How and why we redefined the kilogram

An ounce is an ounce, and a kilogram is a kilogram, but how are these units actually measured? How do your scales know how much a pound or a gram weighs? Since 1889, the kilogram’s definition has been based on a metal artifact stored under lock and key in a vault near Paris. It’s called the International Prototype Kilogram, or Le Grand K, and it is the world standard. What it weighs, the kilogram weighs. No more, no less. Le Grand K was created (along with the rest of the metric system) during the French Revolution when scientists and revolutionaries were united in their desire to remake the world. This meant reforming the French language, the calendar, and the country’s weights and measures. The idea was to make these units accessible... Continue reading…