Gravitational Lensing

Mass bending light into arcs, rings, and multiple images — Einstein’s telescope made of spacetime.

Core Principles & Analysis

• Eddington’s 1919 eclipse measurement of starlight bending made Einstein a household name.
• Lensing maps dark matter: the Bullet Cluster shows mass separated from its gas.
• Perfect alignments draw Einstein rings; microlensing blips have revealed exoplanets.