The film was noted for its accuracy, with some scenes being taken word-for-word out of the book or real life events. Many of the changes are small embellishments or changes from real life. For example, Oppenheimer was not as excited about his discovery of black holes as shown in the film since he did not know how significant it would become. The study was indeed released on the same day Germany invaded Poland, as shown in the film. During the Trinity test, Donald Hornig had his hand on the kill switch for a faster reaction time and not near it as depicted in the film. Truman did call Oppenheimer a "crybaby" but in a letter to Dean Acheson one year later, not immediately after meeting Oppenheimer.