Bryce5 with gamma correction in PSP7. Maybe it isn't abstract, dunno. Anyway I found these cool optical illusions where everything seems to move in a slightly disturbing way and decided to see if I could make one in Bryce - this is my attempt.
Not only do the spheres rotate, but you can do another cool thing with this illusion! Try crossing your eyes then focusing on the center circle of any sphere. Now everything looks black & white, with no blue or yellow! Very cool!