Oh please, let's not get all sciency here. This is Superman... I'm sure we could go into all manner of science talk about how it's not possible for a man to lift up a jumbo jet or something.
Enjoy the surreal triumphant return of a childhood hero and appreciate the artists who did the special FX.
No swear words, no nudity, no innuendo, no gangster posturing, street racin' or depravity. Just good old romance and comic book heroism.
And as for Krypton... it was only described as "a graveyard" - no mention as to the planet's integrity. We did see an impressive shattered world in the opening sequence though. And what's to stop wormholes and time-travel coming into things?
I think possibly the idea of the film is to pluck up people's spirits... there were a number of tangible similiarities between the space shuttle disaster, 9/11 and the film.