Relativity
Albert Einstein
Albert Einstein (1879–1955) was a German-born theoretical physicist renowned for developing the theories of special and general relativity, fundamentally altering the understanding of space, time, and gravity. His work earned him the 1921 Nobel Prize in Physics for explaining the photoelectric effect and laid the groundwork for modern physics.
Black hole
A black hole is a region of spacetime where gravity is so intense that nothing—not even light—can escape. Predicted by general relativity and supported by extensive observations, black holes span a wide range of masses from stellar remnants to supermassive objects at galactic centers. Direct imaging, stellar dynamics, X-ray observations, and gravitational-wave detections provide multiple, independent lines of evidence for their existence.
General relativity
General relativity is a 1915 theory of gravitation developed by Albert Einstein that models gravity as the curvature of spacetime produced by energy and momentum. It underpins modern astrophysics and cosmology, predicting phenomena such as black holes, gravitational waves, gravitational lensing, and the expansion of the universe, and has been repeatedly confirmed by high-precision experiments and observations.