# How did Fermi calculate the strength of first nuclear explosion?

• I
• bksree
In summary, Fermi used the "Fermi method" to calculate the strength of the first nuclear explosion. He considered factors such as the weight of uranium-235, energy released in a single fission, and the efficiency of the explosion. His calculation was surprisingly accurate, estimating the energy released at 20 kilotons, close to the actual value of 21 kilotons. This had a significant impact on the development of nuclear weapons and the understanding of nuclear energy. The Fermi method can also be used for other types of calculations, but its accuracy depends on the initial guesses and approximations made.

#### bksree

Hi
There is a story that Enrico Fermi calculated the intensity of the first nuclear test at Los Alamos from the distance moved by scraps of paper. Are there documented details of the calculation in any paper / book ?

TIA

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## 1. How did Fermi calculate the strength of the first nuclear explosion?

Fermi used a method known as the "Fermi method" or "Fermi estimation" to calculate the strength of the first nuclear explosion. This method involves making educated guesses and approximations based on known factors and using simple mathematical calculations to arrive at an estimate. In this case, Fermi estimated the number of fissions that occurred in the explosion and used this information to calculate the energy released.

## 2. What factors did Fermi consider in his calculation?

Fermi considered a few key factors in his calculation, including the weight of the uranium-235 used in the explosion, the amount of energy released in a single fission, and the efficiency of the explosion. He also took into account the size and shape of the explosion, as well as the distance from the explosion to the measuring instruments.

## 3. How accurate was Fermi's calculation?

Fermi's calculation was surprisingly accurate, given the simplicity of his method. He estimated that the explosion released around 20 kilotons of energy, which was very close to the actual value of around 21 kilotons. This demonstrates the effectiveness of the Fermi method for making estimations in the absence of precise data.

## 4. Did Fermi's calculation have any impact on the development of nuclear weapons?

Yes, Fermi's calculation was a key step in the development of nuclear weapons. It helped scientists understand the immense power and potential of nuclear energy and paved the way for further research and development in this field. Fermi's work also contributed to the development of the first atomic bomb, which was used in World War II.

## 5. Can the Fermi method be used for other types of calculations?

Yes, the Fermi method can be used for a wide range of estimations and calculations, not just in the field of nuclear energy. It is a useful tool for making quick and approximate calculations, especially when precise data is not available. However, it is important to note that the accuracy of the calculation will depend on the accuracy of the initial guesses and approximations made.

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