expansion of the universe

Albert Einstein, general theory of relativity, gravitational lensing, Fritz Zwicky, Hubble constant, expansion of the universe, Sjur Refsdal, Orest Chwolson, Arthur Eddington, active galactic nuclei, black hole, Type Ia supernovae, Palomar Transient Factory,

How Astronomers Use Ginormous Natural Lenses to Study Distant Space Explosions

Review: Lessons From Our Exploration of the Cosmos

Why Two Conflicting Measurements of the Universe’s Expansion Have Scientists Excited