the.com/kilogram
The only unit that fired its sacred Paris lump for a quantum upgrade.
means The base unit of mass in the metric system, equal to 1,000 grams.
from From French 'kilogramme,' coined in the 1790s during the metric reform: the Greek 'khilioi' ('thousand') bolted onto 'gramma' (originally a small weight, from Greek for a written letter or scruple). For over a century the kilogram was literally a thing — a platinum-iridium cylinder kept under glass near Paris, 'Le Grand K' — until 2019, when the definition was finally pinned to a constant of nature (the Planck constant) rather than a lump of metal that could gain or lose a few atoms over time.
former bossA platinum cylinder under three glass bells near Paris
the redefinitionSince 2019, defined by Planck's constant instead
weight lossThe old prototype mysteriously shed micrograms over decades
only with prefixThe lone base unit named with kilo built in
a liter equalsRoughly one kilogram of water, by clever design