A review of Answers in Genesis’s ten best evidences for a young earth — summary and conclusion

Over the past five months, I have been examining the claims in the Answers in Genesis series, The 10 Best Evidences from Science that Confirm a Young Earth. This is as good a place to start as any in evaluating YEC claims: since these are what they consider to be their best arguments, we can assume that they are representative of the standards that they maintain in general, and that the other arguments that they are making will not carry any more weight.

Before I started examining these claims, I outlined the Biblical and scientific basis for my review. The age of the earth, and the ages of rock strata, are determined by measuring things, and accordingly, we must meet the demands in Scripture (Deuteronomy 25:13-16; Proverbs 11:1; etc.) that our approach to weights and measurements is honest and accurate.

YECs often respond that measurements still have to be interpreted. This is true, but there are strict rules that such interpretations must follow. It doesn’t take a “secular” or “materialist” worldview to see that your interpretation must be free from arithmetic error, non sequiturs and logical fallacies; that you must neither exaggerate nor downplay the extent and significance of errors and discrepancies; that you must not cherry-pick or fudge the raw data; that you must not quote people in ways that misrepresent them; and that you must not claim that assumptions are not testable when in fact they are. These, and other rules like them, are simply rules of basic honesty and quality control, and they have nothing whatsoever to do with secular materialism, a rejection of miracles, or “compromise.”

This being the case, my question was whether or not they were following the rules.

My findings were as follows:

  1. Very little sediment on the sea floor
    The calculations are invalid: riverine sediment ends up on the continental shelf, while the existing deposits being measured were those on the deep ocean floor.
  2. Bent rock layers that are not fractured
    This claim is blatantly untrue, as can be seen by comparing the example given to higher-quality photographs of the same rock formation both by USGS and by Answers in Genesis themselves. Bent rock layers are fractured.
  3. Soft tissue in dinosaur fossils
    While these findings are surprising, they do not contradict anything that we know about how long soft tissue can last, and in any case they are too rare and too badly degraded to be consistent with a young earth. Furthermore, many YEC accounts exaggerate the state of preservation of what was found.
  4. The faint young sun paradox
    Although it does suggest fine tuning, this says nothing about the age of the earth.
  5. Earth’s magnetic field is rapidly decaying
    This is based on an invalid extrapolation that is contradicted not only by the data, but also by both young-earth and old-earth models of how the Earth’s magnetic field works.
  6. Too much helium in radioactive rocks
    This is a very complex (and therefore error-prone) claim that is compromised by numerous serious errors including sloppy experimental technique, invalid assumptions, fudged data, misidentified rock samples, and a refusal to submit to meaningful peer review.
  7. Carbon-14 in fossils, coals and diamonds
    The measured carbon-14 levels are consistent with known, measured, and well-studied contamination mechanisms.
  8. Short-lived comets
    This denies that the Oort Cloud exists, based on an unrealistic assumption that absence of evidence is evidence of absence. It also disregards calculations of the historic orbits of known comets showing them to have been slingshotted closer to the sun by planets such as Jupiter.
  9. Very little salt in the sea
    This is based on outdated and cherry-picked data, poorly known quantities with huge error bars, and a naive extrapolation of rates that can not realistically be expected to have been the same in the past as they are today. The most up to date research indicates that the amount of salt in the sea is approximately in a state of equilibrium, and that it therefore tells us nothing about the age of the earth.
  10. DNA in ancient bacteria
    This is based on a single disputed study. It has not been satisfactorily demonstrated that the salt deposits and the bacteria themselves were the same age, nor that the salt crystals were undisturbed since their original formation.

Not a single one of these claims provides a shred of evidence for a young earth. Every single one of them — and in fact, every other claim of evidence for a young earth that I’ve ever seen — plays fast and loose with the basic rules and principles of how measurement works, some of them even to the extent of completely disregarding the role of measurement in determining the ages of rock strata altogether. Tiny samples with huge error bars are presented as “overwhelming” evidence for absurd new laws of fantasy physics that would have vaporised the earth if they had any basis in reality. The extent and significance of discrepancies in conventional dating methods is repeatedly blown up out of all proportion, with errors of just 20-30%, and results from techniques pushed to breaking point, being touted as evidence that all dating methods are consistently out by factors of up to a million. Isolated claims that were retracted a century ago are cited as evidence of pervasive systematic fraud in hundreds of thousands of peer reviewed studies right up to the present day. Despite their repeated denunciations of “uniformitarianism,” many of them are based on assumptions of constant rates that are totally out of touch with reality. Some of the claims that they come up with are so bad that it’s very difficult to believe that they really were made by the young-earth PhDs themselves, and not by a hacker or rogue sysadmin messing with their site in an attempt to discredit them.

I would like to be charitable and say that they had just misunderstood things, or perhaps that they were getting a bit carried away with themselves. This could possibly be the case with soft tissue in dinosaur fossils, or bacteria in ancient salts, for example. But that only illustrates the dangers of being too hasty. Proverbs 19:2 says, “It is not good to have zeal without knowledge, nor to be hasty and miss the way.” A more sensible approach would be to adopt a wait-and-see attitude with findings such as these. The world of science sees papers being published on a regular basis that collapse when subjected to the rigours of peer review and attempts to reproduce them.

Unfortunately, there are other examples where it is difficult to be so charitable. The claim about bent rock layers in particular was one such example. YEC organisations insist that it’s ungracious and divisive to accuse them of lying, but when a PhD geologist presents his case with an out-of-focus and badly exposed photograph of a rock formation with students strategically placed in front of the very parts of the formation that contradict him, I find it extremely difficult to see how this could be merely an honest mistake. The best I can say is that he has some explaining to do.

My biggest cause for concern, however, is the extremely unprofessional and hostile attitude that many young-earth PhDs adopt towards critique. Robust criticism should be standard practice in science, as that is how mistakes such as falsehood, arithmetic errors, fallacious calculations, shortcuts, sloppiness, and failure to adhere to proven best practices are shaken out. In many areas of scientific study, mistakes such as these could kill people. Yet we repeatedly see critiques dismissed out of hand as “rescuing devices”, “minor” or even “nitpicking”; while those who raise these concerns — many of them also Bible believing Christians — are denounced as “brainwashed” or “compromisers” or “anticreationists” or “speaking with the voice of the serpent” or worse.

I’m sorry, but this is not honest science and it is not Biblical Christianity. This is a cult.

Now to be fair, not all young-earth creationists are like that. Most rank and file YECs are honest and sincere people who merely lack the scientific understanding to be able to fact-check their claims properly. And they do have some valid concerns about the state of society, the decline of Christian influence, the widespread lack of knowledge of and trust in the Bible, and the way things are heading in general. Their uncompromising approach to Biblical authority is a much needed counterpoint to a world that would jettison the whole lot as nothing more than antiquated myth, rather than recognising it as a foundation, ahead of its time, on which subsequent generations have built.

But it’s misguided to blame all of society’s ills on evolution and millions of years, and quite frankly reckless to try and fight them with claims that are demonstrably and indisputably false. They complain about how they find it difficult to get published in peer reviewed scientific journals, or how they can’t get creationism taught in schools, presenting it as some kind of systematic discrimination by “the establishment.” It’s certainly true that there is an anti-Christian element at work in academia, but when you see the appalling technical quality of young-earth claims, it’s quite clear that that is not what is happening here. Being discriminated against for being a Christian is one thing; being discriminated against for incompetence, sloppiness and dishonesty is a completely different matter. It would be reckless and irresponsible to allow creationism to be taught in schools before creationists clean up their act, demonstrate a commitment to quality, rigour and factual accuracy that at the very least matches that of mainstream science (and certainly, that far, far exceeds the standards that they portray mainstream science as maintaining), and develop the openness to correction and the teachable spirit that the Bible clearly tells us that we should maintain. By elevating tradition and strict literalism over basic honesty and factual accuracy, they are undermining everything that they stand for. And it makes all of us, as Christians, look bad, whether we are young earth or old.

Featured image credit: Wikimedia Commons

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YEC Best Evidence 10: DNA in ancient bacteria

We now come to the last of Answers in Genesis’s top ten claims of evidence for a young earth. This one concerns the discovery of some still viable bacteria in 250 million year old salt crystals — a finding reported in Nature in 2000 by Vreeland, Rosenzweig and Powers.

The brief overview by Georgia Purdom gives very little detail about this discovery. However, Answers in Genesis has a more detailed technical article by Ewert van der Heide that gives some details and attempts an analysis to prove that the bacteria can not be as old as Vreeland et al suppose. The salt deposits, known as the Salado formation, come from the Delaware Basin (which, confusingly, is in Texas, not Delaware). Within these deposits, there are inclusions containing pockets of salt water, and it was in this salt water that the bacteria were found.

Naturally, the age of these bacteria has been greeted with a lot of scepticism by the scientific community as well. Responses by Hazen & Roedder (2001), Graur and Pupko (2001), Willerslev and Hebsgaard (2005), and Nickle et al (2001) among others, insist that the bacteria must be significantly younger than the deposits themselves. Purdom, of course, dismisses their response as “rescuing devices”:

Some scientists have dismissed the finding and believe the Lazarus bacteria are contamination from modern bacteria. But the scientists who discovered the bacteria defend the rigorous procedures used to avoid contamination. They claim the old age is valid if the bacteria had longer generation times, different mutation rates, and/or similar selection pressures compared to modern bacteria. Of course these “rescuing devices” are only conjectures to make the data fit their worldview.

Are the crystals the same age as the deposits?

It’s true that Vreeland et al took great care to eliminate contamination. They sterilised the salt crystal in concentrated hydrochloric acid and concentrated sodium hydroxide, and they reported no bacteria while they were drilling into the crystal, but only when they got to the salt inclusion. So at first glance, this one looks pretty convincing.

But the responses from other scientists aren’t claiming modern contamination. They are proposing that the crystals themselves formed at a later date than the rest of the formation. This could have happened, for example, during a glacial maximum during the past 100,000 years, if water had seeped into the formation, causing some of the salt crystals to dissolve and then re-crystallise. Hazen and Roedder (2001) argued that the clarity of the crystal itself indicated that something along those lines was likely the case, and also pointed out that fluid samples from the Delaware basin vary widely in composition — a fact pointing to a mixture of both ancient and modern waters. Furthermore, as Nickle et al (2001) pointed out, Vreeland et al did not provide any tests to eliminate the possibility that the salt crystals might have subsequently re-formed in this manner:

It is not hard to imagine that water seeped into this formation (e.g., during a recent glacial maximum within the last 100,000 years), resulting in the formation of new salt crystals in an otherwise old geological formation. In contrast to their elaborate controls for contamination, they did not present any data to verify the age of the crystal from which they extracted the bacteria. Hazen and Roedder (2001) have argued that the clarity of the crystal from which they extracted strain 2-9-3 is consistent with this crystal being of a more recent origin. Hazen and Roedder also pointed out that the fluids in the Delaware Basin (the geological region from which Vreeland et al. obtained their sample) are extremely heterogeneous with respect to the “absolute concentration as well as the ratios of halogen, alkali and alkaline-earth ions,” suggesting that this region contains a mixture of ancient and modern waters, though Powers et al. (2001) have countered that such heterogeneity does not necessarily imply that these fluids are from different ages.

The fact remains that Vreeland et al have not managed to convince the scientific community that the bacteria were indeed deposited along with the halite 250 million years ago. There are other quite plausible mechanisms by which they could have been deposited at a later date.

The “rescuing devices” fallacy

Throughout these ten claims, we’ve seen a constant drumbeat refrain of perfectly reasonable old-earth explanations being dismissed out of hand as “rescuing devices.” This reflects the YEC belief that long ages are nothing more nor less than an attempt to fudge things to accommodate the “evolutionary worldview.”

But as I’ve repeatedly made it clear, long ages do not come from an “evolutionary worldview”; they come from measuring things. Remember that in order to build a case that the earth is young, you need to provide robust evidence that hundreds of thousands of high precision and extensively cross-checked measurements are consistently in error by factors of up to a million.

It is simply not sufficient to dismiss any explanations of the data that you don’t like as “rescuing devices” or “only conjectures.” You must provide evidence that rigorously and systematically falsifies them. In every single case that we’ve seen, YEC attempts to falsify these so-called “rescuing devices” have been inadequate at best, in some cases nonexistent, and in others even outright dishonest.

Before YECs can claim a slam dunk with this claim of ancient bacteria, they need to provide solid evidence that the crystals had not recently dissolved and re-formed. They must also provide evidence that the mutation rates really could not account for their great age, if that is what it turns out to be. Nickle et al proposed a couple of tests that could be carried out as a starting point to investigate the matter further. For example, they suggested carrying out a controlled study of mutation rates in this particular strain of bacteria under identical conditions, or testing the samples for the presence of carbon-14.

They will also need to provide other studies to corroborate this one. A single, disputed study is nowhere near sufficient to overturn vast swathes of high-precision, extensively cross-checked data.

Reproducibility is important in science.

This is important. The history of science is littered with extraordinary claims that fell by the wayside because they could not be replicated. One particularly well-known example of spurious results was Fleischmann & Pons’s 1988 claim of having discovered cold nuclear fusion. Other teams were unable to replicate the experiment, and it is now regarded as spurious. A more recent example was the 2011 claim of the OPERA experiment to have discovered faster-than-light neutrinos: this turned out to be a hard to track down experimental error.

This being the case, findings, especially extraordinary ones such as this one, need to be replicated by multiple teams before they can be accepted as evidence. For what it’s worth, this is the same as the Biblical principle that “every matter must be established on the evidence of two or three witnesses.” (Deuteronomy 17:6; Deuteronomy 19:15; Matthew 18:16; 2 Corinthians 13:1.) If we could cite a single disputed study as evidence for anything, we would also be opening the doors to stuff and nonsense like homeopathy, and our hospital emergency departments would look like this:

The fact remains that there is simply not enough data to establish that the bacteria concerned really were the same age as the deposits in which they were found. This claim is yet another example of YECs drawing extraordinarily wide-ranging conclusions from extraordinarily slender evidence. It simply doesn’t work.

Featured image credit: pixabay.com

YEC Best Evidence 9: not enough salt in the sea, or not enough precision in the measurements?

One of the things that’s taken me somewhat by surprise in researching for this blog is the precision that modern radiometric dating methods can achieve. To give just one example, a few years ago researchers at Glasgow University pinned down the date of the K/T impact event, which killed off the dinosaurs, to within just eleven thousand years of 66,038,000 years ago. That’s an accuracy of just one part in six thousand — far tighter than I ever expected!

For what it’s worth, tolerances as tight as these completely falsify the oft-heard young-earth claim that radiometric dating is “guessing at best,” or that long ages are merely a presupposition to try and make space for evolution to happen. It is simply not possible to get results that specific out of vague and non-specific starting points, and “evolutionary presuppositions” are about as vague and non-specific as you can get.

Such high precision results are also the exact opposite of what we see in claims of evidence for a young earth. YEC arguments routinely rely on extremely low precision measurements with huge error bars, poorly known quantities, and rates that nobody expects to have been the same in the past as they are today.

The ninth entry on Answers in Genesis’s top ten list is a textbook example of this. It is the claim that there is not enough salt in the sea for an old earth. This argument says that if you tot up what goes in and what goes out, and divide how much is already there by the difference, you get an upper limit, and the earth (or at least, the oceans) can’t be any older than that.

Exactly what limit does this place on the age of the earth?

Everyone who cites this argument seems to have different ideas about what that upper limit actually is. Many rank-and-file YECs think it’s just a few thousand — I’ve had one person quote me 6,000 and another person quote me 100,000. This person quotes Kent Hovind as thinking it is 5,000 years.

For the most part, if you’re quoting figures this low, you probably just saw this argument on your Facebook feed, shared it without clicking through to read it, and blindly assumed that it must have been somewhere in the region of six thousand years or only slightly more. In actual fact, Andrew Snelling, Answers in Genesis’s geologist-in-chief, who wrote the article in the first place, gives a figure of 42 million years, citing the 1990 paper The Sea’s Missing Salt: A Dilemma for Evolutionists by YEC scientists Steve Austin and Russell Humphreys.

As evidence for a young earth, that is a joke. 42 million years may differ from the modern scientific consensus on the age of the earth by a factor of a hundred, but it also differs from the YEC timescale by a factor of seven thousand. If we are to concede that this falsifies the scientific consensus on the age of the earth, we must also insist that it falsifies the young-earth timescale seventy times more forcefully.

But does it falsify the scientific consensus anyway? In order to answer this question, we must address a question that we need to ask of all young-earth claims.

How large are the error bars?

There’s a deep and fundamental problem with trying to use the amount of salt in the sea to estimate the age of the earth. We are dealing with quantities that are extremely difficult to pin down, highly sensitive to changing climatic and environmental conditions, and as such can not be realistically assumed to have been the same in the past as they are today. There are a lot of different inputs and outputs, some of them not fully understood or completely quantified even today, and it’s very easy to overlook some of them. Even measuring the known quantities is a gargantuan task, requiring massive multi-national surveys over long periods of time. Enormous error bars are par for the course. The values involved change constantly as new and more detailed surveys are undertaken.

Nevertheless, the amount of salt in the sea was actually the basis for some of the earliest attempts to estimate the age of the earth in the pre-radiometric era. The first people to try and come up with a figure were Edmund Halley (1715) and John Joly (1899). Joly’s figure was 90 million years (Hay et al, 2006). More recently, Daniel Livingstone (1963) used data by Clarke (1924) to come up with an estimate of a few hundred million years, with a very wide margin of error that could extend as high as 2.5 billion years. The modern scientific consensus, taking all known data into account, now considers that long-term rates of influx and egress are equal within error bars, and consequently the amount of salt in the sea tells us nothing whatsoever about the age of the earth. (Holland, 2006.)

It is error bars, not evolutionary presuppositions, that have caused scientists to abandon the salt chronometer in favour of radiometric techniques. No matter what your worldview, it is outright ridiculous to reject high-precision results, accurate to one part in 6,000, in favour of low-precision methods whose errors can be ±50% or more.

Of course, Snelling describes all this as a “rescuing device,” and says that “even the most generous estimates” give an upper limit of just 62 million years. However, besides not taking everything into account, Austin & Humphreys’ paper was based on outdated data.

A case in point: halite deposits

One of the most important processes by which salt is removed from the oceans is by evaporation. This leaves behind massive deposits of halite, which can be found in numerous places all over the world. One of the largest halite deposits is found underneath the Mediterranean. There is a lot of evidence that from 5.96 to 5.33 million years ago, the Strait of Gibraltar repeatedly closed off, causing the Mediterranean to dry out and depositing vast quantities of ocean salt on the sea floor. This period, the Messinian Salinity Crisis, came to an end 5.33 million years ago when the Strait of Gibraltar was finally breached one last time and the Mediterranean rapidly re-filled in an event called the Zanclean Flood. A speculative future recurrence of this flood was portrayed in the award-winning xkcd webcomic episode, “Time,” a few years back.

xkcd1190-2907
The sea is rising! The protagonists are shown the future shoreline of the rapidly refilling Mediterranean. From xkcd “Time”.

This episode would have removed a substantial fraction of the salt in the oceans. So too would other large halite deposits that can be found all over the world, in places such as the Dead Sea and the Gulf of Mexico. Austin and Humphreys cite a figure of 4.4×1018 kg for the worldwide inventory of halite, citing Holland (1984). They claim that it is “extremely unlikely” (page 8) that this contains a significant error, as “No major quantity of halite in the earth’s crust could have escaped our detection.”

In actual fact, it turns out that major quantities of halite deposits had escaped our detection, and in the past three decades, many more such deposits have been found in the course of oil exploration. Hay et al (2006) give much more up to date estimates of between 19.6×1018 kg and 35.2×1018 kg, or between four and a half and eight times greater than that cited by Austin and Humphreys. Furthermore, they state that these figures are most likely incomplete (they include no data from Antarctica, for example), and that further exploration and surveys in the future may well push the figure up even higher. They also conclude that, far from increasing, the amount of salt in the oceans has actually decreased since Precambrian times.

Austin and Humphreys’ paper also overlooks several other factors. Glenn Morton points out for example that there are no less than sixteen different known mechanisms for sodium removal that they omitted to take into account, such as plankton concentrating sodium in their bodies, which is then removed from the oceans as sediment when they die.

The 2006 paper by Hay et al (full content here) is a good, comprehensive scholarly survey of the amount of salt in the oceans. It is a lengthy read, but it is easy to understand and it presents a lot of useful data. However, it should be abundantly clear that, once modern, up to date figures are used and all known vectors are taken into account, and given the huge uncertainties and variabilities in the values concerned, the amount of salt in the oceans tells us nothing whatsoever about the age of the earth.

Featured image credit: Gail Hampshire (via Wikimedia Commons)

YEC Best Evidence 8: short-lived comets

The eighth of AIG’s ten best evidences for a young earth is the existence of short-lived comets. Comets lose mass as they come close to the sun, when ice evaporates and dust gets dislodged by the solar wind.

The author of this article, Danny Faulkner, tells us that this means we can easily calculate an upper limit to their ages. He doesn’t tell us how to do so, nor does he quote any figures for this, but he is correct in saying that comets don’t last all that long once they venture into the inner Solar System. For example, Halley’s Comet is only expected to last another 10,000 years or so.

He tells us that comets can get kicked out of the Solar System by gravitational interactions with the planets. What he doesn’t tell us is that comets can also get captured into the Solar System by exactly the same interactions. In fact, NASA ran some calculations on Comet 67P/Churyumov–Gerasimenko (the one that was visited by Rosetta and the Philae lander) and found that this was exactly what happened to it:

Analysis of the comet’s orbital evolution indicates that until the mid-19th century, the closest it got to the Sun was 4.0 AU (about 373 million miles or 600 million kilometers), which is roughly two-thirds of the way from Mars’ orbit to that of Jupiter. That far from the Sun’s heat, it would not sprout a coma or tails, so it was invisible from Earth.

But scientists calculate that in 1840, a fairly close encounter with Jupiter must have sent the comet flying deeper into the inner solar system, down to about 3.0 AU (about 280 million miles or 450 million kilometers) from the Sun. Churyumov-Gerasimenko’s perihelion (closest approach to the Sun) drifted a bit closer to the Sun over the next century, and then Jupiter gave the comet another gravitational kick in 1959. Since then, the comet’s perihelion has stood at about 1.3 AU, which is about 27 million miles (43 million kilometers) outside Earth’s orbit.

So it’s not uncommon for long-lived comets to come in from the outer Solar System, be captured by one of the planets, and turned into short-lived comets. The Oort Cloud and the Kuiper Belt are believed to be the source of these long-period comets in the first place.

Yet Faulkner dismisses the Oort Cloud as a “rescuing device” concocted by “evolutionary astronomers” (as a reminder: there’s no such thing as an “evolutionary astronomer”) saying that “there is no evidence for the supposed Oort cloud, and there likely never will be.” He also cites the large size of the Kuiper Belt asteroids and their composition as evidence that the Kuiper Belt can not be the source of these comets.

“Pluto’s surface is young!”

In July 2015, the New Horizons space probe flew past Pluto and sent back pictures of a surface that looked much more pristine and smooth than what we see on other rocky planets and moons in the Solar System. The same author, Danny Faulkner, wrote this in response to these pictures:

Compounding this problem for a 4.5-billion-year age for the solar system is the fact that Pluto is located in a particularly crowded part of the solar system. Pluto orbits the sun in a region with many other large objects that are too small to be planets and are also orbiting the sun. Presumably, thus far we have found only the larger members of this second asteroid belt, the first belt being mainly between the orbits of the planets Mars and Jupiter. We would expect that for each of these bodies in this second asteroid belt there would be many more much smaller bodies. Therefore, Pluto ought to be undergoing impacts today at a higher rate than most other objects in other portions of the solar system.

So … on the one hand, we are told that the Kuiper Belt is too sparsely populated to be able to provide a steady supply of short-term comets, yet on the other hand, we are being told that it is so densely populated that it must be pulverising Pluto’s surface to smithereens! Which is it?

Absence of evidence is not evidence of absence.

The reason for the large size of known KBOs is that the smaller ones are too hard to see, not that they don’t exist. Comet-sized objects (about 10-20 km) in particular are right at the resolution limits of our telescopes at that distance, and looking for them is complex and expensive. We also know that objects in both the asteroid belt (Gladman et al, 2009) and the Kuiper Belt (Fraser & Kavelaars, 2008) follow a power law distribution in terms of size, with smaller ones being far, far more common than larger ones. Consequently, Faulkner’s claim that the Kuiper Belt objects are all too large and sparse to account for the origin of comets is completely out of touch with reality.

After New Horizons visited Pluto, NASA conducted a search for Kuiper Belt objects for it to visit as a follow-up. The potential candidates had to meet some fairly stringent criteria in terms of size, distance and position in the sky, and the fact that they managed to find three possible targets is further evidence that there is no shortage of material in the Kuiper Belt.

Ultimately, this argument boils down to “absence of evidence is evidence of absence.” While absence of evidence may be evidence of absence if it is something that we expect to see, such as sequenceable DNA in 6,000 year old dinosaur fossils, it most certainly is not evidence of absence if it is something that we don’t, such as small objects beyond the resolution limits of our telescopes.

The Oort Cloud may not have been directly observed, but it has good explanatory power, and its existence has never been falsified. Besides, which is more plausible an explanation — that the Oort Cloud exists, or that hundreds of thousands of independent, high-precision measurements whose commercial incentives strongly favour correctness over ideological convenience are all consistently in error by up to a factor of a million?

Featured image: Comet Hyakutake, by Bill Ingalls/NASA (source: Wikipedia)

YEC Best Evidence 7: ancient carbon-14 — intrinsic or contamination?

One common thread that turns up time and time again in young-earth arguments is taking a scientific dating technique, pushing it to breaking point, and claiming that because it doesn’t always give the correct results at the extremities, that automatically means that all conventional old-earth dating methods are hopelessly broken everywhere.

It’s a bit like trying to bake a cake by using a weighbridge — the huge scales that are normally only used to weigh ten ton lorries — to measure out your butter, eggs, flour, sugar and fruit, then, when the results turn out all mushy and inedible, claiming that this proves that Jamie Oliver, Mary Berry, Nigella Lawson, Gordon Ramsay, and Ina Garten haven’t the faintest idea about cooking.

truck_on_weighbridge
This is not how you bake a cake.
(Image source: Wikipedia.)

Why do ancient coals and diamonds contain carbon-14?

The seventh of Answers in Genesis’s ten best evidences for a young earth is one such example of this argument. It is the claim of the RATE project that they had found carbon-14 in ancient coals and diamonds. Carbon-14 has a half-life of 5,750 years, and samples more than a million years old should not contain any detectable radiocarbon at all. So what is going on?

The RATE project’s complete technical report, written by John Baumgardner, starts off with a listing of samples in the scientific literature that should, in theory, have no measurable radiocarbon. It summarises the listing with two histograms:

The first point to note here is that the amount of radiocarbon found in each case was low. Radiocarbon results are often quoted as a percentage of modern carbon-14 levels (pMC or %MC) with modern levels being approximately one molecule of carbon-14 to every 1012 (one trillion) molecules of carbon-12. The RATE team reported that Precambrian (non-biological) samples give results of 0-0.12 pMC, while Phanerozoic (biological) samples give 0.05-0.65 pMC. These figures are comparable to the levels obtained from studies of known contamination mechanisms.

Yet Answers in Genesis dismisses contamination as “rescuing devices” and “hackneyed defences.”

“Rescuing devices” or sloppy science?

Contamination is no mere “rescuing device”; it is a systematic error. Systematic errors have to be accounted for and eliminated before any conclusions can be drawn: this is one of the first things that you learn in a first year undergraduate physics practical class. To dismiss contamination — or any other kind of systematic error — as a “rescuing device” or a “hackneyed defence” in this cavalier manner encourages Christians to adopt a sloppy and indisciplined approach to science that, in any other area of scientific inquiry, would kill people. (The pharmaceutical industry is just one example that comes to mind here.)

Andrew Snelling makes the following claim about contamination:

Yet for thirty years AMS radiocarbon laboratories have subjected all samples, before they carbon-14 date them, to repeated brutal treatments with strong acids and bleaches to rid them of all contamination. And when the instruments are tested with blank samples, they yield zero radiocarbon, so there can’t be any contamination or instrument problems.

This claim is not true. “Repeated brutal treatments with strong acids and bleaches” will in fact introduce modern carbon-14, not eliminate it. Preparing samples for carbon-14 dating is a complex process; the samples have to be combusted to convert them to CO2 and then chemically reduced to graphite. Furthermore, many samples need to be chemically separated — for example, to extract cellulose from wood or collagen from bone. Every step in the process will introduce more contamination. This is why the Precambrian samples gave lower readings than the Phanerozoic samples — because they were already simple graphite, they typically only required a mechanical surface cleaning.

For what it’s worth, this is not merely a “uniformitarian assumption of evolution and millions of years.” The effects of processing on carbon-14 levels have been studied and characterised extensively, with whole journals such as Radiocarbon dedicated to the subject. One way of doing so is to measure the radiocarbon in a sample, then subject it to further processing, then take a second reading and measure the difference between the two. In fact, two of the entries in Baumgardner’s list — numbers 21 and 40 — report precisely this. They were from the same samples as numbers 62 and 79, but were recycled in order to try to characterise how much modern carbon would be introduced by pre-processing using methods such as the “brutal treatments with strong acids and bleaches” of which Dr Snelling speaks. The differences were 0.25pMC and 0.14pMC respectively, demonstrating that it takes just two or three steps of sample chemistry to introduce enough contamination to account for the levels reported.

Many of the other items on Baumgardner’s list also included reports of similar studies characterising identifiable contamination vectors. AMS results after sample processing can be compared with radiation counting (for example by scintillation or a Geiger counter) beforehand, as was the case in sample 10. The ratios of carbon-14 to carbon-12 and carbon-13 can be studied. Results from different laboratories can be cross-checked.

In addition to sample chemistry, contamination can also be introduced in situ, for example, when coal is permeated by groundwater, or when nitrogen is bombarded by electrons from decay products of nearby uranium. It can also be introduced when the samples are collected, or when they are being packaged ready for storage.

Then there is instrument background.

Snelling claims that blank samples yield zero radiocarbon. Again, this claim is untrue. Kirk Bertsche, a physicist with extensive experience in AMS spectroscopy design and also in preparation of samples for carbon-14 dating, has a detailed critique of the RATE project’s radiocarbon claims, in which he outlines several different potential sources of instrument background:

  1. ion source “memory” of previous samples, due to radiocarbon sticking to the walls of the ion source, thermally desorbing, and then sticking to another sample
  2. mass spectrometer background, non-radiocarbon ions that are misidentified as radiocarbon, sometimes through unexpected mechanisms
  3. detector background, including cosmic rays and electronics noise

For a full treatment of the subject, I would recommend that you read Dr Bertsche’s essay. His explanations come from years of experience designing and building the accelerator mass spectrometers used in radiocarbon dating, so he has extensively studied the different possible contamination vectors. He goes into some detail about how radiocarbon laboratories identify and characterise contamination — and he makes it clear that they do so with considerably more rigour and painstaking attention to detail than the RATE team would have you believe. Dr Bertsche is also an evangelical Christian, and as such, his interest in the subject is more out of concern for factual accuracy in our apologetics than in conforming to a particular ideology.

It is also important to note that potential sources of contamination have not been fully quantified, and that additional, as yet unknown contamination vectors could be at work. The current scientific consensus is that contamination in radiocarbon dating can reach levels of up to about 0.5 pMC. In any case, experimental error or sloppy laboratory procedure could also increase contamination, and consequently solid peer review and replication of the results are essential.

The study of solar neutrinos demands radiocarbon-free fossil fuels

It turns out that carbon-14 contamination is an important question in the physics community for reasons other than radiometric dating. Physicists studying solar neutrinos need to find sources of carbon that contain a 14C content of less than one part in 1020. Kathleen Hunt has this to say about it:

It turns out that the origin and concentration of 14C in fossil fuels is important to the physics community because of its relevance for detection of solar neutrinos. Apparently one of the new neutrino detectors, the Borexino detector in Italy, works by detecting tiny flashes of visible light produced by neutrinos passing through a huge subterranean vat of “scintillation fluid”. Scintillation fluid is made from fossil fuels such as methane or oil (plus some other ingredients), and it sparkles when struck by beta particles or certain other events such as neutrinos. The Borexino detector has 800 tons of scintillant. However, if there are any native beta emitters in the fluid itself, that natural radioactive decay will also produce scintillant flashes. (In fact that’s the more common use of scintillant. I use scintillant every day in my own work to detect 14C and 3H-tagged hormones. But I only use a milliliter at a time – the concept of 800 tons really boggles the mind!). So, the physics community has gotten interested in finding out whether and why fossil fuels have native radioactivity. The aim is to find fossil fuels that have a 14C/C ratio of 10-20 or less; below that, neutrino activity can be reliably detected. The Borexino detector, and other planned detectors of this type, must keep native beta emissions to below 1 count per ton of fluid per week to reliably detect solar neutrinos. (In comparison, my little hormone vials, here in my above-ground lab, have a background count of about 25 counts per minute for 3.5 milliliters.)

The upshot of this is that there is a strong motivation to determine not only where radiocarbon in fossil fuels comes from, but how to predict where to find deposits that don’t have any. In the course of their research, the scientists concerned have discovered that carbon-14 levels in ancient coals vary widely, and strongly correlate with the presence of uranium deposits nearby:

So, the physicists want to find fossil fuels that have very little 14C. In the course of this work, they’ve discovered that fossil fuels vary widely in 14C content. Some have no detectable 14C; some have quite a lot of 14C. Apparently it correlates best with the content of the natural radioactivity of the rocks surrounding the fossil fuels, particularly the neutron- and alpha-particle-emitting isotopes of the uranium-thorium series. Dr. Gove and his colleagues told me they think the evidence so far demonstrates that 14C in coal and other fossil fuels is derived entirely from new production of 14C by local radioactive decay of the uranium-thorium series. Many studies verify that coals vary widely in uranium-thorium content, and that this can result in inflated content of certain isotopes relevant to radiometric dating (see abstracts below). I now understand why fossil fuels are not routinely used in radiometric dating!

The fact that there is a direct, measurable correlation between carbon-14 levels in fossil fuels and the presence of nearby uranium means that this can not be any kind of “rescuing device,” but that it is indeed a real, measurable effect. And the fact that they need to get their hands on eight hundred tons of radiocarbon-free deposits puts this one into the same category as oil exploration in general: they are under strong incentives to come up with explanations that are correct rather than ones that are ideologically convenient.

“Radiocarbon of the gaps”

Now Dr Bertsche does admit that radiocarbon in ancient coals and diamonds can not always be fully accounted for by known sources of contamination. However, appealing to “intrinsic radiocarbon” is premature until and unless you have ruled out the possibility of unknown sources.

If “intrinsic radiocarbon” were indeed a viable explanation, we would expect to see it consistently across all kinds of samples, at levels well in excess of those that could be explained by contamination. We would not expect to see it in some materials but not in others, and we would certainly not expect different tests on the same samples to give significantly different results. Nor would we expect to see any kind of correlation with the presence of nearby radioactive rocks.

But that is not what is observed. As Dr Bertsche says, radiocarbon levels show many significant patterns that are simply not consistent with the “intrinsic” hypothesis:

While some materials, e.g., coals and carbonates, often do show radiocarbon contamination that cannot be fully accounted for, resorting to “intrinsic radiocarbon” raises more questions than it answers. Why do only some materials show evidence of this intrinsic radiocarbon? Why does some anthracite and diamond exist with no measurable intrinsic radiocarbon? Why is its presence in carbonates so much more variable than in other materials, e.g., wood and graphite? Why is it often found in bone carbonates but not in collagen from the same bone? Since intrinsic radiocarbon would be mistakenly interpreted as AMS process background, why do multi-laboratory intercomparisons not show a much larger variation than is observed? Why does unprocessed diamond seem to have less intrinsic radiocarbon than processed diamond?

The fact remains that not only are the levels of carbon-14 found in ancient coals and diamonds too low to rule out contamination, but they also follow trends and patterns that strongly indicate that this is the case. Given that contamination vectors have been extensively studied and quantified, it simply isn’t realistic to dismiss them as “rescuing devices” or a “hackneyed defence.” Young-earth advocates need to demonstrate that hundreds of thousands of other measurements are all consistently in error by factors of up to a million, and the reported levels of radiocarbon in ancient coals and diamonds fall far, far short of doing so.

Featured image credit: Wikimedia Commons