What’s with all this love for the redone explosions? What’s that blast ring even supposed to be?
It’s called the Praxis Effect. According to Wikipedia, astronomer Phillip Plait says that the Special Edition version of the Death Star explosion in Star Wars is physically the most realistic, although the orientation of the shock wave and the trench are not at the correct angle. In Return of the Jedi Special Edition, the angles are correctly aligned.
Apparently the shock wave from the Alderaan explosion would radiate outward in a more spherical manner, but either way I think the new explosion effects look aesthetically better than the old ones.