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Platinum-Iridium
  • adj. Standard, against which all others of the same category are measured. Usage silly. The notion is that one of whatever it is has actually been cast in platinum-iridium alloy and placed in the vault beside the Standard Kilogram at the International Bureau of Weights and Measures near Paris. (From ~9 to 1960, the meter was defined to be the distance between two scratches in a platinum-iridium bar kept in that same vault --- this replaced an earlier definition as 10^(-7) times the distance between the North Pole and the Equator along a meridian through Paris; unfortunately, this had been based on an inexact value of the circumference of the Earth. From 1960 to 1984 it was defined to be 1650763. 73 wavelengths of the orange-red line of krypton-86 propagating in a vacuum. It is now defined as the length of the path traveled by light in a vacuum in the time interval of 1/299,792,458 of a second. The kilogram is now the only unit of measure officially defined in terms of a unique artifact. ) "This garbage-collection algorithm has been tested against the platinum-iridium cons cell in Paris. " Compare golden.