Losing a little weight
From the
Wall Street Journal:
The Fate of the Kilo Weighs Heavily on the Minds of Metrologists
In a vault beneath a 17th-century pavilion on the outskirts of Paris sits a platinum cylinder known as Le Grand K. Since 1889 it has been the international prototype for the kilogram, the standard against which all other kilos are measured.
But over the years, scientists have noticed a problem: Le Grand K has been losing weight. Weigh-ins at the International Bureau of Weights and Measures show that the bar has shed approximately 50 micrograms�roughly equal to a grain of sand.
The problem has vexed scientists who monitor the kilo the way tabloids track the waistlines of Valerie Bertinelli and Kirstie Alley. The stakes, however, are weightier.
"It's a scandal that we've got this kilogram hanging around changing its mass and therefore changing the mass of everything else in the universe!" Bill Phillips, a Nobel Prize winning physicist, exclaimed at a scientific summit in London this week. No one knows for sure what went wrong with Le Grand K, but some theorize it lost weight from being cleaned.
Dr. Phillips and other mandarins of metrology were gathered at Britain's Royal Society to debate an urgent question in the science of measurement�how to re-define the basic unit of mass, as well as other measurements such as the second, ampere, kelvin and mole.
Curious - the science of metrology is a fascinating one. I started learning electronics when I was a child (Dad taught me to solder when I was six) and back then, measuring a voltage to two or three decimal places required some fairly sophisticated lab equipment. Now, I have a hand-held multimeter that is good for five and it cost me under $300. All of the other meaurements have advanced just as rapidly.
Posted by DaveH at January 29, 2011 8:21 AM