John Barrow on the Big Bang Singularity
Several months ago I wrote about the following quote which William Lane Craig very commonly uses in debates in order to bolster his Kalam Cosmological Argument:
At this singularity, space and time came into existence; literally nothing existed before the singularity, so, if the Universe originated at such a singularity, we would truly have a creation ex nihilo.
– John Barrow & Frank Tipler, The Anthropic Cosmological Principle (1986), page 442
In my response (and also in a different post), I explained that it is unlikely that the universe originated with a singularity. Although the famous Hawking-Penrose theorems predict such a singularity, these theorems are known to be problematic because they are based mainly on Einstein’s general relativity and neglect quantum mechanics. Therefore, the above quote is fairly useless to anybody trying to argue that the universe was created from nothing. Interestingly, I recently discovered a book by John Barrow (the co-author of the quote), titled The Book of Nothing (2000) (amazon) in which he makes the same point. On page 289, Barrow writes
The interesting thing about the singularity that is predicted by [the Hawking-Penrose] theorems is that there is no explanation as to why it occurs. It marks the edge of the Universe in time. There is no before; no reason why the histories begin; no cause of the universe. It is a description of a true creation out of nothing.
He continues on the next page:
However, it is important to realise that they are mathematical theorems not cosmological theories. The conclusions follow by logical deduction from the assumptions. What are those assumptions and should we believe them? Unfortunately, the two central assumptions are now not regarded as likely to hold good. We expect Einstein’s equations of general relativity to be superseded by an improved theory that successfully includes the quantum effects of gravitation. … It is widely expected that this new improved theory will not contain the singular histories that charicterised Einstein’s theory, but until we have the new theory we cannot be sure.
And if this isn’t enough, Barrow goes on:
There is a more straightforward objection to the deduction of a beginning using the theorems of Penrose and Hawking. The assumption is that gravity is always an attractive force. When the theorems were first proved this was regarded as an extremely sound assumption and there was no particular reason to doubt it. But things have changed.
Barrow says that theories within particle physics as well as the theory of inflation seem to contradict this assumption, and since 1981, most physicists and cosmologists believe there to be a repulsive force within gravity. Barrow also notes that, “Indeed, the recent observations of the acceleration of the expansion of the Universe today, if correct, demonstrate there exists matter which displays gravitational repulsion.”
Barrow concludes this section on page 291 by writing, “Thus the old conclusions of the singularity theorems are no longer regarded by cosmologists as likely to be of relevance to our Universe.”