Atomic Bombings of Hiroshima and Nagasaki Notes

Causes

  • Unprovoked attack on Pearl Harbor in 1941 by Japan.

  • Ongoing battles in the Pacific, including Iwo Jima and Okinawa.

  • Intense strategic fire-bombing of 67 Japanese cities by the USA over six months.

  • Emperor Hirohito ignored an ultimatum and refused to surrender.

  • U.S. President Truman wanted to end the war to prevent further casualties.

First Event: Hiroshima

  • On August 6, 1945, a lone bomber flew over Hiroshima.

  • The plane dropped an atomic bomb, "Little Boy," and veered away.

  • The bomb exploded, reaching a temperature of several million degrees in one millionth of a second.

  • The USA asked Japan to surrender, but Japan refused.

Pre-Cursor

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

  • Fearing German development, the Americans started their own work, code-named "The Manhattan Project."

  • Scientists involved in the project wrote to President Roosevelt, pleading that the weapon not be used.

Overall

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

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

  • Emperor Hirohito surrendered to the USA.

  • The war in the Pacific was over.

  • World War II was over!

Immediate Results

  • Firestorm and intense heat melted roof tiles and incinerated nearby humans.

  • Wind blast swept outward at 500-740 miles/hour.

  • Radioactive ash fell as black rain.

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

Second Event: Nagasaki

  • Three days after Hiroshima, when Japan still refused to surrender, the USA dropped a second bomb, "Fatman,” on Nagasaki.

Results

  • This marked the first and only use of an atomic bomb in warfare.

  • The USA emerged as the world's superpower.

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

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

  • Most of the dead were civilians.

  • This marked the official end to the War in the Pacific.

  • V-J Day (Victory over Japan) was declared.

  • This signified the official end to World War II.

Long Term Results

  • Over the next 50 years, many people died from the bomb's effect (mainly cancer)

  • Service held each year on the day of the bombing to remember victims
    Fear of further nuclear war began (Cold War)