1. ATOMIC BOMB ON JAPAN
JUSTIFIED OR
UNJUSTIFIED?

2. MANHATTAN PROJECT
Project to develop the first nuclear weapon (atomic bomb)
Led by American scientist J. Robert Oppenheimer
Project took 3 years to complete and successfully developed three weapons
First test (Trinity Test) on July 16, 1945 near Alamogordo, Mexico (Plutonium bomb)

3. J. Robert Oppenheimer

4. Bombs Dropped on Japan
On August 6, 1945 a uranium bomb code-named “Little Boy” was dropped over Hiroshima, Japan
On August 9, 1945 a plutonium bomb code named “Fat Man” was dropped over Nagasaki Japan

5. “LITTLE BOY”
The “Little Boy” design consisted of a gun that fired one mass of uranium 235 at another mass of uranium 235, thus creating a supercritical mass. Once the two pieces of uranium are brought together, the initiator introduces a burst of neutrons and the chain reaction begins, continuing until the energy released becomes so great that the bomb simply blows itself apart.

6. “LITTLE BOY”

8. “FAT MAN”
The initial design for the plutonium bomb was also based on using a simple gun design (known as the "Thin Man") like the uranium bomb. As the plutonium was produced in the nuclear reactors at Hanford, Washington, it was discovered that the plutonium was not as pure as the initial samples from Lawrence's Radiation Laboratory. The plutonium contained amounts of plutonium 240, an isotope with a rapid spontaneous fission rate. This necessitated that a different type of bomb be designed. A gun-type bomb would not be fast enough to work. Seth Neddermeyer, a scientist at Los Alamos, developed the idea of using explosive charges to compress a sphere of plutonium very rapidly to a density sufficient to make it go critical and produce a nuclear explosion.

9. Casing around “Fat Man” to prevent premature explosion

10. “FAT MAN”

11. -Hiroko Nakamoto, a survivor at Hiroshima
Unjustified
“For the first time, my heart wast filled with hate, bitter hate, for a people who could do this. I remembered a propaganda poster we had been shown of American laughing as they looked at corpses of Japanese soldiers. At the time I did not believe it. But I believed it now…”
-Hiroko Nakamoto, a survivor at Hiroshima

12. Unjustified Repsonse, as taken from
Seattle Times
Japan was ready to call it quits anyway. More than 60 of its cities had been destroyed by conventional bombing, the home islands were being blockaded by the American Navy, and the Soviet Union entered the war by attacking Japanese troops in Manchuria
American refusal to modify its “unconditional surrender” demand to allow the Japanese to keep their emperor needlessly prolonged Japanese resistance.

13. “Friends and neighbors were dead. Everything we owned was gone
“Friends and neighbors were dead. Everything we owned was gone. The riveres where we had enjoyed boating on summer evenings were filled with dead bodies floating in the water. People were screaming as they lay along the banks of the rivers.”
-Nakamoto

14. A demonstration explosion over Tokyo Harbor would have convinced Japan’s leaders to quit without killing many people
Even if Hiroshima was necessary, the U.S. did not give enough time for word to filter out of its devastation before bombing Nagasaki
The bomb was used partly to justify the $2 billion spent on its development and conventional firebombing would have caused significant damage.
The two cities were of limited military value. Citizens outnumbered troops five or six to one.

15. JUSTIFIED
“I regarded the bomb as a military weapon and never had any doubt that it should be used…..when It talked to Churchill he unhesitatingly told me that he favored the use of the atomic if it might aid to end the war….”

16. Justified Repsonse, as taken from Seattle Times
The Japanese had demonstrated near-fanatical resistance, fighting to almost the last man on the Pacific islands, committing mass suicide on Saipan and unleashing kamikaze attacks on Okinawa. Fire bombing had killed 100,000 in Tokyo with no discernible political effect. Only the atomic bomb could jolt Japan’s leadership to surrender

17. -Henry Stimpson, U.S. Secretary of War
“The face of war is the face of death; death is an inevitable part of every order that a wartime leader gives. The decision to drop the atomic bomb was a wartime decision that brought death to over a hundred thousand Japanese….this was the least abhorrent choice. It stopped the fired raids and strangling blockaded; it ended the ghastly specter of a clash of great land armies.”
-Henry Stimpson, U.S. Secretary of War

18. With only two bombs ready (and a third on the way by late August 1945) it was too risky to “waste” one in a demonstration over an unpopulated area
An invasion of Japan would have caused casualties on both sides that could easily have exceeded the toll at Hiroshima and Nagasaki
The two targeted cities would have been firebombed anyways
Immediate use of the bomb convinced the world of its horror and prevented future use.
Impressed U.S.S.R and prevented joint occupation of Japan

19. “This is the greatest thing in history.”
-Harry Truman, after learning of the success of the dropping of the bomb on Hiroshima

20. Effects of the Bomb
A nuclear explosion produces several distinct forms of energy that have damaging effects: blast, thermal radiation, electromagnetic pulse, direct nuclear radiation and fallout
Fallout may continue its descent for about 24 hours.