The more scientists are discovering about the universe, the more perplexed they are in trying to understand exactly how it works. Many are going to extremes, putting forth theories of extra dimensions and parallel universes. Most of the universe is made up of "dark energy," a completely unknown force that is pushing all of space apart.

"Then there is the 'fine-tuning' problem," writes Charles W. Petit. "The universe appears marvelously constructed to produce stars, planets, and life. Scientists have calculated that if the force binding atomic nuclei were just 0.5 percent different, the processes that forge atoms inside stars would have failed to produce either carbon or oxygen; —key ingredients to life. If gravity were only slightly stronger or weaker, stars like our sun could not have formed. Yet physicists see no reason why the constants of nature are set just so.

"To some, this is all good news. Perhaps, as many religious people say, God exists and wants it this way—; case closed. For many scientists, who try to avoid supernatural explanations, the accumulation of mysteries merely signals that the time is right for a breakthrough."