Source: wikibot/alternative-approaches-to-redefining-the-kilogram
= Alternative approaches to redefining the kilogram
{wiki=Alternative_approaches_to_redefining_the_kilogram}
The kilogram was redefined in 2019 based on fundamental constants rather than a physical artifact, such as the International Prototype of the Kilogram (a platinum-iridium cylinder). This new definition relies on fixed values of the Planck constant, the speed of light, and other physical constants.