Young-earth creationism and the forest fallacy

Redwood Regional Park, near Oakland, California

Redwood Regional Park, near Oakland, California

Introduction

How old is the earth and its fossil layers? According to geologists, the earth is 4.56 billion years old, and the fossil layers, which document the proliferation of living species through the eons, are millions of years old.

Yet a 2014 Gallup poll found that 42% of Americans believed that God created humans essentially in their present form, within the past 10,000 years, and millions still believe the earth itself, if not the entire universe, was created only a few thousand years ago.

While such notions have no currency among mainstream scientists, a handful of “scientific creationists” continue to tilt against the windmills of modern science, arguing that the radiometric dating techniques used by geologists and other scientists are not valid.

The latest in this genre is a series of articles written by Vernon R. Cupps, who is affiliated with the Institute for Creation Research (ICR) in Dallas, Texas. Cupps analyzes several different types of radiometric “clocks” and concludes:

Evolutionists may claim that radioactive dating methods prove the earth’s strata to be millions of years old, but they won’t tell you that those methods are built on a house of cards that cannot bear the weight of scientific scrutiny.

So what are the facts here? Are radiometric techniques, which used by scientists to measure the ages of the geologic eras, indeed “built on a house of cards”? Are there grounds for “reasonable doubt” about the geologic ages?

Analysis

In reading through Cupps’ articles, one admires his tenacity. He is evidently much more knowledgeable about this subject matter than most creationists. His frequent use of sophisticated scientific terms, formulas, facts and figures may impress many readers, even some with scientific training. But in the end, these arguments fall far short of anything that truly constitutes a substantive challenge to the scientific consensus.

Here are just a few of the difficulties with this material:

  1. To begin with, it should be emphasized that this material has not appeared in any peer-reviewed scientific forum. If Cupps truly believes that he has identified some issues that challenge, even tangentially, any of the established radiometric dating techniques, then he needs to write up the results as a no-nonsense technical report and submit it to a reputable scientific journal in the field.
  2. Cupps’ series starts with a quote from David Gross, a Nobel-prize-winning physicist who, at the 2005 Solvay Conference in Physics in Brussells, Belgium lamented that “The state of physics today is like it was when we were mystified by radioactivity. They were missing something absolutely fundamental. We are missing perhaps something as profound as they were back then.” But the topic of this conference was “The Quantum Structure of Space and Time,” a topic far, far removed from the basic and very well understood physics of radiometric dating. It is, in the present author’s view, completely inappropriate for Cupps to use this quotation here.
  3. Cupps asserts that “Diffusion rates of 4He (helium) … suggest that only thousands of years of decay have occurred.” But it is well known that helium leaks very rapidly out of minerals at relatively low temperatures. When these diffusion rates are properly measured, they are consistent with the amount of 4He loss necessary to explain these discrepancies. Indeed, 4He retention ages in the millions and even tens of millions of years are routinely measured, representing the most recent time that the mineral in question sufficiently cooled.
  4. Cupps claims that the potential for variations in rates of radioactivity discredits these radiometric techniques. But as noted geochronologist Brent Dalrymple explains,

    Although changes in the decay rates of a few elements have been observed under special circumstances, no changes have ever been detected in any of the nuclides used for dating, and none of significance is theoretically expected.

    Cupps asserts that alpha-decay rates of 228Th may be increased by a factor of 10,000 under conditions which give rise to pressure waves, and “these conditions could easily have existed during the Flood.” But Cupps fails to mention that these variations were produced in special piezoelectric experiments, not in an environment that could naturally arise in geological strata.

  5. Cupps asserts that many radiometric measurements involve a “homogeneity assumption.” But modern mass spectrometers used in radiometric dating can obtain reliable dates even from microscopic-sized grains of material, such as a single zircon, so that homogeneity is no longer a significant issue. For example, the SHRIMP mass spectrometer can obtain a reliable age on a specimen as small as 30 microns.
  6. Cupps claims that uncertainties in measurements of the half-life of various isotopes, such as the 87Rb to 86Sr decay, render age measurements unreliable. But the Rb-Sr decay is now known quite precisely as 48.8 billion years. Cupps mentions earlier measurements of 47.7 billion in 1964 and 49.7 billion in 2003. But it obviously does not matter one iota whether the half-life is 47.7 billion, 49.7 billion or 48.8 billion years. Such differences would only make one or two percent difference in any age measurement — e.g., a geologic date of one billion years might be reduced to “only” 980 million years, not even remotely in the ballpark claimed by young-earth creationists. It is disingenuous to suggest otherwise.

With regards to item 4 (variations in rates of radioactivity), it should be noted that scientists do indeed have “time machines” that can peer into the distant past and ascertain whether rates of radioactivity were the same back then. For example, in 2011, when astronomer Peter Nugent observed a new supernova explosion in the Pinwheel Galaxy (21 million light-years away), he and his team observed the laws of physics in general (and of radioactivity in particular) playing out in exquisite detail, identical to experiments in laboratories today. This is in spite of the fact that this explosion occurred 21 million years ago.

Reasonable doubt?

Cupps’ general approach in this material will be familiar to anyone who has studied courtroom strategy — the defense attorney highlights anomalies in the prosecution’s case, in an attempt to raise “reasonable doubt” in the mind of the jury.

For example, Cupps emphasizes the fact that certain radiometric measurements have been wrong. He cites the example of rocks taken near a volcano in New Zealand that were variously dated at 3.5 million, 133 million, 200 million or more years old, yet the rocks were known to be less than 60 years old. Let us ignore for the moment whether these techniques are even appropriate for measuring dates of such a sample (which, if taken in a salt water environment, can be distorted by known effects), and simply accept the fact that these measurements were incorrect, for whatever reason. Does any of this invalidate the science of radiometric dating?

Unfortunately for creationists, there are a lot more than a handful of radiometric dates in published literature. Most likely there are over 100,000 individual measurements, in tens of thousands of carefully conducted and peer-reviewed studies, with radiometric ages measured in state-of-the-art laboratories, and results published in reputable scientific journals. Each year thousands of new measurements, using the latest technologies and methodologies, are added to the literature.

As a single example of the current state-of-the-art in the field, in February 2013, an international team of researchers led by U.C. Berkeley geochronologist Paul Renne, using a state-of-the-art argon-argon technique, found that a large comet or asteroid impact in the Yucatan peninsula area occurred 66,038,000 years ago, and the global mass extinction at the time occurred 66,043,000 years ago. Given that these dates differ by no more than the statistical error bars of the measurements (11,000 years), they are essentially identical. Thus these new findings offer dramatic confirmation to the theory that the comet or asteroid impact caused the extinction (although climate-related phenomena prior to that time may have exacerbated stress on these species).

The forest fallacy

But even if one takes many of Cupp’s arguments and examples at face value, what is more likely: (a) that the examples he highlights are possibly unexplained instances of experimental error?; or (b) that over 100,000 carefully conducted peer-reviewed measurements, including the Yucatan comet-asteroid study mentioned above, are all simultaneously mistaken, not merely off by a few percent but by factors of thousands and millions from their true values? Obviously the first choice, the scientific consensus, is incomparably more likely.

This is a classic instance of the “forest fallacy” — finding a few faults with some bark here and there, and then trying to assert that the entire forest doesn’t exist.

In other words, it isn’t good enough for Cupps to pick a few faults at some of the vast literature of published results. Instead, he and his colleagues must demonstrate, using solid scientific reasoning and data, written up in soberly written technical reports and submitted to a reputable scientific journal, why essentially all of these measurements are wrong: did they all make the same mathematical error? (exceedingly unlikely); did they all make the same experimental error? (exceedingly unlikely). Criticizing some techniques and individual measurements, but leaving many, many others untouched, just won’t cut it.

The forest still stands.

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