A guy named Derek Muller has made the perfect sphere ever. It is made of single crystal of silicon 28 atoms to solve the measurement problems in the weight, for which he started a project some time ago by the name of Avogadro Project.
The sole purpose of this of this project is to get rid of the dependency of kilogram on a the measurement of a physical object and this where the perfect sphere comes in. Since we know the spacing of silicon atoms very well, we can precicely calculate the number of atoms in the sphere. Hence causing us to measure the kilogram more accurately.
Via (RichChannel)
