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Standard Kilogram Gains Weight
mrbluze writes "The standard kilogram weights used by countries around the world for calibration have variably increased in mass by tens of micrograms. This poses a threat to the precision and comparability of measurements in science, engineering and trade. The problem is due to surface contamination, but a safe method of cleaning the weights has only recently been devised by the use of ozone and ultraviolet light (abstract). 'The ultraviolet light-ozone treatment removes hydrocarbon contamination that has built up on the metal surface, gunk that comes from the emissions of an industrial society. Cumpson suspects that because the kilos living in national labs have been retrieved and handled more frequently than the international kilo, more carbon-containing contaminants have built up on them over time. Incubating the kilograms with a set amount of ozone and ultraviolet light "gently breaks up the carbonaceous contamination at the surface."'"
I think the kilogram should be adjusted upwards every holiday season ...
Nothing like a bit of seasonal normalisation on the scales to justify festive binges.
Has anyone measured the standard ounce or hogs head lately?
BTW: we've spoken with the frenchies, they'll stop feeding the standard KG more than one bacon and cheese croissant per day.
Calling someone a "hater" only means you can not rationally rebut their argument.
how do they know this reliably?
Use the method they used to determine this to define 1KG
If you'd all use imperial, this wouldn't happen. Just need to know how long that guy's foot is.
"First they came for the slanderers and i said nothing."
He (or she) redefines the standard.
Now all we need are electronic scales that can receive updated firmware via the internet.
seal it in something already, its not a desk toy. There would be no gunk if it was not exposed to it
That why I'm glad to live in America, where we still use the good old pound. Now all I have to do it sit back and watch your metric world unravel.
I guess obesity really *IS* an epidemic problem.
Hey.... somebody had to say it.
File under 'M' for 'Manic ranting'
Just to preempt all comments about imperial or home-grown measurement systems: All measurement systems in the world are defined from the metric base units, which are in turn defined from a few physical constants and this kilogram prototype. When the kilogram prototype gains mass, this affects the kilogram, pound, liter and fluid ounce equally.
The mass of X number of molecules of element Y = 1 gram.
Like there is for the second:
"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom."
This is the same problem for any mesure system (including Imperial system).
The only chance is that USA is the only developped country that still use it as a reference. So there is little issue for the world if a pound reference change thru time or space.
Comment removed based on user account deletion
Everyone had been thinking it, but when international standards had to be changed to accommodate the weight gain, Kilo decided to cut out the daily Big Gulps
It is being worked upon, to make the kilogram a sphere of a specified diameter of a pure element. The element chosen is silicon and as a mm is defined very well this will avoid all these problems as a new standard can be made and measured repeatably in every country. Did work in this field some years ago with contact with the people involved.
A few years ago, the kilogram reference standard was losing mass -- coincidentally, they said it had lost 50 g, the amount of mass it's now said to have gained. So it should be just right by now.
http://www.sciencedaily.com/releases/2007/09/070921110735.htm
Although I'm sure you're kidding, it's probably worth bringing up the following 2 bits of trivia
1. Sadly, the American "pound-weight" has mostly been defined in terms of the kilogram and has its most recent official relationship updated in 1959 (now exactly 0.45359237 kg, down from 0.4535924277 kg back 1901).
2. The kg artifact itself is soon to be rendered obsolete. In 2014, the kg is likely to be redefined in terms of the planck constant (well technically, planck constant will be fixed to a specific number and since it has the units kg*m^2/s, and the second and meter are defined in terms of oscilations of a Ce133 atom and the speed of light, these will now determine the kilogram).
That is until we discover a grand unifying theory where the Planck constant is not actually a constant. Then you can really see the world unravel...
We need a weapon of mass destruction!
In the title it's "Standard Kilogram Gains Weight", in the description you say "variably increased in mass". There _is_ a difference between weight and mass. I understand that the minutiae of this may be lost on you since you're sourcing articles from pop news sites. Care to update one of those to reflect on this? Is this due to the acceleration of the Earth (weight is a function of mass and acceleration)?
As long as you can exactly count all of the atoms in a weight. Otherwise it's more useless for comparative measurement than a king's foot.
Use a perfect crystal (or almost perfect), measure it's size, and multiply to get the atom count. It's a little more complex than this, but it works.
It was made in the 1800s. Why they haven't made a new one is anyone's guess.
It's an archaic system that needs revising. Cleaning something and not expecting it to not change is a little like the heisenberg uncertainty principle. How can you clean something through physical contact and not expect a change?
Now you're just trading for an inaccuracy of linear measure. With a KG weight it's impossible (under any current technology) to create a perfectly geometric crystal. And with the scale needed to guarantee it's a perfectly geometric crystal it's impossible to accurately sum enough of them to make exactly a KG.
No, it's defined as "the mass of the international kilogram prototype". There are alternative proposals (the Avogadro Project, counting the Silicon-28-atoms in a defined sphere of Silicon-28 and the Watt balance), but none of them is ready yet to replace the Kilogram prototype.
Since it is the standard, surely its the world that needs to bend a little (space-time wise) to fit in with the new standard? surely the standard (master) kilo still weighs exactly 1 kg by definition?
Most silicon monocrystals are grown by the Czochralski process, in the shape of cylinders up to 2 m long and 30 cm in diameter (figure on the right)
The size of the monocrystal is not the problem.
From http://www.acpo.csiro.au/avogadro.htm
The limiting factors currently are:
The variability from sample to sample of the isotopic abundances M(Si)
The content of impurities and vacancies (n)
Realisation of accurate density standards (m,V)
You can read all about the new kg here...
Maybe the meter is somewhat arbitrary, but in particular weight can be measured against i.e. 1 liter of pure water?
http://en.wikipedia.org/wiki/New_SI_definitions
"The definition of the kilogram is undergoing a fundamental change - the current definition defines the kilogram as being the mass of the international prototype kilogram, the new definition relates it to the equivalent energy of a photon via Planck's constant.
Current definition: The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
Proposed definition: The kilogram, kg, is the unit of mass; its magnitude is set by fixing the numerical value of the Planck constant to be equal to exactly 6.62606X×1034 when it is expressed in the unit s1m2kg, which is equal to Js.
One consequence of this change is that the new definition makes the definition of the kilogram dependent on the definitions of the second and the metre."
It seem that the legal definition of pound is bound to the kilogram: http://en.wikipedia.org/wiki/Pound_(mass)
"The pound or pound-mass (abbreviations: lb, lbm, lbm, [1]) is a unit of mass used in the imperial, United States customary and other systems of measurement. A number of different definitions have been used, the most common today being the international avoirdupois pound which is legally defined as exactly 0.45359237 kilograms."
This is not a surprise as the USA have, from the international point of view, endorsed the SI units since a half century.
The meter is based on the speed of light.
You can't define a distance based on speed.
You need a well defined speed AND TIME unit.
It doesn't get any better from there...
Then zero the scale with that weight, and fill the container with absolutely pure water. The weight of that water is exactly 1 kg. No special reference needed (although you can make a reference from this).
When do you consider it "full"? Water has the nasty habit to form a spherical surface due to surface tension. Do you consider it full when the middle or the border is aligned with the "full" mark on your comtainer? And good luck getting any "absolutely pure" water that does not fall apart into ions and reforms all the time... look up the definition of ph-value. millions of hydrogen ions are making water not acidic.
bickerdyke
The've choosen platinum as it is already the most inert material they could find. And even if they might be less reactive, inert gases are completly out due to handling issues.
bickerdyke
Perhaps you should read this document from NIST about the history of weights and measures in the US.
According to this document...
1827 a troy pound was obtained from London.
1828 a brass artifact (which was compared to this troy pound) declared standard for the US mint, not the avoirdupois pound
1866 the metric system was made lawful for commerce in the US. Legally defines avoirdupois pound as (1/2.2046) kg
1875 17 governments (incl the US) established the international bureau of weights and measures
1890 The US receives standard kilogram artifacts #4 and #20 for use as the national prototype
1894 The US tweaks the definition of the pound relative to this kilogram artifact to make it closer to the UK pound
The US makes various other tweaks over the years in the pound's definition relative to the standard kilogram artifact that the US government maintains.
The "troy" pound artifact is only used for Mint operation in the US and is not related to the avoirdupois pound used in commerce.
Also all NIST calibrations are done in metric units (as of 1959).
Actually, the US government has defined the imperial units as a converted value of metric units ever since the Mendenhall Order back in 1893.
In other words, the imperial values are pegged to the metric definition. The conversion values are not for "acceptable use" - they are the very definition.
NIST is where one of the copies of the standard kilogram is kept. NIST prefers SI standards.
http://www.nist.gov/pml/wmd/metric/metric-program.cfm
Office of Weights and Measures "ensures traceability of state weights and measures standards to the SI", so while there may be "standard pound" of sorts, it's measured back to SI standard (kg) to keep them in check.
http://www.nist.gov/pml/wmd/
Serving time in Aristotelean prison for violating laws of physics
Well obesity is now a major problem in most developed countries, so no surprise here.
Oh, you mean the International scientific community's attempt to redefine the Kilogram? It's called the "dildo" but they are having trouble all agreeing on the proper pronunciation. So for now they're continuing to measure up against this dildo-shaped hunk of alloy that apparently gains weight over the years and every so often has to be rubbed off ceremoniously by a skilled handler with a strap of leather dipped in alcohol.
This has been suggested, but it is not yet possible to do to the same accuracy as the standard kilogram.
You can not make water pure enough. You can't build a container cubical enough. And you can't account for the weight of your container exactly enough.
Are these people fucking retarded?
Are the world's foremost experts on measuring "fucking retarded"?
Here's a hint: "No."
Wow, you fail. If the US had some miraculous metal that could maintain a very constant mass, with greater accuracy than the IPK, then such a thing could also be used for the kilogram. But you are wrong, and they don't. Any artifacts the US does use for mass calibration, which includes at least their official copy of the kilogram, are also subject to the same kind of fluctation in mass that the international prototype kilogram is for many of the same reasons, if not more because it's handled far more frequently than the IPK is.
By reading this signature, you hereby agree with the content of the above comment.
The density of water is dependent on temperature and pressure. Pressure is defined as a unit of force per unit area (Newtons per square metre). Force is subsequently defined in terms of mass times acceleration (1 N = 1 kg * 1 m/s^2). Congratulations, you have just created a definition of mass that is dependent on itself. Also, the ability to purify water and measure its volume to a high enough accuracy and precision is extremely difficult.
By reading this signature, you hereby agree with the content of the above comment.
How does this compare to the weight it's been losing over the years?
"I'm not sure I like the fugnutish tone you used in your post!" -RogL (608926)-
One thing I learn in school, you HAVE to get the units right. BTW, honk if you love slugs.
So a special interest group is pushing for the US to adopt the metric system, and now the kilogram is heavier. This means that American's weighing themselves in metric won't seem as heavy because the number will be lower therefore there will no longer be an obesity crisis in the US.
To explain it to those still on the imperial system:
It would be like currently saying you weigh 300 pounds (which is morbidly obese regardless of what the View or Oprah says), but then the standard weight of a pound increases, so now you weight only 220 pounds, which is only mildly obese so go eat a cheesesteak without guilt.
Of course moving to metric alone will make Americans seem less heavy because 300 lbs is only about 136 kg which is a positively svelte number.
I haven't thought of anything clever to put here, but then again most of you haven't either.
The variance was one part in 20 million - well within modern measurement error. Probably about 22-25 million by now as they continued to diverge withing their individual environments.
They know the volt to a high decimal precession in Josephson junction. There are equations that can convert a volt into a mass.
Planck's mass has been proposed too. But we dont know the unit of action to enough decimal places.
The most accurate measurement is the unit of time from atomic excitation in lasers. Thats 14 to 18 decimal places. You have to start taking account of the two kinds of relativities around the 9th decimal place etc. The volt measurement bootstraps off of this.
Physics Today used to publish a quadrennial report on the the "state of the constants". This included revisions from experiment. And research on improvements. Fascinating reading.
They should not ever be handled, they should be in a sealed clean room.
Troll is not a replacement for I disagree.
Well actually it kind of sounds like they are. They chose a standard KG weight that would increase in mass over time at different and unmeasurable amounts, with no way to stop or reverse this.
I think that is a pretty good definition of retarded.
Troll is not a replacement for I disagree.
At the time that the standard kilogram was reported to be losing mass, an opinion column by Crispin Sartwell in the Los Angeles Times on June 3, 2003 pointed out that this was a weapon of mass destruction:
"....Now one suspects that in the long run the kilogram cylinder will continue to shed atoms. By my calculations (or rather, those of my wife, who can do stuff like multiply), at a rate of 50 micrograms per century, the cylinder will disappear entirely in 200 billion years.
Then the kilogram itself will disappear, which entails that all objects will weigh an infinite number of kilograms: Any given feather or dust mote will be infinitely heavy. And, at that point, the universe will collapse under the influence of infinite gravity into a disk about the size of a lentil, inhaling everything into a dimensional wormhole. And that will suck, with infinite force and acceleration.
In other words, that standard kilo platinum-iridium cylinder is the smoking gun, the ultimate weapon of mass destruction."
The standard kilogram is gaining weight and the standard goatse is gaining size.
Do you even lift?
These aren't the 'roids you're looking for.
Do they are gently saying that the dirty hands of the researchers are making these weights inaccurate... You never get enough of "use gloves" & "wash you hands" in the lab. For funding, research and peer finding please refer to the non-profit Aging Portfolio.