The Kilogram sheds 50 micrograms

[QuantumFireball]

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 mystery is that they were all made of the same material, and many were made at the same time and kept under the same conditions, and yet the masses among them are slowly drifting apart," he said. "We don't really have a good hypothesis for it."

50 micrograms is roughly equivalent to the weight of a fingerprint.

My question, who the HELL measures the weight of a fingerprint?

Maybe the janitor gave it a good wipe-down and cleaned the fingerprint off =)

 

[Sulkdodds]

My question, who the HELL measures the weight of a fingerprint?

One day you're going to get into a situation where a difference in weight equivalent to that of a fingerprint is going to mean the difference between life or death for you.

True!

 

[Maxi]

lol tenchar

 

[lePobz]

About as interesting as spoons.

 

[Sulkdodds]

Personally I think it's really interesting that all our weight measurements are held in relation to a century-old cylinder locked away in a vault in Paris.

 

[The Monkey]

Hmm. Why need a standard?

One kilogram is the exact weight of one litre of water.
One litre is 1 dm^3 (0,001 m^3)
One metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.

So the kilogram can be traced to the speed of light, why bother with a standard weight?

 

[DEATHMASTER]

sell it on ebay

 

[QuantumFireball]

Hmm. Why need a standard?

One kilogram is the exact weight of one litre of water.
One litre is 1 dm^3 (0,001 m^3)
One metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.

So the kilogram can be traced to the speed of light, why bother with a standard weight?

... ouch ...

 

[Atomic_Piggy]

sell it on ebay

Thread over.

 

[kirovman]

Aliens took it.

 

[Viperidae]

Hmm. Why need a standard?

One kilogram is the exact weight of one litre of water.
One litre is 1 dm^3 (0,001 m^3)
One metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.

So the kilogram can be traced to the speed of light, why bother with a standard weight?

Because water's properies change based on elevation and air pressure. Metal's doesn't.

 

[Cheomesh]

Viperidae, they would make the measurement at STP.