According to the Standard Big Bang model, the universe began in the form of a singularity – a point of infinite density and infinitesimal (zero) volume. And although there are problems with extrapolating the Standard model this far back, William Lane Craig seems willing to ignore them so that he can continue claiming that the universe came “from nothing and by nothing.”
But how does the Standard model allow him to make this claim? Well, a singularity’s property of having “zero volume” is pretty easy to square away with the idea of “nothing,” but as for the singularity’s “infinite density,” Craig has a completely different explanation:
This event that marked the beginning of the universe becomes all the more amazing when one reflects on the fact that a state of “infinite density” is synonymous to “nothing.” There can be no object that possesses infinite density, for if it had any size at all it could still be even more dense.
– W.L. Craig, “The Existence of God and the Beginning of the Universe” (first published 1991; updated 2002).
If you’re finding yourself thinking, “…uh …what!?” after reading that then you’re not alone. This is an extremely sloppy piece of work, and it’s hard to imagine that Craig, a man with two PhDs, could have seriously written such a thing. Here are three problems with this argument:
#1: Craig writes, “…if [the singularity] had any size at all…” but the singularity predicted by the Standard model doesn’t have any size at all. So to put it bluntly, this means that Craig’s justification doesn’t even apply to the proper situation.
#2: Craig writes “There can be no object that possesses infinite density,” but the singularity is defined as a state of infinite density. So, even if his justification for this claim made sense, all it proves is that singularities, as they are defined by physics and mathematics, cannot exist. And because the Standard model predicts this singularity, it only means that the standard model is incorrect in this regard (which is probably true).
#3: Craig is claiming that “‘infinite density’ is synonymous with ‘nothing,”” but he only attempts to demonstrate that a state of “infinite density” is impossible. It simply doesn’t follow. As the philosopher Wes Morriston pointed out,
No one would suppose that it follows from the fact that there can be no round squares, that “round square” is synonymous with “nothing.” But neither should anyone suppose it follows from the fact (assuming it is a fact) that there can be no infinitely dense objects, that “infinite density” is synonymous with “nothing.”
To compound the confusion, Craig goes on to quote Fred Hoyle saying that the universe, according to the Standard Big Bang model, was shrunk down to “nothing at all.” But as I’ve elaborated upon in a previous post, Hoyle was only talking in terms of volume – he didn’t even mention density.
Furthermore, in the glossary to The Inflationary Universe (amazon), theoretical physicist Alan Guth notes that a singularity should also have an infinite pressure and an infinite temperature. How does Craig explain these properties as being “synonymous with nothing?” As far as I’ve looked, he never does, but I can assume that his explanation would be as ridiculous as the one he gives for infinite density.
Whenever William Lane Craig is forced to retreat from his use of the Standard Big Bang model, he will often cite a paper by Arvind Borde, Alan Guth, and Alexander Vilenkin:
…three leading cosmologists, Arvin Borde, Alan Guth, and Alexander Vilenkin, were able to prove that any universe which has, on average, been expanding throughout its history cannot be infinite in the past but must have a past space-time boundary.
The 2003 Borde-Guth-Vilenkin paper (pdf) shows that “almost all” inflationary models of the universe (as opposed to Dr. Craig’s “any universe”) will reach a boundary in the past – meaning our universe probably doesn’t exist infinitely into the past.
Dr. Craig seems to interpret this information as “the universe definitely began to exist” although that is a bit presumptuous. For example, this theorem doesn’t rule out Stephen Hawking’s no-boundary proposal which states that time may be finite without any real boundary (just like a sphere is finite in surface area while it has no “beginning”).
Furthermore, the author of the Arizona Atheist blog asked Vilenkin if his theorem with Guth and Borde proves that the universe had a beginning, and Vilenkin responded:
[I]f someone asks me whether or not the theorem I proved with Borde and Guth implies that the universe had a beginning, I would say that the short answer is “yes”. If you are willing to get into subtleties, then the answer is “No, but…” So, there are ways to get around having a beginning, but then you are forced to have something nearly as special as a beginning.
However, Craig’s main problem is that a beginning of the universe can still be described in scientific terms. Nothing in the Borde-Guth-Vilenkin paper suggests a beginning from “absolute nothingness” (as Craig often claims). In fact, the opposite is true. The authors write,
What can lie beyond the boundary? Several possibilities have been discussed, one being that the boundary of the inflating region corresponds to the beginning of the Universe in a quantum nucleation event.
This “quantum nucleation event” refers to a paper Vilenkin wrote in 1982 (pdf) which discusses the universe coming into being through quantum mechanics. Interestingly, many theists use Vilenkin’s paper as evidence that the universe came from “literally nothing” but Craig has already criticized this work.
Oddly, I’ve been unable to find any article of Craig’s (scholarly or otherwise) which actually quotes from the 2003 Borde-Guth-Vilenkin paper. Instead he almost exclusively quotes a paragraph from Vilenkin’s 2006 book Many Worlds in One (amazon) which discusses the 2003 paper:
It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape, they have to face the problem of a cosmic beginning (pg. 176).
Now that’s a pretty straight forward quote which at least seems to favor Craig’s argument, but on the very same page Vilenkin writes,
Theologians have often welcomed any evidence for the beginning of the universe, regarding it as evidence for the existence of God … So what do we make of a proof that the beginning is unavoidable? Is it a proof of the existence of God? This view would be far too simplistic. Anyone who attempts to understand the origin of the universe should be prepared to address its logical paradoxes. In this regard, the theorem that I proved with my colleagues does not give much of an advantage to the theologian over the scientist.
Vilenkin then concludes this statement by suggesting that cosmic origins could be described in “purely scientific terms” – a task which he attempts in the chapter which follows.
William Lane Craig commonly uses four quotes (Kenny, Davies, Barrow/Tipler, Hoyle) to lend support to his claim that the beginning of the universe came from “nothing,” and all four describe what is called the “Standard” Big Bang model (that is, if they describe a model at all). But what is the standard model?
David Harrison (physics department at the University of Toronto) gives a brief explanation:
There was a big bang some 15 billion years ago, when the size of the universe was zero and the temperature was infinite. The universe then started expanding at near light speed.
According to this model, the universe began as a state of infinite density, infinite temperature, and zero size which is often referred to as a singularity – the “zero size” is why it is often described it as “nothing” (whether or not a singularity is “nothing” will be explained in a later post). At first glance, these properties are mathematically incoherent; just try plugging zero and infinity in any density equation, and you can get all sorts of nonsense. But Roger Penrose and Stephen Hawking later solved these problems which temporarily saved the standard model … that is until Hawking realized his mistake:
It is perhaps ironic that, having changed my mind, I am now trying to convince other physicists that there was in fact no singularity at the beginning of the universe—as we shall see later, it can disappear once quantum effects are taken into account
– A Brief History of Time (1988), page 50
Of course, quantum mechanics isn’t the only problem which plagues the standard Big Bang Model. Harrison points out three more:
- The flatness problem: Why is the matter density of the universe so close to the unstable critical value between perpetual expansion and recollapse into a Big Crunch?
- The horizon problem: Why does the universe look the same in all directions when it arises out of causally disconnected regions? This problem is most acute for the very smooth cosmic microwave background radiation.
- The dark matter problem: Of what stuff is the Universe predominantly made? Analysis of the gravitational interactions of galaxies shows much more matter than we can see. Nucleosynthesis calculations suggest that this dark matter of the Universe does not consist of ordinary matter – neutrons and protons?
And he continues by stating that “the list is slated to grow” (he wrote this back in 2001, mind you). Even Dr. Craig admits the problem with the standard model:
The standard Big Bang model needs to be modified in various ways. For example, the model is based on Einstein’s General Theory of Relativity. But Einstein’s theory breaks down when space is shrunk down to sub-atomic proportions. We’ll need to introduce quantum physics at that point, and no one is sure how this is to be done.
Dr. Craig goes on to say that “none of these adjustments need affect the fundamental prediction of the standard model of the absolute beginning of the universe” but this is irrelevant. If Dr. Craig wants to continue making the claim that the universe came from “nothing” then he should stop using the standard model. A model which, according to Harrison, hasn’t been well-accepted since the early 1990s.
As theoretical physicist/cosmologist Alan Guth writes in the preface of his 1997 book The Inflationary Universe (amazon),
The traditional big bang theory has become widely accepted because, as far as we can tell, it gives an accurate picture of how our universe has evolved . . . However, although the standard big bang theory is very successful, there is good reason to believe it is incomplete.
NASA has a pretty cool feature called Ask an Astrophysicist in which you can ask a question to an astrophysicist. (duh!)
Well, about a month ago I asked the following question:
In various pop-science books and TV documentaries, astronomers and physicists sometimes refer to the universe expanding from ‘nothing.’ But what exactly do they mean by ‘nothing?’ Does that mean no matter, no energy, no space, no time, no physical laws, no vacuum, etc?
And this was the answer I received:
No one knows. Our understanding of physics does not extend this far. From a short time after the Big Bang until now, the broad history of the universe is becoming pretty well understood (though with big mysteries like dark energy and dark matter and a lot of other fascinating details to be filled in). But we have no current understanding of the very beginning.
Dr. Randy A. Kimble
JWST I&T Project Scientist
While I think “no current understanding” sounds a bit too absolute (after all, there certainly are a lot of very good ideas in theoretical physics), it really underscores the fact that we really don’t know much about the initial moments of the universe.