Gravitational Lenses

Part of Hall of the Universe.

Gravitational lenses_HERO AMNH/D. Finnin

General relativity describes how space is curved by mass. Around high concentrations of mass, the curvature of space becomes strong enough to make space behave like a lens.

Some clusters of galaxies act as gravitational lenses, magnifying and distorting the images of background galaxies.

An ordinary view of galaxies is transformed …

… just as if we were looking at it through a piece of curved glass.