Redefinition of the kilogram will not make the kilogram more precise, but it will make it more stable. A physical object can lose or gain atoms over time, or be destroyed, but constants remain the ...

Deep underneath the Parisian suburb of Saint-Cloud, in a vault that can only be opened by three people wielding three different keys, there lies a hunk of metal that is so crucial to the world of ...

Constants are supposed to be, well, constant. In physics there are a number of fundamental constants, such as the speed of light, Planck's constant, and the charge of an electron that are essential to ...