Kilogram change could lead to chaos in the world of weight, warn scientists

A team of scientists have proposed a mechanism for cleaning the official kilogram prototype - known as the International Prototype Kilogram (IPK) - which was recently discovered to have been changing its mass by around 50 micrograms. The IPK,  which consists of an alloy of 90 percent platinum and 10 percent iridium (Pt-Ir) and has a density of approximately 21500 kg/m3, is maintained at the International Bureau of Weights and Measures (BIPM) in Sèvres near Paris... To continue reading, subscribe to Science Recorder today.