Australia has been busy creating a pair of the world's most round objects, ever. Made from silicon, these two spheres measure exactly 93.75 millimeters (about 3.7 inches) in diameter. It's taken months and months of work, combined with some extremely advanced measurement tools, to create these beauties.
They weren't just created for their artistic appeal, either. They are the next step in the age-old problem of coming up with an exact measurement of the kilogram. The KG is the only standard measurement left that's based on a physical object - currently the KG is determined exactly by a pile of platinum and iridium that's around 120 years old. It sits in France and is causing problems as it seems to be changing slightly compared with other copies worldwide. The plan is to come up with an exact number of silicon atoms in the spheres - that will become the new standard of the kilogram.