When you read a paper you disagree with, you have a number of options. The easiest is to shrug one’s shoulders and mutter darkly that nothing better could be expected from that lab. More productively, one can write a blog post exposing the papers weakness; run the gamut of hostile reviewers and editors to try to publish a comment that rebuts the paper (if the journal accepts correspondence); or publish a new paper that will convince everybody (or not). There is a radical alternative: to submit an allegation of research misconduct to the author’s university. When the complaint is dismissed, ask the police to investigate the author for misconduct in public office. When they decline, engage solicitors to bring a private prosecution against the university registrar who dismissed the original complaint.
Keenan’s complaint is against Christopher Ramsey, a professor at Oxford University who developed the OxCal program for calibrating radiocarbon dates. Christopher is always exceptionally helpful when users get stuck when using OxCal (as I often do) – he is a very valuable member of the palaeoecology and archaeological community. What did he do to incur Keenan’s wrath?
Keenan’s initial complaint contained two allegations. The first was that Ramsey continues to use standard methods for radiocarbon calibration rather than adopting Keenan’s proposed alternative. This was not surprising – Keenan’s suggested procedure for calibrating radiocarbon dates was nonsense, and eventually even he admitted that and withdrew that part of the complaint. I note he has still not retracted his paper. Research misconduct?
The second allegation was that Ramsey had used some inappropriate statistical methods. Keenan failed to show that the choice of methods made any material difference to the results.
Keenan’s complaint was withdrawn and reissued with a new allegation that Ramsey had failed to consider the potential bias of volcanic CO2 on radiocarbon dates from Thera.
Thera was a volcano in the Aegean Sea that erupted about 1600BCE, destroying most of the island in one of the largest Holocene eruptions. The eruption of Thera is a key chronological marker in the archaeology of the Eastern Mediterranean, and the date is contentious. Estimates based on Egyptian dynastic chronology suggest that the eruption may have occurred over a century later than indicated by radiocarbon dating. This discrepancy potentially points to errors either in the radiocarbon dates linked to the eruption, the dynastic chronology, or the evidence (mostly pottery) used to tie Thera into the dynastic chronology.
Carbon dioxide emitted by volcanoes contains essentially no 14C, so if it is incorporated into organisms it will bias radiocarbon dates. If a sample contains 1% volcanic carbon, it will appear to be 80 years too old. This is well known – plants growing near fumaroles and other vents appear to be hundreds of years old – and has even been shown from Santorini, the remnants of Thera. This effect decays rapidly with distance from the vent.
The potential for volcanic, or other sources depleted in 14C, to bias the dates of the Thera eruption are discussed by Wiener and Earle (2014). Höflmayer (2012), who previously supported the younger date for the Theran eruption, argues that as the dates from several different contexts on Santorini, Crete, and elsewhere are concordant, it is unlikely that incorporation of volcanic CO2 by the samples from Santorini is important. Further, he shows that changing the statistical methodology, avoiding (I think) Keenan’s second accusation, the result is essentially unchanged. Höflmayer (2012) suggests that the dynastic chronology may contain some errors and that some of the archaeological evidence linking the Theran eruption to the Egyptian chronology is more uncertain that previously thought. When these potential errors are taken into consideration, the offset between the archaeological and radiocarbon dates is greatly reduced.
The age of the Theran eruption remains contentious, but Keenan has turned what should be a matter for research and debate into a legal action.
In the unlikely event that Keenan’s private prosecution ever reaches court, I predict it will not end to his satisfaction. The judges who sat on Simon Singh’s appeal against the British Chiropractic Association proved reluctant to adjudicate on scientific disputes
We would respectfully adopt what Judge Easterbrook, now Chief Judge of the US Seventh Circuit Court of Appeals, said in a libel action over a scientific controversy, Underwager v Salter 22 Fed. 3d 730 (1994):
“[Plaintiffs] cannot, by simply filing suit and crying ‘character assassination!’, silence those who hold divergent views, no matter how adverse those views may be to plaintiffs’ interests. Scientific controversies must be settled by the methods of science rather than by the methods of litigation. … More papers, more discussion, better data, and more satisfactory models – not larger awards of damages – mark the path towards superior understanding of the world around us.“