How do you figure out of your enemy is detonating nukes if you live in a pre-spaceflight era? Put microphones on balloons and listen for the explosions

My favorite Roswell conspiracy is that the debris was the fourth nuke from WWII. The first one was at Trinity, second Hiroshima, third Nagasaki, fourth is supposedly sitting, unfueled of course, in the Smithsonian. There is a conspiracy that they put it on a V-2 to see how it would handle rocket flight, it crashed and the 'crazy writing' was left-handed German from the captured German engineers.

It was a balloon! it was a cover up! WAKE UP PEOPLE!