General relativity predicts twice as much bending in light as it passes near massive objects than Newton's theory predicts,<ref>http://www.mathpages.com/rr/s6-03/6-03.htm</ref> a phenomenon known as [[gravitational lens|gravitational lensing]]. A large number of instances of gravitational lensing have been observed, and it is now a standard astronomical tool.<ref> http://imagine.gsfc.nasa.gov/docs/features/news/grav_lens.html</ref> <ref> http://astro.berkeley.edu/~jcohn/lens.html</ref> <ref> http://www.iam.ubc.ca/~newbury/lenses/glgallery.html</ref> | General relativity predicts twice as much bending in light as it passes near massive objects than Newton's theory predicts,<ref>http://www.mathpages.com/rr/s6-03/6-03.htm</ref> a phenomenon known as [[gravitational lens|gravitational lensing]]. A large number of instances of gravitational lensing have been observed, and it is now a standard astronomical tool.<ref> http://imagine.gsfc.nasa.gov/docs/features/news/grav_lens.html</ref> <ref> http://astro.berkeley.edu/~jcohn/lens.html</ref> <ref> http://www.iam.ubc.ca/~newbury/lenses/glgallery.html</ref> |