Corrected entry: In the scene when Lex's commission is increased and he decides to take control of the business, when he holds up the bill for nuclear man to burn if you watch carefully you can see that as soon as it catches fire Lex's hand and the bill both disappear.
Corrected entry: Given the subway's crowded, there's no reason Superman couldn't fly the hurt engineer to the hospital.
Correction: There were already paramedics and authorities there to take care of the engineer. It'd be pointless to fly him to a hospital when he's already being helped.
Corrected entry: When Superman plants the evil super guy on the far side of the moon in the elevator, the sun eventually shines through to revive him. The problem is that the moon spins on an axis that prevents the dark side from ever seeing the sun. This is why we only ever see a single view of the moon.
Correction: We only see one side of the moon because the moon always has the same side turned towards us. The sun however shines on all sides. When it is full moon it is dark on the other side, when it is new moon, the "dark" side of the moon is fully lit.
Corrected entry: In the health club, a barbell is handed to Clark Kent. In keeping with his "weakling" persona, Clark lurches forward from the weight of the barbell and falls on his face. In the next scene, he is getting up from his BACK.
Correction: He's handed the weight, he falls forward and out of frame, lets go of the weight when he's out of frame, falls back, then enters into the frame again.
Corrected entry: When Superman is on the moon and straightens the American flag and Nuclear-Man comes from behind and knocks Superman and the flag down, the next shot shows both men fighting on the ground with the sun shining behind them. If that is the only source of light in the solar system, where is the light coming from in front of them?
Correction: From the moon's surface. It's bright. That's why you can see the moon from earth. The same way you can see a person's face even if the sun is behind him.
Corrected entry: Since the super-powered villan is a clone of Superman, shouldn't he look like Superman? Lex Luthor never mentioned using anyone else's DNA to create the super villan. The movie makers could have created another image of Christopher Reeve. It was done in the previous Superman movie when Clark Kent is battling with the bad Superman in the auto junk yard.
Correction: Lex used some of his own DNA and mixed it in with supermans. This explains the change of look and why Lex Luthor is the voice for the clone.
Corrected entry: When Nuclear-Man freezes Superman in space, how come it's such a uniquely designed block of ice Superman is encased in? And besides, if Nuclear-Man was created via the sun, how come he can freeze things? He must have been chewing Winterfresh gum at the time.
Corrected entry: The capes of both Supermen ruffle when they are on the moon - it must be windy up there.
Correction: This is not a mistake. The mistake is in thinking that there has to be air or wind present for the capes to "ruffle". The energy to cause the motion in the capes comes from the movement of the bodies they are attached to. Footage of the moonwalks show the American flag appearing to "ruffle" while being planted by Armstrong. It's the exact same effect.
Corrected entry: In the museum, Lex Luthor snips a piece of Superman's hair, which is displayed suspending a 1000 lbs weight. If the hair is strong enough to hold a weight that heavy, how can Lex cut it with an average hedge clipper?
Correction: Look closely - there are little white things that are attached at bottom and top, keeping the hair in place. He cuts those and pulls the hair out.
Correction: Pause the movie and advance frame-by-frame. When the bill is set on fire, you can see Lex quickly lower his hand.