A pound just isn't what it used to be.
A pound, by definition, is .453597 kilograms.
And a kilo, by definition, is the weight of a cylinder of 90% platinum and 10% iridium standing 1.54212598 inches high and 1.54212598 in diameter.
The official International Prototype kilo cylinder is in a triple-locked vault at the International Bureau of Weights and Measures in Sevres, France. But there's a problem. The official cylinder now weighs 50 milligrams less than the unofficial cylinders stored in the same vault.
What happened to the missing milligrams? Barring theories of alien abduction and mass dilation, no one knows.
The official international standards for length, volume and time remain unchanged.