7 The Nuclear Bomb

Jacob Marasco

7.1 Introduction

Keywords

  • Radiation: Energy that comes from a source and travels through space at the speed of light and can damage the DNA in our cells.
  • Isotopes: Two or more types of atoms that have the same atomic number and position in the periodic table.
  • Manhattan Project: Research and development undertaking during World War II that produced the first nuclear weapons.
  • Trinity Test: The code name of the first detonation of a nuclear weapon.
  • Hiroshima: A city that is located on Japan’s Honshu Island and on August 6, 1945, it was the sight of the first Nuclear bomb dropped on a city during war.
  • Nagasaki: A city that is located on the northwest coast of the island of Kyushu. On August 9, 1945, just three days after the Hiroshima bombing, Nagasaki would be bombed as well.

 

Learning Objectives

By the end of this chapter, students should be able to:

  • Comprehend the true dangers of radiation and the nuclear bomb
  • Understand why the Manhattan Project began
  • Differentiate between Hiroshima and Nagasaki
  • Understand why those who created the bomb were scared of it.
  • Tell what date the first bomb was made and tested.

 

It is a normal day in the city. Birds are chirping, and everyone is going through their regular routine. Out of nowhere, a blinding light followed by a blast destroys everything in sight. The surrounding areas are covered in radiation, and every living creature within a few miles is dead. This is the nuclear bomb, and this is what the citizens of Hiroshima and Nagasaki experienced at the end of World War ll.

The first atomic bomb, or nuclear bomb, was invented on July 16, 1945, by ​​J. Robert Oppenheimer during the Manhattan Project. The Manhattan Project was a research and development operation that began at the start of World War II that produced the first nuclear weapons. The project was led by the United States and had the support of the United Kingdom and Canada. The Manhattan Project was initially created because there was a fear that Nazi Germany had been building these types of weapons since the 1930s.

7.2 What is a Nuclear bomb?

Key Takeaways

  • Learning how nuclear bombs worked
  • Compare the differences between different atomic bombs.

 

Also known as the most powerful weapon on earth, the nuclear bomb has only been used in war twice; however, the consequences it brings to the environment and to the population are unmeasurable. There are many questions as to what a nuclear bomb is and all of the different types of variations there may be to how it works.

How it works:

In order for the nuclear bomb to work, it has to start either an uncontrolled or controlled fusion. This usually occurs when some sort of chemical explosive force a uranium or plutonium core to implode to critical mass. This means that the atoms are so close together that if a neutron ejected from an atom, it would cause the rest to do the same, and this would cause a nuclear reaction and, thus, an explosion.

Thermonuclear bombs or Hydrogen (H) bombs:

The most common type of nuclear bombs used today is thermonuclear bombs, also known as Hydrogen bombs. Thermonuclear bombs get their power from an uncontrolled, self-sustaining chain reaction. In this reaction, isotopes of hydrogen combine under extremely high temperatures to form helium and this, in turn, creates a process known as nuclear fusion. These bombs are known as the second generation of nuclear weapons, and those that were researched and developed in World War ll were not nearly as powerful. These bombs are known as uranium and plutonium bombs.

Urianium vs Plutonium:

The destructive power of the Uranium bomb was first represented in the bombing of Hiroshima. The bomb, also known as little boy, consisted of 60 kg of U-235 at its core. What does this mean? Around 99% of all Uranium has an atomic weight of 238; however, 235 is the number that requires the least initial mass prior to the detonation.

The use of the Plutonium bomb was represented in the bombing of Nagasaki. The bomb, also known as Fat man, consisted of 10 kg of Pu-239 at its core. Unlike Uranium, almost every combination of Plutonium isotopes can be used to make a nuclear weapon. However, Pu- 238 and Pu-239 are the most effective.

For the construction of the bomb, around 52 kg of Uranium is needed for the construction; however, only 8 kg of Plutonium is needed. This means that Plutonium is much stronger and is used the most in the making of nuclear weapons.

7.3 The Manhattan Project

Key Takeaways

  • Why The Manhattan Project started.
  • What they accomplished during the Manhattan Project.

Early in 1939, the world’s scientific community discovered that German physicists had learned how to make an atomic bomb. Fearing the Axis powers and the type of weaponry they had, president Franklin D. Roosevelt decided to take the world’s leading scientific minds, as well as the U.S. military, and make their own weapon, one that they could defend themselves with. This is the start of the Manhattan Project.

Figure 7.1 Reunion of atomic scientists on the 4th Anniversary (1946) of the first controlled nuclear fission chain reaction, pictured in front of Bernard A. Eckhart Hall at the University of Chicago.“Manhattan Project” by The university of Chicago is in the Public Domain

The Manhattan Project officially began on August 13, 1942, and didn’t end until August of 1945. Contrary to other beliefs, the project never occurred under New York City; instead, it Manhattan Projectwas located in Los Alamos, New Mexico. In 1939, many scientists who were escaping fascism in Europe eventually fled to the United States. They, along with other  U.S. intelligence operatives, reported that the Germans are already working on developing nuclear weapons. Fearing the safety of his country and the rest of the world, President Franklin D. Roosevelt gave the go-ahead to begin the Manhattan Project. During this time, the project included scientists such as J. Robert Oppenheimer and Edward Teller. They and many other scientists created and tested the Worlds first nuclear bomb on July 16, 1945, also known as the Trinity Test. The test site was located in the desert near Alamogordo, New Mexico. When the bomb was dropped, none of the scientists were ready for what they were about to witness. There was a blinding flash that was visible from up to 200 miles away and a mushroom cloud that reached up to 40,000 feet. The aftershock from the blast even blew out windows from houses that were further than 100 miles away. Soon, word reached President Truman that the test was successful and the World had now entered the age of nuclear technology.

 

Figure 7.2 An artist’s rendition of Chicago Pile-1

“The Manhattan Project” by Atomic Heritage Foundation is in the Public Domain

Scientists working under Oppenheimer’s supervision had developed two different types of nuclear bombs. One was a uranium-based bomb called “the Little Boy,” and the other was a plutonium-based weapon called “the Fat Man.” The difference between the two was not just the size (The fat man was bigger and more powerful), and the Fat man was also tested at Trinity. With the completion of both designs, they would soon become the most important part of ending the war in the Pacific theater.

7.4 Hiroshima and Nagasaki

Key Takeaways

  • Why the United States bombed Hiroshima and Nagasaki
  • Consequences of the bombings.

Despite the fact that many people believe the bombing of Hiroshima and Nagasaki was unethical and barbaric, it was the only way to prevent millions of deaths for both the Allies and the Japanese.

Reasons for the bombing:

After the events of Pearl Harbor on December 7, 1941, and the following day on December 8th, The United States declared war on the empire of Japan. The plan was to capture many small islands in the South Pacific that Japan had already conquered. These small islands held vital airstrips that would be needed for an all-out invasion of mainland Japan. The invasion, also known as “Operation Downfall,” was a big risk for the United States. If they had done the same thing as they did in the smaller islands, the casualty rate for both civilians and soldiers of both Japan and the United States would reach the millions. President Truman and other U.S Generals knew that Japan would rather die than surrender, and In order to prevent this all-out massacre, they decided to drop two nuclear bombs on two different cities, Hiroshima and Nagasaki.

Hiroshima:

Hiroshima is a city with (at the time) a population of around 350,000 and is located on Japan’s Honshu Island. On August 6, 1945, at around 8:15 in the morning, an allied  Boeing B-29 Superfortress bomber dropped the first ever nuclear bomb codenamed “little boy” onto the city of Hiroshima. The damage was much more severe than anyone could have expected. The temperatures at the epicenter of the explosion reaches as high as 12,600 degrees Fahrenheit. The initial explosion killed around 80,000-100,000 people immediately, and thousands more would eventually die in the next few weeks from the radiation.  Two-thirds of the city area was completely destroyed, and “Nuclear shadows” remained of the people who got caught in the intense thermal radiation.

Figure 7.3 A mushroom cloud rises moments after the atomic bomb was dropped on the city of Nagasaki on Aug. 9, 1945, three days after the U.S. dropped an atomic bomb on Hiroshima.     “Atomic cloud” by OLIVIA B. WAXMAN is in the Public Domain

Nagasaki:

Nagasaki is a city with (at the time) a population of around 255,000 and was located on the northwest coast of the island of Kyushu. On August 9, 1945, just three days after the Hiroshima bombing, another Boeing B-29 dropped the second-ever nuclear bomb, codenamed “fat man,” onto the city at around 11 in the morning. Fat Man detonated at an altitude of about 1,650 feet over the city of Nagasaki. Fat man was also close to a thousand pounds heavier than little boy and around 40 percent more powerful. The bomb was dropped above many different factories and other military facilities. Thousands of civilians were already evacuated at the time; however, the impact was just as devastating. Everything in the middle of the blast was completely annihilated and more than 14,000 homes vanished from existence. Those who were close to the blast vaporized just like they had in Hiroshima. Around 40,000 people died on the first day, and around 30,000 would die by the end of the year. These two instances were the only time in history when a nuclear bomb was used in war.

7.5 The Evolution

Key Takeaways

  • The advancement in the Nuclear bomb since WWII.
  • Different types of Nuclear weapons.

After the bombings of Hiroshima and Nagasaki, the world now knows the catastrophic consequences of the nuclear bomb, however that didn’t stop many countries from continuing this research. Following WWll, there was an immediate arms race to build these dominant weapons, and quickly. Neither country wanted to sit around and wait while their rivals build bombs that could completely wipe them off the grid. This eventually led to the Cuban missile crisis and the cold war. Today, there are many different and much more powerful nuclear bombs. Some can be fired from submarines, and others can be guided rockets that can fly across the world and directly hit their targets. This is not the end, either. There is still more research and practice being done that would ensure complete dominance, and no country will stop until they achieve that.

Living through the Hiroshima and Nagasaki Bombings.

Taeko Teramae

On the day of the bombing, Hiroshima survivor Taeko Teramae was one of the thousands of students mobilized to help fill Hiroshima’s wartime labor shortages. Assigned to the city’s Telephone Bureau, she was located on the building’s second floor when she heard a “tremendous noise.” The walls quickly collapsed on themselves and all of the lights went out. “I began to choke on the consequent smoke— poisonous gas, it seemed like—and vomited uncontrollably,” wrote Teramae in a 1985 article for Heiwa Bunka magazine.

Teramae managed to escape by jumping out of a second-story window and climbing down a telephone pole. But when she tried to cross the Kyobashi River to safety, she found its only bridge in flames and the city she’d left behind “engulfed in a sea of fire.”

Chapter Summary:

In today’s society, our technology is so powerful, and nuclear weapons are much easier to obtain that any detonation of a nuclear bomb would cause an automatic World War 3. This, in turn, would completely wipe out any and all populations across the world, and yet, countries still threaten each other with this power. They believe if their rivals have these weapons, then it is only right to defend themselves in the same way. This, in turn, creates a never-ending cycle until something terrible happens. The bombs that were first invented in the 1940s may not be nearly as powerful, but they set humanity into a completely new stage of life, warfare, and possibly survival.

Review Questions

Food For Thought

Do you believe that dropping the bomb on Hiroshima and Nagasaki was a good idea?

Do you believe that we should continue researching nuclear weapons and making better ones?

Do you believe nuclear bombs should be banned?

References:

Bomb decision handouts – Harry S. Truman. www.trumanlibrary.gov. (n.d.). Retrieved November 22, 2022, from https://www.trumanlibrary.gov/public/BombDecision_Handouts.pdf

Encyclopædia Britannica, inc. (n.d.). Atomic bombings of Hiroshima and Nagasaki. Encyclopædia Britannica. Retrieved November 21, 2022, from https://www.britannica.com/event/atomic-bombings-of-Hiroshima-and-Nagasaki

Encyclopædia Britannica, inc. (n.d.). Manhattan project. Encyclopædia Britannica. Retrieved November 21, 2022, from https://www.britannica.com/event/Manhattan-Project

Farrell, J. (n.d.). Making (Common) Sense of the Bomb in the First Nuclear War. Clemson University Libraries – Login. Retrieved November 9, 2022, from https://www-jstor-org.libpr oxy.clemson.edu/stable/4 0642724?sid=primo&seq =5#metadata_info_tab_contents

History.com Editors. (2017, July 26). Manhattan project. History.com. Retrieved November 9, 2022, from https://www.history.com /topics/world-war-ii/themanhattan-project

History.com Editors. (2017, September 6). Atomic Bomb history. History.com. Retrieved November 9, 2022, from https://www.history.com /topics/world-war-ii/ato mic-bomb-history

Letter from the Scientific Panel of the Interim Committee. Atomic Heritage Foundation. (n.d.). Retrieved November 9, 2022, from https://www.atomicherit age.org/key-documents /letter-scientific-panel-i nterim-committee

Meilan, S. (2020, August 5). Nine harrowing eyewitness accounts of the bombings of Hiroshima and Nagasaki. Smithsonian.com. Retrieved November 9, 2022, from https://www.smithsonia nmag.com/history/nineharrowing-eyewitnessaccounts-bombings-hiroshima-and-nagasaki-1 80975480/

Solly, M. (2020, August 5). Nine harrowing eyewitness accounts of the bombings of Hiroshima and Nagasaki. Smithsonian.com. Retrieved December 5, 2022, from https://www.smithsonianmag.com/history/nine-harrowing-eyewitness-accounts-bombings-hiroshima-and-nagasaki-180975480/

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From G.I. to Z: A Generational Guide to Technology Copyright © by Jacob Marasco is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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