|Feature Article - June 2016|
|by Do-While Jones|
Uranium isotopes should be in equilibrium if the Earth is more than 2 million years old—but they aren’t.
Before we explain why uranium isotopes prove that there hasn’t been enough time for all the various forms of life to evolve, let’s begin by telling you the back story behind this essay.
Some might say it is a slight exaggeration to call Sean Pitman a “famous creationist,” but he certainly is well known in creationist circles. 1 He is the author of the book, Turtles All the Way Down. 2
Recently, on a religious website,3 he posted a rebuttal to ten common arguments against a young Earth. Those ten arguments involve tree rings, ice core layers, thick volcanic ash layers, DNA, potassium-argon dating, argon-argon dating, fission track dating, varves, and dinosaur soft tissues and radiocarbon. After discussing each of those in detail, he provided links to 11 arguments in favor of a young Earth. Those young Earth arguments are based on continental erosion rates, mountain sedimentary layer erosion rates, ocean sediment influx vs. subduction, detrimental mutation rate for humans, radiocarbon in dinosaur fossils, coal, and oil, preserved proteins in fossils, paraconformities, erosion rates between layers, pure thick coal beds, minimal bioturbation between layers, and worldwide paleocurrent patterns. He later posted another article on the subject. 4
We have addressed a few of these arguments in previous letters, but tend not to talk about them because this is a NEWS letter, and these arguments between creationists and evolutionists are decades old—they aren’t new. Furthermore, they appear on many creationist sites and in creationist books, so you have probably heard them already. There is no value added if we simply parrot these tired old debates.
We believe that although these Young Earth arguments are strong, they are not compelling because they tend to rely upon reasonable, but unverifiable, assumptions about rates and/or initial conditions.
In his post, Dr. Pitman did not provide a link to our argument for a maximum 2 million year age of the Earth based upon the ratio of uranium isotopes,5 possibly because he was unaware of it. As far as we know, we are the only ones to ever have advanced that argument. So, to get wider distribution, we mentioned it in a response to his blog post.
No evolutionist has ever written to us to refute our argument. One creationist, whose first name ironically is Darwin, tried to verify our numbers as soon as our essay was published, and was unable to do so. When he brought this fact to our attention, we discovered that there must be a numerical error; but after checking and rechecking our work, we could not find our error. Eventually, we realized that the error was in Table S-1 of the peer-reviewed article in the journal Science. The column heading of that table said that the numbers were the isotope ratios; but in fact the numbers were actually decay rate ratios. We ran a correction the following month. 6 Darwin confirmed the correction. The correction actually made our argument stronger.
So, our corrected argument has stood unchallenged for nearly four years. Still, we hoped that Dr. Pitman would examine our argument and evaluate it. Here is his response:
It’s an interesting but fairly complicated argument that really doesn’t seem to me to be clearly in favor of one side or the other (young or old Earth) – because of the primary reason that I don’t generally trust radioactive “clocks” to begin with. That is, rocks or crystals that contain radioactive materials aren’t really closed systems. In any case, here’s the basic argument you’ve presented on your website, as far as I can tell, and my problem with it in a nutshell.
After 2 million years, whatever amount of 234U that was originally created would all be gone – which seems pretty straightforward due to the relatively rapid decay rate of 234U. Therefore, all the 234U in the world today would have to have been created by the decay of 238U, and the rate that 234U is being created by the decay of 238U would equal the rate at which 234U was being lost through radioactive decay – which is good so far. So, everywhere uranium is found, the rate of production should equal the rate of loss. However, this isn’t what is generally found in real life. In real life there are places with much higher levels of 234U than there should be. Some places have up to eight times, or more, than the expected levels of 234U. How can such findings be explained?
One possibility, of course, is that the Earth itself is less than 2 Ma and that the original created level of 234U was quite high and has yet to be exhausted because of the Earth’s young age. However, another option (which seems much more likely to me) is that unequal contamination is to blame due to the fact that the rocks and crystals being evaluated simply aren’t closed systems. This scenario also seems more likely to me given the fact that almost all groundwater throughout the world has a ratio of 234U/238U that is >1 (evidently since 234U is a bit more water soluble than 238U). This throws everything off and makes the uranium clock completely unreliable as far as I can tell.
Fair enough. But rather than argue with him I simply asked,
Please give me the references for the facts that “almost all groundwater throughout the world has a ratio of 234U/238U that is >1” and “234U is more water soluble than 238U.”
He promptly responded with the requested references:
“In soils and rocks, the activity of 234U and 238U is identical; they are said to be in secular equilibrium. In natural waters, however, the 234U is slightly more soluble and the activity ratio of 234U to 238U varies from 1:1 to more than 20:1. Consequently, the conversion from activity to mass or vice versa, requires knowledge of the concentration of each of the three uranium isotopes.” 7
“238U decays via two very short-lived intermediates to 234U (Fig. 12.2). Since 234U and 238U have the same chemical properties, it might be expected that they would not be fractionated by geological processes. However, Cherdyntsev and co-workers (1965, 1969) showed that such fractionation does occur. In fact, natural waters exhibit a considerable range in 234U/238U activities from unity (secular equilibrium) to values of 10 or more (e.g. Osmond and Cowart, 1982). Cherdyntsev et al. (1961) attributed these fractionations to radiation damage of crystal lattices, caused both by emission and by recoil of parent nuclides. In addition, radioactive decay may leave 234U in a more soluble +6 charge state than its parent (Rosholt et al., 1963). These processes (termed the ‘hot atom’ effect) facilitate preferential leaching of the two very short-lived intermediates and the longer-lived 234U nuclide into groundwater. The short-lived nuclides have a high probability of decaying into 234U before they can be adsorbed onto a substrate, and 234U is itself stabilised in surface waters as the soluble UO2++ ion, due to the generally oxidising conditions prevalent in the hydrosphere.” 8
Before we address the substance of Dr. Pitman’s position, we would like to note the difference in tone between emails we get from creationists and emails from evolutionists. When we get emails from creationists who disagree with us, they politely state why they disagree, presenting facts relevant to their position.
If you look back over the emails from evolutionists we have published in past newsletters, you will see that evolutionists typically just make emotional attacks against me and religion. When pressed for specific factual errors, the general response is, “There are too many to list.” When asked for just one factual error on the list, they either don’t respond, or just make more personal attacks.
We have no doubt that Dr. Pitman is passionate about his beliefs—but his passion does not overrule his rationality. He knows what he believes, and has scientific reasons for his beliefs.
On the other hand, the emails we get from evolutionists indicate such an emotional bias that it is impossible to reason with them. Facts don’t matter.
Dr. Pitman provided evidence that water contains more 234U than one would expect. There is no argument about that. The question is, “Why is there so much?” Is it because 234U is more soluble? Or is it because there is more 234U available in rocks to be dissolved?
In the article that inspired our first essay on the topic,9 four of the six rocks analyzed to determine the age of the cave paintings (O-80, O-110, O-22, and O-69) had measurements of 234U that were higher than equilibrium. Sample O-110 had nearly an 8:1 ratio! Just two (O-30 and O-9) had ratios of less than 1. Two thirds of the rocks analyzed had decay ratios greater than 1, so there is evidence that some rocks have more 234U than expected to be available to dissolve.
In many locations, the ratio of uranium isotopes is not in equilibrium. Our argument is not based on a single, isolated place where uranium isotopes are not in equilibrium. It is commonly known (by people who measure these things) that uranium isotopes are often not even close to equilibrium.
Dr. Pitman’s first reference came from “Uranium in Drinking Water”, published by Radiation Safety Engineering, Inc. It deals with how to calculate the maximum uranium contamination levels in drinking water to see if they conform to Environmental Protection Agency regulations. It never occurred to them that these measurements would have anything to do with creation or the theory of evolution, so there is no creationist bias, or evolutionist bias, in these measurements. They measured ratios varying from 1:1 to 20:1 in water.
Dr. Pitman’s second link goes to chapter 12 of Radiogenic Isotope Geology by Alan P. Dickin, Professor, School of Geography & Earth Sciences, McMaster University, Ontario, Canada. In it, he notes the problem of “excess 234U” in water when trying to use uranium to calculate the age of coral. He suggests a method that can be used to “correct” the inaccurate dates resulting from the excess 234U.
The widespread observation of uranium isotope disequilibrium is an undeniable fact. One can’t argue with a fact like that.
On the other hand, the explanation for why this is commonly (perhaps even universally) observed, is open to reasonable debate.
Ours is the simple conclusion: When the planet was created, there were different amounts of various uranium isotopes in different places, and there has not yet been time for them to reach equilibrium.
The evolutionary conclusion is that 234U must be more soluble in water than 238U, and water must be moving the 234U around disturbing the equilibrium. They speculate that, when uranium decays, it must fracture the crystal in such a way that makes 234U more soluble than 238U. There is no good reason to believe this, other than that it is the only thing they can think of to explain the observable evidence that uranium isotopes are not commonly in equilibrium. They are just grasping for a straw to explain the unexplainable.
Remember that professor Dickin wrote, “Since 234U and 238U have the same chemical properties, it might be expected that they would not be fractionated by geological processes.” He is right about that. Chemical properties are determined by the number of protons, not the number of neutrons, in the atom. All uranium atoms have 92 protons—that’s what makes the atom a uranium atom. The most common form of uranium, 238U, has 146 neutrons. 234U has only 142 neutrons; but that should not change its solubility.
It is possible to use science to determine which conclusion is correct—but (to our knowledge) it hasn’t been done. The key issue is whether or not 234U naturally occurring in rocks is more soluble than 238U. So, the simple scientific solution is to measure uranium isotope solubility. Here’s how we would do it, if we had the necessary equipment.
If 234U is more soluble than 238U, then the radiation ratio of each rock at the end of the experiment will be lower than it was at the beginning of the experiment (because there is less 234U in it) and the ratio of radiation coming from the water will be higher than the initial radiation ratio of that rock (because there is proportionally more 234U in the water).
If both are equally soluble, the radiation ratio of the water will equal the final radiation ratio of the rock, which will equal the initial radiation ratio of the rock.
If both isotopes are equally soluble, it blows the conventional old-earth explanation for why uranium isotopes aren’t in equilibrium out of the water.
This is how science works. You do an experiment to determine the truth. You don’t just make up plausible stories.
Let’s hope someone looking for a PhD thesis reads this article and gets a grant to do this experiment and settle the question once and for all.
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2 Available from http://www.detectingdesign.com/
5 Disclosure, July 2012, “U-Series Dating”
6 Disclosure, August 2012, “U-Series Correction”
7 Radiation Safety Engineering, Inc., “Uranium in Drinking Water”, http://www.radsafe.com/?page_id=203
8 Alan P. Dickin, Professor, Radiogenic Isotope Geology, Cambridge University Press, http://www.onafarawayday.com/Radiogenic/Ch12/Ch12-3.htm
9 Disclosure, July 2012, “U-Series Dating”