The kilogram is redefined, and scientists say it was worth the weight
Tuesday, May 28, 2019 - 22:29
in Physics & Chemistry
In a subterranean vault in a suburb of Paris lies a small, rarely seen metal cylinder known as Le Grand K. For 130 years, this golf-ball-sized hunk of 90% platinum and 10% iridium has served as the international prototype kilogram. That means it was the single physical object by which all other...