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The international kilogram conundrum[Weights have mysteriously fluctuated]
LA Times ^ | 17 Apr 2008 | Jia-Rui Chong

Posted on 04/20/2008 5:58:33 PM PDT by BGHater

In the more than a century since 'perfect' platinum-iridium cylinders were first used as the world's kilogram standards, their weights have mysteriously fluctuated. Scientists are rethinking what the measure means.

GAITHERSBURG, MD. -- Forty feet underground, secured in a temperature- and humidity-controlled vault here, lies Kilogram No. 20.


(Excerpt) Read more at latimes.com ...


TOPICS: Science
KEYWORDS: kilogram; standards; weights
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To: CodeToad
Yep, we all know that the metric system was not born out of necessity or by scientists. It was born out of politics and still is.

Oh for heaven sakes. You claim to be a scientist, not an engineer, not a computer programmer, who uses the English system. And, you claim the SI system is political, despite the fact that it is simpler to use. You also claim that SI is "arbitrary." Well, in some sense, all measurement systems are.

As has been said, the meter was originally defined as a fraction of the distance between the pole and the equator. It was not redefined because the scientists were stupid. It was redefined to make the standard easier to use.

In the same way, the nautical mile is not defined as a distance. It is based on angular measure. It's the distance that one angular minute of longitude subtends on the earth's surface. That's why it is convenient for navigation. But, if the meter is no good because the earth is not a perfect sphere the same problem would apply to the nautical mile.

And to the rest of you, a Kilogram is a unit of MASS and alway, alway, always has been. You can compare it to other masses with a balance, as has been said before. A balance does not measure weight. Weight is measured by a spring scale. Or, you can measure mass with something called an inertial balance. This is basically a spring system that oscillates at different frequencies depending on what MASS is put on it. 9th graders learn the difference between mass and weight in physics class. If you don't know, please don't embarrass yourselves by debating a point that is not debatable.

In the same way, the SI system is not debatable. It is one of several measurement systems that is in wide agreement. All measurement systems are arbitrary in their fundamental definitions. But the SI, and related systems, are decimal. So, it is much easier to use and much less likely to cause errors than using "pounds mass" or "pounds weight" or "slugs" because these are confusing by their nature. Would you claim that British pounds, pence and farthings were superior to 100 pennies to the dollar? Even when engineers work in inches, they now divide the inch into tenths, hundredths and thousandths, not eighths and sixteenths.

There are other measurement systems in use that work well in their domain and scientists may mix systems a bit for convenience. You wouldn't expect an astronomer to measure in microns or an atomic physicist to measure in light-years. Navigation, surveying or other disciplines may use other systems but that doesn't make those systems universally superior in some way. Bushels may be a convenient unit for an agricultural scientist. But to claim SI is based on nothing and a political plot is extraordinarily narrow minded.

141 posted on 04/21/2008 9:42:18 AM PDT by freedom_forge
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To: freedom_forge

But...but...but...don’t you know? It’s all been traced back to a commie plot started by atheist homosexual pedophiles! [/sarc]


142 posted on 04/21/2008 9:52:34 AM PDT by arderkrag (Libertarian Nutcase (Political Compass Coordinates: 9.00, -2.62 - www.politicalcompass.org))
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To: freedom_forge

For all your ranting all you did was support the politics of SI and state how stupid you are that anything not divisible by 10 is too much for you. No wonder our scientific education has gone to the dogs, we’re too lazy to get past simple math.


143 posted on 04/21/2008 9:56:10 AM PDT by CodeToad
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To: ko_kyi

lol. nice.


144 posted on 04/21/2008 9:56:52 AM PDT by CodeToad
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To: CodeToad

It is smarter to use an easier system. Period.


145 posted on 04/21/2008 9:59:26 AM PDT by arderkrag (Libertarian Nutcase (Political Compass Coordinates: 9.00, -2.62 - www.politicalcompass.org))
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To: ApplegateRanch

I’m going to use that the next time I’m asked “Do I look fat in this?”


146 posted on 04/21/2008 10:02:59 AM PDT by Syncro
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To: freedom_forge

What’s with your obsession with that old antiquated radix 10 number system such as SI anyway? This is the computer age, baby! Computers use radix 2. Come on, get with it.

Computers do not multiple nor divide by 10 so easily. They can operate on radix 2 numbers far faster and they are the natural number system of the digital age, sow why would anyone care about using a paper based decimal point system such as the metric system?


147 posted on 04/21/2008 10:36:03 AM PDT by CodeToad
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To: tokenatheist

Tears of laughter are competing with plain old tears. This thread is how the world sees conservatism.


148 posted on 04/21/2008 11:04:23 AM PDT by js1138
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To: CodeToad
What’s with your obsession with that old antiquated radix 10 number system such as SI anyway? This is the computer age, baby! Computers use radix 2. Come on, get with it.

I prefer Hex. It's shorter to write. When I did my graduate research many, many years ago, we had a measurement instrument that displayed lights representing octal. What a pain in the butt it was, at first, for me to convert octal to decimal in my head so I could take notes.

Then, in my first job, I put together a data acquisition system. It was like going to heaven. No conversion, no notes even.

149 posted on 04/21/2008 11:39:10 AM PDT by freedom_forge
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To: CodeToad
For all your ranting all you did was support the politics of SI and state how stupid you are that anything not divisible by 10 is too much for you. No wonder our scientific education has gone to the dogs, we’re too lazy to get past simple math.

True, I do rant sometimes and, true, I don't like doing arithmetic and never did. How is a decimal system a political issue? And considering when SI was invented, how does that relate to the more recent phenomenon of scientific education going to the dogs? Or did I misunderstand?

150 posted on 04/21/2008 11:44:37 AM PDT by freedom_forge
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To: Nathan Zachary

This article is about how the masses of the standard kilograms have fluctuated on the parts per billion scale and the need to replace them with standards based on physical constants and not even more arbitrary artifacts. No one cares about the weight since that isn’t what the kilogram measures. You are just polluting this thread with pure garbage.


151 posted on 04/21/2008 7:24:11 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: Politicalities

Just ignore Nathan Zachary and CodeToad. These two are prime examples people who like to talk a big game, but don’t really know a thing. And they’ll probably be upset at me for point out the obvious.


152 posted on 04/21/2008 7:27:16 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: PugetSoundSoldier
Scientists have proposed two ways to redefine the unit of mass. The first is based on the Planck constant and requires a 1-kilogram mass to be supported against Earth’s gravity using a precisely measured magnetic force.

That may be one way for defining mass. I prefer using a different physcial constant - Avagadro's number. This proposale is to use isotopically pure silicon to form a sphere with an exactly known quantity of atoms. That avoids having to use a material suceptible to magnetic fields and to gravity, both of which would have to be calibrated and standardized. Earth's mass changes and it's gravity field is not purely homogeneous, plus all the corrections for celestial motion based on location. An ideal standard should minimize all other interactions as much as possible. But don't explain any of that to Nathan Zachary. He simply doesnt understand the dimensions of units and their physical meanings.

153 posted on 04/21/2008 7:33:15 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: Bellflower

Obviously you have never read a genetics journal. What you say is pure bunk. The eviodence is that species have changed. Evolution explains why. Then, 100 years later, modern genetics confirmed this theory. It’s the cornerstone of biology. TO deny that is essentiall a denial of modern science and must be stopped. Religious superstition not rooted in anything observable or testable is a cancer on intellectual and technological acheivement in the country. It must be avoided even if it makes Bible humpers uncomfortable in their ignorance.


154 posted on 04/21/2008 7:38:14 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: CodeToad
For all your ranting all you did was support the politics of SI and state how stupid you are that anything not divisible by 10 is too much for you. No wonder our scientific education has gone to the dogs, we’re too lazy to get past simple math.

Wrong. Our number system is base 10 so it is entirely logical to use a base 10 measurement system. SI does that. And it doesn't make the math any easier unless all you are focussed on is the ease of computation. So you think we should go back to 5/64 plus 9/128 minus 3/16 as a basis for teaching our kids? You think we should export products based on U.S. Standard units when the rest of the world is using SI? Decimal measurment units remove unnecessary difficulties and let us better understand what the numbers are telling us rather than worry about challenging fractional math. Moreover, decimal units work for scientific notation when dealing with different scales and significant figures, something older measuring systems do not consider. What you are saying just doesn't make sense. The rest of the world would resist products from here if they are incompatibe with their own, standardized system and would require retooling just to work with American components. That's where the politics comes in. People don't want something not congruent with how they operate. The U.S. standard system isn't even the same as the Imperial system, even though many of the terms are the same for crying out loud! That kind of confusion is the source of most problems, not the SI system itself. But if you go into the hard sciences, almost everything is done in SI, some in cgs (which is derived from SI), but there are some dinosaurs still using U.S. Standard for business.

155 posted on 04/21/2008 7:50:19 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: CodeToad

And one other point. The rest of the workd is using base 10 SI units and they are getting ahead of us in science and math. They must be lazier dogs, then, but it isn’t giving us an advantage. They just find a more efficient way of doing things.


156 posted on 04/21/2008 7:52:01 PM PDT by doc30 (Democrats are to morals what an Etch-A-Sketch is to Art.)
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To: freedom_forge; CodeToad
"the SI, and related systems, are decimal. So, it is much easier to use"

Is that so? Then what about the metric constant for gravitational acceleration? Kind of blows a huge hole in your theory huh?

157 posted on 04/21/2008 8:27:03 PM PDT by editor-surveyor (Turning the general election into a second Democrat primary is not a winning strategy.)
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To: doc30
The eviodence is that species have changed.

You've made a personable attack but offer no proof or concrete evidence of your premise. Are you saying that genetic evidence says that species have changed from one species into another through the addition of genetic information or are you saying that there has been changes within the boundaries of given species? What form of change? Mutations? Specification at the cost of a reduction of genetic information? That there is adaptation and change of form within the boundaries of a kind is not at question. The only question and where is your proof is that you seem to be stating as known fact that there is absolute genetic proof that one kind has changed into another through the addition of continually more complex genetic information. I would appreciate for you to please support your position with facts rather than nonproductive insults.

158 posted on 04/21/2008 8:59:26 PM PDT by Bellflower (A Brand New Day Is Coming!)
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To: Richard Kimball

Dumb. Too bad.


159 posted on 04/21/2008 9:07:10 PM PDT by Octar
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To: editor-surveyor
doc30: the SI, and related systems, are decimal. So, it is much easier to use
editor-surveyor: Is that so? Then what about the metric constant for gravitational acceleration? Kind of blows a huge hole in your theory huh?

What an astonishingly dumb question! You don't understand what doc30 is talking about at all.... BTW, the strength of the SI are not (only) the basic units, but the derived ones...

160 posted on 04/22/2008 12:50:28 AM PDT by bezelbub
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