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.
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.
