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An examination of Answers in Genesis's ten best evidences for a young earth

This post is more than 6 years old.

Posted at 09:00 on 04 September 2017

Posts in this series:

  1. Sediment on the ocean floor
  2. Bent rock layers
  3. Soft tissue in dinosaur fossils
  4. The faint young sun paradox
  5. The earth's magnetic field
  6. Helium in radioactive rocks
  7. Carbon-14 in fossils, coals and diamonds
  8. Short-lived comets
  9. Salt concentration in the oceans
  10. DNA in ancient bacteria

So far, I've looked mainly at the scientific consensus on the age of the earth, how it is determined, and the misconceptions about it that tend to float around in some Christian circles — in particular, those propagated by the young-earth creationist organisations. As we've seen, the science concerned is far, far more robust than they make it out to be, the YEC objections to it do not stand up to scrutiny, the underlying historical assumptions are not untestable as they claim, the evidence is demonstrably not based on differences in worldview, numerous independent lines of evidence place a lower limit on the age of the earth far, far in excess of six thousand years, and that attempting to reinterpret it otherwise descends into total absurdity.

However, the young-earth organisations point to other lines of evidence indicating that the earth is indeed only six thousand years old. If they are right, then we have a problem, because it means that different lines of evidence that we see in nature contradict each other. Either the evidence must be ambiguous, or there must be some other factor at work.

In 2012, Answers in Genesis published a series of articles titled The 10 Best Evidences from Science That Confirm A Young Earth. The lines of evidence that they gave were as follows:

  1. There is too little sediment on the sea floor.
  2. Rock layers that are bent without fracturing.
  3. Soft tissue in dinosaur fossils.
  4. The Faint Young Sun paradox.
  5. The earth's magnetic field is rapidly decaying.
  6. Radioactive rocks contain too much helium.
  7. Carbon-14 has been found in fossils, coals and diamonds.
  8. Comets lose mass too quickly for them to be long-lived.
  9. There is very little salt in the sea.
  10. DNA has been recovered from 250 million year old bacteria.

The list is prefaced by a long sermon telling us that we must take the Bible as our starting point. Before I look at their claims themselves, I shall therefore start by doing precisely that.

You may have heard it said that the Bible is not a science textbook, and that the purpose of Genesis 1-11 is not to give us a scientific overview of origins. Regardless of what you think of that statement, the Bible does have some strong things to say about how we are to approach science. In particular, any physical evidence that we cite in support of our respective positions must be based on honest reporting and honest interpretation of accurate information. Rejecting the scientific consensus may be faith, but misrepresenting it is lying, and will ultimately backfire.

We see this in the Bible's demands for honesty in how we handle weights and measures. Deuteronomy 25:13-16 says this:

13Do not have two differing weights in your bag — one heavy, one light. 14Do not have two differing measures in your house — one large, one small. 15You must have accurate and honest weights and measures, so that you may live long in the land the Lord your God is giving you. 16For the Lord your God detests anyone who does these things, anyone who deals dishonestly.

Other Bible verses demanding honest use of weights and measures include Leviticus 19:35-36; Ezekiel 45:10; Proverbs 11:1; Proverbs 16:11; Proverbs 20:10; Proverbs 20:23; Hosea 12:6-7; Amos 8:4-8; Micah 6:10-13. Repeatedly in the Bible, we are told that dishonest weights and measures are an abomination to the Lord.

And remember that weights and measures are the foundation on which science is built.

When discussing creation and evolution, it is important to bear this in mind. The Bible has far, far more to say about the need for honesty and integrity than about either the age of the earth or evolution. If the physical evidence which I acknowledge that God Himself has created points to an ancient earth and common ancestry for humans and animals, and even all life on earth, then we need to be honest about that. On the other hand, if the evidence really is ambiguous, or if it really does indicate that the earth is young after all, then so much the better.

There are a few other points worth making here. The first is that any scientific claim must submit to testing and correction through expert peer review. Proverbs 12:1 tells us, "Whoever loves discipline loves knowledge, but whoever hates correction is stupid." Proverbs 27:6 tells us, "Wounds from a friend can be trusted, but an enemy multiplies kisses." In particular, corrections of a purely technical nature must be resolved before any claims can be made, no matter who those corrections come from, and especially if the corrections come from specialists in the subject matter concerned. The second is that scientific findings must be reproducible. The scientific principle of reproducibility has a Biblical precedent in the legal principle that "every matter must be established on the testimony of two or three witnesses" (Deuteronomy 17:6; Deuteronomy 19:15; Matthew 18:16; 2 Corinthians 13:1). One study by a single research group is therefore not sufficient to establish evidence for anything.

So, when evaluating the evidences for a young earth, here are the questions that I will be asking.

1. Does it get its facts straight? In other words, is it actually true? As we shall see, at least one of these arguments (number 2, bent rock layers) is not.

2. Does it actually place a specific numerical limit on the age of the earth at all? Many of these arguments do not, but only attempt to provide counterexamples to conventional dating methods. Some of them (in particular, numbers 2 and 4) do not place any numeric constraints on anything at all. Others appeal to "common sense" that certain processes can not take "millions of years" while disregarding actual measurements and observations that indicate that they can.

3. Is it measuring the right things? We shall also see an example (number 1, too little sediment on the sea floor) which attempts to calculate a limit for the age of the earth by dividing two completely unrelated measurements, leading to a result which is totally meaningless.

4. How well defined are the limits it places on the age of the earth? Radiometric dating gives results that are accurate to within ±5%, frequently better than ±1%, and in the best cases, better than one part in a thousand. On the other hand, most of these arguments rely on quantities that are extremely difficult to measure, and in some cases completely unknown. For example, we have only a rough idea of how long it takes bones and soft tissue to decay and fossilise under average conditions, and the upper limit on how long it takes the last remnants to fully mineralise under optimal conditions is completely unknown.

5. Are its assumptions realistic? No scientist blindly assumes that rates are constant; one must either attempt to determine precise limits to how much they could have varied, or else establish solid theoretical and observational reasons as to why they could not. There are good reasons, both theoretical and experimental, to believe that nuclear decay rates have always been constant, while on the other hand, the rate of influx of salt or sediment into the oceans is highly sensitive to environmental and climatic conditions.

6. How rigorously have the "rescuing devices" been falsified? It is completely unscientific (and in fact, intellectually dishonest) to hand-wave alternative explanations and sources of error such as contamination as "meh, rescuing devices." Alternative explanations have to be carefully and systematically ruled out, and in particular, sources of error such as contamination must be accounted for before any firm conclusions can be drawn.

7. What are the sources of its data? Are they up to date and representative of the latest research? Does it represent them fairly and accurately, or does it cherry-pick and quote mine them?

8. What is the extent of its data? Have the findings come from a single study, or has it been confirmed by other findings from elsewhere? One study — especially if it is disputed, controversial, or extraordinary — is not enough to establish a scientific finding. Similarly, studies based on small sample sizes are very unlikely to be reliable. If we could accept one-off studies based on small samples, we would also be giving a free pass to anti-vaxxers, astrology, homeopathy, water divining, and reading tea leaves.

9. Have they received a level of scrutiny appropriate to their complexity? Some claims, such as number 6 (helium in radioactive rocks) are technically very complex both theoretically and experimentally, and very complex claims are easy to get wrong, difficult to get right, and easy to "fudge" in ways that can be difficult to spot. In particular, scrutiny from experts in the subject matter concerned needs to be particularly heeded, as only they will be familiar with the existing research, the relevant best practices, and the various pitfalls and gotchas.

10. How have they responded to critique? In particular, how have they responded to criticisms of a purely technical nature? I am not concerned about them introducing religious presuppositions into science, so much as with arithmetic errors, mis-cited sources, cherry-picked data, hand-waved estimates, invalid analogies and the like. In these cases, the only correct responses are to either (a) fix the problem, or (b) provide evidence that they would not significantly affect the result. All claims that critiques are "petty and nitpicking" must be backed up by calculations or other evidence to prove that they really are as petty and nitpicking as they claim them to be.

Starting from next week, every second week I will examine each of these ten evidences in turn, to see how they fare when faced with questions such as these.

Featured image credit: Wikimedia Commons