Unveiling the Myths: Could Nuclear Bombs Ignite the Atmosphere?

The Birth of Nuclear Physics and Fission

During the infancy of nuclear physics, scientists recognized that large unstable atoms could trigger ongoing nuclear decay via fission, releasing massive energy. This groundbreaking discovery paved the way for the development of nuclear reactors and weapons, fundamentally changing the landscape of energy and warfare.

Fission involves splitting large radioactive atoms, while fusion involves combining light atoms under extreme conditions to release energy. While fission was harnessed relatively quickly, fusion required conditions so extreme that it naturally occurred only in stars. This distinction set the stage for the development of different types of nuclear technology.

The First Nuclear Reactors: Nuclear Piles

The first nuclear reactors were called "nuclear piles," built by simply piling enough large radioactive atoms together. These early reactors marked a significant milestone in harnessing nuclear energy, providing a controlled way to release the energy stored in atomic nuclei.

Detonating a nuclear bomb created unprecedented conditions on Earth, producing a blast wave hotter and more compressed than the atmosphere had ever encountered. This led to concerns about the potential consequences of such an explosion on a global scale.

The Fear of Atmospheric Fusion

The Earth's atmosphere contains significant amounts of light atoms like nitrogen, which led some to worry about potential fusion reactions. The fear was that the bomb's shock wave might reach conditions to fuse atmospheric nitrogen, potentially creating a self-sustaining fusion reaction.

Despite initial fears, scientists familiar with the required energies could dismiss the idea, but they still did the math to confirm it wasn't a real danger. Early calculations showed that the conditions and energy required for a self-sustaining atmospheric fusion reaction were not achievable.

The Manhattan Project and Fusion Concerns

The Manhattan Project scientists worried that an atomic bomb might cause atmospheric gases to undergo fusion due to high temperatures and pressures. If such fusion occurred, it could theoretically lead to a chain reaction encompassing the whole globe, but this was found to be highly unlikely.

Fission bombs can cause some fusion reactions nearby, but not enough to trigger a chain reaction. Fusion bombs work by focusing the energy of a fission bomb to create conditions for fusion, but this doesn't cause a runaway effect due to rapid vaporization.

Dispelling the Myths

The story of scientists fearing atmospheric ignition has been exaggerated over time; initial calculations quickly ruled it out as a possibility. Theoretical research initially left room for concern due to incomplete understanding of nuclear processes.

Scientists like Hans Bethe realized early on that they needed more understanding to rule out runaway fusion of atmospheric nitrogen. Once more understanding was gained, calculations showed it was 100% impossible for a nuclear bomb to ignite the atmosphere.

A Misinterpretation of Early Concerns

The idea that scientists were worried about atmospheric ignition is a misinterpretation; they simply did the math as part of their theoretical work. Early calculations using primitive equations suggested a worst-case scenario might ignite the atmosphere, but further advances quickly disproved this.

The notion of igniting the atmosphere was a "what if" theory, similar to fears about the LHC creating black holes, and was quickly shown to be impossible. This highlights the importance of thorough scientific research and the evolution of our understanding of nuclear processes.