Later on, more liberal government policies were put into place; daimyo and officials were encouraged to take more ronin into their service as samurai. However, this option only could serve a minority of ronin; in an era of peace, few clans needed the large number of samurai that they would need in times of war.
The atomic bomb was not invented by any country, it was  invented in 1933 by Leo Szilard (he was in London at the time, so  when he patented the invention he sold it to the â¦ British Admiralty  who classified it to keep the idea away from the Nazis).
Einstein's greatest role in the invention of the atomic bomb was signing a letter to President Franklin Roosevelt urging that the bomb be built. The splitting of the uranium atom in Germany in December 1938 plus continued German aggression led some physicists to fear that Germany might be working on an atomic bomb.