Discoveries that led to the nuclear race:

The Beginning
In Rome, 1930, a scientist named Enrico Fermi tries to create new radioactive isotopes by bombarding different types of atoms with neutrons. While he succeeded in creating many of these isotopes, he did not notice that uranium released large amounts of energy during these bombardments.

In Berlin, a few years later, two scientists named Otto Hahn and Fritz Strassmann discovered that uranium did not transcend to an element higher in the periodic table, but split into two elements lower, which together had the same mass as uranium. Hahn wrote about their discoveries to a colleague named Lise Meitner. Meitner brought this knowledge on to her nephew, who at that time worked for Niels Bohr, who later brought the results to America.
Later on, among other American scientists, Leo Szilard discovered that if fission occurs, two or three neutrons will be released, which again could split other atoms. That was the discovery of the principles of chain reactions.

Due to the fear WW2 caused, many scientists in Europe fled to U.S.A. Albert Einstein, Enrico Fermi, Leo Szilard, Edward Teller, Max Born and Niels Bohr were among these scientists.

Why the Manhattan Project was Started
At that time, Germany was the leading country within research and science. There was a fear of that the German government might be using this new technology to develop new weapons. This fear was strengthened when Hitler in 1939 captured export of uranium. This made Albert Einstein write a letter to President Roosevelt

The letter was delayed due to Hitler's attack on Poland 1st of September, 1939, and Roosevelt was not available until 11th of October. The president studied the letter, which explained the terrible consequences German nuclear weapons would have. The letter was four pages long, but here is a quote from the letter:

    "This new phenomenon would also lead to the construction of bombs, and it is conceivable - though much less certain - that extremely power-full bombs of a new type may thus be constructed. A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory. However, such bombs might very well prove to be too heavy for transportation by air."

This letter made President Roosevelt react at once, with the statement "This requires actions at once". A committee was appointed to build a nuclear bomb, but the concluded with that building this type of bomb was only theoretical possible, so the project drowned in a beurocratic swamp. The project was not given any more funding until summer 1940, when National Defence Research Committee (NDRC) was founded. In September the same year, the project got $40.000.

Spring, 1941, the project started to move the right way. Physicists in England wrote a report containing instructions on how to use uranium in a bomb. This led to the conclusion that a nuclear bomb could be built within the next two years. The report also contained instructions how to separate the radioactive uranium-isotope, u-235 from regular uranium, u-238. In addition to these instructions, it also included some information on using plutonium as explosive material, and making the bomb compact enough for aerial transport.

This made NDRC come up with this conclusion: "If one of these bombs are to be made, the explosion will be thousand times more powerful than any explosion we've seen so far. It might also become a significant factor in the outcome of a war. This made Roosevelt react. "When a couple of scientists in the war-coloured England were able to make this sort of progress, how far have the scientists in Germany come, with the full support of Hitler?

The First Reactor
To make sure that the use of plutonium in a nuclear bomb, a nuclear reactor had to be built to prove that it worked. The work started in the metallurgic laboratory of the University of Chicago. The work was led by Enrico Fermi, who in 1938 fled from Italy after he had won the Nobel Price.

The result was CP-1 (Chicago Pile #1). It was built in an abandoned squash field under a soccer stadium. December 2nd, 1942, man first tamed the nuclear energy. Fermi's reactor produced 0.5 watts of energy. This was all that was needed to prove that the releas4e of energy from the nuclear core was enough to build a bomb.

The Manhattan Project Starts
By the end of the year 1942, they started to build a bomb from the same technology acquired earlier.
But there were still a few things that had to be solved:
  • How to separate sufficient amounts of uranium.
  • How to produce plutonium.
  • How the bomb should be designed.

Robert Oppenheimer was elected as the leader of the Manhattan Project in 1943. The project got help from many European scientists who had fled from the war. More than 100.000 workers were involved in the Manhattan Project. The Manhattan Project was spread over three different sites. "Site W" by Hanford, "Site X" by Oakridge, and "Site Y" by Los Alamos.

Here is a brief description of the different sites and their functions:
  • Site W: Three reactors were made to produce the necessary amount of plutonium.
    Several hundred grams of plutonium were produced every day.

  • Site X: This site was specially made to separate the two uranium-isotopes, U-235 and U-238.
    In the beginning, electromagnetics were used to separate the two isotopes, but later, a method
    Involving gas proved more effective.

  • Site Y: Built in an isolated area in the northern New Mexico, this was the residential area of
    the many scientists involved, and their families.

The Test Draws Near
The work mostly continued without anyone raising questions, but September 30th, 1944, long before they were sure that the bomb would work, James Conant and Vannevar Bush wrote a letter to the Secretary of War. They stated that the bomb should be demonstrated before it was used. During May 1945 this question was raised again, only this time by Arthur Compton. But as early as July 1944 Niels Bohr had written a letter to the president, stating that the nuclear bomb could be a threat to mankind. A committee was founded to study all the problems that would follow after a nuclear bomb had been used. This committee met 8 times between 9th of May, and 19th of July. The final decision on testing the bomb was taken the 31st of May, 1945. The 12th of July 1945 the committee received a letter from a group of scientists that stated that a sudden attack on Japan was not recommended. They meant this because that if USA was the first nation to release this horror on mankind, they would loose the support of the majority.

The committee disregarded this and came to these conclusions:
  1. The bomb was to be used against Japan as quickly as possible.
  2. It was to be used against a military target with surrounding civilian population.
  3. It was to be used without warning
In July, 1945, the scientists moved to a ranch approximately 160Km south of Site Y, in a valley with the convenient name, Jornada del Muerto (journey of death).

On the 16th of July, 1945, The sky over the valley was lit four times stronger than the sun usually did. A Mushroom-shaped cloud rose from the test-site. This made Oppenheimer quote from the Hindu-writing, Bhagavad-Gita: "Now I have became death, the end of the world!". This explosion carried mankind into a new age with nuclear technology. The bomb named Gadget exploded with a force equal to 19.000 tons of TNT, and the bomb dropped over Nagasaki had a force equal to this.

What did the other nations do, then?
Germany did not do much. Hitler had underestimated the power of a nuclear bomb, and did not approve a nuclear-bomb project.

Russia, who had been spying on USA for a long time acquired knowledge of that USA was doing research on a new type of powerful bomb as early as in 1943. So when President Truman on the 24th of July, 1945, told Stalin about their new weapon of war, he was surprised that Stalin did not ask any questions.

The Hydrogen Bomb
After the Soviet Union had acquired nuclear weapons in 1949, the idea of making a hydrogen-bomb rose. By taking deuterium and tritium and fusionize them into helium, larger amounts of energy gets released than when using fission. In the beginning, the scientists thought that there was no limit¹ of what amount of energy you can climb up to, using fusion. The Russian research on, and development of the hydrogen bomb² was one of the many factors that started the.cold war.

1 Atleast that was the theory. There IS a limit of the power, since most of the matter supposed to be fusioned is flung away rather than exploding, when building a bomb the size of Chicago

2 Some of my sources state that USA made the first h-bomb, but the majority says Russia did, therefor i rely on that. Correct if i'm wrong.