Developed the atomic detonators for the Manhattan Project. Was on board the Enola Gay as it dropped the bomb.
Pushed for the development of thermo-nuclear weapons.
Together with J. Allen Hynek he was a member of the January 1953 Durant Panel Report in which the recent UFO waves were debunked as paranoia and considered no threat to national security. According to the panel the phenomenon should be ignored because the “irrelevant reports” were “clogging the channels of communication”. According to Hynek the Pentagon wouldn’t allow any other position on the subject.
Joined the board board of IDA (JASON Society) and stayed until 1967.
In 1965, Alvarez X-rayed the great pyramid of Khafre (Giza) in search for hidden chambers. Initially the team reported all kinds of anomalous behavior which made their data unreadable, but quickly thereafter they reported that there weren’t any problems.
Analyzed the Zapruder film in 1967. Came up with the “jet-recoil theory” to explain why Kennedy’s head snapped backwards when shot. This helped convince the Church Committee in 1976 that Kennedy’s headshot could have been caused by a bullet from behind, indicating Oswald was the sole assassin.
Received the Nobel Prize for physics in 1968.
In 1980, together with his son, Alvarez published the theory that an asteroid wiped out the dinosaurs 65 million years ago.