Could the SI system be breaking down? The kilogram (yes, THE kilogram) is no longer that.
The International Prototype Kilogram (IPK) has been surreptitiously changing its weight.
Is it insured? Is it accredited? How do they accredit the traceability of the standard from which all others are derived?
The pascal, newton, joule; they all depend on it.
It’s only 50 micrograms out at the moment, so I suppose we can ignore it for a while. But would inspectors ignore it if it were your kilogram and they accredited it? Are they going to be looking for all our uncertainty of measurement calculations to be redone?
That would undermine the “confidence” they sell, wouldn’t it? So I suppose they’ll just ignore it. Give it the Nelson’s eye or something.
I no longer have confidence in them. Do you?
Fear not! From 2014 they will calculate the kilogram from Planck’s Constant. Traceability will be to a mathematical construct, as the other six base units of the SI have been redefined. A virtual kilogram. An irreducibly correct kilogram. An eternal value we can again have confidence in. Until the next time. A fundamental change, yet the superstructure will remain the same. I don’t predict a riot. Maybe it really doesn’t matter at all…