(creationism, pseudoscience) The discredited theory that the speed of light has decreased over time, proposed by creationists in order to support the belief that the universe is a few thousand years old even though there are objects visible today that are billions of light years away (whereas a constant speed of light would indicate that the universe is billions of years old and so contradict this belief).

(physics) Radioactive decay by emitting an alpha particle.

plural of alpha decay

(computing, less common) Synonym of bit rot

(finance) A second-order measure of derivative price sensitivity, expressed as the instantaneous rate of change of delta with respect to time.

(historic preservation) State of preservation where no attempt is made to improve a ruin, but rather to keep it from deteriorating any further.

A hypothetical process whereby spacetime undergoes a phase transition (decays) into a lower-energy state.

(physics) A chained series of the products of nuclear decay of a particular isotope

A decrease where the rate of decrease is proportional to the amount remaining.

plural of exponential decay