Timechanging

Timechanging is a broad term used to describe changes in the rate at which time is measured or experienced. In physics, timechanging describes phenomena that cause clocks to run faster or slower relative to a reference frame. Gravitational time dilation, predicted by general relativity, makes clocks tick more slowly in stronger gravitational fields. Special relativity shows time dilation due to relative motion. In cosmology, the expansion of the universe can alter the relationship between local time and cosmic time, and time-dependent fields can influence the evolution of physical systems.

In mathematics, a time change is a reparameterization of a process by a monotone increasing function of time. Formally, if X(t) is a stochastic or dynamical process, the time-changed process X(tau(t)) reflects a re-scheduling of its evolution. Time changes are central to subordination and to the study of stochastic differential equations with time-varying inputs.

In philosophy and cognitive science, timechanging refers to the subjective experience of time’s passage, which can be accelerated or slowed by attention, emotion, or aging. In technology, timechanging can include practical adjustments to timekeeping and synchronization, or policies like daylight saving time that alter the social clock.

Timechanging is thus not a single phenomenon but a family of related ideas about how time can be measured, experienced, or modeled to reflect varying rates of change in different contexts.