2.  Nuclei of atoms split into smaller parts,
producing free neutrons, and releasing a
lot of energy in the form of kinetic energy
and electromagnetic radiation.
 Spontaneous fission happens very slowly
in nature.
 Induced fission happens in nuclear
reactors and bombs. Heavy elements are
bombarded with neutrons that split their
nucleaus.
 Uranium 235—very fissile form of
uranium
 Uranium 238—not so fissile form, used in
reactors to make plutonium
 Plutonium 239—very fissile form of
plutonium

4.  Atom bomb—a portable
atomic reactor designed to
release as much energy as
possible as fast as possible
before the reactor explodes.
 The massive explosion
causes hot, low density air
to rise so rapidly that it curls
back on itself and forms a
mushroom cloud in the air.

6. 32 detonators, whose charged point inward and squeezed
The plutonium core, initiating nuclear reaction.

7.  The theoretical possibility of developing an
atomic bomb was not a secret. Fission had
been discovered in Berlin, and word of the
breakthrough had spread quickly around the
world. The scientific basis for a sustained, or
even explosive, chain reaction was now clear to
any well-versed research physicist. Most
physicists initially may have thought an
explosive chain reaction unlikely, but the
possibility could not be entirely discounted.

8.  A Hungarian-American physicist
who worked on the Manhattan
Project he was probably the first
scientist to think seriously of
building real atomic bombs. Was
a great political thinker also. He
worked with Enrico Fermi at
Columbia and then at University
of Chicago on developing the
bomb. If anyone truly saw the
bomb from start to finish, it was
Szilard.
 He also was the co-holder, with
Enrico Fermi, of the patent on the
nuclear reactor.

9.  Conducted the first
nuclear fission experiment
at Columbia University,
developed the first
nuclear reactor, and
demonstrated the
existence of new
radioactive elements
produced by neutron
irradiation. Worked in the
Chicago on the Manhattan
Project.
 Won the Nobel Prize in
1938.

10.  Danish physicist, developer
of quantum theory.
 Gained crucial insights on
the nature of uranium and
plutonium isotopes. Worked
at Los Alamos during the
Manhattan Project.

11.  Physicist E=MC2
,
relativity in early 1900s.
 Co-authored, with
Szilard, to President
Roosevelt, which
warned him of the
possibilities of nuclear
weapons, delivered in
October 1939.

13.  British scientist who studied under
Ernst Rutherford.
 In 1932, he proved the existence of
neutrons. Neutrons, since they are not
electrically charged, need not overcome
any electric barrier and are capable of
penetrating and splitting the nuclei of
even the heaviest elements. Paved the
way towards the fission of uranium 235
and towards the creation of the atomic
bomb.
 He was awarded the Nobel Prize for
Physics in 1935.

14.  In 1929 he invented the
cyclotron, a device for
accelerating nuclear particles
to very high velocities
without the use of high
voltages. He was involved
with the Manhattan Project
from nearly the beginning.
He was in charge of the
electromagnetic separation
work at Oak Ridge,
Tennessee.
 He won the Nobel Prize in
Physics in 1939.

15.  Founder of the American
school for theoretical physics,
Berkeley.
 Scientific director of the
Manhattan Project, based in
Los Alamos, New Mexico.
“The Father of the Atomic
Bomb.”
 After the war, he was chief
advisor to the US Atomic
Energy Commission to
control the use of nuclear
weapons.

16.  World War II erupted at a moment when the
promise of atomic energy had progressed from
being possibile to being probable. It was not
clear whether this energy could be released
explosively however.

17.  Many magazines and
newspapers in the late 1940s
were filled with stories touting
the benefits of virtually free and
unlimited energy, and
predictions of everything from
"atomic cars" to "atomic
medicines." The belief that
nuclear energy would ultimately
prove more beneficial than
harmful was strongest among
those who had the most
education.

18.  1941 Szilard had recently
succeeded in the enrichment
of uranium convincing
scientists in the still-neutral
United States to keep secret
the results of their atomic
research, and, as a result, the
Germans could not learn of
their own mistakes from the
open scientific literature.

19.  Anything related to the
topic of fission
disappeared from
scientific publications in
the US and Britain.
 German physicists heard
rumors and suspected an
atomic bomb project was
underway in Britain, the
United States, or both,
but that was all.

20.  On October 15, 1942 Groves asks Dr. J. Robert
Oppenheimer to head Project Y, the new planned
central laboratory for weapon physics research and
design at Los Alamos, New Mexico.
 Fermi built CP-1 in Chicago.
 Groves took the fissile material programs out of
the hands of the scientists and placed them under
the management of industrial corporations like
DuPont and the Kellog Corporation.

21. Plutonium Production Reactors
Headquarters:
Plutonium Processing
Testing
Assembly Buildings
Thermal Diffusion Plant
Graphite Reactor
Electromagnetic Plant
CP-1 (Chicago Pile #1)
CP-2 and CP-3 Nuclear Reactors

22. On December 2, 1942, physicists
working under top-secret conditions at
the University of Chicago, created the
world’s first controlled, self-sustaining
nuclear chain reaction. Nobel prize-
winning physicist Enrico Fermi
directed the experiment. “We’re
cooking!” was the exuberant reaction
recorded when the experiment
succeeded. (The data shown on these
notebook pages is the record of the
nuclear reactor’s response to the
movement of the control rods.)

23.  The Second World War and the Manhattan Project
transformed a small number of specialized
researchers into the largest and one of the most
secretive research projects ever undertaken,
bringing them to one of four locations in the US to
work on the Manhattan Project.
 Scientists who had once raced to publish their
results learned to speak in codes accessible only to
those with a "need to know." Indeed, during the
war the very existence of the man-made element
plutonium was a national secret.

24.  All the scientists knew is that they were gathered to
build atomic weapons before the Germans could
develop them. In 1943, measured spontaneous
fission rates were so high that gun assembly was
abandoned and bomb-making was undertaken.
 This discovery was a turning point for Los Alamos,
the Manhattan Project, Oppenheimer was forced to
make implosion research a top priority, using all
available resources to attack it. A complete
reorganization of Los Alamos Laboratory was
required.

26.  August 6, 1945: Little Boy bomb, dropped by the
U.S. B-29 Enola Gay, explodes with the force of 15
kilotons of explosive. (The U-235 weapon was
considered very inefficient, with only 1.38% of its
material fissioning.)
 August 9, 1945: Fatman bomb dropped by the U.S.
B-29 Bock's Car, explodes with the force of 22
kilotons of explosive.
 The United States expected to have another atomic
bomb ready for use in the third week of August,
with three more in September and a further three in
October.

27.  Hiroshima--Americans estimated that 4.7 square
miles of the city were destroyed. 69% of
Hiroshima's buildings were destroyed and another
6–7% damaged. 70,000–80,000 people, or some 30%
of the population of Hiroshima were killed
immediately, and another 70,000 injured.
 Nagasaki--Because of Nagasaki's hilly terrain, the
damage was somewhat less extensive than that in
relatively flat Hiroshima. An estimated 39,000
people were killed outright by the bombing at
Nagasaki; a further 25,000 were injured.

28.  15m radius fireball, shock
wave
 Thermal burns—infrared
heat whatever was facing the
blast.
 Radioactive debris deposited
by ‘black rain.’
 Uniform radiation burn—
electromagnetic waves (like
the sun’s rays but really high
energy) detach electrons from
atoms in your skin cells,
degrading tissues all over
your body.
white
fabric
reflects
more
infra-red
light than
dark
fabric

29.  Sixteen hours after the bombing, the White
House released a statement by President Harry
S. Truman, who was en route from the
Potsdam Conference aboard the U.S.S.
Augusta. "It is an atomic bomb," Truman
announced, "harnessing . . . the basic power of
the universe. The force from which the sun
draws its power has been loosed against those
who brought war to the Far East."

31.  In early 1944 officials began a carefully designed
public relations program in to both allay public
inquisitiveness and satisfy the legitimate public
need to know. They perceived that, from the
standpoint of security, the release of some selected
information would make it easier to maintain the
secrecy of the highly classified aspects of the
project.
 The public relations program had 2 parts:
preparation of a series of public releases and
preparation of an administrative and scientific
history of the project.

32.  The well-known science reporter for
the New York Times, wrote all the
press releases for the Manhattan
Project, was the only journalist
allowed access to it. Witnessed the
Trinity test and flew in the plane that
dropped the atomic bomb on
Nagasaki. During this time, he was on
the payroll of the US War
Department.

33.  And he became a staunch advocate of the atomic
bomb long before the atomic bomb was ever
dropped. Throughout the 1930's he was
advocating for research into the use of atomic
power, such that he earned a nickname, "Atomic
Bill.”
 His ten-part series profiling the bomb, would win
him and the Times a Pulitzer Prize in 1946.
 He withheld what he knew about radioactive
fallout across the southwestern desert that
poisoned local residents and livestock. He kept
mum about the spiking Geiger counters all around
the test site.

34.  After the first bomb was dropped on Hiroshima, the government
handed The Times the records and on Aug. 7, 1945, Laurence’s
secrets were finally revealed on the front page.

35. The Smyth Report—a
document released not long
after the bombing, descibing
the Manhattan Project and the
atomic bomb. “The Smyth
Report was intended to
control the amount and nature
of information on the bomb
released to the public.”
Dictated to the science public
what was now considered
‘declassified.’

36.  Despite undergoing extensive security
review before release, the Smyth
Report was criticized by politicians as
having "given away the secret of the
A-bomb."
 The Smyth Report did mention fission
of uranium and the kinds of facilities
used, but did not contain any details
on creating a functional weapon, nor
any illustrations. It did not outline
how one would actually construct an
atomic bomb.
 It was made clear that persons either
disclosing or securing additional
information without authorization,
Groves declared, would be "subject to
severe penalties under the Espionage
Act."

37.  No journalist was on
the ground to see the
effect of the
Hiroshima and
Nagasaki bombs.
The world's media
crowded onto the
USS Missouri off the
coast of Japan to
cover the surrender
of the Japanese.

38.  Australian war correspondent Wilfred Burchett – who had eluded the censors – had
been the first reporter to cover the A-bomb aftermath.
 NAGASAKI, Sept.9 (cdn) — The atomic bomb’s peculiar "disease," uncured because it is untreated
and untreated because it is not diagnosed, is still snatching away lives here.
 London Daily Examiner article
 In response, the US government flatly denied reports of deadly radiation and its
lingering effects, and accused Burchett of falling for Japanese propaganda. The Times
headlined Laurence’s story on September 12: "US Atom Bomb Site Belies Tokyo Tales:
Tests on New Mexico Range Confirm that Blast and Not Radiation Took Toll.
 Chicago Daily News reporter George Weller, a Pulitzer Prize-winning journalist
dispatches were stopped in 1945 by US military censors, were just recently discovered by
his son in 2005. Both Weller and another reporter had documented the atrocities in post-
bombing Japan, but only one successfully made it to press.
 The Los Angeles Times on September 16 1945 published a front page article "By George
Weller Chicago Daily News Foreign Service Nagasaki. (Delayed) U.S. Prisoner Sees
A-Bomb Rip Nagasaki.
Wilfred Burchett George Weller

39.  The immediate public response to news of the Manhattan Project
and the atomic bombings of Japan, as filtered through the project's
public relations efforts, was overwhelmingly favorable. When
asked simply "do you approve of the use of the atomic bomb?", 85
percent of Americans in one August 1945 poll replied "yes."
 Over time, other reactions to the abrupt beginning of the atomic age
began to emerge. These ran the spectrum from dark pessimism
about the future of the human race to an unbounded utopian
optimism.
 A certain sense of remorse also slowly began to build among the
public, especially as details became known of the destruction at
Hiroshima and Nagasaki
 August 21, 1946, issue of The New Yorker magazine was devoted to
stories of the devastation of Hiroshima.

40.  Szilard Petition, first version, July 3, 1945 - called
atomic bombs "a means for the ruthless annihilation
of cities." It asked the President "to rule that the
United States shall not, in the present phase of the
war, resort to the use of atomic bombs.” 155 scientists
at Los Alamos signed.
 many signers urged the A-bomb be demonstrated to
force Japan's surrender, and then be locked under new
international controls to forestall a post-war nuclear
arms race.
 Oak Ridge petition, July 13, 1945 - Szilard's petition
inspired a similar petition at Oak Ridge.
 Oak Ridge petition, late-July 1945 - Another petition at
Oak Ridge called for the power of the bomb to be
"adequately described and demonstrated" before use.

41.  Director J. Robert
Oppenheimer forbade the
petition's circulation.
 On July 17th, 1945, the day
after the first A-bomb was
tested, Szilard bundled his
signed petition sheets into a
manila envelope, addressed
it to the President, and
passed it up the Army's
chain-of-command. But,
alerted by Oppenheimer,
General Groves had his
subordinates delay the
petition until he received
word from Tinian Island in
the Pacific that the bombs
were ready to be dropped.
 Groves kept Szilard from
publishing the petition in
Science magazine by having
it declared "Secret”.

42.  Copyright, August 15, 1960, U.S. News & World Report.
 President Truman Did Not Understand
 NEW YORK
 Q Dr. Szilard, what was your attitude in 1945 toward the question of dropping the atomic bomb on
Japan?
 A I opposed it with all my power, but I'm afraid not as effectively as I should have wished.
 Q Did any other scientists feel the same way you did?
 A Very many other scientists felt this way. This is particularly true of Oak Ridge and the
Metallurgical Laboratory of the University of Chicago. I don't know how the scientists felt at Los
Alamos.
 Q At the Oak Ridge and Chicago branches of the A-bomb project, was there any division of
opinion?
 A I'll say this: Almost without exception, all the creative physicists had misgivings about the use of
the bomb. I would not say the same about the chemists. The biologists felt very much as the
physicists did.

43.  “Their petition highlights a cruel duality
shared by all scientists: eager to reveal
nature's secrets, they are then often powerless
to influence how their discoveries are used.”
William Lanouette, 2009

44.  September 1945 Y-12 shutdown begins.
 August 15, 1947 The Manhattan Engineer
District is abolished.
 Los Alamos persisted, developing further
atomic weapons such as fission/fussion
hydrogen bombs.