Atomic Bomb Timeline
This timeline shows events that occured during the development of the atomic bomb.
Albert Einstein's Letter
Albert Einstein's letter to President Roosevelt.
On August 2, 1939, Albert Einstein warned President Franklin Roosevelt that Germany was gathering resources to produce an atomic bomb. Germany had discovered that Uranium-235 could be turned into a new energy source capable of creating an explosion of mass destuction. Einstein suggested that the United States start building its own nuclear research centers and begin mining uranium. He
described how a single atomic bomb, carried into a port by ship, could destroy the entire port and surrounding territories. This gave the U.S. a priority that had to be completed. Mining soon began in Oakridge, Tennessee for Uranium; and
Hanford, Washington for Plutonium to create atomic bombs.
described how a single atomic bomb, carried into a port by ship, could destroy the entire port and surrounding territories. This gave the U.S. a priority that had to be completed. Mining soon began in Oakridge, Tennessee for Uranium; and
Hanford, Washington for Plutonium to create atomic bombs.
The First Atomic Bombs
The Manhattan Project atomic research team was formed, and the first atomic bombs were developed by the United States, from 1939 to 1945. The first test of the atomic bomb was on July 16, 1945. The first bomb, named Little Boy (small one, on the left), was a uranium-powered bomb that exploded with a force of 15 kilotons, roughly equivalent to 30 million sticks of dynamite. The second one, called Fat Man (on right), was a plutonium-powered bomb that imploded when activated. With a force of 21 kilotons, the plutonium in Fat Man collapsed into itself, causing an effect like that in a black hole. This was equivalent to about 42 million sticks of dynamite.
The First Atomic Bombs Are Used In Japan
The decision to use the atomic bombs was prompted by Japan's refusal to surrender. On August 6, 1945, Little Boy was dropped on the Japanese city of Hiroshima. It was detonated at 1,900 feet and missed its target by just 800 feet. It completely destroyed 60 percent of the city, killing 70,000 residents
instantaneously. Anything directly below the detonation was vaporized, and a mushroom cloud rose 40,000 feet in the air. Shadows were burned into surfaces.
Three days later, on August 9, Fat Man was dropped on Nagasaki. Time was needed between drops to acquire more plutonium for Fat Man. The bomb was detonated at 1,650 feet, instantly killing
over 40,000 people. Over the next several weeks, thousands more died of radiation poisoning, burns, and other effects of the atomic explosions. The world would witness, for the first time, what an atomic bomb could do to a thriving city.
instantaneously. Anything directly below the detonation was vaporized, and a mushroom cloud rose 40,000 feet in the air. Shadows were burned into surfaces.
Three days later, on August 9, Fat Man was dropped on Nagasaki. Time was needed between drops to acquire more plutonium for Fat Man. The bomb was detonated at 1,650 feet, instantly killing
over 40,000 people. Over the next several weeks, thousands more died of radiation poisoning, burns, and other effects of the atomic explosions. The world would witness, for the first time, what an atomic bomb could do to a thriving city.
Atomic Bombs Produced In Other Countries
Soon after the United States dropped their atomic bombs on Japan, other countries began producing their own atomic weapons. Some of these countries, such as Russia and China, posed great potential threats to the world by having these weapons of mass destruction. Other countries, like the US and England, developed atomic bombs for defensive purposes only, and did not intend to attack other nations. With all the different countries testing their new atomic weapons, it was producing a hazardous effect on the atmosphere and on humans. The radiation generated by the bombs were causing massive atmospheric pollution, and contaminated areas on land and water where the bombs were detonated. Nuclear testing was being conducted in many different ways: above ground, underground, underwater, and in space.
Nuclear Test Ban Treaty
After much debate about testing, it was agreed to stop worldwide nuclear testing altogether. The Nuclear Test Ban Treaty was proposed to the United Nations in May, 1955. The treaty was approved, and lasted from November 1958 until August of 1961, when the Soviet Union announced its plans to resume testing atomic bombs. It conducted 31 atmospheric tests over the next three months, including one for a 58 megaton atomic bomb, the Tzar Bomb, which created an enormous spike in atmospheric pollution. Then-President, John F. Kennendy, resumed testing as well, but continued negotiations with the Soviets to find an end.
The Cuban Missile Crisis, in November 1962, brought the reality of nuclear warfare much too close for comfort. President Kennedy sent Averell Harriman, an experienced negotiator, to Moscow to negotiate a new treaty. On August 5, 1963, U.S., Soviet and British officials signed the Limited Nuclear Test Ban Treaty, which limited testing to underground only. The treaty also pledged an end to all environmental contamination by radioactive substances, and a halt to the armaments race. Thirty-three years later, the United Nations adopted the Comprehensive Nuclear Test Ban Treaty, which banned all testing of atomic bombs, including underground. It was signed by seventy-one nations.
The Cuban Missile Crisis, in November 1962, brought the reality of nuclear warfare much too close for comfort. President Kennedy sent Averell Harriman, an experienced negotiator, to Moscow to negotiate a new treaty. On August 5, 1963, U.S., Soviet and British officials signed the Limited Nuclear Test Ban Treaty, which limited testing to underground only. The treaty also pledged an end to all environmental contamination by radioactive substances, and a halt to the armaments race. Thirty-three years later, the United Nations adopted the Comprehensive Nuclear Test Ban Treaty, which banned all testing of atomic bombs, including underground. It was signed by seventy-one nations.