Friday, December 19, 2014

Dark Matters

Recently I've been reading about proposals to explain the "Dark Matter" phenomenon by modifying the law of gravity, as opposed to invoking some unseen form of matter. The original proposal along those lines was MOND: Modified Newtonian Dynamics, invented by Israeli physicist Mordehai Milgrom. Modified Newtonian Dynamics: A Review is an excellent summary of the observational evidence and theories as of late 2011. It mentioned some mind-blowing gravitational lensing phenomena some of which have resulted in spectacular images.

Einstein Cross

Einstein Ring



Cluster CL0024+17 
The blue streaks near the center of CL0024+17 are not part of the cluster itself, they are images of galaxies much further way which have been magnified and distorted by the gravitational lensing effects of this massive cluster.