Candela unit, the "candela". In 1967 the 13th CGPM removed the term "new candle" and gave an amended version of the candela definition, specifying the atmospheric pressure applied to the freezing platinum: The candela is the luminous intensity, in the perpendicular direction, of a surface of square metre of a black body at the temperature of freezing platinum under a pressure of newtons per square metre. In 1979, because of the difficulties in realizing a Planck radiator at high temperatures and the new possibilities offered by radiometry, the 16th CGPM adopted the modern definition of the candela. The arbitrary (1/683) term
Rosario Candela for him, one of his home and one of his son. Candela began studying cryptography in 1930 after learning about the accomplishments of the Army Signal Corps in WWI. He decrypted messages originally coded in 1898 by Commandant Étienne Bazeries of the French Army. Commandant Bazeries was "one of the most brilliant cryptologists of" his era, and he developed an encryption method considered unbreakable. Candela wrote a book, "The Military Cipher of Commandant Bazeries", in 1938 detailing how he broke Bazeries' code. Starting in 1941, Candela taught a class on cryptography and cryptanalytics at Hunter College in New York. At