system
Given the following post, respond as if you're commenting on Reddit:
human
[Fallout] Is it possible that the Children of Atom are right about nuclear explosions giving birth to new universes, and the Fallout universe itself was born in the bombing of Japan at the end of WWII (which is where its events start deviating from real history)?

In terms of resonating with the series' established themes, I'd say it sounds like a pretty strong theory, but it does leave the question: how would realities subsequently created by additional atomic explosions within the *Fallout* universe, such as the hundreds during armageddon, respectively diverge?
gpt
A major theory of mine is that Fallout endured what was similar to what we Elder Scrolls fans call a "Dragon Break" Back when ESII had multiple, very different ending they explained that massive impacts and events can sometimes result in massive breaks in reality that can diverge universes. A universe may split in two and one could be wildly different from the other. Sometimes the universes converge again and people are left wondering what the hell happened.

Perhaps when the US dropped the bombs on Hiroshima and Nagasaki the impact was so disruptive to the universe it resulted in a similar phenomenon. Some people have even speculated that paranormal events like the Dunwich Building or Listening Point Bravo might be points where the two realities cross.