Kilogram Reference Losing Weight

doubleacr writes "Ran across a story on CNN that says 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 Kilogram is not losing weight

[allanc]

The Kilogram is defined in reference to the chunk of metal in Paris. It's the *definition* of the Kilogram.

Therefore, the Kilogram is not getting lighter.

We're all getting heavier.

Governments have been doing this for years!

[dada21]

If you look over history, governments have taken metals that were supposed to be a certain weight, and mysteriously removed weight from them and still called the weight the same thing.

Look at the standard weight known as the "dollar" (thaler). It used to be the equivalent of 1/20th of an ounce of gold. Then it was 1/35th of an ounce of gold. Last month that same dollar weight standard was 1/650th of an ounce of gold, and today I believe it is 1/711th of an ounce of gold.

The Roman Empire leaders also had mysteriously disappearing weights... Their Denarius lost over 99% of its official weight over just a few hundred years.

It is definitely a mystery...

The metre must be shrinking then...

[flyingfsck]

Ah, so that explains the obesity epidemic, but my ever increasing middle indicates that the metre must also be shrinking at the same time.

This must be the reason ....

[Anonymous Coward]

... why Americans use ounce-feet (or something) instead.

Re:The Kilogram is not losing weight

[Anonymous Coward]

Paris Hilton has a metal dildo that weighs exactly 1 kilogram?

Impressive.

Has anyone checked Ebay?

[Anonymous Coward]

How much on the black market for a microgram off the ole standard?

obligatory...

[abes]

but don't worry, it will regain the weight after a couple of months.

Re:Sublimation?

[snowgirl]

Could it be a few atoms drifting off in the vapor? Well, why wouldn't the copies' atoms be drifting off as well?

This is called sublimation [wikipedia.org]. And it's the first thing that I thought of myself as well.

Stop cleaning it!

[eknagy]

If that old lady who plugs that vacuum cleaner into the UPS every day at 05:00 would stop cleaning it, there would be no such problems with gravity!

Mmmkay...

[TofuDog]

You need to drop at least 250 micrograms to really experience the magnitude of the kilogram, man... Wow, Mr. Mackie, Drugs -are- bad. It's not just reference mass lost -Where is my mind? -you thieving Pixies. woooo-oooooh.

I am finally able to answer the dreaded question..

[this great guy]

The wife: Don't you think I am gaining weight ?
Me: No honey, it's just the kilogram that is getting lighter.

Re:The Kilogram is not losing weight

[E++99]

"Humor. It is a difficult concept. It is not logical."

Nevertheless, the moderation system of this forum may serve to alert you to the utilization of humor, as posts utilizing it are often accompanied by a "Funny" indicator. In such cases, correction of fact can generally be assumed unnecessary, as said facts will likely have been intentionally misstated as a means of producing said humor.

I like the US customary system

[OrangeTide]

foot-pounds and even inch-pounds. It's so neat.

"The metric system is the tool of the devil! My car gets forty rods to the hogshead, and that's the way I likes it!"

Re:Not any more

[flyingfsck]

So time is speeding up then?

Re: Kilogram Reference Losing Weight

[QuickFox]

Keeping G constant,

It's in France. Are you sure you can trust the French to do that?

hmmmm

[Anonymous Coward]

Date: September 16, 62002

Location: God's Court

"God": My angels, we have a problem. The Universe we created 6000 years ago is about to die.

"Angel 1": Holy shit dude, you suck. You were supposed to create the universe for eternity. This is like, what the fifth time?

"Angel 2": What are the humans figuring it out again?

"God": Well, frankly, yes. A few are close, again. They keep learning as we expected, but we didn't account for how fast they would learn. All these exponentials. As you all know, the fabric of their reality only works as long as no consciousness figures out how I did it. Once they do, we are morally obligated to treat them as alive.

"Angel 1": Can't we just fuck with them again? You know, turn off a few suns or create another particle or something?

"God": (Sighing deeply) We don't have much choice. We have to do something sublte, yet significant... Bob, would you go ahead and start changing how mass is calculated. Make it something that will be hard to find.

Angel 2 smiles, and turns around to his machine, and starts typing furiously...


sudo cp /var/lib/reality/core/constants/MassCalulator.rb /tmp/MassCalulator.rb.orig
sudo emacs /var/lib/reality/core/constants/MassCalulator.rb
sudo /usr/sbin/reload_constants.rb


The screens shift slightly, a few numbers flutter

"Angel 2": It is done, Joe.

"Angel 1": Hey, who wants to grab a beer?

--
My future is coming on;think twice, that's my only advice;Tóg do chroísa. Tar trí na stoirmeacha.

Re:The Kilogram is not losing weight

[Eternauta3k]

The meter was originally 1/10,000,000 of the distance between the equator and the North Pole along the meridian running through Paris. (No chauvinism there...)

Yeah, cause that meridian is so different to the rest _

Proof of non-biological evolution!

[Max Littlemore]

I thought that originally the kilogram was defined in terms of water, the mass of 10 square cm of water.

This is almost true, although it's 1000 cubic cm or 1 litre rather than 10 square cms. Mathematics, however, has evolved.

10 cubic cm can be described as the volume of a cube with ten cm per side, or 10 x 10 x 10 = 1000 cm3. At least that's how it was. These days, multiplication has mutated slightly, so 10 x 10 is now 99.9999994482 +/- 0.0000000002. This means that the mass of a litre of water has indeed changed slightly, while the standard kilogram remains correct. In fact, the mass of a litre of water is now subtly different depending on the shape of its container, an effect which is more evident with larger containers. A 50 litre cube of water without handles is indeed heavier than a 50 litre flexible bag with a nice long handle attached to a harness.

While this doesn't currently pose any major problems, I for one pity the engineers when cartesian geometry evolves opposable thumbs.

Re: Kilogram Reference Losing Weight

[swillden]

It's not losing weight, it's losing mass!

Really? Wow, that's even bigger news! The kilogram reference is losing mass but somehow maintaining weight!! Is this unexplained increase in the Earth's gravitational field localized or general? What strange phenomenon is increasing gravity by the precise amount required to offset the reduced mass?

This observation of yours is going to require us to rethink large parts of physics.

Eat that, Eurotrash!!

[commodoresloat]

Proof at last that the imperial system of weights and measures is superior to that silly "metric" fad....

Re:The Kilogram is not losing weight

[Alien Being]

It is different. It scales the height of the collective French ego.

Unit of force

[SkyFalling]

If you think the kilogram is in bad shape, consider the dire fate of the Newton (the SI unit of force, a.k.a. weight). Newton's been decomposing for centuries -- there's no way he weighs the same as he used to!

Re:The Kilogram is not losing weight

[Entropius]

In physics we talk about the masses of things from single atoms to galaxies.

In that range, 1 ~= 2

The Ultimate Weapon of Mass Destruction?

[AllTheGoodNamesWereT]

This was in the news in mid-2003. On June 3 of that year, the Los Angeles Times [latimes.com] ran a very funny column by Crispin Sartwell ("Crispin Sartwell teaches philosophy at the Maryland Institute College of Art") titled "Kilo Crisis Could Bring Down the Universe," which is unfortunately no longer available for free on their website. Here's an excerpt:

The kilogram is defined as the weight of the standard cylinder, whatever it may be. It is logically impossible for the kilo cylinder to lose or gain weight, at least within the metric system of measurement, because it is itself the standard by which all weights must be judged.

Thus it is impossible to "discover" that the cylinder has lost weight. The instruments by which the cylinder is weighed are wrong because the cylinder itself, by definition, is always right. Indeed, it is possible that the rest of the material in the universe, including the silicon atom, has become slightly heavier. But it is not possible that the weight of that cylinder has changed.

[....]

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.

Why don't we just do again what we did for the m?

[Entropius]

A while back the meter was defined artificially, by some marks on a post.

Then someone got the idea to peg it to another unit. Time and space are related, and the conversion between them is the speed of light. So the solution to the problem was to adopt a precise definition of c, thus defining the meter in terms of the second (defined elsewhere) and the speed of light (a constant).

Couldn't we peg the kilogram to either the meter or the second as well, using another fundamental constant as the conversion. Planck's constant is the obvious one. Here's a clunky definition:

Define the joule to be "The energy difference between two states which interfere with a frequency of 1.50919067 × 10^33 cycles per second" or "6.626068 × 10^-34 joule is the energy difference between two states which interfere with a frequency of 1 cycle per second." What is a second? That's defined empirically, based on a transition in cesium. Or you could define a joule as some fraction of the energy carried by a photon with such-and-such wavelength, or however you want to do it.

Now you've got the joule, the meter, and the second defined. The second is the only empirical one; the other two are defined in reference to it and two fundamental constants of the universe, h and c.

Then you define the kilogram as that mass which, when moving at a speed of 2N meters per second, has a kinetic energy of N joules, in the limit of small N (to dodge the relativistic correction). Or you could calculate the relativistic correction at 2 meters per second and put it into the definition.

obvious ploy by us government

[drfireman]

Shave a little off the kilogram reference, everyone who measures their weight in kilos gains a little. US residents are largely unaffected, and it helps squelch stories about the American obesity epidemic. I'll bet if you turn the Secretary of Health and Human Services upside-down, 50 micrograms of metal shavings drops right to the floor.

Dyslexics Untie

[pipingguy]

I just want to know what a klingongram is; a measure of mass or a method of communication.

Re:I like the US customary system

[John Hasler]

"The metric system is the tool of the devil! My car gets forty rods to the hogshead, and that's the way I likes it!"

Your car is burning 63 gallons every eighth of a mile. And you like it. Ok...

Re:The Kilogram is not losing weight

[azenpunk]

we need to have a 'pendantic olympics'. the top prize would be a kick in the teeth. here goes my performance: water itself is not pure H2O, since the term water predates the knowledge of the chemical formula, however even the empirical formula for water comes out to H2O (assuming the only ions present are H3O+ {there's never really any naked protons in solution, top that!} and OH-, no sodium ions or chloride or anything like that). scores: 4.7, 4.6, 4.1, 1.6 (french judge), 4.4, 4.6 totaling: 24.0, er...23.99999999 if we're going by the metric standard.

Re:The metre must be shrinking then...

[fractoid]

I'm sorry dude, but unlike the kilogram, the metre isn't defined based on an artifact but rather it is defined based on the speed of light in a vacuum, so unless that changed, the metre hasn't either.

Fixed. Otherwise, you'd have to pay 20% more for sheet glass because meters inside the glass would be shorter than meters outside the glass. :P

Re:Not any more

[ArsonSmith]

Ok, I got a flash light and a dirt devil. Anyone have a watch? Preferably with a seconds hand. Lets check how accurate this is.

Re:It must not lose mass!

[ArsonSmith]

I don't think you understand the gravity of the situation.

Re:The Kilogram is not losing weight

[jollyreaper]

That's one reason we are trying to make a perfect sphere to replace the reference kilogram. Then we will have a definition of the kilogram in terms of number of silicon atoms.

Good luck on that. This reference bar is certainly worse than we've sphered.

Don't break the seal, please...

[Nefarious Wheel]

I remember hearing some years back about a graduated set of calibrated weights sent to Kennedy Space Center -- very expensive, environment-controlled copies calibrated against the standard in Paris. The set arrived in good condition, but the quartermaster who received them had instructions affix an identification plate to all inbound goods received, and complained that some of the smaller weights had turned out to be too small to drill and rivet...

Re:The Kilogram is not losing weight

[loshwomp]

we need to have a 'pendantic olympics'

Oooh, can I compete? I guess for starters I'll point out that the word you're looking for is 'pedantic'.

Re:The Kilogram is not losing weight

[camperdave]

Unless he wants to enter the jewelry dangling event.

Re:The Kilogram is not losing weight

[iocat]

This is why we need to continue to use the English system. The metric system seems all orderly, till you realize the core definitions are based on lame french stuff. In my world, a mile is a mile, based on my Nike+iPod telling me I have gone a mile (ideally backed up with Lance Armstrong or that English chick congratulating me). A yard is the distance between King George's nose and the tip of his finger. A foot is 12 inches. And a pound is what my scale tells me I have too many of.

Anyway, I measure most things in Smoots.

Re:The Kilogram is not losing weight

[Eiron]

Because a Newton is fruit and cake?

Re: Kilogram Reference Losing Weight

[Anonymous Coward]

Obligatory xkcd reference [xkcd.com]

Re:The Kilogram is not losing weight

[OakDragon]

See, we have this thing called "The First Law of Thermodynamics."

And in this house, we obey the laws of thermodynamics! [snpp.com]

Re:General relativity

[zippthorne]

I blame global warming, myself. If only the US had ratified Kyoto, this wouldn't be happening.

I predict...

[Tablizer]

...an Al Gore film about this someday.

Re:The metre must be shrinking then...

[Basehart]

When I was a kid I thought a foot was the length of Julias Ceasars foot and a metre was the length of Napoleon Bonapartes foot. When I found out later that a metre was considerably longer than a foot I deducted that Napoleon must have had really long feet. I later found out that Napoleon was also a very short fellow which made my mental image even more ridiculous. To this day whenever I hear the name I think of this short guy with three foot long feet.

Re:The metre must be shrinking then...

[iamacat]

You misunderstood the background. Napoleon was not a tall fellow, but he was a great lover.

Re:The metre must be shrinking then...

[edittard]

So the whole of Europe got their asses kicked ... by a hobbit?

Re:The metre must be shrinking then...

[somersault]

"The meter has a long history"

Your posting privileges have been revoked for 2 months, or until such time as you show the adequate remorse necessary to prove that you are sorry for such a shameless pun.

Re:The Kilogram is not losing weight

[Moderatbastard]

I don't know why the ^2 sign didn't show up

Maybe the system's smart enough to know the difference between area and volume?

Re:I have a watch.

[somersault]

Yeah they just made up weird standards to confuse us after they'd sorted out the whole year thing. The people who invented time - the french - actually have watches that go up to a nice round 100, and have 1000 days every year. That's why a lot of europeans can be caught napping in our afternoons, or having more than 3 meals per 'day'. I can't say any more at this juncture.

Re:Not any more

[Anonymous Coward]

Sir, you are suggesting caesium is responsible for obesity. I find that rather hard to believe.

Re:The metre must be shrinking then...

[Da Fokka]

Even worse. A French hobbit.

Re:Not any more

[BobPaul]

This begs the question, as under the International System of Units, the second is currently defined as 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.

You forgot the question that is begged.

Re:The metre must be shrinking then...

[aliquis]

But then we have E=MC^2, and if the energy in the universe is constant (in solid or other form) then the speed of light is related to the amount of mass and if everything is getting heavier the speed of light is droping!

And then the meter is getting smaller aswell, which explains why his middle region measures more of a meter today!

Re:The funniest part

[Just Some Guy]

It might be old news for many here, but I can't stop laughing at the irony.

If that's an unceasing chucklefest for you, then I'm pretty sure you need to get out more.

Re:Not any more

[Gnavpot]

FYI, he was defining a second, and you're defining a meter.

It must be pretty embarrassing to have the user name "PhysicsPhil" when you make a mistake like that.

Re:The metre must be shrinking then...

[Impy the Impiuos Imp]

> or until such time as you show the adequate remorse necessary

How do you define "adequate"? Sorry to be lawyerly here, but you can't leave it so vague. Do you have a metric?

Re:Not any more

[operagost]

Clearly, the kilogram reference should be constructed of cesium-133. This will remove all ambiguity.

Re:The Kilogram is not losing weight

[khallow]

The "pendantic gambit" wins again. For you sports fans who missed it, here's the strategy:

1. Player A dumps an utterly pendantic post. Misspell pendantic deliberately.

2. Player B comes around and notes "Hey, it's spelled p-e-d-a-n-t-i-c."

3. Player B gets kicked in teeth.