Candela was chosen so that the new definition would precisely match the old definition. Although the candela is now defined in terms of the second (an SI base unit) and the watt (a derived SI unit), the candela remains a base unit of the SI system, by definition. If a source emits a known luminous intensity "I" (in candelas) in a well-defined cone, the total luminous flux "Φ" in lumens is given by where "A" is the "radiation angle" of the lamp—the full vertex angle of the emission cone. For example, a lamp that emits 590 cd with a radiation angle
Félix Candela works. Candela also benefited from the budget implemented by Ruiz Cortines in the area of education. Candela became a professor in Mexico, which is what he did for the remainder of his career. Felix moved to the United States and taught at University of Illinois at Chicago from 1971-1978. Candela was hired as a Professor of Architecture at the university's Chicago Circle campus (now University of Illinois at Chicago) on September 1, 1971, a position he held until 1978. Source: Fausto Giovannardi, ed.: "Felix Candela, Builder of Dreams" Candela's drawings, correspondence, personal and professional papers, and writings are held in