| Field | Nuclear physics |
| Impact | Intense international tension and debate over the development and use of atomic energy and armaments |
| Subject | The study of atomic nuclei and their interactions |
| Timeline | Pioneered in the 18th century, ushering in the 'Nuclear Age' by the mid-20th century |
| Emergence | Much earlier than in our own timeline |
| Applications | Energy production • Nuclear weapons |
| Key Discoveries | Nuclear fission • Nuclear fusion |
Nuclear physics is the branch of physics that deals with the study of atomic nuclei and the interactions between them. It encompasses the processes of nuclear fission and nuclear fusion, which became the foundation of both nuclear power generation and nuclear weapons. The emergence of nuclear physics as a distinct scientific field occurred much earlier in this timeline compared to our own reality.
The concept of the atom as the fundamental building block of matter was first proposed in the 1700s by John Dalton, a British chemist and physicist. Over the following decades, Dalton's atomic theory was refined and expanded through the work of J.J. Thomson, Ernest Rutherford, and others. These pioneers established the basic structure of the atom, with a small, dense nucleus orbited by lightweight electrons.
In 1896, Henri Becquerel discovered the phenomenon of radioactivity, in which certain atomic nuclei spontaneously emit energetic particles or electromagnetic radiation. This paved the way for the groundbreaking work of Marie Curie and Pierre Curie, who identified several new radioactive elements and laid the foundations for the emerging field of nuclear physics.
The early to mid-20th century saw a rapid acceleration in the understanding and application of nuclear physics. In 1938, Otto Hahn, Fritz Strassmann, and Lise Meitner demonstrated the process of nuclear fission, in which heavy atomic nuclei split into lighter ones, releasing tremendous amounts of energy. Around the same time, Hans Bethe and others made major advances in the understanding of nuclear fusion, the combining of light nuclei to form heavier ones.
These breakthroughs quickly led to the development of nuclear weapons. In the late 1940s, nations such as the United Kingdom, Soviet Union, and France conducted their first successful atomic bomb tests, and a global nuclear arms race ensued. The devastating use of atomic bombs against Japan in 1950 ushered in the "Nuclear Age," in which the threat of nuclear war hung over international politics.
Concurrently with the military applications of nuclear technology, scientists and engineers also pursued the peaceful use of nuclear fission and fusion for power generation. The first nuclear reactor was built in 1942 in the United States, and commercial nuclear power plants soon followed in the 1950s and 1960s.
By the 1970s, nuclear power had become a major global energy source, providing a reliable, carbon-free alternative to fossil fuels. Countries like France, Japan, and India came to rely on nuclear plants for the majority of their electricity. The nuclear industry continued to evolve, with newer reactor designs offering improved safety, efficiency, and waste management.
The rapid spread of nuclear technology, both for weapons and energy, has been a source of ongoing geopolitical tension and public controversy. Many nations have sought to develop their own nuclear weapons programs, leading to concerns about nuclear proliferation and the risk of nuclear war. High-profile incidents like the Chernobyl disaster in 1986 have also raised safety and environmental concerns about nuclear power.
Proponents argue that nuclear energy is essential for meeting global energy demands and transitioning away from greenhouse gas-emitting fossil fuels. Critics, however, continue to voice concerns about radioactive waste, the risk of catastrophic accidents, and the potential for nuclear materials to be diverted for military use. These debates show no signs of resolution as the world grapples with the legacy and future of nuclear technology.
