100 Quiet Wonders of the Night Sky

... grounding us in cycles larger than ourselves. Gravity bends light,

creating cosmic lenses. Einstein's theory of general relativity revealed that massive

objects, like stars and galaxies, warp the fabric of spacetime. Light traveling

near them follows this curvature, bending like a ray passing through a lens.

This effect, called gravitational lensing, allows astronomers to see objects that

would otherwise be hidden. Sometimes a distant galaxy is magnified and distorted into

arcs or rings by a massive cluster in the foreground. Other times, a star is briefly

brightened when another star passes in front of it, bending and focusing the light.