Saturday, September 6, 2014

God, physics and Stephen Hawking


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The modern scientist who today most closely matches Einstein's role and fame in his time is Professor Stephen Hawking. Last year a biographical movie about Hawking was televised in Australia. It concentrated on his amazing triumphs against the difficulties caused by his motor neurone disease, rather than his science.
Nevertheless, the physics did get some exposure. In his justly famous book, A Brief History of Time, Hawking outlines his theory of how the Big Bang occurred, that is, how the universe got started.
In this book he makes it clear his theory is just that, a theory, which is far from being proven. However, a number of people have not only assumed it is correct, but have drawn all sorts of strange philosophical and theological conclusions from it.
Hawking himself is partly to blame here, since, when he strays into these areas (which are outside his expertise), he makes some elementary errors. Fortunately, he also makes one excellent and insightful statement that gets to the crux of the "God-question".
One of the difficulties of the "normal" Big Bang theory is that it says that at the beginning of time the universe "exploded" outwards from a state of zero size and infinite density and temperature.
You see, however much mass and/or energy the universe had, fitting them into something of zero volume is a mathematical nightmare. You can discover this by dividing any number by zero on a calculator. What do you get? An error message. You simply can't divide by zero. Unfortunately, at the beginning of the universe our mathematical laws of physics seem to try. So, in reality, when we talk about infinite density at the origin of the cosmos, we are basically saying our formulas stop working there.
Hawking thinks he can solve this problem by replacing this initial "singularity" with a tiny region where time is effectively a part of space at first but separates out as a distinct dimension. (This tiny region is where Hawking's talk of "imaginary time" is most relevant.) In other words, the "beginning point of time" or t = 0 disappears. Hey presto, no singularity, no dividing by zero, no inexplicable bits. Also, in Hawking's model that region creates its own initial conditions through a "quantum physics" equation that, among other things, acts something like a random-number generator.
Now, since in the classical model the conditions at the beginning are not set by the theory, some people have thought this was God's only job, with the laws of physics doing the rest from then on - leaving God with nothing to do under Hawking's hypothesis!
So, what's wrong with this approach? Well, for a start, it makes a number of incorrect assumptions about how philosophy and theology have seen the relationship between God and the Cosmos. First, God here is conceived as causing the Universe's existence only at its beginning, whereas He is traditionally understood to be constantly its "ground of being" (as He exists outside of time).

God-question

Second, the idea that God's only role is to set up a pattern of matter or energy, after which the laws of physics take over, is absurd. The laws of physics themselves require an explanation. That means even if the laws produced the starting configuration, the "God-question" is not avoided. Third, the idea that the Cosmos only requires a Cause if it had a beginning was shown to be false long ago by St Thomas Aquinas.
Aquinas noted that even if the world had existed for an infinite amount of time it could still not explain its own existence. The fundamental question is not "What is it?" or "How does it work?" or even "Was there a beginning?", which are the questions asked by science. No, the fundamental question is "Why does it exist at all?". All science ever does is explain processes of change.
It always has to assume two things: that there are "laws" which govern how the universe works and that there is something for these laws actually to govern. And Hawking makes this very point himself. Speaking of the one equation that he hopes will be discovered to describe the Cosmos, he says "it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe?"
The answer of Natural Theology (a branch of philosophy) to that last question is that you cannot explain all these beings that happen to exist, but don't have to, by appealing to another "thing" which just happens to exist. That would just expand the range of unexplained beings. We need to have a being which just is, as it is Existence Itself, and so does not need another thing to give it existence. This Being, then, could have given existence to everything else.
But the most crucial error of Hawking, is where he says it appears God "does not now intervene" in the Universe. No evidence is given for this statement in the book, it is simply presumed. But in fact there is a great deal of evidence that God is not simply "watching us from a distance", in splendid isolation.
Not only did He reveal himself in actions and words to the Jews through their history, He chose to come and live with us as the Jewish man Jesus - and then to die and rise again for us, to give us a new kind of life.
The crucial question for us then becomes, will we accept His "intervention" on our behalf? Will we allow the one who breathed fire of existence into the equations to breathe His life into us?

Fr Matthew Kirby is a priest of the Anglican Catholic Church and a senior physics teacher at the St Mary's Campus of All Saints' College in Maitland, NSW.

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