“Unless a grain of wheat falls into the earth and dies, it remains alone; but if it dies, it bears much fruit.” – John 12:24
“The last enemy to be destroyed is death...Death is swallowed up in victory.” – 1 Corinthians 15:26, 54
"The greater the sin, the greater the mercy, the deeper the death and the brighter the rebirth.” - C. S. Lewis
"This story...has the very taste of primary truth." - J. R. R. Tolkien

Tuesday, September 7, 2010

Stephen Hawking on God, Gravity, and the Question of Existence

In his new book The Grand Design, which will be available Thursday (September 9), Stephen Hawking states,

"Because there is a law such as gravity, the Universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the Universe exists, why we exist...it is not necessary to invoke God to light the blue touch paper and set the Universe going."
To be fair, I have not read Hawking's book, and perhaps my questions are answered there.  What I have written here is only a response to the little I do know of Hawking's worldview.

As an aspiring graduate student in physics currently working towards my PhD at Penn State, and hoping to focus my research in the area of cosmology, I am fascinated by Hawking's suggestion that gravity could play such an important role in the origin of the universe.

But it seems to me (if I am wrong, someone please correct me), that something is wrong with Hawking's reasoning, at least in this excerpt.  Hawking claims to have found "the reason there is something rather than nothing."  But look at the premise behind this reason: "because there is a law..."  Hawking assumes the existence of something (gravity, in this case) in order to explain the fact of existence.

Now, there is nothing wrong with reducing the question of why the universe exists to the question of why gravity exists (that is, of describing the universe, on a solely scientific level, in terms of gravity), but when Hawking claims that this is why anything at all exists, his reasoning (or at least his language) becomes a bit circular.  Where did gravity come from? [1]

Gravity, presumably, either (A) does not count as something real, or (B) exists necessarily.  Case A seems problematic to me - it may be what physicist and priest John Polkinghorne calls an "abuse of language."  In response to the idea that the universe pulls itself into existence from a quantum vacuum, Polkinghorne writes "only by the greatest abuse of language could such an active and structured medium be called nihil [nothing]...in quantum theory, when there is 'nothing' there, it does not mean that nothing is happening" (The Faith of a Physicist 75).  In other words, there isn't really nothing there.  Maybe Hawking attempts a similar language trick in order to reduce the reality of gravity to nothing.  He certainly seems to do in this sentence by saying that the universe comes from "nothing"...but by means of gravity.

Case B is more promising.  Perhaps what seems to be great complexity in the universe can actually be reduced to a few or even just one simple and elegant law.  Perhaps what appears to be a contingent universe that could have turned out differently is really part of a larger physical reality that is necessarily generated by one simple and necessary principle: gravity.  This one basic principle is logically or mathematically necessary - it could not possibly have been other than it is.

But I ask, is gravity alone really so self-evident, so necessary that it should exist instead of nothing?  By itself, is it so great a thing that it can exist actively and of its own accord, rather than being caused to exist?  Is this basic mathematical/physical law really so self-sustaining, so powerful in a sense, that it can and must bridge the infinite gap between reality and nothing?  Wouldn't nothing at all make more sense than one basic law? [2]

The self-existent foundation of all reality must be something truly great.  It must explain itself to some degree, as an alternative to nothing.  In my view, gravity alone doesn't have that kind of explanatory power.  Do you ever have moments, as I do, when you glimpse for a brief second that, instead of nothing at all, there is a reality?  If we are careful not to take existence for granted, but instead to recognize it for the shocking and troubling and mysterious and wonderful fact that it is, we may not be content to say, "ah, gravity - that explains why anything should exist."

Hawking, like other philosophically-minded scientists, has used the word "God" to describe the laws of physics.  He is definitely on to something here.  Believers may be afraid of deifying mathematics or the laws of physics, preferring to think of them as entities created by God.  But there is nothing wrong with supposing that this basic principle (perhaps gravity) is part of God's own divine nature, that is, in saying that while God is more than the necessary laws of mathematics or physics, he might not be less.  This is perfectly consistent with traditional ideas of God.  The Christian idea of the Trinity, for example, implies that number is inherent to God's very being (see "A Theology of Mathematics"), and if mathematics, why not necessary mathematical laws?

You might ask, why make God more than this basic law?  Doesn't that explain things well enough?  In my view, it does not.  The world may be built on physics, but it is more than that.  Beauty, moral truth, purpose, love...these are objective realities that cannot be fully accounted for by scientific explanations* (see "Dawkins, the God of the Gaps, the Domain of Science, and the Question of Existence").  Only ultimate Love and Beauty at the foundation of reality can adequately account for these deep and moving realities.  Only ultimate goodness and power can account for our confident and reasonable intuition that there is a good purpose for human existence.
*Although they may in part: see "Evolution as God's Instrument."

Hawking says there is no need for hypothesizing a personal God.  If you're only looking at the world on a physical, scientific level, this is true.  But if you open your eyes to the whole of reality, which is far greater than the sum of its parts, you might wonder whether gravity alone can explain it all.  We need all of God, not just part of him (and the law behind gravity might be that).  Hawking invokes gravity instead of God to "set the Universe going."  I would rather invoke them both together: gravity to account for things on a scientific level, and God as the greater reality and context within which we can understand the existence of gravity - and everything else we experience - in better light.

[1] The obvious question for the believer is "where did God come from?"  When I ask where gravity came from, I only mean to imply that it cannot explain its own existence.  In my view, God does have this kind of explanatory power.
[2] Again, the related question the believer must face is "wouldn't nothing at all make more sense than God?"  Our answer must be that God, if we were able to comprehend him as he is, would clearly be more self-evident and more obvious than nothingness.  Gravity is not the whole picture - God alone is so great that he explains his own existence.

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