You’re confusing iOS, where you are in a walled garden, with macOS, where you can just do whatever the hell you want (There’s a recovery partition you can boot to where you can disable just about every bit of security that’s not hardware much like booting to grub in Linux)
From my understanding, the lead content is on the inside of the vacuum flask. Which is why it passed testing several times before someone cut it open and actually tested the inner material.
China has been engaged in hostilities with India trying to expand their border in the last year, so the “You silly westerners don’t understand China doesn’t do war anymore” is exactly the kind of bullshit nonsense that people are being critical of pro-China users. Arunachal Pradesh does not belong to China.
Had Japan not surrendered, we had another nuke en route (The demon core was around already, we just had to slap it into the mechanism), and could have had a fourth reasonably quickly. (We had processed a huge chunk of the fuel for the fourth pit before we dropped our first bomb) It was just after that where the US couldn’t just keep setting them off because the timescales to generate the plutonium was measured in several weeks.
Last Podcast on the Left did a decent, though immensely gory, series on the Manhattan Project recently.