The Beginning of the Atomic Age
I. Discovery of nuclear fission
1. In Berlin, Germany in 1938, chemists Otto Hahn, Fritz Strassmann and physicist Lise Meitner discovered that the uranium atom could undergo fission when continually bombarded by neutrons, which resulted in the release of an enormous amount of energy. The discovery of “nuclear fission” is often considered the beginning of the atomic age.
i. Meitner was of Jewish ancestry and narrowly fled to Holland before facing Nazi persecution, and therefore could not be involved in the publishing of these findings. While Hahn and Strassmann continued to experiment, letters to Meitner led her to conclude that their results were nuclear fission.
ii. Meitner’s observation that a chain reaction of nuclear fission had vast explosive potential led the scientists Leó Szilárd, Edward Teller, and Eugene Wigner to persuade Albert Einstein to inform US President Franklin Roosevelt of the threat of German use of this.
II. From Europe to America
1. Three Hungarian émigré scientists, Leo Szilard, Eugene R. Wigner, and Edward Teller prompted fellow émigré Albert Einstein, who had the publicity, to write a letter to President Roosevelt warning him of the potential consequences of nuclear fission. It is known as the Einstein-Slizard Letter.
i. Szilard, Wigner and Teller felt that it was their responsibly to alert some higher authority before the information could be used by Hitler’s Nazis.
2. Banker and economist Alexander Sachs had no official White House position but was a close friend of Roosevelt and acted as a presidential adviser. Sachs was to present Roosevelt with the Einstein-Slizard letter. The letter was delivered on October 11, 1939.
i. Sachs met with Roosevelt again to discuss the urgency of the letter. Roosevelt decided to pursue nuclear development because of this.
ii. On October 19, 1939 Roosevelt wrote back to Einstein informing him that he would setup the Advisory Committee on Uranium consisting of Sachs and representatives from the Army and Navy to study uranium.
3. On October 11, 1941 Roosevelt wrote to Winston Churchill to offer British nuclear physicists a plan whereby they could work in the United States. After this point American scientists began working with émigré scientists to conduct nuclear research.
4. America’s atomic program grew rapidly after the Japanese attack on Pearl Harbor in December 1941. Roosevelt set up a National Defense Research Committee (NDRC), to mobilize science for war, and later, the Office of Scientific Research and Development (OSRD).
i. The discovery of plutonium in 1940 – which had higher fission probability than uranium -- plus a series of optimistic reports from the British scientists, led by physicist Rudolph Peierls, strengthened the fledgling American efforts.
5. By late 1941, the British were confident that a U-235 bomb could be developed before the hostilities were over.
6. Less than three months after the Manhattan project begun, physicist Enrico Fermi headed a team of scientists that inaugurated the first controlled nuclear
chain reaction.
chain reaction.
i. Borrowing a squash court at the University of Chicago football stadium, Fermi and several students piled up 500 tons of graphite amidst 50 tons of uranium and uranium oxide in a matrix until the pile reached 48 layers. It took a little over a month to build the structure. All went as scheduled, however, and at 2:30 on December 2, 1942, about forty people watched the world's first self-sustaining nuclear reaction.
III. The Manhattan Project
1. In June of 1942 the nuclear program was turned over to the army. On September 17, 1942, Major General Leslie R. Groves, the man who had helped supervise the building of the Pentagon, was placed in charge of the Manhattan Engineer District. It was later known as the Manhattan Project.
i. He had clashes with a number of scientists but proved to be a no-nonsense administrator.
2. Under the combined efforts of the army, industry, and labor, gigantic facilities for the production of fissionable material were established at Oak Ridge, Tennessee, and Hanford, Washington.
i. Their tasks were to produce sufficient quantities of the fissionable U-235 and of plutonium for the bombs. At the time the operations began, these materials existed only in microscopic quantities.
ii. Cooperation of the giants of American industry -- Kellex, DuPont, Union Carbide, Chrysler, Eastman Kodak, Allis-Chalmers, General Electric, Westinghouse, Stone-Webster, and numerous others -- proved crucial to its success.
3. By 1945, the project had 40 laboratories, which employed 200,000 people. The project was given overall responsibility of designing and building an atomic bomb. The group was led by Dr. J. Robert Oppenheimer.
4. The Manhattan Project produced two different types of atomic bombs, code-named Fat Man and Little Boy.
i. Fat Man relied on the rare Uranium-235.
ii. Little Boy, a more complicated design, used man-made Plutonium-239, which used the discoveries made by Fermi.
5. Great Britain made significant theoretical contributions to the Manhattan Project. Germany had progressed little with their development of the atomic bomb from the starting of the war to the end and therefore they were unsuccessful. The Russians built a program that grew increasingly active as the war drew to a conclusion, but the first successful Soviet test was not conducted until 1949. In Japan the atomic bomb research effort could not maintain a high priority due to a decrease is resources.
i. Only the Americans, late entrants into World War II and protected by oceans on both sides, managed to take the discovery of fission from the laboratory to the battlefield and gain a short-lived atomic monopoly.
6. About $2 billion and years of effort were invested into the Manhattan Project.
IV. Site Y
1. The Los Alamos site, or Site Y, as it was officially known, housed the central research for the Manhattan Project. The Los Alamos site was created for two main reasons.
i. First, the project needed a special weapons laboratory that would put the bomb together.
ii. Second, Groves wanted to provide the scientists a site where they were not restricted by his security measure. From the beginning, he had insisted that the people involved with the various aspects of the Manhattan Project know only enough to carry out their own jobs effectively.
a. This "compartmentalization" of tasks lay at the heart of all Manhattan Project security. It proved so effective that no information ever reached German hands.
b. Compartmentalization however was a hindrance at the scientific level. After the war, Leo Szilard complained that Groves's insistence on compartmentalization actually hindered the development of the bomb by eighteen months.
c. Despite compartmentalization, German-born physicist Klaus Fuchs provided crucial intelligence that facilitated the acquisition of the atomic bomb by the Soviet Union. As early as 1941, when working on Great Britain's nuclear program, Fuchs began to relay classified information to Russia. Later working on the Manhattan Project, he provided Soviet scientists with facts on virtually every aspect of the project's research. When the U.S.S.R. finally tested its own atom bomb on August 29, 1949, Stalin's scientists detonated a near-perfect replica of the American Plutonium weapon.
2. In early 1942, Groves decided that the project needed to create a new, isolated site where the scientists could all come together and talk openly. In the summer of 1942, after a brief search, Groves, Major John Dudley, and the newly appointed head of this installation, California physicist J. Robert Oppenheimer, selected the region of Los Alamos, New Mexico.
i. 9 000 acres was acquired for the site. At the end of the war, close to 6 500 people were living on the Hill.
ii. Scientists working at the Los Alamos site included Neils Bohr and his son, Aage, Enrico Fermi, Edward Teller, I.I. Rabi
V. The Trinity Site
1. The “Trinity site” was the location of the first detonation of a nuclear weapon. It was at a location 56 km southeast of Socorro, New Mexico on the White Sands Proving Ground, headquartered near Alamogordo.
2. At exactly 5:30 Mountain War Time on the morning of July 16, 1945, the first nuclear weapon was successfully detonated.
i. William L. Laurence wrote: a great green super-sun climbing in a fraction of a second to a height of more than 8,000 feet… Up it went, a great ball of fire about a mile in diameter, changing colors as it kept shooting upward, from deep purple to orange, expanding, growing bigger, rising as it was expanding, an elemental force freed from its bonds after being chained for billions of years.
3. Scientists at first were ecstatic about the success of the detonated, but shortly after realized the possible implications of their achievement.
i. Stan M. Ulam wrote: Only with Trinity did the scientists comprehend the full potential of the forces they had unleashed. The power of the fissioned atom was greater than anyone had ever imagined.
VI. Roosevelt to Truman
1. On April 12 1945, few weeks before Germany’s unconditional surrender, Roosevelt passed away and Harry S Truman was sworn into the presidency.
2. Truman was unaware of many of the developments with nuclear technology Roosevelt had undertaken. In a forty-five minute meeting Secretary of War Henry Stimson, Truman was summarized the Manhattan Project.
3. The Potsdam Declaration was issued on July, 1945. President Truman, the Prime Minster of Great Britain, Clement Atlee, and Joseph Stalin represented the Soviet Union met at Cecilenhof in Potsdam.
i. The Potsdam Declaration laid out specific terms of a Japanese surrender to bring about a peaceful resolution and end the fighting. It required unconditional surrender by the Japanese.
a. The declaration explained that unconditional surrender “does not mean the extermination or enslavement of the Japanese people” and that it does not mean national suicide.
ii. The Japanese rejected the terms because they would not allow for the surrender of the Emperor. The declaration explained that unconditional surrender “does not mean the extermination or enslavement of the Japanese people” and that it does not mean national suicide.
4. Truman made the decision to use the atomic bomb to stop the conflict in Japan instead of organizing an invasion. Reasons for doing so included:
i. The JCS 924, a comprehensive government report by the Joint Chiefs of Staff regarding the details of an invasion of Japan, stated that an invasion would result in half a million American casualties and “many times that number wounded”.
ii. Americans suffered 31 000 casualties in Luzon and 63 000 in Okinawa, and Truman was reluctant to keep his military pushing on this way on the Pacific theatre.
iii. Truman wanted to exact revenge for the attack on Pearl Harbor
iv. The use of atomic weapons would demonstrate American power to the rest of the world, and in particular, Stalin and the Soviet Union
VII. Hiroshima and Nagasaki
1. At approximately 2:00 a.m. on August 6, 1945, a bomber named the Enola Gay left the island of Tinian for Hiroshima, Japan carrying Little Boy, the uranium bomb. At 8:15 a.m., Little Boy exploded, instantly killing 80,000 to 140,000 people and seriously injuring 100,000 more.
i. This mission was piloted by Colonel Paul Tibbets. The Enola Gay was carrying Little Boy—a bomb that was expected to knock out almost everything within a 5km area. Measuring over 3m long and almost 75cm across, it weighed close to 5 tons and had the explosive force of 20,000 tons of TNT.
ii. About 30 minutes after the explosion, a heavy rain began falling in areas to the northwest of the city. This "black rain" was full of dirt, dust, soot and highly radioactive particles that were sucked up into the air at the time of the explosion and during the fire. It caused contamination even in areas that were remote from the explosion.
2. On August 9 another American B-29 bomber, Bock's Car, left Tinian carrying Fat Man, the plutonium bomb. Nagasaki was chosen as the target. The bomb exploded at 11:02 a.m. Of the 286,000 people living in Nagasaki at the time of the blast, 74,000 people were killed and another 75,000 sustained severe injuries.
3. The dropping of the atomic bombs is considered the beginning of the atomic age.
Technology in World War II
I. Weaponry: Aircrafts
1. In the Western European Theatre, air power became crucial throughout the war, both in tactical and strategic operations. Superior German aircraft, aided by ongoing introduction of design and technology innovations, allowed Hitler’s armies to overrun Western Europe with great speed in 1940, largely assisted by lack of Allied aircraft.
2. There were three basic types of combat aircraft in the American arsenal in World War II -- fighters, medium/light bombers, and heavy bombers.
3. Fighters
i. One of the least successful American fighters in World War II was the P-39 Airacobra.
1. Top speed: 360 mph; Ceiling: 15 000 ft; Weapon: 37mm cannon designed to destroy tanks and other ground targets.
ii. Another fighter in service early in the war, but one that performed at a higher level, was the P-38 Lightning. It featured a "forktail" design with a rear boom connecting the two fuselages
1. Top speed: at 25 000 ft, it could reach speeds in excess of 400 mph; Ceiling: 30 000 ft; Weapon: 20mm cannon as well as four .50-caliber machine guns, and could carry rockets and bombs
iii. Like all American fighters except the P-38, the F6F Hellcat was a single-engine aircraft. It was employed primarily over the vast expanses of the Pacific Ocean and flown primarily by the Navy and Marine.
1. Ceiling: 38 000 ft; Weapon: it carried six .50-caliber machine guns, along with bombs or rockets. It had a radius of 1 500 mi, making it ideal for the sea
iv. The P-47 Thunderbolt was one of the most successful American fighter planes of World War II, especially at strafing ground targets. Heavily armored and reasonably maneuverable for a large aircraft, it entered service in significant numbers in 1943 and provided American bombers in Europe with a medium-range escort fighter.
1. Ceiling: 35 000 ft; Weapon: up to eight .50-caliber machine guns in its wings and was ideal for carrying bombs or rockets; Radius: 700mi
v. Perhaps the most successful American fighter in World War II was the P-51 Mustang. In terms of air-to-air combat, maneuverability, range, and sheer joy to fly, the Mustang was unquestionably the best American fighter.
1. Radius: 900 mi; Speed: cruising speed of 360 mph and a top speed of 440 mph; it was very good for dive bombing from 4,000 feet to 6,000 feet in about a 70 to 80 degree dive
4. Light/medium bombers
i. American medium bombers in World War II were used mostly for low-level tactical bombing missions.
ii. One of the most common American medium bombers was the twin-engine
B-25 Mitchell. The B-25 usually carried a six-man crew for its low-altitude, ground-support missions. It had an effective range of 1,350 miles and an average cruising speed of 230 mph. The typical B-25 had a dozen .50-caliber machine guns in its nose, two more in the top turret, two more in the tail, and a few more in the waist position. The Mitchell could carry about 3,000 pounds of bombs or eight five-inch rockets.
B-25 Mitchell. The B-25 usually carried a six-man crew for its low-altitude, ground-support missions. It had an effective range of 1,350 miles and an average cruising speed of 230 mph. The typical B-25 had a dozen .50-caliber machine guns in its nose, two more in the top turret, two more in the tail, and a few more in the waist position. The Mitchell could carry about 3,000 pounds of bombs or eight five-inch rockets.
iii. Another widespread American medium bomber was the B-26 Marauder. Powered by two engines, it carried a seven-man crew. It had range of 1,150 and cruising speed of 216 mph. It could haul up to 4,000pounds of bombs and a total of twelve .50-caliber machine guns placed at various points of the aircraft.
5. Heavy bombers
i. They were the most expensive and complicated aircrafts. They were built to destroy the enemy's vital industrial resources and infrastructure.
ii. More four-engine B-24 Liberators were built than any other combat aircraft in American history. It had a range of about 2,100 miles and could carry close to 10,000 pounds of bombs. Its top speed was about 300 miles per hour, with a cruising speed of 210 miles per hour. The B-24 had with .50-caliber machine guns from nearly every side of the ship. Depending on the mission it flew, the Liberator required a crew of eight to ten men.
iii. America's best-known and most glamorous bomber was the B-17 Flying Fortress. The B-17 could withstand terrific punishment and still get its crew home. It was another four-engine bomber, and designed for deep penetration, strategic bombing raids over the enemy's homeland. There were more than ten .50-caliber machine guns throughout the aircraft. It had a ceiling of 35,000 feet, a cruising speed of 160 mph, and a range of more than 1 800 miles; it could carry up to 17,000 pounds of bombs on short missions.
II. Weaponry
1. Arms
i. A very large range of guns, mortars, artillery and bombs were use during WWII.
ii. The M1 Garand (officially the United States Rifle, Caliber .30, and M1) was the standard rifle used in WW2 for the American infantry. The Garand officially replaced the bolt-action M1903 Springfield as the standard service rifle of the US Armed forces in 1936.
iii. The Colt M1911 was the standard handgun used the by US Armed Forces in WW2. Designed by John M. Browning, and was the standard-issue side arm from 1911 to 1985. It is known for its use of short recoil.
2. Tanks
i. Allies were never able to meet the superiority of German tanks (e.g. the Panzer, Tiger, Panther) during WWII; however Americans were able to produce more tanks.
ii. The Light Tank M2 and M3 were the earlier tanks used by the US Forces.
iii. The Medium Tank M4 became the main tank used by the Allies. Production of M4 tanks surpassed 50 000 units.
III. Logistical Support
1. Aircraft Carriers
i. Ships that have the primary mission of acting as a base for incoming or outgoing airplanes. Aircraft carriers replaced battleships as the main part of the fleet.
ii. On April 18, 1942 Col. Doolittle and a group of pilots went on a mission to raid Tokyo. Doolittle and his pilots launched their planes from the carrier Hornet. This raid was highly successful and boosted the morale of the American citizens and struck fear into the heart of Japan.
IV. Communications and intelligence
1. The invention of the RADAR (RAdio Detection And Ranging) and SONAR (SOund And Navigation Ranging) revolutionized naval and air warfare.
i. Enemies lost the element of surprise from their attacks because radars were able to detect them beforehand.
ii. The first practical radar system was produced in 1935 by the British physicist Sir Robert Watson-Watt.
iii. The Chain Home system was a system of radar stations which could detect aircraft flying at minimum altitude level of 500 ft used in Britain.
2. When Germany had a massive airstrike on England in 1940 the radar proved its usefulness. Even though the German air force greatly outnumbered the British Royal Air force, they were defeated because the radar could easily detect German airplanes even through bad weather.
3. The impact of computers in WWII is seen when British and Polish code breakers were able to break the German Enigma Machine code.
V. Medicine
1. The Scottish bacteriologist Sir Alexander Fleming discovered penicillin in 1928 but dismissed his observations as mere anomalies. Ten years later, a team of scientists at Oxford University rediscovered Fleming's work but sought American help for further development.
2. In 1941 John Davenport and Gordon Cragwall, representing the pharmaceutical company Pfizer lead the production of penicillin for greater use.
3. Penicillin made a major difference in the number of deaths and amputations caused by infected wounds among Allied forces, saving an estimated 12–15% of lives.
VI. Industry
1. Production in the US
i. over 300 000 aircrafts
ii. over 88 000 tanks and self propelled guns
iii. over 70 000 larger tanks and self propelled guns
iv. over 2 million machine guns
v. 22 complete air craft carriers
vi. By the end of 1942 USA had 5.4 million member army, 700 000 minority troops, over $68 billion worth of small arms, munitions, war supplies and ships ready for battle
2. General Motors had $13 billion in wartime manufacturing contracts
3. The Munitions Program of 1940 maintained an army of at least 1.2 million, created production facilities (munitions factories), and the Air Corps. $6 billion was spent fortifying America’s borders.
4. The Victory Program of 1941 allocated $ 34 billion to provide equipment for American soldiers. Army G-4 officers responsible for supplies, and they determined that new weapons, uniforms, and handy war supplies were needed. This would cost $150 billion by the time of the Pearl Harbor attack.
5. The Lend-Lease Act of 1941 was an agreement that America would supply the Allies with weapons indefinitely in exchange for future payments. Over $30 billion worth of supplies were allocated for Britain, $11 billion to the Soviet and $3 billion to France.
Timeline
August 2,1939 Albert Einstein writes to FDR concerning the use of uranium as a new source of energy, this plays a role in the formation of the Manhattan project
September 1, 1939 World War II begins
September 3rd, 1939 Britain enters the WWII
October 11, 1939 Alexander Sachs met with President to discuss the letter
October 19, 1939 FDR wrote back to Einstein informing him that a committee to research on the atomic bomb has been set up
December 6 1941 FDR gives the Manhattan Engineering District authority to create an atomic bomb,
December 1941: The United States Enters World War II
April 12, 1945 FDR dies, Harrry Truman is names the 33rd President of the United States
May 8, 1945: Germany surrenders
July 16, 1945 The world's first atomic detonation takes place in the 'Trinity Test' at Alamogordo, New Mexico.
July 21, 1946 President Truman orders atomic bombs to be used
July 26, 1945 Potsdam Declaration is issued calling for the “unconditional surrender of Japan”
July 28, 1045 Potsdam Declaration is rejected by Japan
August 6, 1945 Little Boy, a uranium bomb, is detonated over Hiroshima, Japan.
August 9, 1945 The second atomic bomb to hit Japan, Fat Man, was scheduled to be dropped at Kokura. However, because of poor weather the target was moved to Nagasaki
September 2, 1945, Japan announces its formal surrender.
The Atomic Age: Scientists in National and World Affairs. Articles from the Bulletin of the Atomic Scientists 1945-1962. Book by Morton Grodzins, Eugene Rabinowitch; Basic Books, 1963. 616 pgs.
The Day the Sun Rose Twice: The Story of the Trinity Site Nuclear Explosion, July 16, 1945. Book by Ferenc Morton Szasz; University of New Mexico Press, 1984. 236 pgs.
Deadly Sky: The American Combat Airman in World War II. Book by John C. McManus; Presidio Press, 2000
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