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Regardless of how fervently the ACLU expert biology witnesses might propound the merits of biological evolution, the ACLU well knew that neither the geological evolution of the earth nor the biological evolution of life was even remotely credible without the support of vast amounts of time. So in the last analysis, the cornerstone of the ACLU case rested on establishing the plausibility of an ancient age of the earth. This is why Dalrymple's testimony about the reliability of radioactive dating was crucial to their intent of overturning Act 590.
The State Challenges Radiometric Dating Techniques
Under cross-examination Dalrymple was asked to affirm his confidence in uniform radioactive decay for increasingly greater times in the past. Although he expressed belief in a uniform decay process for the past 4.5 billion years, continued cross-examination brought him to admit his uncertainty about this assumption for earlier periods in the history of the universe, saying that his area of expertise did not extend to that time. Quoted below from the official trial transcript are segments of the cross-examination by Deputy Attorney General David Williams:
Q Is constancy of the rate of radioactive decay a requirement for radiometric dating? A Yes. It is required that radiometric dating be based on constant decay rates, at least within limits of significant areas, and what I mean by that is that if the decay rates were to change a percent or two, that would probably not significantly alter any of our major conclusions in geology. [p. 112] Q To the best of your knowledge, has the rate of radioactive decay always been constant? A As far as we know from all the evidence we have, it has always been constant. We have no, either empirical or theoretical, reason to believe it is not. Q So as far as you know, it would have been constant one billion years ago, the same as it is today. A As far as we know. Q Five billion years ago? A As far as we know. Q Ten billion years ago? A As far as we know. Q Fifteen billion? A I don't know how far back you want to take this, but I think for the purposes of geology and the age of the solar system, we are only interested in using radiometric dating on objects we can possess in our hand, so we only need to take that back about four and a half or five billion years.
I think whether it's been constant fifteen billion years is irrelevant. We have no way of getting samples that old. We can only sample things that have been in the solar system. [Smith 1982b, p. 449, l. 8 to p. 450, l. 13]
Notice the change in Dalrymple's position on the constancy of the decay rate. In his direct testimony (see Chapter 8) he claimed to know that radioactive decay rates had been constant without any time qualification whatsoever. Likewise during the initial part of his cross-examination, he affirmed they had been constant at least ten billion years. However, at the fifteen-billion-year mark he apparently senses that Williams is approaching the presumed time of the Big Bang. He then begins to backtrack and suddenly reveals that "we only need" them to be constant for the last four and a half billion years. In other words, at this point in the cross-examination, it appears that the requirement, or "need," to establish credibility of the evolutionary model determines how far back in time evolutionists are willing to affirm constant decay rates.
Williams must have realized this was a startling revelation, for he continued pressing Dalrymple to find out more about the decay rates and, in addition, to probe just what evidence he had for their constancy over the last several billion years.
Q How old is the solar system, to the best of your knowledge? A As far as we know, it is four and a half billion years old. [p. 113] Q The solar system itself? A The solar system itself. Now, when we talk about the age of something like the solar system, you have to understand that there was a finite period of time over which that system formed, and we may be talking about a period of a few hundred years, so it is not a precise point in time, but some interval. But compared with the age of the solar system, it is thought that that interval was probably rather short—a few percent. Q Are you aware of when those scientists hypothesized or when the so-called big bang occurred, how many years ago? A No, I am not sure exactly when that was supposed— Q Would the rate of radioactive decay have been constant at the time of the big bang? A I am not an astrophysicist. I don't know the conditions that existed in the so-called primordial bowl of soup, and so I am afraid I can't answer your question. Q So you don't have any opinion as to whether it was constant then? A That's out of my field of expertise. I can't even tell you whether there were atoms in the same sense that we use that term now. Q But you did state that it had always been constant as far as you knew, but now you state you don't know about the big bang, whether it was constant then; is that correct? A Well, what I said, it's been constant within the limits in which we are interested. For the purposes of radiometric dating it hardly matters whether it was constant at the moment of the big bang. Let me say this— Q I don't want to interrupt you. A That's all right. Q You say as far as you are concerned, for the purposes of your concern it has been constant as far as you know, and your purposes go back to the age of the earth for four point five billion years; is that correct? A Yes, that's correct. Q But you base that age of the earth on the assumption or on this requirement that it has always been constant; is that correct? A That is not entirely—That's correct, but it is not an assumption. It is not fair to calculate it that way. In a certain sense it is an assumption, but that assumption has also been tested.
For example, if you look at the ages of the oldest, least disturbed meteorites, these objects give ages of one point five to four point six billion years. A variety of different radioactive decay schemes, schemes it at [sic, that have?] different half lives. They are based on different elements. They would not give those identical ages if the rate of decay had been [sic, had not been?] constant.[p. 114] Q But do those schemes that you mentioned there rely upon the requirement that the rate of radioactive decay has always been constant as well? A Yes, they do. Q So all methods you know would rely upon this, what you termed a requirement and what I termed an assumption; is that correct? A That is correct. Q The rate of decay is a statistical process, is it not? I think you testified yesterday to that. A Basically, it is. Q Would you agree that any deviation in the rate of decay would have to be accompanied by a change in physical laws? A As far as we know, any change in decay would have to be accompanied by a change in physical laws, with the exceptions that I mentioned yesterday. There are small changes known in certain kinds of decay, specifically in electron capture, a tenth of a percent. Q What do you consider the strongest evidence for the constant rate of radioactive decay? A Well, I don't think I could give you a single piece of strongest evidence, but I think the sum total of the evidence, if I can simplify it, is that rates of decay have been tested in the laboratory and found to be essentially invarient [sic, invariant].
Theory tells us those rates of decay should be invarient [sic, invariant]. And when we are able to test those rates of decay on undisturbed systems; that is, systems that we have good reason to presume have been closed since their formation clear back to the oldest objects known in the solar system, we find we get consistent results using different decay schemes on isotopes that decay at different rates.
So that is essentially a synopsis of the evidence for constancy of decay. [Smith 1982b, p. 450, l. 14, to p. 454, l. 6]
It is most informative to compare the responses that Dalrymple gave in his direct testimony and cross- examination. The last chapter revealed that in his direct testimony Dalrymple claimed that "tests consistently show . . . that the earth is billions of years old." When questioned what those tests were, the response was "radiometric dating techniques." And when asked why "geochronologists rely upon" these techniques, the reply was that "radioactivity is the only process that we know of that has been constant through time for billions of years."
The above cross-examination reveals, however, that Dalrymple's confidence in constant decay rates in the distant past rests on his belief that the assumption of constant decay has been tested. For one test he cites the fact that [p. 115] decay rates are observed to be constant at present. Of course this is not a test about events in the past, but simply an observation about the present. His only other test for constant decay rates was that certain samples give consistent results when they are analyzed for different radioactive elements having different decay schemes. Attorney Williams, apparently perceiving there was a flaw in this presumed test, continued to press Dalrymple on this point.
Q Did you say— But is it not true that as long— Well, if the rate of decay has varied and as long as the variation would have been uniform, would you still get these consistent results? A It is possible to propose a set of conditions under which you could get those consistent results. THE COURT: Excuse me. I didn't understand that. THE WITNESS: I think what he is saying is, is it possible to vary the decay rate in such a way that you could still get a consistent set of results by using different decay schemes, and I think it is always possible to propose such a set of circumstances, yes.
So that question is in the nature of a "what if," and one can always come to the conclusion that you can restructure science in such a way to make that "what if" happen. But that is not the sort of thing we usually do unless we have good reason to presume the physical laws have changed, and we presume they have not.
The same is true with things like the speed of light, gravitational constant and so forth. May I elaborate just a little bit more? We are not talking about small changes in decay. If the creation scientists are correct and the earth is only ten thousand years old, we are talking about many orders of magnitude, thousands of times difference. The difference between the age of the earth that scientists calculate and the age that the creationists calculate are different by a factor of four hundred and fifty thousand. So you don't have to perturb the constancy of decay laws a little bit; you have to perturb them a lot. [Smith 1982b, p. 454, l. 7 to p. 455, l. 11]
In the above responses my respected colleague now admits that consistent results obtained by different decay schemes do not actually prove constant decay in the past after all. He then attempts to reduce the impact of this admission by noting that varying decay rates would involve changes in physical laws. His only argument against this possibility is plainly stated: scientists "presume they [physical laws] have not" changed. But the [p. 116] presumption that physical laws have not changed over the course of time is just the uniformitarian principle. Thus, his entire testimony concerning constant decay rates and an ancient age of the earth was hinged on his faith in this unproven principle. No proof was given for constant decay rates and an ancient age of the earth because no proof exists.
Indeed, when Dalrymple said, "If creation scientists are right and the earth is only ten thousand years old . . . ," his main argument against an earth this young was that this meant decay laws had to be perturbed "a lot." But Dalrymple provided no evidence to show this had not occurred sometime in the past. In short, he was unable to scientifically counter the possibility of a young earth. Unfortunately for the State, this was not generally understood at any time during his cross-examination. And there was something else of equal importance for the State's case that went undetected.
We have already noted the change in my colleague's stance on the decay rate: from his confident, opening assertion that the decay rate has always been constant to his somewhat defensive position that its constancy beyond a certain point is irrelevant. We now refocus on that part of the cross-examination when State Attorney David Williams asked whether the radioactive decay rate had been constant at the time of the Big Bang. The reply was:
I am not an astrophysicist. I don't know the conditions that existed in the so-called primordial bowl of soup, and so I am afraid I can't answer your question. [Smith 1982b, p. 451, ll. 9-11]
Dalrymple's reticence to commit himself fully on the one assumption that supports the entire evolutionary framework—the uniformitarian principle— together with his earlier assertion that it was irrelevant whether the decay rate was constant beyond a certain time, placed the ACLU case in a very vulnerable position. If the State had drawn attention to the implications of these statements, this would have greatly reduced the credibility of the ACLU position for the remainder of the trial. His response also allowed him to avoid questions about the supernatural nature of the Big Bang. Quite possibly the ACLU realized such questions could open up the proverbial Pandora's box. Any witness who testified about the evolutionary beginning of the universe would give the State the opportunity to focus on the Big Bang as an event not subject to known scientific laws. It would then have been evident that evolution as well as creation requires a supernatural beginning. Thus the cornerstone of the ACLU strategy would have crumbled!
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Earth Science Associates