1945: Building the Bomb

1945: Building the Bomb

Timeline Image: 
Oppenheimer and Groves

1945 Feb 28

A meeting between J. Robert Oppenheimer, General Leslie Groves, George Kistiakowsky, James B. Conant, Richard Tolman, Hans Bethe, and Charles Lauritsen is held to fix the design approach for the plutonium bomb. It is agreed that work will focus on the solid core Christy gadget, use explosive lenses, use a modulated initiator, and electric detonators. The use of Composition B and Baratol for the lenses was also decided, as was the multiple lens configuration and detonator arrangement. However none of these approaches or components have been proved yet.

1945 Feb 19

Marines land on Iwo Jima, a Japanese observation post for the B-29 raids. Over the next two months 6,281 marines are killed, and 21,865 are wounded in capturing the island from 20,000 defenders.