On the Vastness of the Universe
|August 30, 2010||Posted by Barry Arrington under Intelligent Design|
Nevada is mostly empty; I mean really empty. Ninety percent of the state’s residents live in the vicinity of Las Vegas or Reno, and the rest of the state is all but uninhabited. I realized just how empty the state is when I was riding my motorcycle across the desert last month, and I passed a sign that said “Next Gas 167 Miles.” They weren’t kidding. My bike’s range is only a little over 200 miles, and if I hadn’t stopped to top off my tank, I would have run out of gas in the middle of the desert.
This is the kind of riding I love the best. Riding hour after hour through a vast emptiness, alone with my thoughts, the wind in my face, and the deep-throated throb of my engine in my ears, fills me with a peace and joy that is difficult to describe. One day my two friends and I decided to just keep on riding after the sun went down, and at about 11:00 we stopped in the middle of the desert and turned off our motorcycles. There was no moon that night and the wind had died down. No other vehicles were on the highway, so we were alone in the quiet darkness, the only sound the pinging noises made by our engines as they cooled in the night air.
Hundreds of miles from the lights of the nearest city, the night sky was stunning. The Milky Way was clearly visible from one horizon to the other. Antares glowed like a tiny ruby in the heart of Scorpio. My friends and I just stood there, gaping in awed silence at the numberless points of twinkling light in the celestial sphere. Then John said, “I wonder why God made the universe so big.”
John’s comment got me to thinking. Why is the universe so big, with billons of galaxies and with each galaxy containing billions of stars, there are more stars in the universe than grains of sand in all the beaches of the world.
The vast size of the universe along with the earth’s comparative insignificance have often been used as an argument against the Christian view of God. The argument goes something like this: When our poor benighted ancestors thought we lived in a cozy little universe that revolved around the earth at its center, the Christian view of God might have made sense. But now we know better. We have the Copernican Principle (or the “Principle of Mediocrity”), which tells us that the universe is not cozy, and the earth is not at its center. The universe is larger than we can possibly understand, and, cosmically speaking, the earth is an insignificant speck of dust orbiting a slightly less insignificant speck of dust in one galaxy out of billons. Surely God would not create such a vast universe to support only life on earth; now that would be a waste of a truly cosmic proportions.
As it turns out, there are good reasons to doubt every premise of this argument.
1. The Ancients Were Not Stupid.
Let’s deal with the first assertion, that the ancients believed we live in a small universe. Consider Psalm 8: “When I consider your heavens, the work of your fingers, the moon and the stars, which you have set in place, what is man that you are mindful of him, the son of man that you care for him?” The psalmist looked at the multitude of stars in the night sky and realized that he was tiny and insignificant in a vast universe. It is truly a conceit of the modern age that the ancients naively believed they lived in a small and cozy universe in which the earth and man figured significantly, and that only now with our telescopes and other instruments of science do we understand the vastness of the universe and our relative insignificance.
Consider also Ptolemy’s Almagest, which was written in the early 100’s AD. It was the standard text on astronomy for over a thousand years. In chapter 5 of book I of the Almagest, Ptolemy writes: “The earth, in relation to the distance of the fixed stars, has no appreciable size and must be treated as a mathematical point.” So it turns out that the ancients were not as naive about the size of the universe as modern skeptics would have us believe.
2. The Earth is Almost Certainly a Very Special Place
No one supposes that the Earth is at the exact geometric center of the universe anymore. Nevertheless, there are good reasons to believe that it is a very special place, perhaps even unique. In recent years astrophysicist Guillermo Gonzalez has led the way in demonstrating that the existence of life is far from likely. In fact, it is exceedingly improbable and the conditions of the Milky Way galaxy, the sun, the solar system, the moon and the earth itself are remarkably fine-tuned for the existence of life.
According to Gonzalez, “The claims by many Copernican Principle advocates over the centuries, that life is commonplace on other celestial bodies, has been a spectacular failure. . . . Since it is Earth’s ability to support life that many take to be its most important quality, it is clear that this is a major failure of the metaphysical version of the Copernican Principle if the actual conditions which support life are so rare that they may only exist for Earth.”
3. The Universe is Exactly the Right Size
Finally, it turns out that the universe is not “too big” after all. In fact, it is exactly the size it must be in order to support life. Rich Deem summarizes just a few of the “just right” parameters which make the universe ideal for the existence of life:
It turns out that the universe could not have been much smaller than it is in order for nuclear fusion to have occurred during the first 3 minutes after the Big Bang. Without this brief period of nucleosynthesis, the early universe would have consisted entirely of hydrogen. Likewise, the universe could not have been much larger than it is, or life would not have been possible. If the universe were just one part in 10^59 larger, the universe would have collapsed before life was possible. Since there are only 10^80 baryons in the universe, this means that an addition of just 10^21 baryons (about the mass of a grain of sand) would have made life impossible. The universe is exactly the size it must be for life to exist at all.