But in the late 1980s, scientists noticed that the original kilogram was about 50 micrograms lighter than its brethren. Because mass measurements are relative, it's tough to determine whether the replicas are getting heavier or the original is getting lighter. [...] Over the last two decades, Cumpson and others have developed such a method. It's based not on manually scrubbing the metal chunks but on exposing them to ultraviolet light and ozone about once per decade. Recently, Cumpson fine-tuned the procedure and added another step: a pure water rinse to remove dust particles. The final recipe is now available online in the journal Metrologia. [...]There's another kilo-contaminant, though, one that sticks too stubbornly to remove: Mercury atoms from trace amounts of free mercury in labs that once used mercury-based thermometers. "Mercury's a most unfortunate contaminant," Cumpson said. "It's difficult to remove, it forms a strong metallic bond with platinum."
"Most unfortunate!"
It's scientific understatement like that that explains why you never hear anything about the "misadventure" with the platinum-iridium CONS cell in Paris back in 1987. The horror, the horror.
Kilogram - you and me, man. You and me. Let's be New Year's Resolution buddies.
What happened? Did its CDR point to itself, leaving researchers to conclude in a panic that nature does refcounting?
"Sufficient progress has been made in National Metrology Institutes around the world to give serious consideration to updating the present definitions of the kilogram.... The target uncertainty for the most accurate of such measurements is 20 microgram per kilogram.... The present situation has been examined by the CODATA Task Group on Fundamental Constants based on work published through the end of 2010. They conclude that the present uncertainty of the Planck constant from all relevant experimental approaches is the equivalent of 44 microgram per kilogram. The CGPM will not adopt the proposed new definitions until present difficulties are resolved."
These people are still planning to make a bunch of reference artifacts, but they can't figure out how to take 44 µg/kg of uncertainty down to 20 µg/kg, even though they've been cross-calibrating their existing physical artifacts against each other since 1889?
"it is a prerequisite that for all the activities of daily life, a kilogram will still be a kilogram; water will still freeze at zero degrees Celsius, etc."
Boring!
PtIr CONS FTW.
(Also just noticed that PtIr can sort-of be pronounced pointer. Heh.)
But in the late 19██s, scientists noticed that the original SCP-2205 was about 50 micrograms lighter than its brethren. Because [ILLEGIBLE], it's tough to determine whether the replicas are getting heavier or the original is getting lighter. [...] Over the last two decades, [REDACTED] and others have developed such a method. It's based not on manually scrubbing the metal chunks but on exposing them to ultraviolet light and ozone about once per decade. Recently, [REDACTED] fine-tuned the procedure and added another step: a pure water rinse to remove dust particles. The final recipe is now available online in the ███████ ██████████.
There's another SCP-2205-contaminant, though, one that sticks too stubbornly to remove: Mercury atoms from trace amounts of free mercury in labs that once used mercury-based thermometers. "Mercury's a most unfortunate contaminant," [REDACTED] said. "It's difficult to remove, it forms a strong metallic bond with [DATA EXPUNGED]
Please submit this.
I agree strongly with Pavel.
In unrelated news posted here because I'm too pressed for time to try to find a post still open for comments in which it would be more closely on topic, the World Economic Forum at Davos apparently does not share jwz's appreciation of rogue geoengineering. I suspect this is a calculated ploy to spur international cooperation on such mitigation solutions.
Citizens demand that you submit this!
Well played!
I thought this said "Keeping the Standard Klingon From Gaining Weight Is a Constant Struggle", and I was like, "Yeah, it figures."
Today is a good day to diet!
I take it the tale of the "1987 misadventure" is like that of the Giant Rat of Sumatra; one for which the world is not yet ready?