The question I am going to ask here lies on a thin line between quantum gravity research and philosophy, but I'd thought I'd post it in this forum here to get insights in line with the research on quantum gravity. Basically, in quantum gravity approaches, LQG is background-independent but string theory is background-dependent, so what implications do these two different approaches have for the birth of spacetime? Do they point to space and time always existing (as suggested in the Pre-Big Bang scenario of Veneziano et al.) or that spacetime (at least the 4D spactime of our Universe) arose during the Big Bang (as suggested by GR)? Could it be that the notion of space and time as can be measured is different from a more 'philosophical' notion of space and time as infinite and eternal concepts? I'd appreciate anybody's insights.