The rules of the real world aren't just relaxed for Superman, but every extraordinary character, and you know it. Most things are fine if they are done with a manner of verisimilitude. It's like how a magician doesn't make their tricks seem easy to perform, they'll often show signs of strain, because at the end of the day, they don't want you to think it's a trick, they want you to be tricked. Examples of verisimilitude, though breaking actual laws of physics: Batman's microwave emitter Batman's fusion generator Batman's cape Batman's grapnel (at least how he uses it) Batman's armour (given the thickness of the plates) Batman kicking through a brick and mortar pillar Bane punching through a concrete pillar Spider-Man's super-strength Spider-Man's wall-crawling ability Thor's super-strength Mjolnir (being unliftable) Hulk catching Stark with no damage to Stark In fact, all damage done to Stark Vibranium The Tesseract When the Hulk pulls on a Leviathan's face, and the Leviathan is pulled to the ground. The Hulk was pulling the Levithan against itself, it shouldn't have moved. There's more, but as long as you make the regular Joe's believe, it doesn't matter.