User blog comment:20thCentFopp/Is Marvel’s Thor a Better Written Superman?/@comment-4652104-20131212154417

I agree that Superman breaks virtually every known law of physics, but Thor's mode of flight is equally impossible. Thankfully it was dropped later.

Here's a podcast on the physics of superheroes, you may enjoy this: http://www.startalkradio.net/show/the-physics-of-superheroes/

The comic "Powers" offers an interesting vision of an ageing superman (it's part of vol. 1, but I don't recall the exact issues)