Did space and time start from a nothing-point (singularity)?
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Clarifying the question
- John Wheeler, Geons, Black Holes, and Quantum Foam (2000), 235.
- • Spiros Cotsakis and Peter G.L. Leach: “Usually in cosmology the definition of a singularity is taken to mean a place where some physical quantities, for example the spacetime curvature, densities, temperatures of matter fields etc., become infinite or discontinuous.” [“Is Nature Generic?,” in S. Cotsakis and E. Papantonopoulos (eds.), Cosmological Crossroads: An Advanced Course in Mathematical, Physical and String Cosmology (Springer, 2001), 8.]
- Most cosmologists interpret point as a mere mathematical idealization. For example, in projective geometry, any pair of lines will always intersect at some point. Nevertheless, parallel lines do not intersect in the real plane. So, a ‘line at infinity’ is added to the real plane. This completes the plane, because now parallel lines intersect at a point which lies on the line at infinity. Like the “point” at infinity where parallel lines meet, physicists do not believe the singularity is a real physical state. Instead, this boundary to space-time is in fact equivalent to nothing. Any interval of time is open in the earlier than direction. [See Craig, William Lane and Smith, Quentin. [1993]. Theism, Atheism, and Big Bang Cosmology. (Oxford) pp. 43-44, 146-147, 224-227, 258-261]
• William Lane Craig: "The initial Big Bang singularity is not considered to be part of time, but to constitute a boundary to time. Nevertheless, it is causally connected to the universe. In an analogous way, perhaps we could say that God's timeless eternity is, as it were, a boundary of time which is causal, but not temporally, prior to the origin of the universe." [Time and Eternity (Crossway, 2001), 263.]
• Graham Oppy: “Despite the good fit between non-initial segments of standard Big Bang models and empirical data, there are very few cosmologists who suppose that standard Big Bang models are well confirmed over the entire history of the universe. The sticking point, of course, is the account of the very earliest history of the universe. In standard Big Bang models, there is an initial blow-up scalar polynomial singularity, that is, a point at which physical components of the curvature tensor diverge. There are very few theorists who are prepared to allow that this is a true representation of the earliest history of the universe.” [Arguing about Gods (Cambridge, 2006), 145.] - See “Singularity” defined at “Space-time came from a nothing point
- • Paul Davies: “[We can extrapolate backward from the universe-expansion we see.] If we extrapolate this prediction to its extreme, we reach a point when all distances in the universe have shrunk to zero. An initial cosmological singularity therefore forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity. For this reason most cosmologists think of the initial singularity as the beginning of the universe. On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.” [“Spacetime singularities in cosmology” in J. T. Fraser (ed.), The Study of Time III, 78–9. (Springer Verlag, 1978), 78-9]
• Stanford Encyclopedia of Philosophy: “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 (Nov 2016)] - More technically, all past-directed geodesics terminate at the singularity.
Gott et al.: The universe began from a state of infinite density about one Hubble time ago. Space and time were created in that event and so was all the matter in the universe. It is not meaningful to ask what happened before the big bang; it is somewhat like asking what is north of the North Pole. Similarly, it is not sensible to ask where the big bang took place. The point-universe was not an object isolated in space; it was the entire universe, and so the only answer can be that the big bang happened everywhere. (1976, p. 65) - It is not meaningful to ask what happened before the Big Bang or “where” it took place.
• Gott, Gunn, Schramm, & Tinsley: “Space and time were created in that event and so was all the matter in the universe. It is not meaningful to ask what happened before the big bang; it is somewhat like asking what is north of the North Pole. Similarly, it is not sensible to ask where the big bang took place. The point-universe was not an object isolated in space; it was the entire universe, and so the only answer can be that the big bang happened everywhere.” [Gott, J. R. III, Gunn, J. E., Schramm, D. N., and Tinsley, B. M. “Will the universe expand forever?” Scientific American, (March 1976). 65.]
- E.g. “The Big Bang model describes a universe that is dynamic and evolving, one that started from an extremely hot and dense state at a finite time in the past…” [Ralph A. Alpher and Robert Herman, Genesis of the Big Bang (Oxford: Oxford University Press, 2001), 29.]
OR:
Quentin Smith: “[The expansion] suggests that there is some time in the past when all the galactic clusters, or all the materials in these clusters, were arbitrarily close together, and that this time represents the beginning of the universe.” [“The Uncaused Beginning of the Universe,” in William Lane Craig and Quentin Smith, Theism, Atheism, and Big Bang Cosmology (Oxford, 1993), 109-110.]
According to Einstein’s theory of gravity (General Relativity), “Spacetime tells matter how to move; matter tells spacetime how to curve.”1
One product of this theory is that, in the right conditions, so much spacetime curvature can form that a singularity point of infinite curvature can appear.
Singularity = def. A product of General Relativity (GR), where some physical quantities like spacetime curvature, density, and temperature become infinite or discontinuous.2 The entire existence of space-time itself may even trace back to an initial cosmic singularity. Singularity (The Initial Cosmic) = def. The proposed beginning point of space-time reality (especially for the FLRW Big Bang model). It is a point of zero-size wherein all space, time, and energy existed with infinite density and correspondingly infinite gravitational curvature. [Note: Rather than being an actual physical object, most cosmologists interpret this point as a nonphysical mathematical idealization—a nothing point that constitutes the past-boundary of our Universe’s history.]3 Is it the case that all of physical space-time came into being from an initial cosmic singularity?
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General Relativity's Big Bang model from nothing is true
- • 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. - 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,
(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 - • 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.]
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BGV: Past-eternal expansion requires impossible speeds
- 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)]
(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
• …consider Vilenkin's spacetraveler proof/illustrationSo? 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)
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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.
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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).