Platinum-iridium

2 definitions found

From Jargon File (4.3.1, 29 Jun 2001) [jargon]:

  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 1889 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}.
  
  

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  platinum-iridium
       
           A 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, as the bar defining the standard
          {metre} once was.
       
          "This {garbage collection} {algorithm} has been tested against
          the platinum-iridium cons cell in Paris."
       
          Compare {golden}.
       
          [{Jargon File}]
       
          (1997-02-20)