In “I Don’t Have Enough Faith to be an Atheist” Norman Geisler and Frank Turek say:
The extent of the universe’s fine-tuning makes the Anthropic Principle perhaps the most powerful argument for the existence of God. It’s not that there are just a few broadly defined constants that may have resulted by chance. No, there are more than 100 very narrowly defined constants that strongly point to an intelligent Designer. We’ve already identified five of them. Here are ten more:
1. If the centrifugal force of planetary movements did not precisely balance the gravitational forces, nothing could be held in orbit around the sun.
2. If the universe had expanded at a rate one millionth more slowly than it did, expansion would have stopped, and the universe would have collapsed on itself before any stars had formed. If it had expanded faster, then no galaxies would have formed.
3. Any of the laws of physics can be described as a function of the velocity of light (now defined to be 299,792,458 meters per second). Even a slight variation in the speed of light would alter the other constants and preclude the possibility of life on earth.
4. If water vapor levels in the atmosphere were greater than they are now, a runaway greenhouse effect would cause temperatures to rise too high for human life; if they were less, an insufficient greenhouse effect would make the earth too cold to support human life.
5. If Jupiter were not in its current orbit, the earth would be bombarded with space material. Jupiter’s gravitational field acts as a cosmic vacuum cleaner, attracting asteroids and comets that might otherwise strike earth.
6. If the thickness of the earth’s crust were greater, too much oxygen would be transferred to the crust to support life. If it were thinner, volcanic and tectonic activity would make life impossible.
7. If the rotation of the earth took longer than twenty-four hours, temperature differences would be too great between night and day. If the rotation period were shorter, atmospheric wind velocities would be too great.
8. The 23-degree axial tilt of the earth is just right. If the tilt were altered slightly, surface temperatures would be too extreme on earth.
9. If the atmospheric discharge (lightning) rate were greater, there would be too much fire destruction; if it were less, there would be too little nitrogen fixing in the soil.
10. If there were more seismic activity, much more life would be lost; if there was less, nutrients on the ocean floors and in river runoff would not be cycled back to the continents through tectonic uplift. (Yes, even earthquakes are necessary to sustain life as we know it!)