The Kilogram is Redefined, and Scientists Say It Was Worth the Weight

As of May 20, the kilogram will no longer be defined by Le Grand K — a golf-ball-sized hunk of platinum and iridium — but by a fundamental property of nature known as Planck’s constant, which cannot fluctuate. Researchers devoted to the science of measurement say it’s a turning point for humanity. https://www.latimes.com/science/la-sci-new-definition-kilogram-mole-ampere-kelvin-20190517-story.html#nws=true