"Yet space, time, and causality cannot be proven to be empirically real themselves". This is akin to mathematical axioms that escape proof within a formal system. Of course one can debate whether the analogy applies for space and time as it does in arithmetic, but this is beside the point. My point was that Schopenhauer's quote was not even remotely close to being naive, especially considering when it was said (i.e. years before Godel and others proved similar conclusions).
No it isn't. Unless you understand quantum gravity better than anyone else does, there is absolutely no connection whatsoever between the possible empirical reality of spacetime and causality, and Godel's description of mathematical incompleteness.
Spacetime is observable, not axiomatic. The whole point of theories like loop quantum gravity - and one of the main reasons that the string theories are poor relations - is that LQG theories take an explicit interest in possible mechanisms that explain the observed properties of spacetime and causality.
In the jargon, they are 'background independent.'
For example, take a look at Causal Dynamical Triangulation:
The naivete is that a sophisticated philosopher would understand this, and at the very least not push forward a philosophical argument that really hinges on connotations of words instead of logical/philosophical pillars.
Anyways if the statement didnt have a famous philosophers name attached to it i doubt it would have gotten any response, its a pretty baseline/naive reaction to a complex scientific idea.
Yet, realism is in a completely different level. You can not reason about it using mathematical constructs. (Too bad that's the only tool we have.)
You may be saying this has already been done elsewhere but without references u can't just throw this out there as a given.
To ask what's before beginning of time is akin to asking what is the point more southern point of earth than the Southern pole. Answer is there is none.
In a place where space doesn't exist you wouldn't notice it not existing. Probably because you wouldn't exist as well.