The kilogram is dead; long live the kilogram

The Verge:

Nearly every measurement of weight you’ve ever made, from peeking at your bathroom scale to measuring out flour for a recipe, can be traced back to just a single object: a metal kilogram made of platinum and iridium that resides under lock and key in an underground vault in Paris. It’s called the International Prototype Kilogram, or IPK, and since its creation in 1889 it has been the standard by which the world’s weights are defined. But not for much longer.

But later this week, on Friday, November 16th, a coup is planned in this international ministry of weights. After having served for 129 years as the world’s standard, the International Prototype Kilogram (or Le Grand K, as it’s known locally) will be stood down. Grandees of the International Bureau of Weights and Measures, which regulates the metric system, will gather in Versailles and vote to replace this physical artifact with a definition of the kilogram based on a fundamental constant of nature.

I’ve been following this weirdly fascinating story for years. I loved the idea that an international measurement was represented in reality by one example of it deep in a lab vault in France. I’ll be a little sad when it gets replaced.