Dawn of the the Nuclear Age

[Fivesense]

Any guesses as to the hat worn here?

 

[filfoster]

Not a clue about the hat but would love to see the 'Fat Man' wiring diagram. Likely to have many warnings about mistakes?

 

[David Conwill]

I was expecting to see Oppenheimer's battered Open Road(?). No clue what the one in the photo is--or who the fella wearing it might be.