Australia weighs in to make the PERFECT KILOGRAM

摘要

The kilogram, the unit of mass in the International System (51), is the only one of the seven base units still defined by a physical object. A kilogram is currently defined as: 'that mass which is equal to the International Prototype'. The International Prototype - affectionately known as 'Big K' - being a cylinderofplatinum and iridium keptin a vault at the International Bureau of Weights and Measures (BIPM) near Paris, France.