Origin of the Universe: a Theoretical Model
| Scientific Paper | |
|---|---|
| Title | Origin of the Universe: a Theoretical Model |
| Read in full | Link to paper |
| Author(s) | Rahul Krishna |
| Keywords | Big Bang, relativity, gravity, space-time |
| Published | 2012 |
| Journal | Proceedings of the NPA |
| Volume | 9 |
| No. of pages | 15 |
| Pages | 281-295 |
Read the full paper here
Abstract
Questions about the origin and nature of our universe have always stimulated and exercised every curious mind. While several theories exist, the Big Bang model is widely accepted as the correct model of the origin of our universe. However, some of the observations of the behavior of matter and light in our universe are not yet fully explained by the Standard Big Bang Model. In this paper, some corrections to the Big Bang model are presented, which result in a new model that provides a much better explanation of the observed behavior of matter and light in our universe.
Overview
Presented at the 2012 NPA conference in Albuquerque, this paper does not reject the Big Bang outright. It accepts that there was an explosive origin but replaces the point-sized, infinitely hot initial state with a finite, massive, spinning disc. From that single change Krishna derives a "unique velocity principle" which, he argues, accounts for curved motion under gravity without spacetime curvature, for the flatness of the observed universe, for the Hubble relation and its apparent acceleration, and for galactic rotation curves — all without Dark Matter or Dark Energy.
The polemical target is explicit. Krishna objects that contemporary cosmology invokes two unverifiable ingredients at once, one to keep the universe from flying apart and one to make it fly apart faster, and that between them they are held to constitute 96% of what exists. "What do we know about our universe if the largest and thus, most influential part of it is still obscure to us?" His method is to list what he takes to be internal inconsistencies in the standard account, then to construct a model whose assumptions are chosen so that no conservation law is ever violated.
The argument
Objections to the standard model
The paper opens with nine questions. Among them: why is a supposedly uniform universe disc-like rather than spherical, and how does matter "choose" a direction in which to curve spacetime when gravity acts equally in all directions? What is the mechanism of curvature? How and why did inflation exceed the speed of light? How did large density variations arise in a homogeneous, isotropic initial state without external forces? Why is there a matter–antimatter excess, when pair creation should be symmetric and no spontaneous creation of real pairs is observed? What triggered the expansion, and why does it continue now that the universe is cold?
Two of these he presses hardest. The first is thermodynamic: if expansion was driven by the initial heat, its rate should decline as the energy density falls, and since the mean temperature is now close to zero the rate should be near zero — so a non-declining or increasing rate requires energy density to hold constant or rise as volume grows, i.e. dark energy must be created continuously "in clear violation of the First Law of Thermodynamics." The second is the selectivity of expansion: space is said to expand where there is no matter but not within galaxies, the solar system, planets or asteroids. Against the balloon analogy of Hawking and Mlodinow's The Grand Design he offers a homely test — write on a balloon and inflate it, and the lettering grows too.
The three assumptions
Krishna replaces the standard initial conditions with: (1) at the Big Bang the universe already contained at least as much matter as it does today, so baryon number conservation was never violated; (2) quantum and relativistic effects within the universe at that instant were negligible, so ordinary physics applies to the Big Bang event itself; (3) all that mass formed a single spinning disc.
Assumption (1) forces a non-zero initial size, since otherwise density is infinite. A sphere would satisfy the Friedmann conditions of large-scale isotropy, and the event would then be a super-massive supernova — but a spherical explosion yields a three-dimensional universe, not the flat one observed. A rotating disc, he argues, is the shape that does the required work.
The unique velocity principle
Momentum conservation does the heavy lifting. If the disc had non-zero angular momentum before the event, then not all of its mass can have been converted to radiation, or the angular momentum would have vanished; so most of the mass was ejected as fundamental particles. Each ejected particle carries two velocity components: a radial one, equal in magnitude for every particle and set by the explosion's energy, and a tangential one, proportional to the particle's distance from the disc's axis. Both lie in the plane of the disc — which is what makes the resulting universe planar.
The vector sum therefore differs for every particle, so no two particles move with the same speed and direction. Krishna calls this the unique velocity principle and extends it upward: since the forces binding particles into atoms, atoms into stars and stars into galaxies are internal to those aggregates, each aggregate inherits the vector sum of its constituents' momenta and so also moves uniquely.
He introduces a K-ratio — the fraction of the disc's mass converted to energy at the Big Bang — bounded by the requirement that no particle's net velocity reach c. Since the tangential component is fixed by the rotation, this caps the radial component and hence the energy released, which he offers as the reason the universe has the mass it does. Regional variation in the propensity of different particle combinations to be converted to energy is invoked to seed the density inhomogeneities that become galaxies, and the unique-velocity principle then prevents those inhomogeneities from ever smoothing out.
Curved motion without curved spacetime
Krishna argues that the dimensional analogy behind spacetime curvature is backwards: moving to more dimensions increases the possible curvature of a path, so a path curved in three dimensions cannot be a straight line in four. His replacement mechanism is kinematic. For a body in a gravitationally closed system, the net attraction points toward the system's centre of mass; he calls the line from the body to that centre its C-line. Because the body and the centre of mass are themselves moving with different (unique) velocities, the C-line reorients continuously, so the body's velocity always acquires a component perpendicular to it — and the path curves.
A two-body worked example follows, with body 1 held fixed at the origin and body 2 starting at distance d with velocity V parallel to the y axis. Over an interval ΔT the displacement components are Sx = ½A(ΔT)2 and Sy = VΔT, the separation is updated as D2 = (d − Sx)2 + (Sy)2, and the acceleration is rescaled as A(d/D)2 and resolved into components Acosθ and Asinθ. Straight-line motion requires the slope Sy/Sx to stay constant over every interval; since θ changes, it does not. The one exception — all the initial velocity lying along the line of centres — is precisely what the unique velocity principle is said to forbid.
Supporting evidence offered includes the curved path of an electron in a cathode ray tube deflected by a side charge, where the same C-line argument applies with an electrostatic force and where spacetime curvature plainly cannot be responsible; the ability of a rocket to travel in a straight line near a massive body; and a proposed bench experiment in which charged ball-bearings are flung outward by a central explosive and then allowed to attract each other.
Consequences
Because the two velocity components combine, recession speeds exceed what the tangential component alone would give — which Krishna offers as the reason the expansion appears to be accelerating without any dark energy. The observed small sideways velocities of distant galaxies he takes as direct support for unique velocities. Extrapolating the expansion backwards with no curvature reaches the spinning-disc state well before a point, so the universe is younger than estimated and "the Planck era never happened at all." Accumulation of matter at galactic centres yields black holes; conservation of momentum in aggregation implies that essentially all stars, planets and black holes should be rotating. Light bending requires the photon to have a small non-zero rest mass, and yields a testable difference: a beam aimed exactly at a body should not bend, whereas the curvature model requires bending in every case.
A closing section, "Why Did Einstein Get It Wrong?", argues that Einstein worked before the expansion was known and so could not deduce the unique velocity principle; spacetime curvature was then the only available way to explain why locally dense regions do not collapse quickly, and was, on Krishna's reading, a second patch of the same kind as the Cosmological Constant.
Assessment
The paper's virtue is that it makes a definite ontological commitment and follows it consistently. Rather than adjusting a parameter, it changes the initial state and then tries to derive everything from momentum conservation, and it does supply a concrete numerical procedure — a stepwise integration of the two-body problem — instead of stopping at a picture. The demand that the model introduce nothing unobservable is stated plainly and applied to itself. Several of the opening questions are also legitimate ones that popularisations handle badly: the selectivity of cosmic expansion is genuinely confusing as usually told, and the balloon-lettering point is a fair criticism of the analogy, if not of the physics behind it.
The difficulties, however, run to the foundations. The central kinematic claim is not new physics: that a body with transverse velocity follows a curved path under an inverse-square attraction is Newton's result, and Krishna's two-body integration reproduces exactly Newtonian orbital motion. General relativity was never proposed to explain that; it was proposed to explain the residue left over after Newton — the 43 arcseconds per century of Mercury's perihelion advance, the deflection of starlight at twice the Newtonian value, the Shapiro delay, gravitational redshift as measured by Pound–Rebka, and the orbital decay of the Hulse–Taylor binary pulsar. None of these is mentioned, and the model as presented is silent on all of them. The claim that a rocket can move in a straight line near a massive body is not a counterexample to curvature but a statement about thrust.
The disc geometry is the deepest problem. A rotating disc has a preferred axis and a preferred centre, and Krishna is explicit that the universe has a centre, that the "gravity of the universe" points toward it, and that it is maximal at the outer edge. This is directly contradicted by the isotropy of the Cosmic Microwave Background, which is uniform to about one part in 105 after the dipole is removed, and by the observed statistical isotropy of galaxy surveys — neither of which the paper discusses. The paper invokes the Friedmann conditions to motivate a symmetric shape and then adopts a shape that violates them. Nor is the Hubble relation actually recovered: a difference of tangential velocities scales with distance from the centre, not with distance from the observer, so the model predicts a recession pattern that depends on where in the disc the observer sits — an anisotropy that would be conspicuous and is not observed.
Other steps are asserted rather than derived. The K-ratio is defined but never evaluated, so the claim that it explains the mass of the universe carries no content. The Pauli exclusion principle is used to argue that neighbouring particles in the disc must be dissimilar and that no two bodies can share a velocity; this misapplies the principle, which constrains identical fermions in the same quantum state, not classical bodies with the same velocity vector. The thermodynamic objection to dark energy assumes that expansion is driven by residual heat, which is not the standard claim. The assertion that no acceleration of our own galaxy is observed conflates a change in the expansion rate with a local proper acceleration. And the requirement that the photon have non-zero rest mass conflicts with laboratory bounds, currently below about 10−18 eV, and with the paper's own concession that light must not speed up on entering a gravitational field.
Finally, the model offers no account of the phenomena the Big Bang framework was built to explain: the blackbody spectrum and acoustic peak structure of the microwave background, and the primordial abundances of helium-4, deuterium and lithium. Assumption (1) — that all present matter existed before the event — removes nucleosynthesis from the story entirely without replacing it. As it stands the paper is best read as a statement of dissatisfaction with dark matter and dark energy, joined to a Newtonian kinematic picture that would need to confront the classical relativistic tests before it could be weighed against the account it seeks to replace.