Philosophy of Religion, Part 3: Craig's Kalam Cosmological Argument

Readings: "The Existence of God and the Beginning of the Universe" by William Lane Craig, and a brief selection from J. L. Mackie's book The Miracle of Theism.

I imagine that anyone reading this has already encountered the famous Kalam cosmological argument, which goes like this:

1. Everything which begins to exist has a cause
2. The universe began to exist
3. Therefore, the universe has a cause

You'll notice that nowhere in the argument does it say "therefore, God exists." A person might see this argument out of context and never suspect that it's trying to support theism. This is perhaps the argument's greatest weakness - it proves nothing about God on its own (why can't the cause of the universe be something else - maybe a physical starting point that we can't perceive, or something incomprehensible?). Instead, as reported by a (theistic) classmate of mine, not even Craig thinks of this as a standalone argument for the existence of God. Rather, it is meant to be one piece of evidence in a cumulative case for the existence of God. If the universe does not have a cause, then certainly God does not exist. But if the universe does have a cause, then a creator is at least one possibility, one which must be justified by further means. At the very end of his article, Craig offers a brief supplemental argument that the cause of the universe must be personal. He writes:

"In fact, I think that it can be plausibly argued that the cause of the universe must be a personal Creator. For how else could a temporal effect arise from an eternal cause? If the cause were simply a mechanically operating set of necessary and sufficient conditions existing from eternity, then why would not the effect also exist from eternity?"

Philosophy of Religion, Part 2: Swinburne's Induction

This is the second post about my Philosophy of Religion class. The readings I will discuss today were theologian Richard Swinburne's "The Existence of God" and A. C. Grayling's "Why I Am Not a Believer."

I won't talk much about Grayling's paper, as it is the usual atheistic rant against religion in its many forms. Without context, I wouldn't have been able to distinguish the essay from a passage of "The God Delusion." I was disappointed that our instructor did not select a reading which responded directly to arguments of the sort made by Swinburne. But maybe this was the point. As Grayling writes,

"Part of the sleight of hand at work here becomes obvious when one notes the great difference between what ordinary votaries of a religion believe and what their theologians and high priests say."

 The God that Swinburne defends bears little or no resemblance to the God of religious dogma which people really seem to want to believe in. Without the additional filter of religious tradition, his conception of God is virtually irrelevant to daily life, and might as well lead to a humanistic ethical outlook.

But what is Swinburne's conception of God (as presented in the essay), and how does he arrive at his conclusion? He acknowledges that a deductive inference of God's existence, in which the conclusion is mandatory given the premises, will not hold water. "It is most implausible," he says, "to suppose that such a statement as 'there is a physical universe but no God' ... contains any internal contradiction." Instead, Swinburne uses what he calls an "inductive inference". (Well, "induction" seems to imply an inference to the continuation of a pattern that has happened in the past; it might be better to characterize his argument strategy as "inference to the best explanation," for it is hard to establish a pattern when you only have one universe to reason from). He lays out four criteria that make for good induction, given a hypothesis H and observed phenomena P:

1. If H is true, then one ought to expect P
2. If H is false, then P is very improbable
3. H is simple (i.e., postulates "the existence and operation of few entities, few kinds of entities, with few easily describable properties behaving in mathematically simple kinds of way.")
4. H fits with our background knowledge

Reasonable enough. Now, Swinburne constructs his argument from three pieces of evidence:

1. Why a physical universe exists at all
2. Why this universe obeys orderly physical laws, rather than seethes in chaos
3. Why this universe is fine-tuned to allow the evolution of complex life

Creation Museum: the Failure of Creationist Astrophysics

Last weekend, I went down to Petersburg, Kentucky with a few people from SSA to visit the Creation Museum. Like a lot of things Answers in Genesis does, the Creation Museum seems to offer surprisingly accurate information at first glance, but once they start trying derive their erroneous conclusions from the evidence, it all goes horribly wrong. Case in point, the planetarium show.

It began as a pretty neat presentation of the various constellations visible from our solar system, as well as the various types of stars in them, showing their different colors and relative sizes. So far, so good. Then the narrator of the show began talking about the different life spans of various types of stars. Red stars are relatively cool and burn their fuel slowly, while blue stars are relatively hot and burn through their fuel quickly. Blue stars, according to the narrator, are “a reminder of our universe’s young age.” Wait... what? Indeed, all blue stars are comparatively young, but in this context “young” potentially means several million years old, and the ones we’ve seen blow up were definitely pretty old when they died. Aside from that, let’s examine the logic of this statement: essentially what the narrator said was that “since some things are young, nothing can be old.” That statement was the first car derailed in the trainwreck to come.

Different types of main-sequence stars. Massive blue stars squander their hydrogen fuel in only a few million years, while tiny red stars can make their fuel last for over a trillion years. More info here.

The focus of the presentation then moved to the planets we've discovered orbiting these other stars. Since large planets with short orbital periods are the easiest to detect, a large number of the planets we've discovered thus far have been so-called "Hot Jupiters" - gas giants roughly the size of Jupiter, or bigger, orbiting absurdly close to their parent star (some of them orbit their star closer than Mercury orbits our Sun). Before Hot Jupiters were discovered, it was thought that they shouldn't exist. The area near a star is too hot for gases to condense and form planets. Clearly, they must be the work of God, right? Well, what the narrator neglected to mention was that planets are now known to migrate early on in solar system formation. Interactions with the dust in the star's accretion disk and with other planets can cause new planets to drastically change their orbits before they reach stable ones. Hot Jupiters must have formed farther away from their stars and then migrated inward.

Hot Jupiters: they're very hot. More info about this picture here.

After finishing up talking about our galaxy, the narrator begins talking about other galaxies. He answers a question frequently asked by people who know what a light-year is: “If the universe is only 6,000 years old, how is it that we can see galaxies millions and even billions of light-years away?” The answer: “gravitational time dilation.” That’s right, an effect of relativity - a theory partly built on the principle that the speed of light in a vacuum is always the same - causes the speed of light in a vacuum to be much faster than the speed of light in a vacuum. That’s how light from distant galaxies is able to reach us in such a short time. Obviously, gravitational time dilation has no effect whatsoever on the speed of light. Gravity warps both space and time in such a way that the speed of light remains the same. Besides, there’s not enough gravity in between galaxies to cause this effect to any appreciable extent anyway. Usually when gravitational time dilation comes up, it’s either in the context of extreme gravity (near a black hole or neutron star) or when we have a need for extremely precise clocks (like we do in GPS satellites).

Contrary to what evolutionists would have you believe, it does not take light a year to travel a Lightyear. The unit is named for the famous space explorer, and vanquisher of Zurg, Buzz Lightyear.

The narrator then pointed out his last bit of evidence for a young universe: spiral arms. The claim was that if spiral galaxies are billions of years old, their spiral arms should have wound up so tightly by now that they would be unrecognizable as arms (since inner stars take less time to go around the galaxy than outer stars). This argument reveals a complete failure on the narrator’s part to understand what spiral arms are. They are not groups of stars that orbit the galaxy along with their constituents, they are self-perpetuating density waves that stars pass through as they orbit the galaxy. The arms maintain themselves in the following way: as stars approach a spiral arm, the extra gravity from the arm causes the stars to speed up; as they begin to leave, they slow down and end up spending a disproportionate amount of time within the arm. The reason why we can see spiral arms so clearly in other galaxies is because of the presence of bright blue stars, newly formed from the comparatively dense interstellar medium in the arms (since blue stars only live for a few million years, they die before they leave the arms). Longer, more detailed explanation here.

Stars go in, stars go out. Astronomers have explained that.

As I got up to leave the planetarium at the end of the show, I immediately regretted not speaking up to correct the errors in the show more audibly. Not only because getting kicked out of the Creation Museum would have been funny, but also because I genuinely think that at least some small fraction of the other people in that planetarium actually wanted to learn about astrophysics, and were deprived of that because of their poor choice (or their parents' poor choice) of venue. If I could have gotten even one of these curious, but misinformed, people to question the creationist narrative and do their own investigation, I would have been much more satisfied with relinquishing my $38 to that museum.