A cool paper (note: this is a link to a PDF) on how Superman got his powers, rejecting the Seigel theory that his strength came from Krypton’s higher gravitational force. This paper suggests that his powers came from a unified ability rather than a host.
In this paper we propose a new unified theory for the source of Superman’s powers; that is to say, all of Superman’s extraordinary powers are manifestation of one supernatural ability, rather than a host. It is our opinion that all of Superman’s recognized powers can be unified if His power is the ability to manipulate, from atomic to kilometer length scales, the inertia of His own and any matter with which He is in contact.
More on Superman: Icon vs. Superman, as told by Evan Narcisse and Superman as Clark Kent as Superman