Post Author: Bill Pratt
I was discussing Hawking’s recent book with a regular blog commenter who mentioned that Hawking’s ideas on the creation of the universe were new and that he hadn’t had time to look into them. This got me thinking about whether Hawking really was on to some new formulation of physics that had never been published before.
It turns out the answer is “no,” according to physicist Stephen Barr. In his article, “Much Ado About ‘Nothing’: Stephen Hawking and the Self-Creating Universe,” he traces the genesis of Hawking’s ideas:
The idea that Hawking is now touting is not new—in fact, within the fast-moving world of modern physics it is fairly old. My first introduction to it was reading a very elegant theoretical paper entitled “Creation of Universes from Nothing,” written in 1982 by the noted cosmologist Alexander Vilenkin, who argued that our universe might have arisen by a “quantum fluctuation.”
This idea is sometimes referred to as the quantum creation of the universe. There are different variants, but the basic idea is well-known among particle physicists and cosmologists.
Barr then proceeds to describe the nature of this theory:
Right up front, it must be noted that this idea is extremely speculative, has not yet been formulated in a mathematically rigorous way, and is unable at this point to make any testable predictions. Indeed, it is very hard to imagine how it could ever be tested. It would be more accurate to call these “scenarios” than theories.
Having said this, though, Barr warns readers not to blindly dismiss the idea of quantum creation. He explains that it is based on applying quantum mechanics to entire universes. Although quantum mechanics is well understood at a sub-atomic level, Hawking and others are speculating what quantum mechanics might look like at the level of entire universes.
After expanding upon the theory of quantum creation, Barr ultimately comes to this point:
Perhaps my explanations are not really necessary. Even the most casual readers recognize that the cosmological theories put forward by Hawking do not bear upon larger questions that motivate classical views of creation out of nothing. Non-scientists are quick to ask the obvious questions. Why a system obeying quantum mechanics, M-theory, superstring theory, or whatever laws of physics that make scientific speculations possible in the first place? Why not no system at all, with no laws at all, no anything, just blank non-being?
Let’s put Hawking’s theories in perspective. What exactly can these theories tell us?
Physics scenarios and theories are merely mathematical stories. They may be fictional or describe some reality. And just as the words of a book by themselves can’t tell you whether it’s fact or fiction—let alone have the power to make the world they describe real—so with the equations of a physics scenario. As Hawking once understood, equations may turn out to be an accurate description of some reality, but cannot not confer reality on the things they describe.
Finally, Barr reminds us:
There are two answers to the question: “Why does anything exist rather than nothing at all?” The atheist answers, “There is no explanation.” The theist replies, God. An intelligent case can be made for either answer. But to say that the laws of physics alone answer it is the purest nonsense—as Hawking himself once realized.