Posted on 09/13/2007 1:29:09 PM PDT by presidio9
The 118-year-old cylinder that is the international prototype for the metric mass, kept tightly under lock and key outside Paris, is mysteriously losing weight — if ever so slightly. Physicist Richard Davis of the International Bureau of Weights and Measures in Sevres, southwest of Paris, says the reference kilo appears to have lost 50 micrograms compared with the average of dozens of copies.
"The mystery is that they were all made of the same material, and many were made at the same time and kept under the same conditions, and yet the masses among them are slowly drifting apart," he said. "We don't really have a good hypothesis for it."
The kilogram's uncertainty could affect even countries that don't use the metric system — it is the ultimate weight standard for the U.S. customary system, where it equals 2.2 pounds. For scientists, the inconstant metric constant is a nuisance, threatening calculation of things like electricity generation.
"They depend on a mass measurement and it's inconvenient for them to have a definition of the kilogram which is based on some artifact," said Davis, who is American.
But don't expect the slimmed-down kilo to have any effect, other than possibly envy, on wary waistline-watchers: 50 micrograms is roughly equivalent to the weight of a fingerprint.
"For the lay person, it won't mean anything," said Davis. "The kilogram will stay the kilogram, and the weights you have in a weight set will all still be correct."
Of all the world's kilograms, only the one in Sevres really counts. It is kept in a triple-locked safe at a chateau and rarely sees the light of day — mostly for comparison with other cylinders shipped in periodically from around the world.
"It's not clear whether the original has become lighter, or the national prototypes have become heavier," said Michael Borys, a senior researcher with Germany's national measures institute in Braunschweig. "But by definition, only the original represents exactly a kilogram."
The kilogram's fluctuation shows how technological progress is leaving science's most basic measurements in its dust. The cylinder was high-tech for its day in 1889 when cast from a platinum and iridium alloy, measuring 1.54 inches in diameter and height.
At a November meeting of scientists in Paris, an advisory panel on measurements will present possible steps toward basing the kilogram and other measures — like Kelvin for temperature, and the mole for amount — on more precise calculations. Ultimately, policy makers from around the world would have to agree to any change.
Many measurements have undergone makeovers over the years. The meter was once defined as roughly the distance between scratches on a bar, a far cry from today's high-tech standard involving the distance that light travels in a vacuum.
One of the leading alternatives for a 21st-century kilogram is a sphere made out of a Silicon-28 isotope crystal, which would involve a single type of atom and have a fixed mass.
"We could obviously use a better definition," Davis said.
Find the lb. weight and recalibrate.
I never liked this metric business in the first place.
Quantum tunneling?
It must be mass, since the others did not.
My first reaction too. But, after a little thought, I’ve decided that it’s more likely something that Cheney did.
The answer is itself a question: "Compared to what?"
Atkins Diet?
Silliness - clearly the scale that came up with the 50 microgram difference is off. !-)
Are we talking about Teresa Heinz Kerry?
I have Proton credits for sale. Don’t leave home without them.
“It is kept in a triple-locked safe at a chateau and rarely sees the light of day”
Oh my goodness! Take it out and feed the poor thing!
Ahhh, that explains things - I haven’t been gaining weight over the past decade; it’s that stupid kilo getting lighter...
It's Bush's fault.
This is a weighty matter; perhaps some appropriate puns could lighten this up? (I wouldn’t expect a massive response)
Bringing a Gun Ban to a Knife Fight
When it comes to school violence, our neighbors to the north have some ideas that aren't exactly brilliant either, as Toronto's Globe and Mail reports:
Ontario Liberal Leader Dalton McGuinty said Wednesday that he does not want to see the provinces' schools resort to installing metal detectors and having uniformed security officers patrol the halls in the wake of Tuesday's fatal stabbing at a Toronto high school.
Such a move, he said, would amount to the Americanization of schools in Ontario. . . .
Instead, he said, Ontario needs to distinguish itself from the United States by imposing an outright ban on hand guns.
"Let's ban handguns in Ontario," he said. "Let's ban handguns across the country. Let's declare war against handguns."
A 16-year-old Scarborough youth was stabbed to death on Tuesday on a walkway leading from Winston Churchill Collegiate Institute.
If McGuinty has his way and Canada bans handguns, we'll bet it won't take very long before it occurs to some Canuck delinquent that you can also stab people with a knife.
In a related story, the Associated Press reports on the latest crisis for the metric system:
A kilogram just isn't what it used to be.
The 118-year-old cylinder that is the international prototype for the metric mass, kept tightly under lock and key outside Paris, is mysteriously losing weight--if ever so slightly. Physicist Richard Davis of the International Bureau of Weights and Measures in Sevres, southwest of Paris, says the reference kilo appears to have lost 50 micrograms compared with the average of dozens of copies. . . .
But don't expect the slimmed-down kilo to have any effect, other than possibly envy, on wary waistline-watchers: 50 micrograms is roughly equivalent to the weight of a fingerprint.
A fingerprint may not seem like much, but it can be vital in fighting crime. Is it any coincidence that Canada, which still uses the metric system, is experiencing such an epidemic of violence?
I enjoy Taranto's continual and several times weekly poking fun at the metric system.
I thought metric measurements were based upon physical constants — a meter being based upon one wavelength of a certain frequency of light, a kilogram based upon a litre of water at 4C, etc. I knew there were standards but figured they were outmoded already.
Snort!! I just sprayed a perfectly good mouthful of a Ketel One martini all over my monitor. I can clean that up. Fortunately, the keyboard still appears to be functional . . . .
Do I have to slug you for asking that question? ; )
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