decaying

Decaying is the process of becoming less intact or functional over time. In everyday use, it most commonly refers to the breakdown of organic matter, but it also appears in physics and materials science as the decline of unstable systems and structures.

Biological decay, or decomposition, is carried out by a microbial community and detritivores that metabolize tissues, releasing nutrients back into the environment. The process proceeds through stages—from initial conditioning of the material to bloating, active decay, advanced decay, and dry remains. Rate depends on temperature, moisture, oxygen availability, pH, and the presence of scavengers. Byproducts include gases, liquids, and organic compounds that influence soil chemistry and ecosystem nutrient cycling. Decay is a central component of ecological nutrient recycling and energy flow.

In physics, decay describes the spontaneous transformation of an unstable nucleus or particle into more stable forms. Radioactive decay is characterized by a half-life and follows an exponential law. Energy and particles may be emitted, and the process is random at the level of individual atoms but predictable statistically for large samples. Decay processes underpin dating techniques, medical imaging, and various applications in science and industry.

Materials decay encompasses corrosion, oxidation, weathering, and structural fatigue. Exposure to heat, moisture, chemicals, and mechanical stress drives deterioration. Preventive measures include protective coatings, environmental controls, proper design, and maintenance to extend the life of structures and components.

Metaphorically, decaying is used to describe the decline of systems, buildings, or social institutions, such as urban decay or institutional decay, reflecting gradual loss of function or vitality.