Atomic Bombings of Hiroshima and Nagasaki

Pre-Cursor

  • Throughout the 1930s, the idea of an atomic bomb was circulating.

  • The Americans assembled scientists for the Manhattan Project, fearing German development.

  • Scientists pleaded that their invention never be used.

Causes

  • Unprovoked attack on Pearl Harbor in 1941 by Japan

  • Ongoing battles in the Pacific - Iwo Jima and Okinawa, Japan

  • 6-month intense strategic fire-bombing of 67 Japanese cities by the USA

  • Hirohito ignored an ultimatum and refused to surrender

  • U.S. President Truman wanted to end the war, putting a stop to further casualties

First Event: Hiroshima

  • August 6, 1945: A lone bomber flew over Hiroshima.

  • The plane dropped "Little Boy."

  • Explosion reached millions of degrees in 1/1061/10^6 of a second.

  • USA asked Japan to surrender, but Japan would not.

Immediate Results

  • Firestorm and intense heat.

  • Wind blast (sweeping outward at 500−740500-740 miles/hour).

  • Radio-active ash (black rain).

  • 200,000 people were killed immediately from the effects of the two bombs.

Second Event: Nagasaki

  • After Japan refused to surrender, the USA dropped "Fatman" on Nagasaki three days later.

Overall

  • August 6, 1945: "Little Boy" dropped on Hiroshima at 8:15 am.

  • August 8, 1945: "Fat Boy" dropped on Nagasaki.

  • Emperor Hirohito surrendered to the USA.

  • The war in the Pacific and WWII were over.

Results

  • First and only use of the atomic bomb.

  • The USA became the world's superpower.

  • Emperor Hirohito surrendered 6 days after the second bombing, on August 15, 1945.

  • The bombs killed as many as 140,000 people in Hiroshima and 80,000 people in Nagasaki by the end of 1945.

  • Most of the dead were civilians.

  • Official end to the War in the Pacific.

  • V-J Day (Victory Japan).

  • Official end to World War II.