1. Leo Szilard
• A Hungarian-American physicist who
worked on the Manhattan Project he was
probably the first scientist to think
seriously of building real atomic bombs.
He fled his native country to accept an
offer to conduct research at Columbia
University in Manhattan. Nobel Laureate
Enrico Fermi soon joined him there. Later,
he moved to the University of Chicago to
continue to work 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.

2. Neils Bohr
• Danish physicist, developer of
quantum theory.
• Gained a crucial insight into the
principles of fission - that U-235
and U-238 must have different
fission properties, that U-238
could be fissioned by fast
neutrons but not slow ones, and
that U-235 accounted for
observed slow fission in uranium.

3. Enrico Fermi
• Conducted the first nuclear
fission experiment at
Columbia University,
developed the first nuclear
reactor, and
demonstrations of the
existence of new
radioactive elements
produced by neutron
irradiation. Worked on the
Chicago pile-1 of the
Manhattan Project.
• Won the Nobel Prize in
1938.

4. Albert Einstein
• 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.

5. James Chadwick
• British scientist who studied under Ernst
Rutherford.
• In 1932, he proved the existence of neutrons -
elementary particles devoid of any electrical
charge. 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 o
uranium 235 and towards the creation of the
atomic bomb.
• He was awarded the Nobel Prize for Physics in
1935.

6. Ernest O. Lawrence
• 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.

7. Robert Oppenheimer
• 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.