2. WWII began in 1939.
Axis Powers = Germany, Japan, & Italy
In December 1941, the US joined the United Kingdom as part of the Allied Powers.
The Axis Powers wanted to expand their empires.
Germany 1939
German Empire 1942
Imperial Japan 1939
Imperial Japan 1942
German physicists had been researching how to create even more powerful weapons before WWII even began.

3. Einstein & Fermi learned German physicists could split a uranium atom.
Albert Einstein
Enrico Fermi
German refugee & physicist
Italian refugee & physicist
Einstein & Fermi learned German physicists could split a uranium atom.
So What!
When an atom is split, a tremendous amount of energy is released.
enough energy to power a bomb
But building a bomb was not an easy task!
© 2016 Brainy Apples/Heather LeBlac, LLC

4. The process was very slow moving.
Fermi & Einstein were living in the US.
Fermi traveled to Washington, DC, to share his concerns with President Franklin D. Roosevelt.
Einstein, with the help of Hungarian physicist Leo Szilard, wrote a letter to President Roosevelt urging him to begin an atomic research program.
President Roosevelt did not see the urgency but did agree to begin the process.
October 21, 1939: The Advisory Committee on Uranium met in Washington, DC.
The process was very slow moving.
But the United Kingdom was not wasting any time.
UK physicists were making advancements in harnessing atomic power.

5. UK Prime Minister Winston Churchill agreed to begin development of an atomic bomb on September 3, 1941.
The US realized if the UK was moving forward, they needed to move forward, too.
December 1941: The US began its own project to investigate atomic weapons.
Prior to this decision, the US had only investigated the fission, or splitting, of atoms.
April 1942:
Fermi began to design the world’s first human-built nuclear reactor, called CP-1, at the University of Chicago.
Site of CP-1, under Stagg Field at the University of Chicago.
Leo Szilard is standing.
June 1942:
The Army Corps of Engineers took over since the intent became to build an atomic weapon.
In August it was named the Manhattan Engineer District.

6. The Manhattan Engineer District became known as the Manhattan Project.
September 17, 1942: Colonel Leslie Richard Groves was put in charge of the Manhattan Project.
Colonel Groves reassigned the development of fissile materials from scientists to corporations like DuPont.
October 15, 1942: Colonel Groves asked Dr. Robert J. Oppenheimer to head Project Y.
Project Y
new central laboratory for weapon physics research and design
located at Los Alamos, New Mexico

7. December 2, 1942: Fermi’s group completed CP-1 and the first self-sustaining nuclear chain reaction was a success at the University of Chicago.
Sketch of the world’s first nuclear reactor, CP-1, underneath the grandstands at Stagg Field, University of Chicago.
Recreation of the first self-sustaining nuclear chain reaction at CP-1. Photographers weren’t allowed.
This was the first step in creating an atomic bomb, but there was still much to accomplish.
*Click on the video. The video is a link to History Channel at
The 4 minute video is about the first reaction at CP-1 and how close the Nazis were to their own atomic bomb.

8. Secrecy was maintained.
Two additional nuclear facilities were built at Oak Ridge, Tennessee, and Hanford, Washington.
Nuclear facility at Oak Ridge, TN.
Groves & Oppenheimer
*Click on the video. The video is a link to History Channel at
It is about 4 minute long and it is about the nuclear facility at Oak Ridge, TN.
Weapon development, fissile materials production, and delivery preparations continued for the next two years.
Secrecy was maintained.
Even Harry Truman did not know the true purpose of the Manhattan Project until after he became president in April 1945.

9. Partially assembled Gadget, the world’s first atomic bomb.
July 16, 1945: Dr. Oppenheimer was ready to test the first atomic bomb at the Trinity Site at Alamogordo, New Mexico.
Partially assembled Gadget, the world’s first atomic bomb.
Preparation of Gadget.
Explosion of Gadget.
*Click on the top right photo. The photo is a link to
This 10 second clip shows the explosion of the Trinity Test.
*Click on the lower right photo. The photo is a link to
This video is a little over 2 minutes and it shows three different film rolls of the Trinity Test.
*Click on the video on the top left. It is a link to History Channel at
It is a 2 minute video showing assembly of the Gadget, the world’s first atomic bomb.
fireball; second after detonation
© 2016 Brainy Apples/Heather LeBanc, LLC

10. The world had entered the Nuclear Age.
Windows in civilian homes were shattered up to 100 miles away.
The government created a cover-up story so no one would know the truth.
The recorded temperature at the center of the blast was three times hotter than the center of the sun.
Two men standing in the crater of the test site.
Recorded fallout
*Click on the photo. The photo is a link to a video at History Channel at
The video is about 4 minutes and it is an overview of the Manhattan Project.
The world had entered the Nuclear Age.

11. land invasion drop atomic bomb President Truman had a choice to make.
Although scientists were happy they had been successful after years of exhausting work, they were also fearful of what the future would hold.
President Truman said, “We have discovered the most terrible bomb in the history of the world.”
Germany surrendered in WWII in May 1945.
Japan was still fighting.
President Truman had a choice to make.
land invasion
drop atomic bomb
most likely result in one million US military casualties
save US lives
prolong the war
result in tens of thousands of Japanese casualties
most likely end the war quickly

12. “Little Boy” was a 9,000 pound uranium bomb.
August 6, 1945: An atomic bomb called “Little Boy” was dropped on Hiroshima, Japan.
“Little Boy” was a 9,000 pound uranium bomb.
The blast was equal to 15,000 tons of TNT.
Over 135,000 civilians, including women and children, were killed.
Over 5 square miles of the city were destroyed.
August 9, 1945: An atomic bomb called “Fat Boy” was dropped on Nagasaki, Japan.
“Fat Boy” was a 10,000 pound plutonium bomb.
more powerful than “Little Boy”
*Click on the photo. The photo is a link to an audio at
The audio is of President Truman announcing an atomic bomb has been dropped on Hiroshima. It is about 30 seconds long.
Due to Nagasaki’s valleys and mountains, only 2.6 square miles was destroyed.
over 70,000 casualties

13. Mushroom cloud over Hiroshima. Mushroom cloud over Nagasaki.
*Click on the video. The video is a link to History Channel at
The video is about 3 minutes long about the people who were on the edge of the blast. There are some parts that may be too graphic. Please watch before and decide if it’s appropriate for your students.
*Click on the video. The video is a link to
The video is about 12 minutes long, and it is about the blasts of Hiroshima and Nagasaki. It is the 1946 film Tale of Two Cities from Army-Navy Screen Magazine and presented by the War Department.

14. WWII was over But a new war was brewing…..
Emperor Hirohito realized the devastation that could be unleashed.
August 15, 1945: Japan surrenders in WWII.
WWII was over
But a new war was brewing…..
Klaus Fuchs, a German physicist who worked on the Manhattan Project, stole US secrets of building an atomic bomb.
Fuchs gave those secrets to the Soviet Union.
The US was no longer the only country with the capability to build an atomic bomb.
The emergence of the superpowers and Cold War would follow…..