Corrected entry: In the scene where Superman lifts up the sunken yacht in order to save Lois and her family it shows when he lets go that he was holding that entire half of the ship completely out of the water with one hand. This is impossible, assuming that he was able to lift that much that spot on the ship could not hold that much weight without ripping away from the rest of the ship.
Corrected entry: When Luthor is showing Lois maps of the new continent he intends to create, the final map initially shows a large 'state' marked out in the centre of the star-shaped island, with several other territories making up the points of the star. The shot changes as Luthor heads above deck, and we see the map behind him, but now the borders of the territories have changed and the central state takes up less space.
Corrected entry: As Superman is shown flying literally 3 feet or so above the surface of the ocean, the water is not affected at all. It was established in the beginning of the scene that he was exceeding the speed of sound, and anything flying at that speed that close to the surface of the water would produce a wave/rooster tail of at least 20 feet or so.
Corrected entry: When the bank-robber with the Gatling gun shoots Superman in the eye from close range with his pistol, the bullet flattens and deforms upon impact with Superman's eye, and then falls lazily to the ground directly at their feet. The bad guy even watches as the bullet falls. This shouldn't happen: The bullet should have ricocheted off of Superman's eye with a lot of latent energy since none of it was dissipated upon impact. The bullet would have violently ricocheted away from the area just like the hundreds of bullets fired at Superman from the machine gun did. Also there is no way that any human could react fast enough to actually watch a ricocheting bullet from that short distance.
Corrected entry: An electromagnetic pulse (EMP), such as those caused by the crystal reactions, affects unshielded electronic equipment because it induces a voltage surge in their components, effectively 'frying' them. All affected devices are damaged permanently and would never work again, not even after a few minutes, as they portrayed to do so here.
Corrected entry: On Lex Luthor's Russian-made missile launcher, the second button from the left is labelled "otkaz", which is presumably intended to mean "abort". The correct word would be "otmena". While "otkaz" is a general synonym, in a technological context it means, rather unfortunately, "equipment failure".
Corrected entry: Superman's strength and other superpowers seem to oscillate a lot between scenes in the movie, and for no good reason. Towards the end of "Superman Returns", he is shown lifting an entire landmass out of the ocean, and pushing it into outer space, all while being exposed to Kryptonite. He is also capable of showing up anywhere in the world nearly instantly, as a reporter comments. Yet in one of the first action scenes, he struggles trying to catch up with a plummeting airplane, and has a hard time slowing it down, managing it just before the plane hits the ground. This should be a trivial task for someone of his abilities, yet no in-movie explanation is given for such poor performance. Of course, the real reason is obvious - the plot requires that Superman saves the day just in the nick of time, to create cinematic tension and resolution.
Corrected entry: In the scene where Superman is lifting the newly crated island to space, he stops pushing it, and the island continues into space. Then suddenly, as he looses weight and mass (because the island is gone), Superman falls down towards earth. If he does, so should the island. Alternatively, if the island continues into space, so should Superman.
Corrected entry: Why does gravity seem to be either on or off while on the airplane? Just leaving the atmosphere would not suddenly cause things to start floating as they do.
Corrected entry: In the plane sequence the whole weightlessness is wrong. When the plane is high in the atmosphere the people inside it will still be under the effect of gravity (when the film shows no gravity) and then as it falls you would get effective weightlessness as everything falls at the same speed (yet the film has the gravity switched back on).
Corrected entry: Lex states that the crystals just need water to grow meaning that the new land must be somehow made from water molecules. In that case the land is effectively solidified water, lifted out of the ocean, meaning the worldwide water levels would drop, not rise. None of the flooding could ever happen.