relativistic

Relativistic describes anything related to the theory of relativity, particularly Einstein's special and general relativity. In physics, relativistic effects arise when objects move at substantial fractions of the speed of light or when strong gravitational fields influence spacetime. The term contrasts with nonrelativistic models that assume absolute time and space and ignore such effects.

Special relativity, formulated by Albert Einstein in 1905, establishes the constancy of the speed of light in all inertial frames, leading to time dilation, length contraction, and the relativity of simultaneity. It also introduces the equivalence of mass and energy, encapsulated in E=mc^2, and provides the Lorentz transformations that relate observers in different inertial frames. General relativity, completed in 1915, extends these ideas to accelerated motion and gravitation by describing gravity as the curvature of spacetime caused by mass and energy. Predictions include gravitational time dilation, light deflection by mass, and the expansion of the universe.

Relativistic physics is essential in particle physics and astrophysics. In particle accelerators, particles reach speeds where relativistic dynamics dominate; in astronomy and cosmology, relativistic effects influence the behavior of compact objects, jets, and gravitational waves. The term also appears in relativistic quantum theories, where the principles of relativity are combined with quantum mechanics.

In practical terms, relativistic corrections are routinely applied in technologies such as global positioning systems, which rely on precise timekeeping affected by both special and general relativistic effects. The study of relativity remains a central framework for understanding space, time, matter, and energy.