Universe Loaded With Natural Magnifying Glasses - 03/05/08 03:00 AM
"One of the best tools astronomers have to glimpse the distant universe is a technology that nature invented. Cosmic magnifying glasses called gravitational lenses help scientists zoom in on far-away scenes they could never spot otherwise."
http://www.space.com/scienceastronomy/080304-gravitational-lenses.html
http://www.space.com/scienceastronomy/080304-gravitational-lenses.html