Section V: The Origins and Future of the Universe, from "Is Space the Only Substance in the Universe?"

V.                   THE ORIGINS AND FUTURE OF THE UNIVERSE

(Updated July 21, 2023)

“Big Bang” vs. “Big Bounce”

The “Big Bang” theory has had a widespread following for several decades, to the point of orthodoxy, but requires at least two aspects that do not conform to any known physical process. First, according to the current version of the theory, all of the energy and future mass of the universe would have started at a “singularity,” which has already been questioned above,

and then it would have expanded exponentially in an extremely rapid “inflation” for a fraction of a second before slowing to the known Hubble rate of expansion  No satisfactory mechanism is evident for why and when such an ultra-brief “inflation” phase should begin or end (Hossenfelder 2017, Wolchover 2018).

             The “inflation” aspect of the theory has recently been challenged as unscientific and having failed to solve any of the problems for which it was intended, by Steinhardt, one of its original developers 35 years ago.  Hossenfelder agrees with these arguments, says that “inflation” permits multiple different potential models and is “not any simpler and it doesn’t explain anything.” and jokes that the main use of “inflation” theory is for “churning out papers” (Hossenfelder 2017).

            One strong argument for the “Big Bang” and “inflation” is that the universe is relatively homogeneous or isotropic in all directions. This is credited to the primordial material that became the antecedents of the stars having been symmetrical and in contact prior to “inflation.” The “Nothing but Space” model would permit an alternate explanation for the relative uniformity of the universe. The new space continually appearing everywhere would come from the same source, and consist of uniform “volon” units of space.

            A second persuasive case for the “Big Bang” and “inflation” models is the cosmic microwave background radiation. But alternative mechanisms for this have been proposed (Hossenfelder 2017), which will not be considered here.

             An alternate theory called the “Big Bounce,” now supported by Steinhardt and others, predicts that there could be an endless cycle of expansions and contractions of the universe (Wolchover 2018). Each restart of expansion would presumably start the creation of matter and energy all over again, different than before. It would probably also reset the clock, starting measurable time again from zero. This concept of a harmonic alternation of expansions and contractions is appealing with respect to a “Nothing but Space” model, which could provide an explanation for it as space moved back and forth between our observable dimensions and three alternate dimensions. “Inflation” would not be a necessary part of this concept.  

            Expansion or contraction phases would end and start to reverse when the contracted phase had either reached zero (with all space simply transferred to the other set of dimensions, no “singularity” conceptualized), or at a non-zero volume where there was enough potential energy to force a new expansion; or when the expanded dimensions had acquired the energy or gravitation to contract again, or a combination of these.  Maximum and minimum sizes might be approached  very gradually, without actual “bangs” or “crunches” (see theoretical explanation under next topic).

            One alternative theory on the ultimate fate of the universe is that endless expansion will result in continuous cooling and a “Big Freeze” (Betz 2020).  However, Chiang, et al. (2020) reported that the temperature of galaxy clusters has actually risen about tenfold over the past 10 billion years of expansion, which the authors attributed to the gravitational collapse of “dark matter” and gases to create galaxies (Williams, M. 2020).  

            Almost all the energy on earth (except for thermonuclear from nuclear reactors, and nuclear decay deep underground) ultimately comes from the sun. It is possible to speculate that all or almost all energy and mass in the universe ultimately came from space expansion and deletion over the total history of the universe. The entry and departure of units of space might cause turbulence in existing space, leading to the generation of energy waves, (causing the just-mentioned temperature increase discovered by Chiang), and of vortices as suggested above, that create space deletion and the other properties that we refer to as gravitation and mass. Such energy transfers would remain conserved within the total closed system (Hamiltonian) of visible and invisible dimensions combined. Energy lost or gained during our expansion phase might be reversible during the phase of space contraction in our dimensions (which should be entropy-reducing), and concurrent expansion in the alternate dimensions.

            The “Big Bang” theory likewise suggests that the energy from that process ultimately resulted in the formation of the stars and galaxies. One key difference from that theory is that in the “Nothing but Space” model, creation would be a continual process rather than constituting delayed results of a single explosive event.

The Speed-up and Future of the Hubble Expansion

In recent years, the rates of red-shifting, and thus of the expansion, have been found to have increased over time. This has been puzzling to physicists (Jackson, N. 2015)

            There are four potential explanations, which may all be combined. If v on the left side of the Hubble equation (1) is increasing, and there are no other terms in the equation, either H₀ or s on the right side must be increasing, if not both.

            So the first possibility is that the Hubble constant is not in fact a constant. This has increasingly been considered, and the Hubble constant H₀ is often described as being constant over space but not over time (Siegel 2019, August). In the “Big Bang” vs. “Big Bounce” discussion above, the rate of expansion of the universe was suggested to be part of an oscillation process like that of a spring or pendulum, rather than being constant. That might indeed imply variation of H_0, but there are other possibilities that could cause the current speed-up and a potential later slow-down.

            The second possible explanation is that in the Hubble equation (1), it is not an increase in H_0, but rather of s that is the main cause of the rate increase. The “Nothing but Space” model proposes the continual addition of new three-dimensional units of space to be the cause of the expansion, and one of those dimensions is length in the direction away from any observer, or s.  In the Hubble equation (1), the velocity of recession v is proportional to this distance s, so as s increases, so should v. Since v continually increases, it can be represented as ds/dt, the instantaneous rate of distance/time, and s_i as the instantaneous total distance, as in equation (6):

                                                            ds/dt = H₀*s_i                                                                (5)

            The Hubble equation itself in its differential version (5) implies a continual increase in the rate of expansion, regardless of the model. Applying simple algebra to (5), the ratio of new distance to existing distance will increase with time, as per equation (6):

                                                            ds/s_i = H_0*dt                                                                 (6)

            The sustainability of this increase, however, is unknown. Eventually, it is possible that the rate would slow down because of the additional factors discussed below.

            The third possibility is that there is a missing x term in equation (1), representing the distance from an equilibrium position midway to maximal expansion. If new space were to appear in proportion with existing space, but were also to have come from existing space remaining in the alternate dimensions, then in dramatic contrast to the “Big Bang” theory, the visible universe would have started to expand very slowly because there was hardly any space then. The expansion phase would then speed up, but could not do so indefinitely, because it would be drawing its space from a contraction phase that would eventually  running out of space. This would suggest that expansion would start from nothing, gradually speed up to a maximum value, then gradually slow again and end at a stop.

            The maximal velocity of recession could be at an unknown midpoint, halfway to maximal potential expansion. The fact that the velocity of recession is increasing might suggest that our expansion has not yet reached that midpoint. At either smaller or larger degrees of expansion, the velocity would be slowed. This variation would be analogous to the velocity of an oscillating spring or a pendulum, but unlike those would not necessarily mean that the midpoint was the original position of “rest.” Instead, the midpoint would be an inflection point for both our visible dimensions and the alternate ones, at which maximal rates of expansion in one manifold and contraction in the other would be reached..  As in Hooke’s law where the restoring force is proportional to the displacement from the neutral position, but with a constant k and with a minus sign because the velocity is in the opposite direction of the distance of the current expansion of the universe from the midpoint. The velocity of recession over very long periods of time might therefore be proportional to -kx,

            The fourth possible explanation is a reduction in gravitational force opposing the expansion. The velocity due to space expansion is partially counter-balanced by gravity, which would decrease due to greater distances among galaxies, as per equation (2).

            Combining all of these four factors, the simple Hubble equation (1) could thus eventually become more complicated. The adjustments in equation (7) are highly speculative, but worthy of ongoing philosophical and scientific discussion, because whatever actually happens to the rate of expansion might determine the fate of the universe.

                                                ds/dt = (H_0*s) /(-kx) ₊  (gravitational effects)                          (7)

              (7)