Writing in the New York Review of Books last year, Carl Djerassi declared that with the invention of the birth control pill, “sex became separated from its reproductive consequences” and “changed the realities of human reproduction.” Djerassi would know. The pioneering chemist, who died on Jan. 30 of complications from liver and bone cancer at the age of 91, was dubbed the father of the birth control pill after he created the key ingredient used in oral contraceptives.