



How Old is the Earth A Response to “Scientific” Creationism by G. Brent Dalrymple,

U.S. Geological Survey

Menlo Park, California

[The article: 1984]

[Posted: January 10, 2006] Copyright © 1984-2006[The article: 1984][Posted: January 10, 2006] [From “Evolutionists Confront Creationists”, Awbrey, F. and Thwaites, W. (eds.). Proceedings of the 63rd Annual Meeting of the Pacific Division, AAAS 1, Part 3, California, AAAS. pp. 66-131. Scanned and annotated by Jon Fleming, December 2005. All notes and references are from Dalrymple unless otherwise indicated. All material except the Addendum and notes indicated as being by Jon Fleming are copyright © 1984 G. Brent Dalrymple and are reproduced with permission of the copyright owner.]

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he proponents of “scientific” creationism (for example, 54, 77, 90, 92, 95, 96, 135) claim to have developed a legitimate scientific model for the creation and history of the universe that explains extant scientific observations as well as, if not better than, the current theories and concepts of biology, chemistry, physics, geology, and astronomy. Even a cursory reading of the literature of “scientific” creationism, however, reveals that the creation model is not scientifically based but is, instead, a religious apologetic derived from a literal interpretation of parts of the book of Genesis. Indeed, this literature abounds with direct and indirect references to a Deity or Creator, and citations of the Bible are not uncommon (for example, 22, 77, 90, 91, 96, 97, 99, 131).

The tenets of “scientific” creationism include the beliefs that the Earth, the Solar System, and the universe are less than 10,000 years old (13, 77, 92, 116, 117) and that nearly all the sedimentary rocks on the Earth were deposited in about one year during a worldwide flood (29, 77, 92, 131). Both of these propositions are disproved by a vast and consistent body of scientific evidence.

The ages of the various rock formations, the Earth, the Moon, and meteorites have been measured using radiometric (also called isotopic) dating techniques — atomic clocks within the rocks themselves that, if properly used, reveal the elapsed time since the rocks formed. There is overwhelming scientific evidence that the oldest rocks on the Earth are 3.6 to 3.8 billion years old, that the oldest rocks on the Moon are 4.4 to 4.6 billion years old, and that the Earth, the Moon, and meteorites all formed about 4.5 to 4.6 billion years ago. In addition, these same dating techniques have conclusively verified and quantified the relative geologic time scale (Figure 1), which was independently deduced by stratigraphers and paleontologists on the basis of nearly two centuries of careful scientific observations of the sequence of sedimentary rock units and fossils.

In spite of massive evidence to the contrary, creation “scientists” continue to defend their belief in a very young Earth. Their arguments fall generally into two categories: The first involves criticisms of radiometric dating techniques and data; the second involves various calculations that they claim provide quantitative evidence that the Earth is young. In this paper I explain briefly how radiometric dating methods work and the principal evidence that the Earth is 4.5 to 4.6 billion years old. I also examine in detail some examples of the creationists’ criticisms and calculations and show that they are scientifically meaningless.

Figure 1: Simplified geological time scale. The relative order of the eras, periods, and epochs was determined on the basis of stratigraphy and paleontology. The time scale was independently confirmed and quantified by radiometric dating. After Harbaugh (61). Ages are based on the new decay constants adopted by the International Union of Geological Sciences.

I dedicate this paper to the memory of Max Crittenden, who died of cancer on Thanksgiving Day, 1982. Max was not only a friend and colleague, but was a leader in the effort to preserve the integrity of California science textbooks against the creationists’ attack in the early 1970s. Max was a constant source of encouragement and support in many matters, but especially in my efforts to expose the glaring errors in the creationists’ propaganda about the scientific evidence for the age of the Earth and the vastness of geologic time.

I thank my friends and colleagues Patrick Abbott, Calvin Alexander, Frank Awbrey, Arthur Boucot, Stephen Brush, Max Crittenden, Norman Horowit, Thomas Jukes, Arthur Lachenbruch, Marvin Lanphere, Robert Root-Bernstein, John Sutter, and Christopher Weber, who read an early draft of the manuscript and offered valuable comments, suggestions, and encouragement.