1889, the International Committee on Weights and Measures defined the
kilogram by the weight of a cylinder cast in England of platinum and
iridium. This standard kilogram is secured in a heavily guarded chateau
outside Paris. It is inspected once a year by the only three people who have
keys.
Here’s the problem: Yearly inspections have apparently shown that the
kilogram cylinder has lost weight, approximately 50 micrograms. That’s less
than the weight of a grain of salt, but it’s plenty to send the world of
weights and measures into an epic tizzy. Quantities of human ingenuity are
being expended to re-adjust the kilo and render it eternally precise. For
example, German scientists are working in Russian nuclear facilities to
produce a perfectly round 1-kilo sphere of silicon. Then, by knowing the
number of atoms in the sphere and their distance from one another ...

-- 
Kevin Gowen