In this chapter, Strobel interviews William Lane Craig PHD, THD on whether evidence from astronomy suggests there is a creator.
Craig described the kalam cosmological argument. Kalam is Arabic for "speech" or "doctrine" and the argument is nearly a thousand years old, originating with Islamic theology. The argument has three premises:
1. Whatever begins to exist, has a cause
2. The universe began to exist
3. Therefore the universe has a cause
The first premise may be the hardest to support -- but no scientific experiment has ever created something from nothing. Nothing spontaneously exists. Even when new matter is created, it came from some other matter, or from energy.
The second premise is in the last hundred years is now beginning to become overwhelmingly evident. Most of history, it was believed that the universe has always existed, and Christians had to accept by faith that the universe was brought into existence by God. Now, evidence abounds that the universe had a beginning, and the onus is on science to provide an explanation that is more reasonable than God.
Craig provided two types of evidence that the world began.
1. A philosophical or mathematical argument: It is impossible for there to be an infinite amount of time before now, or there would have been an infinite amount of events that have occurred. The idea of infinity is purely conceptual. It's possible to deal with infinite quantities and ideas in our mind, but it is not descriptive of what can happen in the real world.
2. Astronomical evidence: The big bang, as much as Christian's tend to disagree with and disbelieve, is strongly supported. The most common evidence is that the universe is expanding, the universe is full of so-called background radiation. In 1929, Edwin Hubble first noticed that light from galaxies appears redder than it should. This red-shift is related to the Doppler effect that causes sounds to sound lower when objects are moving away from you. If the universe is expanding as we go forward in time, it suggests the universe would have been smaller further back in time. And in 1965, Penzias and Wilson discovered the universe's background radiation, which exists everywhere we look.
The thing is, Christians have no need to fear the big bang theory. The big bang theory might be able to describe what happened in the earliest moments of time, but it still doesn't describe the origin of the universe. After all, what caused the big bang? Perhaps God created the world using some of the ideas supported by the big bang -- perhaps He didn't and created the universe as described in Gen 1 -- but either way, the fact that science is convinced that the universe had a beginning in the first place makes belief in a creator much easier than when the universe was thought to have existed for all eternity.
The third premise is that the universe must have therefore had a cause.
Craig also described another common alternative to the big bang, Oscillating Model of the universe. This theory suggests that the universe expands and contracts, and expands and contracts, and really does exist forever. This theory might defeat the kalam argument and eliminate the need for a god, but it is not supported by evidence. Not only is the universe expanding, but its accelerating in its expansion. The known laws of physics. To contract, the universe would have to be dense enough to attract itself back together in the Big Crunch. The known amount of matter and known values of gravitational constants and expansion rates predicts the universe will never again contract. Craig also suggested that the laws of entropy suggest that even if the universe was in an oscillating state, the expansions would get bigger each cycle. If we go back in time, they are smaller and smaller, and even the Oscillating Model would have a beginning -- the very problem it was trying to avoid.