How were the Manhattan Project scientists able to predict the possibility of the atmosphere igniting after using an atomic bomb, and how did they come to the conclusion that the atmosphere wouldn’t ignite?

Question

Did the non-zero risk of the atmosphere igniting increase as nuclear weapon yields got larger and larger?

Obviously a result of watching Oppenheimer.

In: 789

Answer 1

I think the key thing is about how dense the ‘fuel’ (the atmosphere) is.

* Assume the atmosphere near the bomb undergoes fusion.
* It will release some extra energy beyond that of what the bomb produced.
* Is that energy enough to fuse at least slightly more air than was just fused?
* It turns out that the air on Earth is sparse enough, that the energy provided by a bit of it fusing, isn’t ennough to fuel an increase amount of air fusing.
* Therefore, there won’t be an endless chain reaction that ~ignites the whole atmosphere.