I would have put this in a comment but I dont have enough rep,
The Turtle which you link to in your question - planet sized turtle is actually a representation of the "discworld" - Now these are fantasy books written by Terry Pratchet which do include magic however IIRC while magic is not used to explain the existence of the discworld. in the books universe "magic" is more like science Quote below from Wikipedia
Magic is the principal force on the Discworld, and operates in a similar vein to real-world elemental forces such as gravity and electromagnetism. The Disc's "standing magical field" is essentially the local breakdown of reality which allows a flat planet on the back of a turtle to even exist. The force called "magic" is really just a function of the relative absence of reality in the local area, much in the same way that the absence of heat is described as "coldness". Magic warps reality in much the same way as the real universe's gravity warps its space-time. The act of performing magic is, essentially, telling the universe what you want it to be like, in terms it can't ignore. This is very draining to magic users, due to Discworld science's Law of Conservation of Reality (which states it takes the same effort to do something with magic as it would to do it mundanely). This is why most Discworld wizards store magic in a staff (with a knob on the end) which is a sort of capacitor for magical energy.
On the Discworld, where magic has more in common with particle physics than Houdini, high-level background magic (most likely a reference to real-world background radiation) occurs when a very powerful spell hits,