I am a total layman in physics, but I've been trying to understand the various existing theories and after reading/watching lectures on QFT for months I still can't find an answer to a few very basic questions.
1) Are quantum fields a property/function of spacetime like color is a property of an object? Meaning they could not exist on their own and are "caused" by existence of spacetime? Or is it the other way around and quantum fields were created first (during the Big Bang) with spacetime emerging from their interactions?
2) In QFT particles are more or less treated as excitations of the underlying quantum fields, but do those excitations happen because something external is causing them (e.g. interaction with another field) or is it something intrinsic (that perhaps can be considered a sort-of property of the field)? + Edit from comments: I am not really asking where particles come from, but rather "how"; i.e. in QFT are they treated as resulting naturally from the existence of quantum fields, or does the theory ignore this point altogether, or does it specify an external source for the field becoming excited?
Thanks a lot in advance!