Did space and time start from a nothing-point (singularity)?

“Yes, after all…
  • General Relativity's Big Bang model from nothing is true

    A cone depicting the expanding universe expands from left to right with a right facing arrow underneath. Einstein is in the background.

    (Big Bang Theory): General relativity (GR) is true, sufficiently accurately describing the full birth-growth of space. Consider three evidences:

    • General relativity makes accurate predictions.
    • Space in fact did expand from a hot-dense space.
    • Other evidences indicate: Physical reality (spacetime) began to exist, growing from a singularity.

    This is relevant because “FLRW models with ordinary matter have a singularity at a finite time in the past.” [Christopher Smeenk, “Philosophy of Cosmology,” in Batterman (ed.), The Oxford Handbook of Philosophy of Physics (Oxford, 2013), 612.]1

    No,

    • Space has an early quantum era (not FLRW); GR won’t apply.
    • Space is not isotropic & homogenous.2
    1. Roger Penrose: “Friedmann-Lemaitre-Roberston-Walker (FLRW) [are] spatially homogenous and isotropic cosmological models. …each model starts with a Big Bang… for the different alternative choices of spatial curvature. In each case, the universe starts form a singularity—the so-called Big Bang—where spacetime curvatures become infinite and then it expands rapidly outwards.” [The Road to Reality: A Complete Guide to the Laws of the Universe (Vintage Books, 2005), 719.]
      Stephen Hawking & George Ellis: “We have seen there are singularities in any Roberston-Walker space-time in which µ > 0, p ≥ 0 and Λ is not too large… the fact that singularities do occur in such models gives an indication that the existence of singularities may be a property of all space-times which can be regarded as reasonable models of the universe.” [The Large Scale Structure of Space-Time (Cambridge, 1973), 142.]
      • See also R. M. Wald, General Relativity (Chicago, 1984), 213-4.
    2. To say the universe is not isotropic and homogenous is to say its not the same from all directions and all places. By way of response, however, [the Universe is expanding from a hot dense state], and the cosmic microwave background radiation is a sort of lingering afterglow. It is measured to be highly isotropic. In fact, thermal radiation temperature various by only a tenth of a thousandth of a kelvin. This is relevant because of the Ehlers-Geren-Sachs theorem[1] (and the Stoeger, Maarten, Ellis update)[2] which can use this data to prove we are therefore in an isotropic and homogenous FLRW spacetime. The relevant papers here are:
      [1]Ehlers, J., Geren, P., Sachs, R. K., “Isotropic solutions of Einstein-Liouville equations.” J. Math. Phys. 9, 1344 (1968)
      [2]Stoeger, W. R.; Maartens, R; Ellis, George (2007), “Proving Almost-Homogeneity of the Universe: An Almost Ehlers-Geren-Sachs Theorem.” Astrophys. J., 39: 1–5,
  • BGV: Past-eternal expansion requires impossible speeds

    Two man are racing. One has an electricity symbol on his head and is losing.

    (BGV Theorem): Any Universe eternally inflating/expanding on average requires infinitely-fast travel Right?

    After all:

    This is relevant because an object traveling infinitely fast in space is impossible, producing philosophical absurdities and violating the causality principle (in Einstein’s special relativity). The fate is symptomatic of a singularity.1

    So? Couldn’t it simply be that: [All forthcoming]

    • Space contracts on average
      • Because of an infinite contraction phase
    • Space is static on average
      • Because of infinite cycling
      • Because of an infinite contraction phase (during time-reversal)
    1. More specifically and technically, this fate for a past tracing so-called “geodesic” is a degenerative symptom (“pathology”) associated with singularities. That is to say, while the theorem is not a singularity theorem—it entails no singularity—its conclusion is nevertheless evidentially symptomatic of a singularity, and either way fits cleanly with the longstanding most simple inflationary theory: the Standard Big Bang model. Consequently, “A model in which the inflationary phase has no end …naturally leads to this question: Can this model also be extended to the infinite past, avoiding in this way the problem of the initial singularity? …this is in fact not possible in future-eternal inflationary spacetimes as long as they obey some reasonable physical conditions: such models must necessarily possess initial singularities. …the fact that inflationary spacetimes are past incomplete forces one to address the question of what, if anything, came before. ["Eternal Inflation and the Initial Singularity," Physical Review Letters 72 (1994): 3305, 3307 (provided by Bill Craig)]
“No, after all…
  • A beginningless universe model is true

    A beginningless universe (or multiverse) model is true. This is relevant because the Standard Big Bang model under review here is not a past eternal model.

  • Singularity-expansion isn't an event

    Singularity-expansions (e.g. The Big Bang) aren’t events. After all, “An event takes place within a space-time context. But the Big Bang has no space-time context; there is neither time prior to the Big Bang nor a space in which the Big Bang occurs.” (SEP).