The trigger timing is what I thought was the hard part. The parts have to arrive all at the same instant in order to set off the chain reaction. One of the designs, Fat Man, was an external sphere that needed to be driven into its core. That was the Nagasaki plutonium bomb. Hiroshima Little Boy was something like a uranium bullet going down a barrel slamming into a uranium target.
In the summer of 1945 my mom was an El Paso college student living with her aunt and uncle. One morning her uncle was up before dawn when the sky to the west lit up like the Sun had come up from the wrong direction.
Oh God Almighty. What an unspeakable sight it must have been.
But were the bombs which fell on Japan really visible that far away, or could your great-uncle rather have witnessed the explosion of the prototype atom bomb, which occurred on July 16th in New Mexico?
Little boy is basically a rilfle barrel
Cordite at top fired by ignited by primer set off by barometric device and Archie radar
Blows I think less enriched uranium down barrel, into more enriched or vice versa causing nuke explosion
Simpler than I would have figured