July 16 is the 73rd anniversary of the Trinity Test, the world’s first nuclear weapons test. At 5:29 a.m., the “Gadget” exploded with a yield of about 15-20 kilotons of TNT.
Manhattan Project veterans recall their reactions to the explosion. For example, chemist Lilli Hornig describes the mushroom cloud: “I remember these boiling clouds and vivid colors like violet, purple, orange, yellow, red, just everything. It was fantastic. We were all shaken up.”