Gravitational lensing causes some distant galaxies to appear brighter:
Australian researchers on Thursday found the optical effect called gravitational lensing is causing some distant galaxies to appear brighter than they really are.According to the study lead author, Professor Stuart Wyithe from University of Melbourne's School of Physics in Australia, the most distant galaxies were being viewed through a kind of cosmic hall of mirrors.
Weak gravitational lensing is a uniquely promising way to learn how much dark matter there is in the Universe and how its distribution has evolved since the distant past.