Definition
The splitting of a heavy atomic nucleus (such as uranium or plutonium) into two or more lighter nuclei, releasing a large amount of energy along with neutrons and radiation. Fission is the process used in nuclear reactors and atomic weapons.
Plain English
Fission is when the center of a heavy atom is split apart, which releases a large burst of energy.
Context Anchor
Seen in aviation when reading about nuclear power, radioactive material, nuclear emergency information, or radiation hazards near an affected area.
Derivation
From the Latin fissio, meaning 'a splitting or cleaving.' The word describes exactly what happens at the atomic level — something heavy is split into smaller pieces.
Why Pilots Care
Fission is not part of normal aircraft operation, but pilots may need to understand the word in safety notices, hazardous-material information, or emergency guidance involving radiation.
Grounding Statement
In fission, the change happens inside the atom itself, which is why it can release far more energy than an ordinary fire or chemical reaction.
Intuition Check
Do not confuse fission with fusion. Fission means splitting atoms apart; fusion means joining atomic centers together.
Example Sentence 1
The energy released by nuclear fission is what powers a reactor's steam turbines.
Example Sentence 2
The fission process releases energy that could be harnessed in specialized propulsion systems.