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.""

Comments

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.

Re:The Kilogram is not losing weight

[Bender0x7D1]

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

We can't use water as a reference since the molecules in the water are constantly splitting into ions and reforming as molecules. So it is essentially impossible to get 1000 cm^3 of "pure" water. It will be some mixture of H2O, H+ and O-- ions. Also, it would be incredibly hard to prevent other molecules from being disolved in the water. A few stray molecules hitting the surface will ruin your reference mass. Not to mention you need a container to keep it in...

The meter is defined in terms of the speed of light so that gives an empirical way to define the kg independent of anything else.

As mentioned above, we could measure a 1000 cm^3 volume, but we couldn't guarantee the purity of the water in that volume.

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.

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 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.

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.

Re:The metre must be shrinking then...

[LiquidCoooled]

Actually, that might be possible.
Light speed is not constant in a gravitational field, if some of the other posters are correct and the kilogram has changed because of a localised gravitational shift, then its possible that the definition of a metre could also have changed..

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?

Kilogram Reference Losing Weight

[MrYotsuya]

It's not losing weight, it's losing mass!. The kilogram is not a measure of weight, but mass. Silly pound-centric editors :p

Not any more

[benhocking]

A meter is defined as the distance light travels in a vacuum in 1/299,792,458th of a second.

Re:Not any more

[flyingfsck]

So time is speeding up then?

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:Not any more

[Anonymous Coward]

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

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.

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.

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 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.

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:It must not lose mass!

[ArsonSmith]

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