Atomic Bombings of Hiroshima and Nagasaki

Atomic Bombings of Hiroshima and Nagasaki: On August 6 and 9, 1945, The United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki respectively. This was the first time that atomic weapons were used in battle. The Atomic bombings of Hiroshima and Nagasaki in 1945 claimed the lives of tens of thousands of people, and numerous more would eventually die from radiation sickness. The Japanese government declared on August 10, the day after Nagasaki was bombed, that it would accept the conditions for the Allies’ surrender as forth in the Potsdam Declaration.

In this article, you will read about the atomic bombings of Hiroshima and Nagasaki, the history of the bombings, the aftermath, and the Manhattan Project which had a major role in the the atomic bombings.

Atomic Bombings of Hiroshima and Nagasaki Dates

The atomic bomb was dropped on Hiroshima on August 6, 1945, in Hiroshima city center and on Nagasaki on August 9, 1945, in the Nagasaki industrial area.

Here in this table, the overview of the atomic bombing of Hiroshima and Nagasaki is provided:

Aspect	Hiroshima	Nagasaki
Date of Bombing	August 6, 1945	August 9, 1945
Bomber	Enola Gay	Bockscar (Necessary Evil)
Bomb Type	“Little Boy” (Uranium-235)	“Fat Man” (Plutonium-239)
Impact Location	Hiroshima city center	Nagasaki industrial area
Casualties	Approximately 140,000 killed	Approximately 70,000 killed
Immediate Effects	Widespread destruction, fires, and a massive shockwave.	Massive firestorms and destruction of industrial facilities.
Long-Term Health Effects	Radiation sickness, increased cancer rates, and birth defects.	Radiation sickness, increased cancer rates, and birth defects.
Japanese Surrender	Following the bombing of Hiroshima, Japan surrendered on August 15, 1945, effectively ending World War II.
Worldwide Impact	The bombings led to the beginning of the nuclear arms race and the Cold War.	Increased awareness of the destructive power of nuclear weapons and efforts to prevent their use.
Memorials	Hiroshima Peace Memorial (A-Bomb Dome) and Nagasaki Peace Park.	Nagasaki Peace Park and the Nagasaki Atomic Bomb Museum.

Background of the Atomic Bombings of Hiroshima and Nagasaki

The first atomic tool was made possible by a discovery made by nuclear scientists in a Berlin, Germany, laboratory in 1938 after Otto Hahn, Lise Meitner, and Fritz Strassman discovered nuclear fission. An atom of radioactive material experiences nuclear fission as its nucleus breaks into two or more smaller nuclei, culminating in an unexpected, powerful release of energy. Nuclear technologies, including weapons, became accessible after the discovery of nuclear fission. Fission reactions supply the energy for atomic bombs. Nuclear fusion and nuclear fission are each employed in thermonuclear weapons, such as hydrogen bombs. Another reaction in which two lighter atoms connect to release energy is nuclear fusion.

What is the Manhattan Project?

The American Atomic Program Takes Shape

• The United States would begin the largest scientific endeavor carried out up to that point while participating in one war in Europe and another in the Pacific. 100,000 people would be involved, along with 37 facilities spread across the nation, more than a dozen university labs, and physicists who have won Nobel Prizes including Arthur Holly Compton, Enrico Fermi, Richard Feynman, Ernest Lawrence, and Harold Urey.
• George B. Pegram of Columbia University initiated the first communication between the scientific community and the US government regarding atomic research. Leo Szilard and Eugene Wigner met with Einstein in July 1939, and the three subsequently traveled to New York to meet with National Recovery Administration economist Alexander Sachs. Sachs approached President Franklin D. Roosevelt and conveyed the significance of nuclear fission to him, aided by a letter from Einstein. Roosevelt established the Uranium Advisory Committee, chaired by Lyman Briggs, head of the National Bureau of Standards.
• The nuclear aspirations of Adolf Hitler were now well-known to American officials. In his letter to Roosevelt, Einstein made clear that Czechoslovakia’s uranium stockpiles had come under the Third Reich’s authority in March 1939. A number of scientists from those nations relocated to the United States later that year to work on the project, which was already well underway. It was decided to work simultaneously on numerous techniques for separating uranium-235 while also conducting research into reactor development because there was no way to tell in advance which technology would be successful in constructing a functional weapon.
• At the University of California, Berkeley, Lawrence, and his team created an electromagnetic separation technique, while Urey’s team at Columbia University experimented with uranium conversion into a gaseous molecule that was then allowed to diffuse through porous barriers. To create even modest amounts of separated uranium-235, both of these processes—especially the diffusion method—required enormously complicated equipment and enormous amounts of electric power. It was soon obvious that a sizable physical infrastructure would need to be constructed to support the endeavor.

From Stagg Field to Los Alamos

• On June 18, 1942, the War Department assigned the Manhattan District of the United States Army Corps of Engineers the responsibility of project construction administration. On September 17, 1942, Brig. Gen. Leslie R. Groves was given command of all Army efforts linked to the project. For this extensive program of atomic research that would cover the nation, the “Manhattan Project” was chosen as the code name.
• In Chicago Pile No. 1, a reactor he constructed on a squash court behind the bleachers of Stagg Field, the university’s football stadium, Fermi oversaw the first self-sustaining nuclear chain reaction on December 2, 1942. It had now been proven that controlled atomic energy release could be used to produce plutonium and generate electricity.
• Groves decided to build the project’s plutonium production facilities on a 580 square mile (1,500 square kilometers) parcel of land in south-central Washington in January 1943. The area was picked because of its relative remoteness, as well as the Columbia River’s enormous supply of cooling water and the hydroelectric plants at Grand Coulee and Bonneville’s plentiful supply of energy.
• A significant amount of the local population had to be relocated because of the development of what is now known as the Hanford Engineer Works. The Wanapum Native American people were forced to migrate to Priest Rapids and lost access to their customary fishing grounds on the Columbia. Residents of Hanford, Richland, and White Bluffs were given 90 days to vacate. In the summer of 1944, the enormous Hanford complex was at its busiest and employed over 50,000 people.
• For the project’s final phases, a location that was even more remote than Hanford was necessary for security and safety concerns. The scientific head of the Manhattan Project, J. Robert Oppenheimer, picked a spot on a remote mesa in Los Alamos, New Mexico, some 55 kilometers (34 miles) north of Santa Fe. In April 1943, the Los Alamos Laboratory, as it was then known, opened its doors to scientists and engineers.
• Under Oppenheimer’s direction, this group was tasked with coming up with strategies for turning the fissionable byproducts of the Clinton and Hanford manufacturing facilities into pure metal and shaping that metal into the elements of a deliverable bomb. The Los Alamos site housed more than 5,000 scientists, engineers, technicians, and their families at its busiest in 1945.

The Trinity Test

• Despite the hundreds of man-hours spent preparing for this moment, a few workers at the Trinity site had concerns that the bomb would set off as anticipated. Nobody in person was able to accurately forecast all the different theoretical variables. Many precautions for security were set into effect in order to be prepared to face any number of disaster situations. Several nearby cities had soldiers deployed nearby in case they needed to be evacuated.
• Groves advised Governor, John J. Dempsey of New Mexico, that that in the case of an emergency, a state of martial law could be necessary to be enforced there. Groves was already nervous about the well-being of Amarillo, Texas, an urban center of seventy thousand residents that was just about 300 miles away. The Army Public Relations Department was prepared with depressing justifications in case a catastrophe occurred and lives were lost.
• On July 16, the test’s planned 4:00 AM start time had to be postponed due to rain. Hubbard’s team eventually came to a decision that the ideal weather would only be prevalent between 5:00 and 6:00 AM. Groves was infamous for saying that he would “hang you” if Hubbard was wrong. Luckily for Hubbard, the sky started to gradually clear.
• Since the weather prediction appeared good, the scientists and the military established camp a few hours before the test’s rescheduled 5:30 AM detonation. The shelters 10,000 yards to the north, west, and south of the tower were the closest. Soldiers resided in these bunkers, which were beneath the supervision of Manhattan Project researchers who were researching the effects of radiation. Twenty kilometers away, in a tower on Compania Hill, the project supervisors could see the shelter.
• At 5:29:45, Gadget detonated with an explosion that was 15–20 kilotons more powerful than the Little Boy bomb introduced in Hiroshima. Everything went smoothly to plan in the end after years of hard struggle. The test produced more TNT than had been anticipated, which was the opposite of what was expected. The complex system of conductors, switches, and detonators created a previously unheard energy explosion.

Atomic Bombings of Hiroshima and Nagasaki Names

Physicist Robert Serber coined the names for the first two atomic bomb designs based on their shapes. “Thin Man” was named after the slim protagonist in a detective novel, while “Fat Man” was named after a rotund character in another novel. A third design was reportedly called “Little Boy,” possibly inspired by a movie character, although the origin remains disputed.

Atomic Bombing of Hiroshima

The first location was determined to be Hiroshima, a manufacturing hub with 350,000 inhabitants that is about 500 miles from Tokyo. The more than 9,000-pound uranium-235 bomb was loaded onto a modified B-29 bomber which was given the name Enola Gay (after the mother of its pilot, Colonel Paul Tibbets) when it reached the American base on the Pacific Island of Tinian. At 8:15 in the morning, the plane dropped the “Little Boy” bomb by parachute; it detonated 2,000 feet above Hiroshima with a detonation equivalent to 12–15,000 tons of TNT, eradicating five square kilometers of the city.

Atomic Bombing of Nagasaki

Although hiroshima bombing had been entirely demolished, the Japanese weren’t going to immediately submit, and on August 9 Major Charles Sweeney drove another B-29 bomber, Bockscar, from Tinian. Sweeney headed to a secondary target, Nagasaki, where the plutonium bomb “Fat Man” was dropped at 11:02 that morning due to high clouds over the initial target, the city of Kokura. The bomb, which was more deadly than the one used at Hiroshima and weighed approximately 10,000 pounds, was intended to generate a 22-kiloton blast. The geological makeup of Nagasaki, which is situated in a number of confined valleys bordered by mountains, lessened the impact of the bomb, reducing the area destroyed to 2.6 square miles.

The Japanese Surrender after the Atomic Bombings

After the nagasaki bombing, Nagasaki’s impact was practically immediate, Truman’s decision to use the bomb would be the topic of conversation and debate for decades. Emperor Hirohito departed from precedent by supporting the enactment of the Potsdam Declaration’s regulations rather than refraining from intervening in political events. The Japanese government announced its intention to surrender on August 10 with the condition that the emperor’s status as a sovereign head of state would not be questioned.

The US Secretary of State James Frederick Byrnes responded on behalf of the Allies following this was rapidly rejected: “From the moment of surrender, the Emperor and the Japanese Government’s authority to rule the state shall be liable to the Supreme Commander of the Ally Powers, who will take any action as he considers appropriate for carrying out the agreement to surrender terms.” Groves had notified Truman by the way that another bomb would be ready for delivery in a few days.

Senior Japanese military commanders attempted a failed coup; however, it was unsuccessful, and on August 14 the Japanese government consented to the terms. The following day, Hirohito announced Japan’s surrender in a prerecorded address that was broadcast via the Japanese broadcaster Nippon Hs Kykai (NHK). It was the first time most Japanese people had encountered the voice of the emperor. On September 2, 1945, the formal surrender letters were signed on the deck of the USS Missouri, formally terminating World War II.

Effects of the Atomic Bombings of Hiroshima and Nagasaki

Casualties, damage, and the legacy of Hiroshima and Nagasaki

The U.S. Department of War made the conclusions of the official inquiry into the bombings of Hiroshima and Nagasaki public on June 30, 1946. It had been put together by the engineers and scientists associated with the Manhattan Project, who had access to information collected by the Atomic Bomb Casualty Commission, the British mission to Japan, and the British Strategic Bombing Survey. Based on this evaluation, Hiroshima lost 135,000 individuals or more than half of its population. The majority of these happened shortly following the explosion. With an estimated population of 195,000, Nagasaki lost 64,000 inhabitants.

In accordance to the report, there are a total of three primary means that atomic bombs affect human beings:

• Burns, including radiation-induced flash burns,
• Mechanical injuries from objects that fly, collapsing constructions, and blast effects, and
• Radiation injuries are entirely from gamma rays and neutrons released at the precise moment of explosion.

About 60% of the casualties in Hiroshima and 80% in Nagasaki were caused by burns. In Hiroshima and Nagasaki, falling debris and flying glass were liable for 30% and 14% of the fatalities, correspondingly. Radiation killed 10% of the population in Hiroshima and 6% of individuals in Nagasaki. In the months following the explosions, no dangerous amount of persistent radioactivity was identified in any of the two cities.

Long-Term Effects (With Some Case Studies)

Researchers came to the conclusion that, with the exception of buildings made of reinforced concrete, nearly every building in Hiroshima within a mile (1.6 km) of Ground Zero was completely demolished. Building interiors had been totally razed and doors, frames, and all windows had been blown out in those that were still unaltered. Of the estimated 90,000 constructions in Hiroshima, more than 60,000 were totally demolished or seriously damaged. Buildings constructed from reinforced concrete in Nagasaki that were 2,000 feet (610 meters) from Ground Zero and possessed walls that were approximately 10 inches (25 cm) thick fell.

Despite all the casualties and damage, they brought about, the bombs appeared to have offered Japan’s territorial integrity an implausible guarantee. Stalin had been prepared to occupy and possibly seize Hokkaido in the two weeks between Hirohito’s address and the formal Japanese surrender, based on documents that were made public after the collapse of the Soviet Union. Stalin saw an opportunity to take command of the northernmost of Japan’s home islands and effectively convert the Sea of Okhotsk into a Soviet lake since he was already promised the Kuril Islands under the circumstances of the Yalta discussions (February 1945).

A topographical oddity helped the main Mazda Motor Corporation facility survive the bombing, and the expansion of the Japanese auto industry would be a major component in Hiroshima’s revival. In Nagasaki, the bombed-out area of the Urakami Basin was restored, and significant portions of the historic city withstood the war to become a top tourist destination. The movements to outlaw nuclear weapons both had their spiritual centers in Hiroshima and Nagasaki. The Hiroshima Prefectural Industrial Promotion Hall, now known as the Atomic Bomb Dome, and the Peace Memorial Park in Hiroshima, which honors those murdered by the bomb, were both named UNESCO World Heritage sites in 1996.

The Japanese government promised the bombing survivors—known as “hibakusha” in Japan—free lifetime medical care. The Atomic Bomb Casualty Commission, which has been known as the Radiation Effects Research Foundation (RERF) since 1975, began executing research on the biological and health effects of radiation in 1947. The large RERF Life Span Study, which examined the health effects of exposure to atomic bomb radiation, sought more than 120,000 hibakushas. The project was an excellent resource for researchers researching the long-term effects of radiation exposure due to the enormous size of the cohort and the open-ended nature of the data-gathering period.

Important Facts on Atomic Bombings of Hiroshima and Nagasaki

1. The first use of atomic weapons in warfare happened during American bombing attacks on the Japanese cities of Hiroshima, which took place on August 6, 1945, and Nagasaki (August 9, 1945) during World War II.
2. The initial explosions claimed the lives of tens of thousands of people, and many more would eventually die from radiation sickness.
3. The Manhattan Project, a top-secret, three-year, $2 billion project that was the largest scientific endeavor to that point, produced the bombs.
4. On July 16, 1945, at the Alamogordo Bombing Range, south of Albuquerque, New Mexico, the first atomic bomb was set off. After this successful test, the United States started transporting nuclear bomb parts to a staging site at Tinian in the Mariana Islands.
5. The B-29 bomber Enola Gay took off from Tinian on August 6, 1945, and bombarded Hiroshima using a uranium weapon kit.
6. Approximately 70,000 people died quickly, and thousands more died from radiation sickness a year later.
7. The B-29 Bockscar hovered over Kokura, its intended target, for some time on August 9, 1945, but the bombardier was unable to sight his Aimpoint due to thick cloud cover.
8. Then, Bockscar traveled to Nagasaki, where it dropped a plutonium implosion bomb that instantaneously killed 40,000 people, according to estimates.
9. Many thousands more people would later pass away from radiation-related causes, just as in Hiroshima.
10. One day after Nagasaki was bombed, on August 10, 1945, the Japanese government declared that it would submit to the terms of the Potsdam Declaration.

Resources related to Atomic Bombings of Hiroshima and Nagasaki:

• Nuclear Weapons by Country
• Warren Buffett Compares AI to Atom Bomb

Summary – Atomic Bombings of Hiroshima and Nagasaki

During World War II, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945. The bombings resulted in widespread destruction and claimed the lives of tens of thousands of people, with many more suffering from radiation-related illnesses. The Manhattan Project, a top-secret initiative, developed the atomic bombs. The bombings played a role in Japan’s surrender, bringing an end to the war. The immediate and long-term effects included devastating impacts on human health and the environment. Today, Hiroshima and Nagasaki stand as symbols of peace and resilience, with memorials advocating for nuclear disarmament. The survivors, known as hibakusha, continue to share their stories to promote peace and awareness about the consequences of nuclear warfare.

FAQs on Atomic Bombings of Hiroshima and Nagasaki

1. What were the atomic bombings of Hiroshima and Nagasaki?

The American bombing strikes on the Japanese cities of Hiroshima and Nagasaki during World War II were the first instances of atomic bombs being used in combat. While Fat Man, the bomb dropped on Nagasaki, was an implosion fission bomb using plutonium, Little Boy, the weapon dropped on Hiroshima, was a gun-assembly fission bomb using uranium.

2. Who was involved in the atomic bombings of Hiroshima and Nagasaki?

Edward Teller was one of the first scientists hired for the Manhattan Project, which was led by American physicist J. Robert Oppenheimer and developed atomic bombs for the US.

3. Why did the atomic bombings of Hiroshima and Nagasaki happen?

The United States decided to unleash atomic bombs on Japan for a variety of reasons. One factor was Japan’s resistance to unconditional surrender. Japan did not want to be captured by American forces because they wanted to keep their emperor and hold their own war trials. The Soviet Union is a further factor in why the United States dropped the atomic bombs, specifically the second one on Nagasaki. As agreed, upon by Joseph Stalin at the Tehran and Yalta conferences in 1943 and 1945, respectively, the Soviet Union declared war on Japan on August 8, 1945, two days after the Hiroshima attack.

4. What are the dates of Atomic Bombings of Hiroshima and Nagasaki?

On August 6, 1945, at 8:15 AM, the first atomic bomb, named “Little Boy,” was released from the B-29 bomber, Enola Gay, over Hiroshima. Three days later, on August 9, 1945, at 11:02 AM, the second atomic bomb, known as “Fat Man,” was deployed over Nagasaki from the Bockscar, another B-29 bomber.

5. Why did America bomb Hiroshima and Nagasaki?

Several factors led to the US decision to drop atomic bombs on Japan. Japan’s unwillingness to surrender unconditionally, their desire to retain their emperor, conduct their own war trials, and avoid US occupation were significant reasons behind this choice.

6. What were the effects of Atomic Bombings of Hiroshima and Nagasaki?

Atomic bombs cause devastating immediate and long-term effects, including instant destruction, fires, and radiation exposure. Immediate impacts include widespread damage, blast injuries, and thermal burns. Long-term effects encompass radiation sickness, cancer, and genetic mutations, leading to enduring health issues in survivors and environmental damage.

7. How is Hiroshima and Nagasaki today?

Today, Hiroshima and Nagasaki have transformed into thriving cities, symbolizing peace and resilience. They host memorials, museums, and peace parks honoring the victims and advocating for nuclear disarmament. Both cities have vibrant economies, modern infrastructure, and a strong commitment to education and cultural heritage.

8. Who are the survivors of Atomic Bombings of Hiroshima and Nagasaki?

The survivors of the atomic bombings in Hiroshima and Nagasaki are known as hibakusha. Many hibakusha have shared their stories to raise awareness about the horrors of nuclear warfare, advocate for peace, and support initiatives aimed at nuclear disarmament.