Thursday, February 25, 2016

Gravity Waves and the Cosmological Argument

The scientific community has been greatly excited by the recent detection of gravity waves which had been predicted by Einstein's theory of general relativity one hundred years ago. Their detection is yet another confirmation of the truth of Einstein's theory and this, in turn, has an interesting philosophical consequence. It reinforces one of the strongest arguments for the existence of God, or something very like God.

Bruce Gordon at Evolution News and Views explains:
The gravity waves detected at the Laser Interferometer Gravitational-Wave Observatory (LIGO) were produced by the collision of black holes about a billion years ago and say nothing about the truth or falsity of inflationary cosmology. What this discovery really provides is additional and exceedingly strong confirmation of Einstein's already well-confirmed theory of general relativity by directly establishing the existence of gravity waves and giving further evidence of the existence of black holes.

The significance of discoveries confirming general relativity relate to one of the implications of the theory itself. As Roger Penrose and Stephen Hawking demonstrated in the late 1960s, regardless of which solution of Einstein's equations is embraced, all backward-traced spacetime geodesics in classical general relativity terminate in a singularity, implying that space-time, matter, and energy all came into existence at some point in the finite past. This, of course, is the essence of Big Bang cosmology.

In other words, the universe began to exist, and there is no physical explanation in cosmology or physics for why this happened. This opens the door to various cosmological arguments, including, of course, the Kalam argument....
The Kalam argument, whose most notable modern defender has been philosopher William Lane Craig, goes like this:
  1. Whatever begins to exist has a cause of its beginning to exist.
  2. The universe began to exist.
  3. Therefore, the universe had a cause of its beginning to exist.
The argument is superficially very simple although arguing for the two premises can get pretty technical. The discovery of gravity waves adds another layer of confirmation on top of the already well-confirmed second premise. Philosophers who wish to avoid the conclusion of this argument have to cast doubt on either the first or second premise, and the progress of science keeps making it harder and harder to do that.

One common, but misplaced objection, is that the argument does nothing to show that the cause of the universe is the God of traditional theism, but this is not correct. The universe is the sum of all contingent entities (i.e. entities which could possibly not exist), including all space and time. Thus, whatever caused such a thing to exist must itself be non-contingent (i.e. it cannot not exist), must be immaterial (since matter is contingent and came into being when the universe did), must transcend space and time (both of which came into existence when the universe did), must be incredibly powerful and intelligent (to cause such a thing as our vast universe), and must be personal.

One reason for imputing this last trait to the universe's cause is that the only potential entities which might at least partially fit the description stated above are either abstract objects, like numbers or platonic forms, or a mind. But abstract objects do not have causal powers and are not intelligent. The number three, for example, can't bring anything into existence. Only minds, which are personal, can do that.

Now it's true that the above description is not an exact fit with the God of theism who is also believed, at least in Christian theism, to be a trinity and perfectly good, but it's pretty close. Too close, in fact, for an atheist to take any comfort in the fact that the argument doesn't lead all the way to the God of Christian theism. It still leads to a being which is very much like the Christian God and which, if such a being exists, renders atheism false.

Here's a short video illustrating the foregoing argument: