Time Hypothesis

Across the major branches of physics, the treatment of time varies significantly, suggesting that time may not be a fundamental, universal quantity. In classical mechanics, time is absolute and external: a uniform parameter against which motion is measured. In special and general relativity, time becomes relative—dilated by velocity or gravitational fields—yet remains a coordinate of a fixed space-time manifold. In quantum mechanics, time is typically treated as a classical parameter, not an operator, and its role in phenomena such as measurement, decoherence, and entanglement is often external and poorly defined.