Good article about changing the definition of what a kilogram really is.
The kilogram has been defined since 1889 by a shiny piece of platinum-iridium held in Paris. All modern mass measurements are traceable back to it – from micrograms of pharmaceutical medicines to kilos of apples and pears and tonnes of steel or cement.
The problem is, the “international prototype kilogram” doesn’t always weigh the same. Even inside its three glass bell jars, it gets dusty and dirty, and is affected by the atmosphere. Sometimes, it really needs a wash.
via Reuters…
