[slice of heaven]

Originally Posted by Mike Boggan

Can I take you back to Einstien's gravitational lensing?
If light is travelling in all directions, why do we see Einstien's Cross and not a halo effect around the star?
Surely the gravitational effect would affect light from every direction, not just from 4 points. Result: a halo.

Mike

http://spiff.rit.edu/classes/phys240...grav_lens.html
Explains it fairly well