The development of the Atomic Bomb took place in Los Alamos, New Mexico not Hollywood. Good gravy there were special effect micro sparks with little or explanation of what they were and why they were in that part of story line. Super sudden time change front, back forward in the story line, caused confusion. Too much of the love scenes not enough on the gritty story line of the making of the most powerful horrific weapon ever made.
The fact is with out the use of the bomb, there would have been a million allied personnel killed and many millions of Japanese killed, along with all with all the destruction to about every town and village in Japan because of the power of conventual weapons vs the Japanese tenacious will to defend their sacred home land (using spears and rocks if they had to) to the last. This fact was not clearly pointed out. Why?