Yes, space is just the structural quality of a fundamental field. But light and matter require the existence of this fundamental field in the first place. Not to be confused with an absolute space and time of Newton.
Unfortunately, I don't follow the logic. I agree matter requires space to exist. But I don't see any fundamental reason why energy/forces must have space/time for existence. It seems there would be a major logic contradiction if energy/force existed within time. I don't see how energy/forces can experience spacetime at the speed of light. Time ceases at the speed of light. If they exist within space/time, they would have to experience spacetime which is a contradiction. Could you explain further the specific rationale for the requirement of spacetime by light/forces.
Gravity is the curvature of spacetime. No spacetime, no gravity.
I am curious whether this is an assumption or a fact. At the moment, I believe we can measure the effects but we haven't been able to locate or determine the exact origin of gravitons. Without locating gravitons, how can we be certain that the curvature of spacetime is the origin of gravitons. Could it be the reverse? Gravity forces as the origin of spacetime? Would we not have the same measureable results?
To me, the major questions are raised by the implications of light and forces existing at the speed of light. Considering time does not exist, how can either light or forces experience the time of spacetime? Assuming spacetime as an integral phenomenum, then neither light nor forces can exist within spacetime because they would then be subject to time. To remain out of time, forces and light must project a field into time and space without entering spacetime to maintain their timeless existence. It seems a logical conclusion that timeless energy/forces must exist outside of spacetime. I think this contradiction would need to be resolved before we would be able to conclude that light/energy exists within spacetime rather than outside.
Here might be an example of force outside of our universes spacetime exerting an effect on our spacetime. Within the event horizon of a black hole, would a force be outside the spacetime of our universe? Within our universe are we affected by the black hole bending spacetime? I believe the answer to both would be yes. The black hole appears to support a force originating outside of our spacetime which impacts our universe's spacetime. Although what exists in the black hole itself, who knows.
Also here is something you may find interesting on space/time, gravity and superstrings.
" Is spacetime fundamental?
Note that string theory does not predict that the Einstein equations are obeyed exactly. Perturbative string theory adds an infinite series of corrections to the Einstein equation
----actual equation at website below----------
So our understanding of spacetime in perturbative string theory is only valid as long as spacetime curvature is small compared to the string scale.
However, when these correction terms become large, there is no spacetime geometry that is guaranteed to describe the result. Only under very strict symmetry conditions, such as unbroken supersymmetry, are there known exact solutions to the spacetime geometry in string theory.
This is a hint that perhaps spacetime geometry is not something fundamental in string theory, but something that emerges in the theory at large distance scales or weak coupling. This is an idea with enormous philosophical implications. "
Full article from here:
http://superstringtheory.com/blackh/blackh4.html