Gravitational lensing

 

The NASA Hubble telescope has captured probably one of the best images demonstrating the gravitational lensing effect.

What happens is that the light behind a supermassive object such as a cluster of galaxies or a black hole is bent by the force of gravity as it travels past that object giving a  repeated (due to the different paths to the viewer the light can take) and distorted (lensing arc)images.A mere seven billion light years away there a cluster of galaxies designated SDSS J1004+4112.Behind this cluster of galaxies at a distance of ten billion light years is a quasar(the brightest objects in the universe,which are found near the edge of the observable universe) .From the viewpoint of the Hubble telescope the light is bent so much that there are 5 images of the same quasar and several images of the same galaxy.Deflection of light by gravity was predicted by Einstiens Theory of general relativity

(Hat tip to http://hubblesite.org)

Black Holes -the award winning website

Just found this award winning website by an astronomer Roeland van der marel  regarding Black holes  -well worth a visit,check it out!  Here is  the link:http://hubblesite.org/discoveries/black_holes/