From the Wall Street Journal – By JEANNE WHALEN
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.
The aim is to tie each to a widely accepted property of nature, rather than to a lump of metal or some other imprecise benchmark. The meter, for instance, was once measured as the distance between two notches on a metal bar. It is now defined as the distance light travels in a vacuum in 1/299,792,458 of a second.
The new definitions are “as big a change as the introduction of the metric system during the French Revolution,” says Terry Quinn, a dapper Briton who organized the seminar and once served as director of the International Bureau of Weights and Measures, which ensures world-wide uniformity of measurements. Frequent clashes about the best approach mean the temperature of debate has at times “risen quite high,” he added, without specifying by how much.
Full story at the Wall Street Journal
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Americans
measure their blood pressure metric
make their spectacles metric
use metric units like Volts and
yes, a WATT is a metric unit and depends on the kilogram.
I thought a second was defined as the time it takes light to travel 299,792,458 meters!
if your argument rests on calling your intended new partners …
If the US were persuadable by reason, they would be metric by now. Like the rest of the world.
“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.”
Just to state the obvious: How could the Big K be losing micrograms, if the Big K defines what a microgram is?
One comment from a metrologist ‘This has changed the mass of everything in the universe’. No it has not. It has changed our figures not anything else.
The answer is simple. The rotation of the Earth is slowing, so the mass has stayed the same while the weight has lessened. This is almost certainly due to the effects of AGW.
Shome mishtake shurely . . spin slows, centripetal force reduces, weight goes up.
When it comes to metric vs imperial I like to dig this little page out: Making An English Foot and Chasing the Greek foot.
Whilst you could argue about cups and teaspoons and so on until you’re blue in the face, the basic measurements of length in customary units are rather less arbitrary than you’d think. I have a suspicion that the basic weights aren’t arbitrary either but I’m not in a position to research it, being nowhere near as smart as the man behind that there blog. 🙂
Okay. My theory is that the cleaning crew is taking home the cleaning rags in their lunch buckets and saving them until they have enough platinum to take a nice long holiday. Brilliant of them, though it could take a while, eh?
“Right! What’s a cubit?”
AG Forester:
Schroedingers cat will know. As always.
Archonix says:
January 29, 2011 at 2:45 am
When it comes to metric vs imperial I like to dig this little page out: Making An English Foot and Chasing the Greek foot.
Whilst you could argue about cups and teaspoons and so on until you’re blue in the face, the basic measurements of length in customary units are rather less arbitrary than you’d think. I have a suspicion that the basic weights aren’t arbitrary either but I’m not in a position to research it, being nowhere near as smart as the man behind that there blog. 🙂
—————————————————————————-
Yep, the trouble with metric measures is that they only roughly correspond with human experience. Even though Australia changed to metric decades ago, people still report height as 5’9″ or 6’2″ rather than the metric equivalent. Part of the problem may be in the scaling. An inch (around the length of a thumb joint) is much more useful in everyday life than a cm. Same goes for a foot, which we have to deal with much more often than a metre. Maybe metrics should incorporate a new measure or measures which recognise these realities.
Still, it is pleasing to hear that there are scientists who, instead of trying to ‘hide the decline’, are actively and publicly looking for the reasons for it.
There are two obvious options here, unless I’m missing something.
1: They know the electrochemical properties of platinum, so they could just deposit another 50 micrograms onto it; and
2: Rename it the Standard 0.999 999 950 Kilogram.
Slacko,
“Hmmm. No adjustment for a relationship between lightspeed and gravitational field strength eh? I wonder how long that’ll stand up.”
No adjustment necessary. The speed of light in a vacuum is constant everywhere to all observers no matter how they are travelling or what gravitational fields are involved. Gravity does not slow down the speed of light – it lengthens the wavelength and reduces the frequency by the same amount. The speed, which is a product of the two, remains the same.
Mooloo says:
January 28, 2011 at 7:54 pm
The resistance of the US to a convenient and international system is nothing to be proud of.
=================
The first point is that all scientists use the metric system – yes even US scientists. I would not argue that the metric system is perfect for science. However, there is nothing convenient about it for the ordinary user, and I applaud the Americans for maintaining their own (British derived) system. We in the UK are sick of overzealous jobsworthies coming down on market traders for daring to sell apples by the pound. To be perfectly honest, it is much more intuitive to gauge lenght in feet, inches and yards rather than the ubiquitous millimetres. When I go into a store to by a sheet of wood, I don’t want to be told it is 2700 millimetre long, and 1257 millimetres long. I then have to do a mental calculation to convert it to something meaningful.
All British measurements are what they are because they served a function. The yard was a measure of textile, the inch is the distance from the joint of the thumb to its tip and the stone was a convenient weight for fishmongers to use. These measurements are all part of a rich heritage of anglo saxon culture, and to stamp them out under the boot of uniforminisms is a great shame, and is something to be deplored, not celebrated.
Not even American made documentaries are safe. When I watch an episode of Mythbusters, and they are driving a car at a certain speed, which I know is in miles per hour because it’s a US vehicle, I get really ticked off when the narrator tells me what the speed is in kilometers per hour. It’s like the US documentary is somehow ‘unclean’ and not fit for British consumption until converted to metric. Appalling!
It seems somewhat superflous to add my two cents worth, but metric measurement is not as simple as some here have implied. In the world of textile manufacturing, the Europeans made very clever and beautifully made flat-bed and rotary knitting machines and looms for generations, but almost every individual manufacturer developed their own standard for screw and bolt threads. They all used metric units of measure, but that’s as far as standardisation went and the problems that arise when such technology is sold across the world is difficult to quantify. The world never hears about it, of course, as engineers the world over don’t shout about problems, they just quietly go about their work successfully sorting such problems out.
Since the international insults are starting to fly, I feel free to offer the following: during the build-up to Gulf War I, when President Bush was trying to build an international coalition to fight Saddam in Kuwait and the French were resisting, my uncle (a military man) opined, “Going to war without the French is like going duck hunting without an accordion.” Absent Napoleon, the French have always been a little “light.” 🙂
Archonix, Johanna —
I can’t lay my hands on the book, and it doesn’t seem to be on line (or, at least, not easily found), but when Thomas Jefferson made his proposal for uniformity in weights and measures he discussed the matter. He thought that the fundamental unit was the gallon, and that the unifying principle was weight — a “wine gallon” of wine weighed the same as a “corn gallon” of grain, thus “…making it indifferent whether the goods were sold by volume or weight”. It might be worth further study.
Regards,
Ric
“pcs77 says:
January 28, 2011 at 5:20 pm
I wish I lost weight every time I cleaned myself!”
Of course you won’t lose weight cleaning yourself, you must have someone else clean you!! I personally have lost 3 lbs (er, light kilograms) by non-self cleaning.
It will make a good museum piece. Retired metrology fans can look at it with a tear in their eye remembering all the good times and measurements but wondering how the standard could have failed.
It was great for its time but maybe the science outgrew the standard before cleaning standards were developed by the French.
Now it is time to move on, I’m thinking carbon or anything to do away with conversion tables.
I congratulate WUWT on having a few recent posts on meterology. For too long this has been the dowdy, boring, second-cousin-twice-removed of the sexy siren ‘climate science’.
Some of the extraordinary leaps of ‘logic’ that have been made by AGW alarmists, especially in modelling, are based in ignorance or misunderstanding of meterology. Whether you are measuring coastlines, temperatures, rainfall or ice levels – believe nothing you because you are told, or, it ain’t necessarily so (UK and US versions respectively).
Anthony’s exercise about the integrity of temperature measuring stations should surely have sent alarm bells ringing. That it goes to the core of ‘climate science’ was considered less important than fancy computer models and Al Gore’s evangelism.
Discussions about measurement are a vital contribution to all of the sciences.
It’s great fun to get a scientist all worked up by suggesting they work in English units (or what I consider “normal” units). Outside of the science community, haggling over 50 micrograms of mass is a total waste of time. The metric system, and all the associated standards defined to however many decimal places, are probably a big help in defining laws of physics or whatever. In the grand scheme of building things to make the world a happy, safer, better place, it makes no difference at all.
I agree with the previous poster that English units are based on useful, intuitive standards. I’ve measured distances with my thumb in construction work, and I’ve measured rope and chain in yards by stretching it from my nose to my fingers. Many things in life are sized to whole English units, as whole units are easier to remember. When building in metric units, you either change the overall size of object to measure in whole units, or you don’t round off. Either way, it just isn’t intuitive.
As an engineer, there aren’t many things I can’t design and build using inches and two decimal places. If I need high precision for machined parts, I’ll use three decimal places, or perhaps four decimal places in rare circumstances. I have yet to see where English units have been a limiting factor on building anything. Cars, boats, buildings, dams, aircraft, spacecraft; they seem to do just fine using inches.
If you want to see problems, then force everyone to stop using intuitive, traditional units and move them to a system that has little reference to everyday life. When I was in elementary school in the ’70s they tried to indoctrinate us with the metric system, and replaced our classroom yardsticks with meter sticks. All I remember about them was that they were around 39 inches long…. The only remnant I see from the big ’70s metric push are two-liter soda bottles.
For those who grew up thinking in metric, great. But I don’t see a compelling need to break a system that works just fine, just to make someone else feel better about themselves. Those who have issues with the US using English units need to take it up with our UK friends. They foisted the system on us long ago.
1. Alert Bernanke. Inflation is a force of nature.
2. There’s a really clever cartoon in there somewhere on the input, output and feedback mechanisms on the temperature of debate ala energy models. I’m not a cartoonist though.
I agree with the sentiment in favor of traditional units for everyday use.
But, as an engineer in the aerospace industry, I have found the metric system to be of wonderful utility through the fact that all the basic units are dimensionally compatible, with no bizarre conversion coefficients. Doing thermodynamics of combustion, for example, is much easier if the heat of combustion is expressed in joules/kilogram instead of BTUs/pound…and I want to eventually get to watts of electric power. The true unit of mass in the English system is the “slug,” a very unintuitive unit. Alternatively, there is a unit of force called the “poundal.” It all depends on whether you want to work in pounds-mass or pounds-force. When you get to the units of viscosity, well…it is almost hilarious.
As a result, I am “bi-metrical;” I can compute in either system. And, by the way, it is perfectly possible to produce to metric dimensions on English-system equipment. All that is required is for the dimensional conversion to be accurate to a compatible level of tolerance. We built missiles that way, and our versions flew better than the French versions (though we got no credit…using the same drawings).
johanna,
I noticed that same thing about Australians and their height about 25 years ago. I was a student intern at Argonne laboratory and there was a gent from NSW there. During an evening of beer consumption and lengthy coaching on the proper way to pronounce the word ‘bastard’, the issue came up of Americans’ reluctance to embrace the metric system. After putting up with a fair amount of good natured ribbing I ask Ken how tall he was. His reply? “5 foot 11, you bastard.”
I wonder if the mass was not lost but the gravitational constant of the planet has dropped it would not be not measurable by tests but it caused everything to lose weight by a grain of sand.