Albert Einstein's theory of general relativity treats space-time as a unified field. Space for much of the course of the physics was regarded as a real substance albeit thin rather than nothing at all. At time = zero in a big bang paradigm with general relativity spaces necessarily is infinitely curved to a singular point of effective non-existence. Mass and energy are requisite for the curvature of space-time with gravity in G.R.
Physical processes can be modeled with time-space reversibility. If gravity did not exist in the early universe then the curvature of space-time shouldn't equal zero--the inference is that the beginning of the Universe would not be at time = zero but a little later instead. The tardy universe context can be overcome with hyperinflation theory evidently.
Immediately after Time equaled zero (along with infinitely curved space) decayed or released its grip, or the word to begin was issued, an inflation of mass-energy and space-time developed for a small fraction of a second and in the absence of gravity (that didn't come into existence until a little later) the Universe increased its size remarkably. Space-time unpacked or decompressed quite a bit-it was the proverbial size of a grapefruit now- and the energy of the universe eventually converted substantially into mass. Apparently, when infinitely compacted, mass is entirely converted to energy-mass unification. Infinitely compacted space has no time or motion and has tremendous potential energy and mass.
What is wrong with this excellent picture of space conceptually? In effect general relativity describes the relationship of mass and energy along with steady-state quantum spacing instead of space itself. Space itself is a volume of nothing. Mass and energy are the something described by general relativity, and the quantification of space-time curvature is the convention used to describe steady-state mass-energy relationships.
Spatial volume itself is nothing at all. It is a remarkable philosophical point for me at least that every sort of infinity exists in space at every point. Space is infinite simultaneous with being nothing at all and not existing anywhere. Sartre called space non-being, however non-being can apply to absence as a condition instead of the physical fact of spatial volume.
The quantification of mass-energy relationships with general relativity is fine enough and effective yet I think the implications for error in treating the quantum field of mass-energy of the Universe is substantial. Vacuum energy for one thing, or virtual particle energy is considered as arising from nothing rather than from a subtler quantum configuration of mass and energy.
Like the force-carrying particles of the sub-atomic realm the macro physical universe as gaps and spacing configured by physical protocols of spin, momentum, quantum mass and so forth. The discrete nature of a quantum field is at once pluralistic and a continuum of monism. The mass-energy field initial endowment of the Universe may expand and smooth itself out through entropy yet it does logically seem to be something like a complex entanglement of knots that eventually unravel transforming into a sheet or membrane. That membrane may be at the opposite end of infinite initial compactness, yet it exists in the absolute nothingness of space.
Perhaps each Universe membrane replete with its configuration of dimensions has an initial quantum value of energy. One must wonder if there is variability in the quantity of mass-energy that can be initially bound at a singularity such that the scale of potential expansion varies. If black holes are a comparable measure then Universe-singularities too might have different initial quantum value for possible scalar field increase.
Transforming Einstein's General Relativity to a paradigm treating space curvature as macro-quantum mass-energy relationships might be a way to renormalize the philosophical criterion of space logically. What is missing is a theory of quantum gravity explaining the metric of general relativity as a subtler microcosmic event-process relationship without invoking space-time.
A Universe regarded as quantum mass-energy embedded in the nothingness of space, finite in contrast to the infinity of nothingness of space-in-itself could take a variety of forms. The spherical universe arising from a singularity seems most logically satisfactory-especially as gravity seems to draw mass into 3 dimensional spheres such as planets. General Relativity allows gravity to reduce Universal mass to a singularity at Time = zero yet if the mass energy of the Universe is compacted to a size smaller than a graviton maybe the power of gravity no longer exists letting the inherent energy of the Universe expand. General relativity does not evidently treat the force-carrying quantum of gravity different from space-time.
If there were four spatial dimensions perhaps gravity would compact mass into hyper-cubes. String theorists have developed the idea of membranes in an 11 dimensional Universe and given thought to a meta-Universal 'Bulk' mother-of-all-Universes field with 3-dimensional membrane universes drifting about in the greater dimensional Bulk Meta-verse-what Dr. Mario Gasperini in 'Before the Big Bang' described as a perturbative field with virtual energy from which matter might coalesce and form into an equal yet opposite Universe before the big bang and medial singularity between Universes (something like the narrow point of an hourglass).
Steinhardt and Turok developed the concept of membrane Universes that collide acting somewhat like a Big Bang without a singularity. I think it's possible to develop the idea of a membrane Universe without so many extra-dimensions as String Theory.
Strings on a membrane surface may be a basic invariant form of texture flux in the energy-mass of the Universal field. Gravity could be a subtler flux relation of the basic Universe-membrane that arises in the history of the Universe, and perhaps will fade out one day too when unknown quantum phase changes occur.
Cyclical membrane Universes in a Bulk Mother-of-all-Universes field without space-time locality (or would there be space-time locality and general relativity in a Bulk hyper-dimensional field of all-possible Universes arising?) are interesting things to consider. Seemingly overlooked is the idea of a single membrane Universe with strings embedded in absolute nothingness without a perturbative vacuum providing an unlimited electrical supply for free.
A Universe membrane field continuum of energy and mass without the space-time as a substance parameter of general relativity ought to be considered within the headlong rush to extrapolate greater and more complex recursive causal explanations for the mechanics of the physical cosmos. Perhaps a single membrane 3-D Universe field could account for phenomena such as dark energy and the accelerating expansion of the Universe. Could the field itself have subtle form changes in relation to the configuration of solid-state forms? Might the spacing of one-dimensional strings change in the field over time in a quantifiable way, or could a non-quantum continuum of expansion occur with entropy invoking something like Boyle's law of gases to draw mass-energy of the membrane into the oblivion of nothingness at a quickening, competitive rate?
Whatever the original field of Being is, variegation in the form of its attributes described with quantification within a monistic Universe of mass and energy might reduce to the classic philosophical problems of being and nothingness existing since Parmenides. That mass could be reduced to infinitely small size as if scale and quantified attributes were stages of temporality on the way presents innumerable additional points to consider.