> but does it say that the Kilogram will be equal to the Planck constant? No, this statement means that Kilogram will give up its place as a fundamental unit t

> but does it say that the Kilogram will be equal to the Planck constant? No, this statement means that Kilogram will give up its place as a fundamental unit to Planck constant. Earlier, Kilogram was used as a fundamental unit, defined by a physical object. Not anymore. The kilogram will be defined by Planck constant. Namely, m = E/c^2 = hf/c^2. > How can they measeure it with 0 error? We can't, all measurements have errors. But we can measure things better than a physical object, which has changed with time. So we only have to measure Plank constant with precision higher than variation of physical object's mass for the purpose of replacing the definition of mass.