Union Kilos

Union Kilos aka kilogram The kilogram is the base unit of mass in the Union wide Standard System of Units ( generally known as “Standard Units” or often called USSU) and is defined as being equal to the mass of the USotG Prototype of the Kilogram (UPK). The concept of defining weight based on a decimal system and using the weight of 1 liter of water  under One Gee was widely accepted as easy to understand and define to most Union beings. The gram was originally defined in 1795 OTT  as the mass of one cubic centimeter of water at 4°C, making the kilogram equal to the mass of one liter of water. The prototype kilogram, manufactured in 1799 and from which the current kilogram is based, has a mass equal to the mass of 1.000025 liters of water. The kilogram is the only USSU base unit with an USSU prefix ("kilo", symbol "k") as part of its name. It is also the only SI unit that is still directly defined by an artifact rather than a fundamental physical property that can be reproduced in different laboratories. Four of the seven base units in the SI system are defined relative to the kilogram so its stability is important. The Standard Prototype Kilogram was commissioned by the General Conference on Weights and Measures (CGPM) under the authority of the Assembly in 2280 and is in the custody of the Science Council - Bureau for Weights and Measures (BIPM) who hold it on behalf of the CGPM. The Standard  Prototype Kilogram (SPK) is rarely used or handled. Copies of the IPK kept by the Science Council  in the Science Council Permanent  exhibit of the Museum of the United Stars on Pluribus.