There are a number of examples of how the various forms of the cosmological argument play out in the real world. The second law of thermodynamics, for instance, is often used as an illustration. However, the best and most easily understood example may be the big bang theory.
In the 1920s Astronomer Edwin Hubble discovered that our universe was bigger than previously thought. In fact, it was much bigger. Before Hubble saw outside our galaxy, the prevailing thought was that our galaxy was the entire universe. He was the first to recognize that ours was only one of billions of galaxies.
Late in the decade, Hubble was studying light from distant galaxies and found it was not what he expected. The light did not correspond to any known element or combination of elements. Then he noticed the light was uniformly shifted to the red side of the spectrum. All the characteristics he expected were still there, just at a slightly different location on the color spectrum. This phenomenon became known as the “red shift.”
