We’ve long known that there were some issues with France’s ‘Le Grand K’, the international prototype for what a kilogram really is. Made in 1879 from platinum and iridium alloy, it is the perfect ...

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the ...

How do you define one kilogram? Easy: it's the exact mass of a metal cylinder called the International Prototype Kilogram, IPK for short, kept in controlled conditions in France. But the standard ...

France holds the world’s standard for the kilogram weight. It’s a cylinder-shaped object that has dictated all other kilogram weights for 130 years now. As it’s made from platinum-iridium though, the ...

On the morning of Friday, November 16, scientists and diplomats crammed into an auditorium in Versailles, a stone’s throw from the Sun King’s gilded chateau. Patrick Abbott, an American physicist, had ...

Hackers, advanced hobbyists, makers, and hands-on physics experimenters are always looking for their next great project, and I think this is a good one: an apparatus to establish the “standard” ...