Jordan Carson Mark was a Canadian-American mathematician best known for his work on developing nuclear weapons for the United States at the Los Alamos National Laboratory. Mark joined the Manhattan Project in 1945, and continued to work at Los Alamos under the leadership of Norris Bradbury after World War II ended. He became the leader of the Theoretical Division at the laboratory in 1947, a position he held until 1973. He oversaw the development of new weapons, including the hydrogen bomb in the 1950s. On the hydrogen bomb project he was able to bring together experts like Edward Teller, Stanislaw Ulam and Marshall Holloway despite their personal differences.
The Ivy Mike nuclear test, November 1952
Edward Teller was a Hungarian-American theoretical physicist and chemical engineer who is known colloquially as "the father of the hydrogen bomb" and one of the creators of the Teller–Ulam design.
Teller in 1958
Teller in his youth
The Hungarian passport Teller carried when he entered the United States in 1935.
Teller's ID badge photo from Los Alamos