In mid-1944, Oppenheimer shifted the focus of work at Los Alamos from research to the design of the two bombs, Fat Man and Little Boy. It was an indication that the project had reached a new stage–the scientists moving from theory to application–and they began to prepare themselves for the first test of their work.
It was decided that Little Boy, the U-235 bomb, needed no test, as its design was basic enough that scientists were certain it would work. But the plutonium bomb, Fat Boy, was less of a sure thing. Oppenheimer and Groves decided to arrange a test, which would be the world's first nuclear explosion.
They selected an isolated area in the middle of the desert near Alamogordo, New Mexico, called the Jornada del Muerto, or "Journey of Death." The desolate land stretched sixty miles to the north and south and forty miles to the east and west. It was code-named "Trinity."
No one knows who named the site, but some have claimed that the name came from Oppenheimer himself. According to this version of the story, Oppenheimer took the idea from a John Donne poem, which read, "Batter my heart, three-personed God; for you / As yet but knock, breathe, shine and seek to mend; / That I may rise, and stand, o'erthrow me, and bend / Your force, to break, blow, burn, and make me new."
There was initial concern about what would happen after the explosion; the scientists realized that they could only complete the test if the wind was traveling in a certain direction. If it was blowing the wrong way, the wind could carry fallout (radioactive dust and debris) over civilized areas. The lead physicists, particularly Oppenheimer, were consumed by anxiety as they waited to see if the test could take place and, more crucially, if the bomb would work.
The wait seemed to last forever.