Did physical reality (spacetime) begin to exist?

“Yes, after all…
  • Spacetime expanded from some singularity (Big Bang or not)
  • General Relativity's Big Bang from nothing model is true

      (Big Bang Theory): General relativity is true or adequate, describing with sufficient accuracy the full birth and growth of space from a singularity.

      This article analyzes three evidences,...
      • …General relativity makes accurate prediction elsewhere.
      • …Space in fact did expand from a hot-dense state.
      • …Spacetime came into being from from some singularity. [See above]

      This is relevant because,

      “If we push backwards far enough, we find that the universe reaches a state of compression where the density and gravitational force are infinite. This unique singularity constitutes the beginning of the universe—of matter, energy, space, time, and all physical laws. It is not that the universe arose out of some prior state, for there was no prior state. Since time too comes to be, one cannot ask what happened before the initial event. Neither should one think that the universe expanded from some state of infinite density into space; space too came to be in that event. Since the Big Bang initiates the very laws of physics, one cannot expect any scientific or physical explanation of this singularity.” [Bruce Reichenbach, “Cosmological Arguments,” in The Stanford Encyclopedia of Philosophy (2017)]

      •… Physical reality did not being to exist at a singularity?

      But so what? Plausibly…
      •…The singularity is preceded by other spacetime regions and/or universes.[Forthcoming]

  • BGV: Past eternal expansion require impossible speeds

      Any Universe eternally inflating/expanding on average requires infinitely-fast travel (Experts1)(Elaboration2)(Justification3).

      •…see Vilenkin's spacetraveler explanation.

      This is relevant because space has been expanding, and yet an object traveling infinitely fast in space is impossible. (It produces philosophical absurdities and violates the causality principle in Einstein’s special relativity).

      But so what? Plausibly… … [All forthcoming]
      •…Space has an infinite contraction phase (i.e. contracts on average).
      •…Space has cycled infinitely (i.e. is static on average).
      •…Space underwent time-reversal from an infinite past (i.e. non-average expansion).

      1. The BGV theorem is widely accepted.

        Alexander Vilenkin: “It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape: they have to face the problem of a cosmic beginning.” [Many Worlds in One (Hill and Wang, 2006), 176.]
        William Lane Craig & James Sinclair: “The Borde–Vilenkin–Guth (BVG) singularity theorem is now widely accepted within the physics community. As of this writing, it has gone largely unchallenged.” [The Blackwell Companion to Natural Theology (Blackwell, 2004), 142.]
        Gott-Li: “The question of first-cause has been a troubling one for cosmology. Often, this has been solved by postulating a universe that has existed forever in the past. Big Bang models supposed that the first-cause was a singularity… with a proper theory-of-everything, one could perhaps push through to earlier times. Inflation has solved some of these problems, but Borde and Vilenkin have shown that if the initial inflationary state is metastable, then it must have had a finite beginning also. Ultimately, the problem seems to be how to create something out of nothing.” [J. Richard Gott and Li-Xin Li, “Can the Universe Create Itself?” (1997), p.41]
        Audrey Mithani, Alexander Vilenkin: “Did the universe have a beginning? At this point, it seems that the answer to this question is probably yes. Here we have addressed three scenarios which seemed to offer a way to avoid a beginning, and have found that none of them can actually be eternal in the past. Both eternal inflation and cyclic universe scenarios have Hav > 0, which means that they must be past-geodesically incomplete. We have also examined a simple emergent universe model, and concluded that it cannot escape quantum collapse. Even considering more general emergent universe models, there do not seem to be any matter sources that admit solutions that are immune to collapse." [Did the universe have a beginning?, http://arxiv.org/pdf/1204.4658.pdf]

      2. We know this because any eternally inflating space would require infinitely fast travel. This is relevant because an object traveling infinitely fast in space is impossible, producing absurdities and violating the laws of relativity.

        James Sinclair: "Vilenkin affirms that any universe (including universes modeled by higher dimensional cosmology, pre–Big Bang cosmology, and so forth,) which, on average, expands has to connect, in a finite time, to a past boundary (pers. comm. with Sinclair, March 4, 2004).
        Alexander Vilenkin: "Our argument shows that null and time-like geodesics are, in general, past-incomplete in inflationary models, whether or not energy conditions hold, provided only that the averaged expansion condition Hav > 0 holds along these past-directed geodesics. (Borde, Guth, & Vilenkin 2003, p. 3)39 A remarkable thing about this theorem is its sweeping generality. We made no assumptions about the material content of the universe. We did not even assume that gravity is described by Einstein’s equations. So, if Einstein’s gravity requires some modification, our conclusion will still hold. The only assumption that we made was that the expansion rate of the universe never gets below some nonzero value, no matter how small. This assumption should certainly be satisfied in the inflating false vacuum. The conclusion is that past-eternal inflation without a beginning is impossible. [Many Worlds in One (2006), 175)

      3. The Borde-Guth-Vilenkin theorem proves any universe expanding on average, including Pre-Big Bang and higher dimensional cosmologies, has a beginning. It explains that if a universe could be expanding on average for a past-infinity of time, then an impossible object would need to be: an inertial object moving at infinity speed—faster than the speed of light.
        Here is a simplification: Imagine a huge helium balloon with stationary ants scattered around it. Suddenly, one flying ant tells his friend, “I’m racing to the tip top to meet the queen!” His friend registers the flight speed as 4mph. However, the next ant he passes only registers his speed as 3 mph, and the next at 2 mph. What’s happening? The balloon is inflating! Similarly, in an inflating space, inertial objects (e.g. a bullet) are registered as slowing down relative to non-inertial objects that are carried by space (e.g. galaxies). From this we can prove all inertial objects have a finite past. If bullet-like are slowing down on average, then as you rewind the tape their speed is faster and faster. However, inertial objects can’t move infinitely fast. They can’t even move faster than the speed of light.
        So, while inertial objects moving through inflating space for the entirety of the space’s existence is possible, it is impossible for an inertial object to have been moving through space for an infinity of time. Therefore, inflating spaces are not past-eternal.

  • Total entropic decay hasn't arrived yet

      Although the 2nd law of thermodynamics says the total entropy of an isolated system can never decrease over time, the Universe's entropy in fact is far from its maximal amount; its useable energy is still winding down.

      As one simple evidence of this,
      •…stars are still burning.

      This is relevant because, if the Universe were past-infinite, the 2nd law of Thermodynamics demands that the universe would have already reached a state of thermodynamic equilibrium (“heat death”; no more useable energy).1

      1. • Paul Davies: “The first is that the universe will eventually die, wallowing, as it were, in its own entropy. This is known among physicists as the ‘heat death’ of the universe. The second is that the universe cannot have existed for ever, otherwise it would have reached its equilibrium end state an infinite time ago. Conclusion: the universe did not always exist.” [God and the New Physics (Simon & Schuster, 1983), 11.]
        • Paul Davies: “[The idea] that the universe has always existed in one form or another-runs into a rather basic paradox. The sun and stars cannot keep burning forever: sooner or later they will run out of fuel and die. The same is true of all irreversible physical processes; the stock of energy available in the universe to drive them is finite, and cannot last for eternity. This is an example of the so-called second law of thermodynamics, which, applied to the entire cosmos, predicts that it is stuck on a one-way slide of degeneration and decay towards a final state of maximum entropy, or disorder. As this final state has not yet been reached, it follows that the universe cannot have existed for an infinite time.” [“The Big Bang - And Before.” The Thomas Aquinas College Lecture Series, Thomas Aquinas College, March 2002. (As cited by Craig)]
        • P. J. Zwart: “…according to the second law the whole universe must eventually reach a state of maximum entropy. It will then be in thermodynamical equilibrium; everywhere the situation will be exactly the same, with the same composition, the same temperature, the same pressure etc., etc. There will be no objects any more, but the universe will consist of one vast gas of uniform composition. Because it is in complete equilibrium, absolutely nothing will happen any more. The only way in which a process can begin in a system in equilibrium is through an action from the outside, but an action from the outside is of course impossible if the system in question is the whole universe. So in this future state of maximal entropy, the universe would be in absolute rest and complete darkness, and nothing could disturb the dead silence. Even if there would by chance occur a small deviation from the state of absolute equalization it would of itself rapidly vanish again. Because almost all energy would have been degraded, i.e. converted into kinetic energy of the existing particles (heat), this supposedly future state of the universe, which will also be its last state, is called the heat death of the universe.” [About Time (North-Holland, 1976), 136.] (As cited by Craig)]
  • Total generalized entropy has not maxed out yet

      generalized 2nd law entropy The 2nd Law of thermodynamics applies to black holes and similar types of horizons (hence the “Generalized 2nd Law”), suggesting that even in a quantum-gravity context (like the Planck era), the conclusion of the Penrose singularity theorm applies.

      So see Aron Wall's paper, “The Generalized Second Law implies a Quantum Singularity Theorem).” in Classical and Quantum Gravity Vol 30 No 16 (2013)] (Updated 2016).

      This is relevant because...

      Aron Wall (Studies quantum gravity and black hole thermodynamics as a Lecturer at the University of Cambridge): “…it strongly suggests that either the universe had a finite beginning in time, or else it is spatially finite and the arrow of time was reversed previous to the Big Bang [i.e. tornadoes put houses back together, and eggs unscrambled themselves]. In the latter case, it could still be said that the universe had a beginning in a thermodynamic sense, because both branches of the cosmology would be to the thermodynamic future of the Big Bang” [Classical and Quantum Gravity Vol 30 No 16 (2013), p.27 on arXive.]

  • Logically, the past must be finite
  • “No, after all…
  • A beginningless universe model is true

      A cosmic model is true wheren the contiguous whole of space and time lacks a beginning.

      This article analyzes ten evidences,...[All Forthcoming]
      •…The Aguirre-Gratton Time reversal model
      •…The Baum-Frampton Cyclic model
      •…The Carroll-Chen Reversed arrow of time model
      •…The Gott-Li model
      •…The Hawking-Hartle “no boundary” proposal
      •…The Linde-type “Eternal Inflation” model
      •…The Penrose Conformal Cyclic cosmology
      •…The Steinhardt/Turok Cyclic model
      •…The Vilenkin “Tunneling from nothing” model
      •…The String Landscape inflationary model
      •…[See more]
      This is relevant because, “If we were able to construct a complete and compelling naturalistic account, the necessity of appealing to God would be diminished.” [Sean Carroll, The Blackwell Companion to Science and Christianity]