Firstly Happy New Year to all forum users.

 

I've just watched the film 'Superman Returns' (for the physics mistakes of course!) which was on over the holidays and noticed that when Superman carried the "kryptonite island" off into he space he gave it an almighty push and off went the island into space however Superman stayed where he was. Wouldn't Superman have been propelled backward with an equal force to that which he gave the island, or are we to assume that Superman has infinite inertia?

Many superheros are apparently endowed with variable inertia (or maybe the writers are endowed with super stupidity?)

 

This was written in 1970 or so.

He's faster than a speeding bullet. He's more powerful than a locomotive. He's able to leap tall buildings at a single bound. Why can't he get a girl?

 

At the ripe old age of thirty-one (*Superman first appeared in Action Comics, June 1938*), Kal-El (alias Superman, alias Clark Kent) is still unmarried. Almost certainly he is still a virgin. This is a serious matter. The species itself is in danger! ...

 

Story concluded at http://www.larryniven.org/stories/Man_of_Steel_Woman_of_Kleenex.shtml.

I guess that all depends on how he actually propels himself. Staying in place while throwing mass away from you is equivalent to moving yourself forward without throwing mass backward (which I'm assuming is the case - he doesn't seem to have any exhaust when he's flying around in space and whatnot). So he would just violate Newton's laws the same way he does whenever he flies.

While this can turn into a fun discussion, it ain't physics.

 

Moved to the "General discussion" section.

perhaps he emits a field that can allow him to use other objects at a distance to provide inertia(like charged particles being moved by magnetic fields) so he could use the earth or even the sun and the rest of the universe?

Maybe it simply appeared that he did not move backwards. Depends what you are comparing his size and position with.