"All that matter … in one Big Bang …,"

[BjarneModerator Super Nova]

“All that matter … in one Big Bang …,” & other cosmological singularities

The first part of this paper contains a brief description of the beginnings of modern cosmology, which, the author will argue, was most likely born in the Year 1912. Some of the pieces of evidence presented here have emerged from recent research in the history of science, and are not usually shared with the general audiences in popular science books. Then, the important issue of the formulation of the original Big Bang concept, in the exact words of Fred Hoyle, is discussed. Too often, this is very deficiently explained (when not just misleadingly) in most of the available generalist literature. Other frequent uses of the same words, Big Bang, as to name the initial singularity of the cosmos, and also whole cosmological models, are then addressed, as evolutions of its original meaning. Quantum and inflationary additions to the celebrated singularity theorems by Penrose, Geroch, Hawking and others led to subsequent results by Borde, Guth and Vilenkin. And corresponding corrections to the Einstein field equations have originated, in particular, R², f(R), and scalar-tensor gravities, giving rise to a plethora of new singularities. For completeness, an updated table with a classification of the same is given.

Mange populære fremstillinger af kosmologiens historie inden for de seneste 100 år tager udgangspunkt i den moderne kosmologi uden hensyn til den historiske udvikling af de anvendte begrebers betydning. Det gælder især for ordet Big Bang.

 

[BjarneModerator Super Nova]

Ordet Big Bang blev skabt af Fred Hoyle i en BBC udsendelse den 28. marts 1949. Hoyle havde altid (som Einstein) ment, at ideen om, at universet kunne have en begyndelse var pseudovidenskab, blot et argument for en skaber:

“… for it’s an irrational process, and can’t be described in scientific terms”; “… belief in the first page of Genesis”.

Gold og Bondi introducerede det perfekte kosmologiske princip som et argument for den ret berømte steady state teori. Hoyle gik en anden vej, idet han alligevel gav skabelsen af stoffet en videnskabelig forklaring. Han introducerede et creation eller C-field med et negativt tryk. Et sådant felt indsat i Einsteins feltligninger resulterer i et univers med den totale energi nul. Skablesen af partikler ophæves af en tilsvarende negativ gravitationsenergi.

Forfatteren fortæller, at Richard C. Tolman alerede i 1934 havde fået en tilsvarende ide:

“… a closed universe can equal zero energy. All mass/energy is positive and all gravitational energy is negative, and they may cancel each other out, leading to a universe of zero energy”

Jeg mener dog ikke, at Tolman havde et skabelsesfelt med et negativt tryk i tankerne.

Fred Hoyle har derimod et C-felt i tankerne, når han i BBC-foredraget kommenterer Lemaitres teori fra 1931 om et Primeval Atom:

“[Lemaitre’s model implies that] … all matter in the universe was created in one Big Bang at a particular time …”.

Et C-felts negative tryk medfører en exponentiel ekspansion (inflation). Hoyle kan ikke tro, at en så enorm exponentiel expansion er realistisk. Han foretrækker steady state teoriens langsomme exponentielle ekspansion.

John Gribbin skriver i Hoyles nekrolog:

“Everybody knows that the rival Big Bang theory won the battle of the cosmologies, but few appreciate that the mathematical formalism of the now-favored version of Big Bang, called inflation, is identical to Hoyle’s version of the Steady State model”

Hoyles ide var, at skabelsen af stof kræver et felt med et negativt tryk.

 

 

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