Entropy of the Universe

Entropy of the Universe

Entropy measures the amount of decay or disorganization in a system as the system moves continually from order to chaos. By that definition I have one of the most entropic offices at Reasons to Believe. More discouraging yet, the entropy in my office is increasing.

But I am not alone.

No matter if it’s an office or something much grander like the Moon, Sun, and even our own galaxy, we observe an increasing buildup of decay or entropy (for a common example of entropy, see figure below).

Figure: Ice melting at room temperature is an example of increasing entropy.

Photo credit: Jon Sullivan, released into the public domain.

Astronomers observe that the entropy measure of the whole universe is increasing at an astonishing rate. But astronomers were not the first to take note of the universe’s headlong rush into increasing disorder and decay. Some 1,800 years before astronomers’ discovery of entropy, the apostle Paul under the inspiration of the Holy Spirit wrote, “The whole creation groans…subject to its bondage to decay.”1

Yet increasing decay is not all bad. Physical life is possible because universal entropy  increases. All organisms take advantage of increasing entropy to run metabolic reactions, such as digestion and energy production. Work is possible because of the universe’s increasing entropy. And because work is possible, human creative activity is possible. With this miraculous creation in mind, our family spends some time on Thanksgiving Day expressing gratefulness to God for making the universe as entropic as He did.

The entropy measure of the universe is important for several other reasons.

  • It determines which features of the universe are reversible and which are not.
  • It constrains the evolutionary history of the universe.
  • In so doing, it can establish which cosmic creation models are valid and which are not.

Thus, measuring the entropy level of the universe sheds light on both the beginning and the end of cosmic history.

In 2003, 2008, and 2009, different teams of astronomers measured the entropy budget of the universe.2 In February 2010, two Australian astronomers, Chas Egan and Charles Lineweaver, improved upon the previous cosmic entropy budget calculations by using the latest measurements of the supermassive black hole mass function.3 (All medium- and large-sized galaxies contain at their centers supermassive black holes with masses ranging from a few hundred thousand to 18 billion times the mass of the Sun.) Egan and Lineweaver found that supermasssive black holes are the largest contributor to the observable universe’s entropy. They showed that these supermassive black holes contribute about 30 times more entropy than what the previous research teams estimated.

Establishing the cosmic entropy measure as 30 times higher than previous estimates significantly strengthens the biblical doctrine of the universe expanding from a single cosmic beginning. Such a high cosmic entropy measure effectively rules out any possibility for an oscillating or multiple-beginning universe. It also rules out speculation about a “fourth law of thermodynamics,” which allows a tiny volume element within the vast cosmos to experience natural flow from disorder and chaos to order and specified complexity so as to explain the origin of life.

It shows, too, that the universe is running out of energy for useful work at a much faster rate than astronomers once thought. It strengthens a point made in 2002 by astronomers Lawrence Krauss and Glenn Starkman that the universe provides only a temporary home for life.4 That is, the present universe offers no ultimate hope, purpose, or destiny for humanity. Only the new creation described in Revelation 21–22 can make such an offer.   

  1. Romans 8:20–22.
  2. Thomas W.Kephart and Y. Jack Ng, “Black Holes, Mergers, and the Entropy Budget of the Universe,” Journal of Cosmology and Astroparticle Physics 11 (November 2003): 011; Paul H. Frampton and Thomas W. Kephart, “Upper and Lower Bounds on Gravitational Entropy,” Journal of Cosmology and Astroparticle Physics 6 (June 2008): 008; Paul H. Frampton, et al., “What Is the Entropy of the Universe?” Classical and Quantum Gravity 26 (July 2009): id. 145005.
  3. Chas A. Egan and Charles H. Lineweaver, “A Larger Estimate of the Entropy of the Universe,” Astrophysical Journal 710 (February 20, 2010): 1825–34.
  4. Lawrence M. Krauss and Glenn D. Starkman, “Life, the Universe, and Nothing: Life and Death in an Ever-Expanding Universe,” Astrophysical Journal 531 (March 1, 2000): 22–30.