In the first two parts of this series (see here and here) I discussed how secular scientists, given their naturalistic worldview, expected to discover that we live in an eternal—and therefore uncaused—universe, as well as in an ordinary solar system. Yet on both scores scientists were surprised by what scientific advances revealed. In both cases, the great contrast for scientists who hold a purely secular worldview is that the universe’s and solar system’s features seem to best comport with the expectations of theism over atheistic naturalism.
In this article I will briefly discuss how the specific expectations of secular scientists concerning Earth’s characteristics were also very different from what science has shown. Again, the results follow a similar pattern of favoring the expectations of one worldview over another.
The Rare Earth Hypothesis
The consensus of secular scientists a half-century ago was that the earth is not a special planet, but rather a mediocre one, with no rare or unique significance. Many scientists thought that since Earth is not at the center of the universe, then it is merely ordinary. For example, in the 1970s and 1980s scientists like Carl Sagan and Frank Drake described the Earth as a typical rocky planet in a nonexceptional place in an ordinary galaxy.
However, this initial expectation has been challenged. The rare Earth hypothesis holds that the earth is distinct as a planet and may even be special. University of Washington scientists Peter D. Ward and Donald Brownlee have led the way in representing this perspective in their book Rare Earth: Why Complex Life Is Uncommon in the Universe.
They argue that the universe is fundamentally hostile to complex life and that microbial life may be common. However, the evolution of biological complexity from simple life on Earth requires an exceptionally unlikely set of circumstances; therefore, complex life is probably extremely rare.
“[A]mong the essential criteria for life are a terrestrial planet with plate tectonics and oxygen, a large moon, magnetic field, a gas giant like Jupiter for protection and an orbit in the habitable zone of the right kind of star.”1
Not all scientists accept this rare Earth view, and some have criticized the hypothesis (see here). Yet scientists who embrace a purely naturalistic worldview expected Earth to prove to be commonplace, but instead they discovered viable reasons to think otherwise.
The rare Earth hypothesis seems to comport well with a theistic, even biblical, worldview, but appears unexpected and out of place from an atheistic, naturalistic perspective. So what would Earth look like if biblical theism were true? Evidently much like it appears right now.
In part four I’ll discuss the topic of human exceptionalism and what scientists anticipated and have discovered about it.
Reflections: Your Turn
For Christians, what does living on a planet that seems specially designed to allow for human life invoke? Visit Reflections on WordPress to comment with your response.
- For more on Earth’s unique features, see Hugh Ross, The Creator and the Cosmos, 4th ed. (Covina, CA: RTB Press, 2018), 199–222.
- For more on the argument to God from fine-tuning, see Kenneth Richard Samples, 7 Truths That Changed the World (Grand Rapids, MI: Baker, 2012), 113–15.